Notes on Ricky

Ansible Command

Mon, 01 Jan 0001 00:00:00 +0000

Lookup

# List all plugins
ansible-doc -t lookup -l

# Use `ansible-doc -t lookup <plugin>` to see detail
ansible-doc -t lookup ping

winrm

- console output

在 hyper-v 那台機器 Enable Winrm 之後一直出現下面的錯誤。在 group 加上一行即可

ansible_winrm_transport=ntlm

hyper-v01 | UNREACHABLE! => {
 "changed": false,
 "msg": "ssl: the specified credentials were rejected by the server",
 "unreachable": true

}

- /etc/ansible/hosts

ansible_user=administrator
ansible_password=password
ansible_port=5986
ansible_connection=winrm
ansible_winrm_server_cert_validation=ignore
ansible_winrm_transport=ntlm

AWS Command

Mon, 01 Jan 0001 00:00:00 +0000

CloudFront

# list distributions
aws cloudfront list-distributions --query '*.Items[*].[Comment,Id,Aliases.Items[0],DefaultCacheBehavior.TargetOriginId]' --output table

# create invalidation
aws cloudfront create-invalidation --distribution-id EATDVGD171BHDS1 --paths "/*"

## check cloudfornt log enable or not
for i in $(aws cloudfront list-distributions --output table --query 'DistributionList.Items[*].Id' --profile route53 | sed '1,3d;$d' | awk '{print $2}')
do
 result=$(aws cloudfront get-distribution --id ${i} --query 'Distribution.DistributionConfig.Logging' --profile route53 | jq .Enabled)
 if [[ "${result}" != "true" ]];then
 echo ${i}
 fi
done

EC2

# list
aws ec2 describe-instances --query 'Reservations[*].Instances[*].[Tags[0].Value,InstanceId]' --output table --page-size 100

ECR

# Get password and login to 12345.dkr.ecr.ap-northeast-1.amazonaws.com
aws ecr get-login-password | docker login --username AWS --password-stdin 12345.dkr.ecr.ap-northeast-1.amazonaws.com

S3

# Copy local file to S3
aws s3 cp ./pic.png s3://bucket_name/dir/

# Sync local local_dir to S3
aws s3 sync local_dir s3://bucket_name --exclude 'gameConfig.json' --acl public-read --delete

snapshot

# list
aws ec2 describe-snapshots \
 --owner-ids self \
 --query "Snapshots[?(Tags[0].Value=='backend')].[SnapshotId,VolumeId]" \
 --region ap-northeast-1

# create
aws ec2 create-snapshot --volume-id vol-02468851c2bc3bc4b --description "gitlab-$(date +%F)" --region ap-northeast-1

# delete
aws ec2 delete-snapshot --snapshot-id snap-1234567890abcdef0 --region ap-northeast-1

sns

region='ap-east-1'
account_id='888886666321'
topic='sa'

# create topic
aws sns create-topic --name ${topic}

# subscribe
aws sns subscribe --topic-arn arn:aws:sns:${region}:${account_id}:${topic} --protocol email --notification-endpoint ricky@gmail.com

# list
aws sns list-subscriptions-by-topic --topic-arn arn:aws:sns:${region}:${account_id}:${topic}

# create alarm
### metric-name
##CPUUtilization -->percent
##NetworkIn -->bytes
##NetworkOut -->bytes
for line in $(aws ec2 describe-instances --query 'Reservations[*].Instances[*].[Tags[0].Value,InstanceId]' --output table --page-size 100)
do
 ID=$(echo ${line}|awk -F ',' '{print $1}')
 VALUE=$(echo ${line}|awk -F ',' '{print $2}')
 aws cloudwatch put-metric-alarm \
 --alarm-name ${ID}_netout \
 --metric-name NetworkOut \
 --namespace AWS/EC2 \
 --statistic Average \
 --period 300 \
 --threshold 2560000 \
 --comparison-operator GreaterThanOrEqualToThreshold \
 --dimensions "Name=InstanceId,Value=${VALUE}" \
 --evaluation-periods 3 \
 --alarm-actions arn:aws:sns:${region}:${account_id}:${topic}
 ##--unit Bytes
 echo "$ID done"
done

WAF

aws wafv2 create-web-acl \
 --name acl_name \
 --scope CLOUDFRONT \
 --default-action Allow={} \
 --visibility-config SampledRequestsEnabled=true,CloudWatchMetricsEnabled=true,MetricName=metric_acl_name \
 --rule

Mount S3 Bucket on EC2

references: How to Mount S3 Bucket on Ubuntu 22.04 with S3FS Fuse

AWS Configure

Mon, 01 Jan 0001 00:00:00 +0000

S3 Bucket Policy

{
 "Version": "2012-10-17",
 "Statement": [
 {
 "Sid": "AllowPublicRead",
 "Effect": "Allow",
 "Principal": "*",
 "Action": "s3:GetObject",
 "Resource": "arn:aws:s3:::bucketName/*"
 }
 ]
}

S3 CORS

[
 {
 "AllowedHeaders": ["*"],
 "AllowedMethods": ["GET", "PUT", "POST", "DELETE"],
 "AllowedOrigins": ["*"],
 "ExposeHeaders": [
 "x-amz-server-side-encryption",
 "x-amz-request-id",
 "x-amz-id-2"
 ],
 "MaxAgeSeconds": 3000
 }
]

ECR Lifecycle Policy

{
 "rules": [
 {
 "rulePriority": 1,
 "description": "Keep only the last 100 images",
 "selection": {
 "tagStatus": "any",
 "countType": "imageCountMoreThan",
 "countNumber": 100
 },
 "action": {
 "type": "expire"
 }
 }
 ]
}

ECR Lifecycle Policy1

{
 "rules": [
 {
 "rulePriority": 1,
 "description": "Remove images with certain tag",
 "selection": {
 "tagStatus": "tagged",
 "tagPrefixList": ["tag1", "tag2"],
 "countType": "imageCountMoreThan",
 "countNumber": 0
 },
 "action": {
 "type": "expire"
 }
 }
 ]
}

ECR Lifecycle Policy2

{
 "rules": [
 {
 "rulePriority": 1,
 "description": "Remove untagged images older than 14 days",
 "selection": {
 "tagStatus": "untagged",
 "countType": "sinceImagePushed",
 "countUnit": "days",
 "countNumber": 14
 },
 "action": {
 "type": "expire"
 }
 }
 ]
}

AWS Terraform

Mon, 01 Jan 0001 00:00:00 +0000

tf

Provider

provider.tf

EC2

Cloudflare docs

Mon, 01 Jan 0001 00:00:00 +0000

Setting CloudFlare Worker for CORS

addEventListener("fetch", (event) => {
 event.respondWith(handleRequest(event.request));
});

async function handleRequest(request) {
 let response = await fetch(request);
 response = new Response(response.body, response);
 response.headers.set(
 "Access-Control-Allow-Origin",
 "frontend-h5.shyc883.com"
 );
 response.headers.set("Access-Control-Allow-Methods", "GET, OPTIONS, POST");
 response.headers.set(
 "Access-Control-Allow-Headers",
 "Content-Type, Authorization"
 );
 response.headers.set("Access-Control-Allow-Credentials", true);
 return response;
}

Terraform_create_record

terraform {
 required_providers {
 cloudflare = {
 source = "cloudflare/cloudflare"
 version = "~> 2.0"
 }
 }
}

provider "cloudflare" {
 email = "cloudflare@gmail.com"
 api_key = "1488ed0d2082ed36c010b773431fd9dcacde1"
 account_id = "06ae012a1ba907df24a220cd14a4fa8b"
}

resource "cloudflare_record" "gitlab" {
 zone_id = "92c6d5010fbacab27d464f4d79c11fce"
 name = "gitlab"
 value = "192.123.168.234"
 type = "A"
 ttl = 300
 proxied = true
}

Terraform_create_page_rule

# Add a page rule to the domain
resource "cloudflare_page_rule" "page_rule_png" {
 zone_id = "92c6d5010fbacab27d464f4d79c11fce"
 target = "www.example.com/*.png*"
 status = "active"

 actions {
 always_use_https = "true"
 browser_cache_ttl = 86400
 cache_level = "cache_everything"
 # edge_cache_ttl = 86400
 cache_key_fields {
 cookie {}
 header {}
 host {}
 query_string {
 ignore = true
 }
 user {}
 }
 # cache_ttl_by_status {
 # codes = "200-299"
 # ttl = 300
 # }
 # cache_ttl_by_status {
 # codes = "300-399"
 # ttl = 60
 # }
 # cache_ttl_by_status {
 # codes = "400-403"
 # ttl = -1
 # }
 # cache_ttl_by_status {
 # codes = "404"
 # ttl = 30
 # }
 # cache_ttl_by_status {
 # codes = "405-499"
 # ttl = -1
 # }
 # cache_ttl_by_status {
 # codes = "500-599"
 # ttl = 0
 # }
 # }
}

# resource "cloudflare_page_rule" "rules" {
# count = "${length(keys("${var.targets}"))}"
# lifecycle {
# create_before_destroy = true
# }

# zone_id = "92c6d5010fbacab27d464f4d79c11fce"
# target = "${var.targets[element(keys(var.targets),count.index)]}"
# actions {
# always_use_https = "true"
# cache_level = "cache_everything"
# }
# priority = "${count.index + 1}"
# }

Terraform_create_rate_limit_rule

# Create rate limit rule
resource "cloudflare_rate_limit" "wss_rate_limit" {
 zone_id = "92c6d5010fbacab27d464f4d79c11fce"
 threshold = 50
 period = 60
 match {
 request {
 url_pattern = "*wss*/*"
 }
 }
 action {
 mode = "ban"
 timeout = 3600
 }
 correlate {
 by = "nat"
 }
}

resource "cloudflare_rate_limit" "frontend_rate_limit" {
 zone_id = "92c6d5010fbacab27d464f4d79c11fce"
 threshold = 50
 period = 10
 match {
 request {
 url_pattern = "*h5*/*"
 }
 }
 action {
 mode = "ban"
 timeout = 3600
 }
 correlate {
 by = "nat"
 }
}

API Document

Common Command

Mon, 01 Jan 0001 00:00:00 +0000

ab

ab -n 20 -c 20 -k https://default.hddv1.com/error

age

# generate public and private keys
age-keygen -o key.txt

# encrypt file with public key
age -r public_key -o file.txt.enc file.txt

# encrypt file with ssh key
age -R ~/.ssh/id_ed25519.pub file.txt > file.txt.enc

# decrypt file
age --decrypt -i key.txt file.txt.enc > file.txt

awk

# To lowercase
uuidgen|awk '{print tolower($0)}' # output: 649612b0-0fa4-4b50-9b13-17279f602a43

# To uppercase
echo 'hello world'|awk '{print toupper($0)}' # output: HELLO WORLD

# 提取子字符串: `substr(string, start, length)`
echo "hello world" | awk '{print substr($0, 1, 5)}' # output: hello

# 全局替換字符串中的正則表達式匹配項: `gsub(regex, replacement, string)`
# 替換字符串中首次匹配的正則表達式: `sub(regex, replacement, string)`
echo "hello world" | awk '{gsub(/world/, "everyone"); print $0}' # output: hello everyone

# 將數字轉換為整數
echo "3.14" | awk '{print int($0)}' # output: 3

# 返回平方根
echo "99" | awk '{print sqrt($0)}' # output: 9.94987

# 指數和對數
echo "2" | awk '{print exp($0), log($0)}' # output: 7.38906 0.693147

caffeinate

# 防止显示器关闭
caffeinate -d
# 保持系统不休眠
caffeinate -i
# 保持 30 分钟
caffeinate -t 1800

certbot

# Install
sudo apt install certbot python3-certbot-nginx python3-certbot-dns-route53

# 1. Generating Wildcard Certificates
sudo certbot certonly --manual --preferred-challenges=dns --server https://acme-v02.api.letsencrypt.org/directory --agree-tos -d *.example.com
### add txt record then press enter to continue

# 2. Generating Wildcard Certificates
sudo certbot certonly -d example.com -d *.example.com --dns-route53 --agree-tos --server https://acme-v02.api.letsencrypt.org/directory

# Automating Renewal
0 0 * * 1 /usr/bin/certbot certonly --dns-route53 -d *.example.com --quiet --post-hook "systemctl reload nginx"

cutycapt

# Capture website page as picture
xvfb-run --server-args="-screen 0, 1024x768x24" cutycapt --url=https://www.google.com --out="/tmp/google.png"

dmesg

sudo dmesg -T | grep -i 'killed process'
# total-vm: 該程序分配的虛擬記憶體總量（含未實際使用）
# anon-rss: 匿名頁面 resident memory（實際佔用記憶體）→ 重點
# file-rss: 映射檔案的 resident memory（如 shared libraries）
# shmem-rss: 共用記憶體的 resident memory

dnscontrol

creds.json
command

dnscontrol get-zones --format=js --out=example.com.js r53 ROUTE53 example.com
dnscontrol get-zones --format=js --out=example.com.js cloudflare CLOUDFLAREAPI example.com

ffmpeg

# Download sample video
wget https://www.sample-videos.com/video321/mp4/720/big_buck_bunny_720p_1mb.mp4 -O test.mp4

# Push stream
ffmpeg -re -i test.mp4 -c copy -f flv "rtmp://209357.push.tlivecloud.com/live/big_buck_bunny_720p_1mb?txSecret=a543b79d9a8c38ace5ce18eea2bd7721&txTime=687E4609"

go

go tool pprof -http=:8081 20250814_024534.heap

k6

k6.js
command

k6 run k6.js

kafka

# list topics
kafka-topics.sh --bootstrap-server 127.0.0.1:9094 --list
# all topics count
kafka-topics.sh --bootstrap-server 127.0.0.1:9094 --list |wc -l

hey

hey -n 200000 -c 500 -h2 -z 30s https://a8-wss.hddv1.com/test

openfortivpn

# https://github.com/adrienverge/openfortivpn
sudo openfortivpn ip:port --username=ricky --pppd-use-peerdns=1

openssl

# 自簽名證書，要把 ca.p7b 匯入 certmgr.msc 的受信任的根憑證授權單位，Chrome 才吃的到。
openssl crl2pkcs7 -nocrl -certfile ca.crt -out ca.p7b

prlimit

# 更改 Max_open_files 遇到參數錯誤，原因為 CentOS6 與 CentOS7 指令不同
# CentOS6
for i in $(ps -ef | grep 'publish/server/game_server' | egrep -v 'grep|startall' | awk '{print $2}'); do echo -n "Max open files=1024000:1024000" > /proc/$i/limits; done

# CentOS7
for i in $(ps -ef | grep gateway | grep -v grep | awk '{print $2}'); do prlimit --pid $i --nofile=1024000:1024000 ; done

siege

siege --time=3s --concurrent=30000 https://a8-h5.hddv1.com/index.html

tr

# cat krypton2
YRIRY GJB CNFFJBEQ EBGGRA
# cat krypton2 | tr a-zA-Z n-za-mN-ZA-M
LEVEL TWO PASSWORD ROTTEN

vegeta

#!/usr/bin/env bash

attack() {
 echo "GET ${1}" |
 vegeta attack -duration=100s -header="User-Agent: baidu" -header="X-Forwarded-For: 47.0.0.1" -rate=500 -timeout=1s |
 vegeta encode |
 jaggr @count=rps \
 hist\[100,200,300,400,500\]:code \
 p25,p50,p95:latency \
 sum:bytes_in \
 sum:bytes_out |
 jplot rps+code.hist.100+code.hist.200+code.hist.300+code.hist.400+code.hist.500 \
 latency.p95+latency.p50+latency.p25 \
 bytes_in.sum+bytes_out.sum
}

if [[ -n ${1} ]]; then
 attack ${1}
fi

## -header="Connection: Upgrade" -header="Upgrade: websocket"

wrk

wrk -t10 -c1000 -d30s -H "User-Agent: baidu" "https://default.hddv1.com/error"

Vagrant with hyper-v provider

Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V -All

Common

# Find out processes swap usage command
for file in /proc/*/status ; do awk '/VmSwap|Name/{printf $2 " " $3}END{ print ""}' $file; done | sort -k 2 -n -r | less

Gitbook

Hide gitbook sidebar default.

Diagrams

Mon, 01 Jan 0001 00:00:00 +0000

Diagrams

https://diagrams.mingrammer.com/docs/getting-started/installation

Docker Command

Mon, 01 Jan 0001 00:00:00 +0000

Build with secret

Dockerfile

# syntax = docker/dockerfile:1.6
FROM golang:1.21.1-alpine3.18
RUN --mount=type=secret,id=mysecret,target=/root/.ssh/id_rsa git clone git@gitlab.com:ricky/repo.git

Command

export DOCKER_BUILDKIT=1
docker build --secret id=mysecret,src=id_rsa -t image .

Compose

# Force pull image
docker-compose up -d --pull always

Create buildx instance

# create buildx instance
docker buildx create --name builder --bootstrap --driver docker-container
# install emulators
docker run --privileged --rm tonistiigi/binfmt --install all

Create Network

docker network create -d bridge --subnet 172.100.0.0/24 --gateway 172.100.0.1 backend_dev

Multiple build-arg

docker build . -f ./scripts/Dockerfile \
 --build-arg Date=$(date) \
 --build-arg Tag=$(git rev-list -n 1 --tags) \
 --build-arg Commit=$(git describe --tags --abbrev=0) \
 -t ops-cli

Multiple platform

# create and use buildx instance
docker buildx create --use --name builder
# build multiple platform
docker buildx build --push --platform linux/arm64,linux/amd64 -t zeyanlin/ops-cli .

Run container in different platform

finch run -it --rm --platform=linux/arm64 zeyanlin/ops-cli /bin/sh

Docker docs

Mon, 01 Jan 0001 00:00:00 +0000

docker-compose

cAdvisor

Elasticsearch

docker-compose.yaml

local dev

docker-compose.yaml

NodeJS

docker-compose.yaml

rstudio

docker-compose.yaml

rsyncd

docker-compose.yaml
rsyncd.conf
rsyncd.secrets
rsync -auz --password-file=/tmp/pass dist user@hostip::myshare

Dockerfile

awscli

Dockerfile

buildx

Dockerfile
docker buildx build --push --platform linux/arm64,linux/amd64 -t zeyanlin/app .

dind

Dockerfile

golang

Dockerfile
docker build --secret id=mysecret,src=id_rsa -t app .

goproxy

Dockerfile
docker buildx build -f goproxy/Dockerfile --platform linux/amd64,linux/arm64 -t zeyanlin/goproxy:latest --push .

Gitlab-ci

rstudio

supervisord

Dockerfile
supervisord.conf
- service with supervisord
  - Dockerfile

File Related Command

Mon, 01 Jan 0001 00:00:00 +0000

File create time

1. Find Inode

$ stat dns.yaml
 File: dns.yaml
 Size: 1003 Blocks: 8 IO Block: 4096 regular file
Device: ca01h/51713d Inode: 3595636 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 1000/ ubuntu) Gid: ( 1000/ ubuntu)
Access: 2022-05-03 12:59:59.996755279 +0800
Modify: 2021-12-10 18:27:54.157585209 +0800
Change: 2022-01-07 14:57:58.619727878 +0800
 Birth: -

$ ls -i dns.yaml
3585173 dns.yaml

2. Find Filesystem

$ df dns.yaml
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/root 101583780 25703988 75863408 26% /

3. Get Create Time

$ sudo debugfs -R 'stat <3595636>' /dev/root
Inode: 3595636 Type: regular Mode: 0644 Flags: 0x80000
Generation: 449657737 Version: 0x00000000:00000001
User: 1000 Group: 1000 Project: 0 Size: 1003
File ACL: 0
Links: 1 Blockcount: 8
Fragment: Address: 0 Number: 0 Size: 0
 ctime: 0x61d7e476:93c13018 -- Fri Jan 7 14:57:58 2022
 atime: 0x6270b6cf:eda51d3c -- Tue May 3 12:59:59 2022
 mtime: 0x61b32baa:25923ce4 -- Fri Dec 10 18:27:54 2021
crtime: 0x61b32baa:25923ce4 -- Fri Dec 10 18:27:54 2021
Size of extra inode fields: 32
Inode checksum: 0x5b176bb2
EXTENTS:
(0):2665902

Display Ubuntu's Message of the Day

sudo chmod +x /etc/update-motd.d/*

List domains

sed 's/ //g' domains-info.md | awk -F '|' '{if($3 ~ /.*\.com/)print $3}' | sort | uniq

GCP Command

Mon, 01 Jan 0001 00:00:00 +0000

monitoring

# list
gcloud alpha monitoring policies list --project="project-prod-a" >project-prod-a.yaml

# update
gcloud alpha monitoring policies update --policy-from-file="project-prod-a.yaml" "project-prod-a"

cloud storage

# Create bucket
gsutil mb -c standard -l asia-east2 gs://prod-a
gsutil iam ch allUsers:objectViewer gs://prod-a

# Upload files
gsutil -m rsync -x ".svn/" -u -d -r srcDir gs://prod-a
gsutil -m cp downloads/*.csv gs://prod-a/data/

# Create CORS file
cat << EOF > /data/cors.json
[
 {
 "origin": ["*"],
 "responseHeader": ["Access-Control-Allow-Origin"],
 "method": ["GET","HEAD","DELETE"],
 "maxAgeSeconds": 3600
 }
]
EOF

# Set CORS
gsutil cors set /data/cors.json gs://prod-a/

# Check CORS
gsutil cors get gs://prod-a/

# Purge CDN
gcloud compute url-maps invalidate-cdn-cache balancer-client-prod-a --host ${} --path "/*"

Git Command

Mon, 01 Jan 0001 00:00:00 +0000

Search in git

git rev-list --all | xargs git grep -F ''

Count commits

git rev-list --count main

View a file of another branch

git show dev:main.go

Take a backup of untracked files

git ls-files --others --exclude-standard -z | xargs -0 tar rvf backup-untracked.zip

Submodule

# Add submodule
git submodule add -b main git@github.com:linzeyan/toha.git themes/toha

# Update submodule
git submodule update --init --remote

# Remove submodule
modulePath="themes/toha"
git submodule deinit -f ${modulePath}
git rm ${modulePath}
rm -rf .git/modules/${modulePath}
git config --remove-section submodule.${modulePath}.
rm -f .gitmodules

commit hash

git rev-parse HEAD

commit tag

git describe --tags

worktree

# list
git worktree list

# add
git worktree add ../dirname branch-name

git config

[user]
 email = zeyanlin@outlook.com
 name = Ricky
 signingkey = 2A4313489FDCA802ED6FCC214B03D879EA73DF37
[commit]
 gpgsign = true

git config1

For golang import package

Gitlab Command

Mon, 01 Jan 0001 00:00:00 +0000

cleanup

doc

# artifacts
gitlab-rake gitlab:cleanup:orphan_job_artifact_files

# expire session
gitlab-rake gitlab:cleanup:sessions:active_sessions_lookup_keys

# lfs
gitlab-rake gitlab:cleanup:orphan_lfs_files

# project
gitlab-rake gitlab:cleanup:project_uploads
gitlab-rake gitlab:cleanup:remote_upload_files

# registry
gitlab-ctl registry-garbage-collect
gitlab-ctl registry-garbage-collect -m

migration

1. Copy Old Crontab、Old /etc/gitlab、update-ca-trust

2. Version should be same

3. Copy newest backup file

4. Stop Services

gitlab-ctl stop unicorn
gitlab-ctl stop puma
gitlab-ctl stop sidekiq
gitlab-ctl status

5. Restore

File must put in /var/opt/gitlab/backup

Gitlab docs

Mon, 01 Jan 0001 00:00:00 +0000

add member by project

Admin Area -> Settings -> General -> LDAP settings -> Lock memberships to LDAP synchronization -> Cancel

backup cronjob

# Backup Gitlab configs
1 0 * * * /usr/bin/tar -zcf /var/opt/gitlab/backups/`date +%Y_%m_%d`_gitlab_config.tar.gz /etc/gitlab &> /tmp/backup.log
# Backup Gitlab data
1 1 * * * /usr/bin/gitlab-backup create STRATEGY=copy BACKUP=`date +%Y_%m_%d` &>> /tmp/backup.log
# Rotate
0 2 * * * /usr/bin/rm -f `find /data/backups/ -name "*.tar*" -mtime +15`

gitlab-ci.yml template

gitbook

golang

gitlab-ci.yml

hexo

gitlab-ci.yml

Static resources

gitlab-ci.yml

template

gitlab-ci.yml

config

gitlab-runner

gitlab-runner.toml

issue

console output while install

[execute] psql: could not connect to server: Connection refused
Is the server running locally and accepting
connections on Unix domain socket "/var/opt/gitlab/postgresql/.s.PGSQL.5432"?

solve

# stop service
sudo gitlab-ctl stop
sudo systemctl stop gitlab-runsvdir.service

# check if there are any postgres processes; shouldn't be
ps aux | grep postgre

# remove process pid
sudo rm /var/opt/gitlab/postgresql/data/postmaster.pid

# start service
sudo systemctl start gitlab-runsvdir.service
sudo gitlab-ctl reconfigure

issue1

解決 Gitlab Pages 限制訪問權限後的 redirect invalid url。

Remove “gitlab_pages” block from /etc/gitlab/gitlab-secrets.json
gitlab-ctl reconfigure

issue2

console output

# Gitlab Container Registry
Error response from daemon: Get https://registry.knowhow.fun/v2/: x509: certificate has expired or is not yet valid

solve

yum install ca-certificates
cd /etc/gitlab
openssl genrsa -out ca.key 4096
openssl req -new -x509 -days 3650 -key ca.key -out ca.crt
openssl genrsa -out server.key 4096
openssl req -new -key server.key -out server.csr
openssl x509 -req -days 3650 -in server.csr -CA ca.crt -CAkey ca.key -set_serial 01 -out server.crt
cp server.crt /etc/pki/ca-trust/source/anchors/
cp ca.crt /etc/pki/ca-trust/source/anchors/
update-ca-trust

issue3

console output

# Gitlab Container Registry
received unexpected HTTP status: 500 Internal Server Error

solve

/etc/gitlab/gitlab.rb

Go Snippet

Mon, 01 Jan 0001 00:00:00 +0000

ETCD TTL

func main() {
 // 创建 etcd 客户端
 cli, err := clientv3.New(clientv3.Config{
 Endpoints: []string{"localhost:2379"},
 DialTimeout: 5 * time.Second,
 })
 if err != nil {
 fmt.Println("Error connecting to etcd:", err)
 return
 }
 defer cli.Close()

 // 设置 TTL (单位为秒)
 ttl := int64(10) // 例如 10 秒
 resp, err := cli.Grant(context.TODO(), ttl)
 if err != nil {
 fmt.Println("Error creating lease:", err)
 return
 }

 // 使用 Lease ID 进行 Put 操作
 _, err = cli.Put(context.TODO(), "my-key", "my-value", clientv3.WithLease(resp.ID))
 if err != nil {
 fmt.Println("Error putting key with lease:", err)
 return
 }

 fmt.Println("Key with TTL successfully set.")
}

gRPC UnaryInterceptor

func unaryInterceptor(
 ctx context.Context,
 req any,
 info *googleGrpc.UnaryServerInfo,
 handler googleGrpc.UnaryHandler,
) (any, error) {
 // 打印被调用的方法名
 fmt.Println("Called method:", info.FullMethod)

 // 打印传入的请求参数
 fmt.Printf("Request: %+v\n", req)

 fmt.Printf("Meta: %+v\n", util.GetReqInfoFromCtx(ctx))
 // 调用实际的 handler
 response, err := handler(ctx, req)
 if err != nil {
 fmt.Println("err: ", err)
 }
 return response, err
}

isRunningTest

// isRunningTest 確認是否在跑測試
func isRunningTest() bool {
 return flag.Lookup("test.v") != nil
}

Go Tools

Mon, 01 Jan 0001 00:00:00 +0000

tools

benchstat

go install golang.org/x/perf/cmd/benchstat@latest

deadcode

go install golang.org/x/tools/cmd/deadcode@latest

httpstat

It’s like curl -v, with colours.

go get github.com/davecheney/httpstat

jsonnet

This an implementation of Jsonnet in pure Go

go get github.com/google/go-jsonnet/cmd/jsonnet

migrate

go install -tags 'mysql,sqlite,sqlite3' github.com/golang-migrate/migrate/v4/cmd/migrate@latest

protobuf

go install google.golang.org/protobuf/cmd/protoc-gen-go@lastest
go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@lastest
go install github.com/google/gnostic/cmd/protoc-gen-openapi@latest

gosec

Golang security checker

go get -u github.com/securego/gosec/cmd/gosec

govulncheck

go install golang.org/x/vuln/cmd/govulncheck@latest

vegeta

HTTP load testing tool and library

go get -u github.com/tsenart/vegeta

dasel

Select, put and delete data from JSON, TOML, YAML, XML and CSV files with a single tool. Supports conversion between formats and can be used as a Go package.

brew install dasel
go install github.com/tomwright/dasel/v2/cmd/dasel@master

hey

HTTP load generator, ApacheBench (ab) replacement, formerly known as rakyll/boom

brew install hey

slides

Terminal based presentation tool

brew install slides
go install github.com/maaslalani/slides@latest

gokart

A static analysis tool for securing Go code

go install github.com/praetorian-inc/gokart@latest

structslop

structslop is a static analyzer for Go that recommends struct field rearrangements to provide for maximum space/allocation efficiency.

go install -v github.com/orijtech/structslop/cmd/structslop@v0.0.8
go get github.com/orijtech/structslop/cmd/structslop

dive

A tool for exploring each layer in a docker image

brew install dive
go get github.com/wagoodman/dive

sttr

cross-platform, cli app to perform various operations on string

go install github.com/abhimanyu003/sttr@latest

gentool

Gen Tool is a single binary without dependencies can be used to generate structs from database

go install gorm.io/gen/tools/gentool@latest

wire

go install github.com/google/wire/cmd/wire@latest

ko

Build and deploy Go applications

go install github.com/google/ko@latest

Talisman

A tool to detect and prevent secrets from getting checked in

GPG Command

Mon, 01 Jan 0001 00:00:00 +0000

Install

brew install gnupg

Generate

gpg --full-generate-key

gpg --list-secret-keys

Generate Problem

$ gpg --full-generate-key
gpg: Sorry, no terminal at all requested - can't get input

Comment out no-tty in ~/.gnupg/gpg.conf

Add to git

gpg --armor --export 51ADF7101CA64B2508AE29EEC279555531A1DD62

Set .gitconfig

git config user.email zeyanlin@outlook.com
git config user.name Ricky
git config user.signingkey 51ADF7101CA64B2508AE29EEC279555531A1DD62
git config commit.gpgsign true

Delete key

gpg --delete-secret-keys 51ADF7101CA64B2508AE29EEC279555531A1DD62

Backup key

# https://www.jwillikers.com/backup-and-restore-a-gpg-key
gpg --list-secret-keys --keyid-format LONG

# Export key as a file, replace email-address and Enter the private key’s passphrase
gpg -o private.gpg --export-options backup --export-secret-keys rickylin@cloud-miner.net

# Restore key and enter the private key’s passphrase
gpg --import-options restore --import private.gpg

If GPG not work

echo 'export GPG_TTY=$(tty)' >> ~/.zshrc
gpgconf -kill gpg-agent
exec $SHELL

Encrypt file

# Encrypt file
gpg --symmetric --cipher-algo aes256 archive_file.tar

# Decrypt file
gpg --output archive_file.tar --decrypt archive_file.tar.gpg

K8s Command

Mon, 01 Jan 0001 00:00:00 +0000

cert-manager

# install the cert-manager CustomResourceDefinition resources
kubectl apply -f https://github.com/cert-manager/cert-manager/releases/download/v1.13.1/cert-manager.crds.yaml

# Add the Jetstack Helm repository
helm repo add jetstack https://charts.jetstack.io
helm repo update

# install the cert-manager helm chart
helm install \
 cert-manager jetstack/cert-manager \
 --namespace cert-manager \
 --create-namespace \
 --version v1.13.1 \
 --set installCRDs=true
 --set prometheus.enabled=false \
 --set webhook.timeoutSeconds=4

# uninstalling
helm delete my-release
kubectl delete -f https://github.com/cert-manager/cert-manager/releases/download/v1.13.1/cert-manager.crds.yaml

# create clusterissuer
kubectl apply -f cert-manager-resource.yaml

# generate certificate
kubectl apply -f cert-generate-resource.yaml

# create ingress controller
kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.8.2/deploy/static/provider/cloud/deploy.yaml

# create ingress
kubectl apply -f cert-ingress-resource.yaml

helm

# install plugin
helm plugin install https://github.com/chartmuseum/helm-push.git

# add repo
## helm repo add --username gitlab-ci-token --password ${CI_JOB_TOKEN} ${CI_PROJECT_NAME} ${CI_API_V4_URL}/projects/${CI_PROJECT_ID}/packages/helm/stable
helm repo add go2helm https://gitlab.go2cloudten.com/api/v4/projects/29/packages/helm/stable --username ricky

# push chart
## https://docs.gitlab.com/ee/user/packages/helm_repository/
helm cm-push ./proxy-0.1.0.tgz go2helm

kompose

kompose --file docker-compose.yml convert

gitlab-runner

link

Linux docs

Mon, 01 Jan 0001 00:00:00 +0000

docker.service

ExecStart=/usr/bin/dockerd -H tcp://0.0.0.0:2375 -H unix:///var/run/docker.sock --bip 10.255.0.1/16 --containerd=/run/containerd/containerd.sock --insecure-registry hub.srjob.co:8888 --insecure-registry registry.knowhow.fun

gd.service

[Unit]
Description=Fetch DNS
After=network.target
After=mysql.service

[Service]
WorkingDirectory=/data/dns
ExecStart=/data/dns/gd -o hourly
ExecReload=/bin/kill -s HUP $MAINPID
Restart=always

[Install]
WantedBy=multi-user.target

openresty.service

[Unit]
Description=The OpenResty Application Platform
After=syslog.target network-online.target remote-fs.target nss-lookup.target
Wants=network-online.target

[Service]
Type=forking
WorkingDirectory=/data/config/nginx
PIDFile=/data/config/nginx/logs/nginx.pid
ExecStartPre=/usr/bin/chown -R root:root /data/nginx
ExecStartPre=/usr/bin/rm -f /data/nginx/logs/nginx.pid
ExecStartPre=/usr/local/openresty/nginx/sbin/nginx -p /data/nginx -t
ExecStart=/usr/local/openresty/nginx/sbin/nginx -p /data/nginx
ExecReload=/bin/kill -s HUP $MAINPID
ExecStop=-/sbin/start-stop-daemon --quiet --stop --retry QUIT/5 --pidfile /data/nginx/logs/nginx.pid
#ExecStop=/bin/kill -s QUIT $MAINPID
KillSignal=SIGQUIT
TimeoutStopSec=5
KillMode=process
PrivateTmp=true
LimitNOFILE=1048576

[Install]
WantedBy=multi-user.target

pm2.service

[Unit]
Description=PM2 process manager
Documentation=https://pm2.keymetrics.io/
After=network.target

[Service]
Type=forking
User=root
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
Environment=PM2_HOME=/root/.pm2
PIDFile=/root/.pm2/pm2.pid
WorkingDirectory=/game/publish
ExecStart=/lib/node_modules/pm2/bin/pm2 start game_api.json manage.json
ExecReload=/lib/node_modules/pm2/bin/pm2 reload all
ExecStop=/lib/node_modules/pm2/bin/pm2 kill

[Install]
WantedBy=multi-user.target

logrotate

/data/gameapi/logs/*.log {
create 0644 nobody root
daily
rotate 30
dateext
missingok
notifempty
compress
sharedscripts
postrotate
/bin/kill -USR1 `cat /data/gameapi/logs/nginx.pid 2>/dev/null` 2>/dev/null || true
endscript
}

mermaid notes

Mon, 01 Jan 0001 00:00:00 +0000

details

看我

你看不到我看不到我

class

classDiagram
Class01 <|-- AveryLongClass : Cool
Class03 _-- Class04
Class05 o-- Class06
Class07 .. Class08
Class09 --> C2 : Where am i?
Class09 --_ C3
Class09 --|> Class07
Class07 : equals()
Class07 : Object[] elementData
Class01 : size()
Class01 : int chimp
Class01 : int gorilla
Class08 <--> C2: Cool label

classDiagram

flow-link

flowchart LR
A --o B
B --x C

D o--o E
E <--> F
F x--x G

flowchart

flow-link1

flow-shapes

graph LR
id1[方框]
id2(帶有圓角的方框)
id3([體育場形狀])
id4[[子例程]]
id5[(圓柱狀)]
id6((圓形))
id7>非對稱形狀]
id8{菱形}
id9{{六角形}}
id10[/平行四邊形 1/]
id11[\平行四邊形 2\]
id12[/梯形 1\]
id13[\梯形 2/]
id14(((雙圓)))

flowchart

flow-subgraphs

flowchart TD
c1-->a2

 subgraph one
 a1-->a2
 end

 subgraph "`**two**`"
 b1-->b2
 end

 subgraph three
 c1-->c2
 end

flowchart

gantt

gantt
dateFormat YYYY-MM-DD
title Adding GANTT diagram functionality to mermaid
section A section
Completed task :done, des1, 2014-01-06,2014-01-08
Active task :active, des2, 2014-01-09, 3d
Future task : des3, after des2, 5d
Future task2 : des4, after des3, 5d
section Critical tasks
Completed task in the critical line :crit, done, 2014-01-06,24h
Implement parser and jison :crit, done, after des1, 2d
Create tests for parser :crit, active, 3d
Future task in critical line :crit, 5d
Create tests for renderer :2d
Add to mermaid :1d

gantt

git

gitGraph
commit
commit
branch develop
checkout develop
commit
commit
checkout main
merge develop
commit
commit

er

erDiagram
CUSTOMER }|..|{ DELIVERY-ADDRESS : has
CUSTOMER ||--o{ ORDER : places
CUSTOMER ||--o{ INVOICE : "liable for"
DELIVERY-ADDRESS ||--o{ ORDER : receives
INVOICE ||--|{ ORDER : covers
ORDER ||--|{ ORDER-ITEM : includes
PRODUCT-CATEGORY ||--|{ PRODUCT : contains
PRODUCT ||--o{ ORDER-ITEM : "ordered in"

erDiagram

journey

journey
title My working day
section Go to work
Make tea: 5: Me
Go upstairs: 3: Me
Do work: 1: Me, Cat
section Go home
Go downstairs: 5: Me
Sit down: 3: Me

erDiagram

Network docs

Mon, 01 Jan 0001 00:00:00 +0000

Synology Active Backup for Bussiness backup task failed

Due to IP change last week

Firewall policy create NAS_to_ESXi。
虛擬機器 -> 任務清單 -> 刪除任務。
虛擬機器 -> VMware vSphere -> 管理 Hypervisor -> 刪除舊的 IP，新增新的 IP。

Set LACP for Synology NAS and NETGEAR switch

NETGEAR

Switching -> LAG -> LAG Configuration -> ch1 -> 41、42 -> Apply。
ch1 -> Description: NAS、LAG Type:LACP -> Apply。
Switching -> VLAN -> Port PVID Configuration -> g41、g42 PVID:99、VLAN Member:10-14,17-23,99,101、VLAN Tag:10-14,17-23,99,101 -> Apply。

Synology

控制台 -> 網路 -> 網路介面 -> 新增 Bond。

Set NAT in FortiGate

1. 政策&物件 -> 虛擬 IP -> 新增

名稱: IT-VPN
介面: wan2
對外 IP: 0.0.0.0

埠號轉發

協定: TCP
外部服務埠號: 19979
對應到埠號: 19979

2. 政策&物件 -> IPv4 政策

From zone wan2 to zone Knowhow_Vlan
From any to IT-VPN

Juniper SRX 320

# 查看當前軟體版本號
show system software

# 查看系統啟動時間
show system uptime

# 查看硬體板卡及序號
show chassis haredware

# 查看硬體板卡當前狀態
show chassis environment

# 查看主控板（RE）資源使用及狀態
show chassis routing-engine


# 查看當前防火牆併發會話數
show security flow session summary

# 查看當前防火牆具體併發會話
show security flow session

# 清除當前 session
clear security flow session all

# 檢查全域 ALG 開啟情況
show security alg status

# 查OID
show snmp mib walk decimal 1.3.6.1.2.1.2.2.1.2

# 設定政策
set security policy zones from-zone to-zone

# 查看路由表
show route

# 查看 ARP 表
show arp

# 查看系統日誌
show log messages

# 查看所有介面運行狀態
show interface terse

# 查看介面運行細節資訊
show interface ge-x/y/z detail

# 比較修改
show | compare rollback ?
show | compare rollback 1

# 查看系統
show system

# 查看設定
show configuration

# 動態統計介面資料包轉發資訊
monitor interface ge-x/y/z

# 動態報文抓取（Tcpdump，類似 ScreenOS snoop命令）
monitor traffic interface ge-x/y/z

Network Related Command

Mon, 01 Jan 0001 00:00:00 +0000

Check port status

# `(echo >/dev/tcp/${host}/${port})`
(echo >/dev/tcp/192.168.57.24/80) &>/dev/null && echo "open" || echo "closed"

timeout 1 bash -c '>/dev/tcp/192.168.57.24/80 &>/dev/null' && echo "open" || echo "closed"

timeout 1 bash -c '>/dev/tcp/192.168.57.24/80' && echo "open" || echo "closed"

Block subnets

ip route add blackhole 192.168.0.0/24

Kill sessions

# ss
sudo ss -K state TIME-WAIT
# or conntrack
sudo conntrack -D -p tcp --state TIME_WAIT

connect IPs

ss -tnH state established \
| awk '{
 peer = $5; if (peer == "") peer = $NF # 取 Peer Address:Port（某些版本欄位可能不同）
 sub(/,$/, "", peer) # 去掉可能的逗號
 gsub(/[\[\]]/, "", peer) # 去掉所有中括號
 gsub(/::ffff:/, "", peer) # IPv4-mapped IPv6 無論出現在開頭還中間都移除
 sub(/%[^:]+/, "", peer) # 去掉 IPv6 的 scope（如 %eth0）
 sub(/:[0-9]+$/, "", peer) # 去掉最後的 :port
 print peer
}' \
| sort | uniq -c | sort -nr

websocat connect MQTT

websocat -v --binary --protocol=mqtt ws://57.77.71.2:8083/mqtt

Nginx docs

Mon, 01 Jan 0001 00:00:00 +0000

map

# map
map $remote_addr $limit_key {
 35.229.201.209 "";
 default $binary_remote_addr;
}
# wss.conf
limit_req_zone $limit_key zone=websocket:10m rate=20r/s;
limit_req_status 499;

server {
 location = / {
 limit_req zone=websocket nodelay;
 limit_req_log_level warn;
 }
}

rewrite

1

# https://localhost/img/nginx.svg can access /data/nginxconfig.io/src/static/nginx.svg
location /img {
 rewrite '^/img/(.*)$' /static/$1;
 }

location /static {
 root /data/nginxconfig.io/src;
 index nginx.svg;
}

2

# https://localhost/photo/nginx.svg can access /data/nginxconfig.io/src/static/nginx.svg

location /photo {
 root /data/nginxconfig.io/src;
 try_files $uri /$uri @pic;
}

location @pic {
 rewrite '^/photo/(.*)$' /static/$1;
}

3

# remove prefix path and allow proxy_pass POST
location /upload/ {
 proxy_set_header Host $host;
 proxy_set_header X-Real-IP $remote_addr;
 proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
 root /data/nginx/html;
 # Remove path
 rewrite ^/upload/(.*) /$1 break;
 proxy_pass https://logo$uri$is_args$args;
 # Proxy_pass POST
 proxy_http_version 1.1;
 proxy_set_header Upgrade $http_upgrade;
 proxy_set_header Connection 'upgrade';
 proxy_cache_bypass $http_upgrade;
 #proxy_redirect https://logo/ /;
}

location / {
 proxy_set_header Host $host;
 proxy_set_header X-Real-IP $remote_addr;
 proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
 root /data/nginx/html;
 index index.html index.htm;
}

grafana behind nginx

server/ssl.conf

ssl_certificate /etc/ssl/go2cloudten.com.crt;
ssl_certificate_key /etc/ssl/go2cloudten.com.key;
ssl_ciphers "EECDH+ECDSA+AESGCM:EECDH+aRSA+AESGCM:EECDH+ECDSA+SHA384:EECDH+ECDSA+SHA256:EECDH+aRSA+SHA384:EECDH+aRSA+SHA256:EECDH+aRSA+RC4:EECDH:EDH+aRSA:HIGH:!RC2:!RC4:!aNULL:!eNULL:!LOW:!IDEA:!DES:!TDES:!3DES:!MD5:!EXP:!PSK:!SRP:!DSS:!EXPORT:!ANON";
ssl_prefer_server_ciphers on;
ssl_protocols TLSv1.2 TLSv1.3;
ssl_session_timeout 50m;

server/proxy.conf

proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

grafana.conf

server {
 listen 443 ssl;
 server_name grafana-test.go2cloudten.com;
 server_name grafana.go2cloudten.com;
 include server/ssl.conf;
 include server/proxy.conf;
 access_log logs/grafana.log json;
 error_log logs/grafana.error.log warn;
 location / {
 proxy_pass http://grafana;
 proxy_connect_timeout 300;
 proxy_read_timeout 700;
 proxy_send_timeout 700;
 proxy_set_header Host $host;
 proxy_set_header Upgrade $http_upgrade;
 proxy_set_header Connection "Upgrade";
 }
}

Pandoc Command

Mon, 01 Jan 0001 00:00:00 +0000

texlive

macOS

# brew install textlive
# npm i -g mermaid-filter
# Render mermaid
pandoc -F mermaid-filter -o readme.pdf readme.md

Ubuntu

# sudo apt install pandoc -y
# sudo apt-get -y install texlive-latex-recommended texlive-pictures texlive-latex-extra texlive-fonts-recommended
# npm i -g mermaid-filter
pandoc -F mermaid-filter -o readme.pdf readme.md

Redis Install Command

Mon, 01 Jan 0001 00:00:00 +0000

Install

# Ubuntu22.04
sudo add-apt-repository ppa:redislabs/redis
sudo apt install redis-server

SSH Command

Mon, 01 Jan 0001 00:00:00 +0000

Generate ssh key

# RSA
ssh-keygen -m PEM -t rsa -b 4096 -C "zeyanlin@outlook.com"

# ED25519
ssh-keygen -t ed25519 -C "dev" -f ~/.ssh/ed25519

ssh config

Host private.example.com
ProxyCommand /usr/local/bin/cloudflared access ssh --hostname %h

tmux

iTerm2

tmux -CC

Telegram Command

Mon, 01 Jan 0001 00:00:00 +0000

getUpdates

curl 'https://api.telegram.org/bot1234567890:KE9zNTZ8RGcxJTMlI29EJElKeU9QQExm3%E/getUpdates' | jq .

sendMessage

# chat
curl 'https://api.telegram.org/bot1234567890:KE9zNTZ8RGcxJTMlI29EJElKeU9QQExm3%E/sendMessage?chat_id=-12345&text=hello'

# thread
curl 'https://api.telegram.org/bot1234567890:KE9zNTZ8RGcxJTMlI29EJElKeU9QQExm3%E/sendMessage?chat_id=-12345&text=hello&message_thread_id=14'

Vagrant docs

Mon, 01 Jan 0001 00:00:00 +0000

Vagrantfile template

docker

Nginx

hyperv

virtualbox

Vagrantfile

vmware

Vagrantfile

multi

Vagrantfile

others

common

Vagrantfile

Metasploitable3

Vagrantfile

Zabbix docs

Mon, 01 Jan 0001 00:00:00 +0000

send alert

Use Webhook, Create Channel and Webhook in Mattermost, and put script to $(grep AlertScriptsPath /etc/zabbix/zabbix_server.conf).
Create Media types in Zabbix(Administration -> Medai types).
Add media to user(Administration -> Users -> Media).
Create action(Configuration -> Actions -> Trigger actions)。
Debug(Write log in script).
1. Media types:
  1. PROBLEM:\nProblem started at {EVENT.TIME} on {EVENT.DATE}\n 問題: {EVENT.NAME}\n 主機: {HOST.NAME}\nSeverity: {EVENT.SEVERITY}\n 目前數值: {EVENT.OPDATA}\n 問題 ID: {EVENT.ID}\n{TRIGGER.URL}
  2. RECOVERY:\nProblem has been resolved at {EVENT.RECOVERY.TIME} on {EVENT.RECOVERY.DATE}\n 問題: {EVENT.NAME}\n 持續時間: {EVENT.DURATION}\n 主機: {HOST.NAME}\nSeverity: {EVENT.SEVERITY}\n 問題 ID: {EVENT.ID}\n{TRIGGER.URL}

zabbix server

/etc/zabbix/zabbix_server.conf

Zabbix Server perform high loading, and slow query. Increase ValueCacheSize solve this problem.

Array

Mon, 01 Jan 0001 00:00:00 +0000

array

package main

import (
 "fmt"
)

func main() {
 a := [5]int{1, 2, 3, 4, 5}
 t := a[3:4:4]
 fmt.Println(t[0])
}

A. 3
B. 4
C. compilation error

Answer

Try it
B

Channel

Mon, 01 Jan 0001 00:00:00 +0000

channel

package main

import (
 "fmt"
 "time"
)

func main() {
 ch := make(chan int, 1000)
 go func() {
 for i := 0; i < 10; i++ {
 ch <- i
 }
 }()
 go func() {
 for {
 a, ok := <-ch
 if !ok {
 fmt.Println("close")
 return
 }
 fmt.Println("a: ", a)
 }
 }()
 close(ch)
 fmt.Println("ok")
 time.Sleep(time.Second * 100)
}

Answer

Try it
ok
panic: send on closed channel

channel1

package main

import (
 "fmt"
)

func main() {
 c := make(chan int)
 close(c)
 val, _ := <-c
 fmt.Println(val)
}

Answer

Try it
0

Context

Mon, 01 Jan 0001 00:00:00 +0000

context

package main

import (
 "context"
 "fmt"
)

func f(ctx context.Context) {
 context.WithValue(ctx, "foo", -6)
}

func main() {
 ctx := context.TODO()
 f(ctx)
 fmt.Println(ctx.Value("foo"))
}

A. -6
B. 0
C. <nil>
D: panic

Answer

Try it
C

context1

package main

import(
 "fmt"
 "encoding/json"
 "context"
)

func main() {
 data, _ := json.Marshal(context.WithValue(context.Background(), "a", "b"))
 fmt.Println(string(data))
}

Answer

Try it
{"Context":{}}

Defer

Mon, 01 Jan 0001 00:00:00 +0000

defer

package main

import (
 "fmt"
)

func main() {
 defer_call()
}

func defer_call() {
 defer func() { fmt.Println("1") }()
 defer func() { fmt.Println("2") }()
 defer func() { fmt.Println("3") }()

 panic("4")
}

Answer

Try it
3
2
1
panic: 4

defer1

package main

import (
 "fmt"
)

type Person struct {
 age int
}

func main() {
 person := &Person{28}

 defer fmt.Println(person.age)

 defer func(p *Person) {
 fmt.Println(p.age)
 }(person)

 defer func() {
 fmt.Println(person.age)
 }()

 person.age = 29
}

Answer

Try it
29
29
28

defer2

package main

import (
 "fmt"
)

type Person struct {
 age int
}

func main() {
 person := &Person{28}

 defer fmt.Println(person.age)

 defer func(p *Person) {
 fmt.Println(p.age)
 }(person)

 defer func() {
 fmt.Println(person.age)
 }()

 person = &Person{29}
}

Answer

Try it
29
28
28

defer3

package main

import (
 "fmt"
)

var a bool = true

func main() {
 defer func() {
 fmt.Println("1")
 }()
 if a == true {
 fmt.Println("2")
 return
 }
 defer func() {
 fmt.Println("3")
 }()
}

Answer

Try it
2
1

defer4

package main

import "fmt"

type temp struct{}

func (t *temp) Add(elem int) *temp {
 fmt.Print(elem)
 return &temp{}
}

func main() {
 tt := &temp{}
 defer tt.Add(1).Add(2)
 tt.Add(3)
}

A. 132
B. 123
C. 312
D. 321

Answer

Try it
A

Goroutine

Mon, 01 Jan 0001 00:00:00 +0000

goroutine

package main

import (
 "fmt"
 "time"
)

func main() {
 ch1 := make(chan int)
 go fmt.Println(<-ch1)
 ch1 <- 5
 time.Sleep(1 * time.Second)
}

A. 5
B. deadlock
C. compilation error

Answer

Try it
B

Interface

Mon, 01 Jan 0001 00:00:00 +0000

interface

package main

import (
 "fmt"
)

type People interface {
 Show()
}

type Student struct{}

func (stu *Student) Show() {}

func live() People {
 var stu *Student
 return stu
}

func main() {
 if live() == nil {
 fmt.Println("AAAAAAA")
 } else {
 fmt.Println("BBBBBBB")
 }
}

Answer

Try it
BBBBBBB

interface1

package main

import (
 "fmt"
)

type People interface {
 Speak(string) string
}

type Student struct{}

func (stu *Student) Speak(think string) (talk string) {
 if think == "love" {
 talk = "You are a good boy"
 } else {
 talk = "hi"
 }
 return
}

func main() {
 var peo People = Student{}
 think := "love"
 fmt.Println(peo.Speak(think))
}

Answer

Try it
compilation error
cannot use Student{} (value of type Student) as People value in variable declaration: Student does not implement People (method Speak has pointer receiver)

interface2

package main

import "fmt"

type T1 struct {
 String func() string
}

func (T1) Error() string {
 return "T1.Error"
}

type T2 struct {
 Error func() string
}

func (T2) String() string {
 return "T2.String"
}

var t1 = T1{String: func() string { return "T1.String" }}
var t2 = T2{Error: func() string { return "T2.Error" }}

func main() {
 fmt.Println(t1.Error(), t1.String())
 fmt.Println(t2.Error(), t2.String())

 fmt.Println(t1, t2)
}

Answer

Try it
T1.Error T1.String
T2.Error T2.String
T1.Error T2.String

interface3

package main

import "fmt"

func main() {
 var p [100]int
 var m any = [...]int{99: 0}
 fmt.Println(p == m)
}

Answer

Try it
true

Iota

Mon, 01 Jan 0001 00:00:00 +0000

iota

package main

import "fmt"

const (
 x = iota
 _
 y
 z = "zz"
 k
 p = iota
)

func main() {
 fmt.Println(x, y, z, k, p)
}

Answer

Try it
0 2 zz zz 5

iota1

package main

import "fmt"

const (
 a = iota
 b = iota
)

const (
 name = "name"
 c = iota
 d = iota
)

func main() {
 fmt.Println(a, b, c, d)
}

Answer

Try it
0 1 1 2

JSON

Mon, 01 Jan 0001 00:00:00 +0000

json

package main

import (
 "encoding/json"
 "fmt"
)

type AutoGenerated struct {
 Age int `json:"age"`
 Name string `json:"name"`
 Child []int `json:"child"`
}

func main() {
 jsonStr1 := `{"age": 14,"name": "potter", "child":[1,2,3]}`
 a := AutoGenerated{}
 json.Unmarshal([]byte(jsonStr1), &a)
 aa := a.Child
 fmt.Println(aa)
 jsonStr2 := `{"age": 12,"name": "potter", "child":[3,4,5,7,8,9]}`
 json.Unmarshal([]byte(jsonStr2), &a)
 fmt.Println(aa)
}

A. [1 2 3] [1 2 3]
B. [1 2 3] [3 4 5]
C. [1 2 3] [3 4 5 6 7 8 9]
D. [1 2 3] [3 4 5 0 0 0]

Answer

Try it
B

json1

package main

import (
 "encoding/json"
 "fmt"
 "time"
)

func main() {
 t := struct {
 time.Time
 N int
 }{
 time.Date(2020, 12, 20, 0, 0, 0, 0, time.UTC),
 5,
 }

 m, _ := json.Marshal(t)
 fmt.Printf("%s", m)
}

A. {“Time”:“2020-12-20T00:00:00Z”,“N”:5}
B. “2020-12-20T00:00:00Z”
C. {“N”:5}
D. <nil>
E. 其他

Answer

Try it
B

Len

Mon, 01 Jan 0001 00:00:00 +0000

len

package main

func main() {
 var x *struct {
 s [][32]byte
 }

 println(len(x.s[99]))
}

A. panic
B. compilation error
C. 32
D. 0

Answer

Try it
C

len1

package main

const s = "Go101.org"

// len(s) == 9
// 1 << 9 == 512
// 512 / 128 == 4

var a byte = 1 << len(s) / 128
var b byte = 1 << len(s[:]) / 128

func main() {
 println(a, b)
}

A: 0 0
B: 0 4
C: 4 0
D: 4 4

Answer

Try it
C

len2

package main

var s = "Go101.org"

// len(s) == 9
// 1 << 9 == 512
// 512 / 128 == 4

var a byte = 1 << len(s) / 128
var b byte = 1 << len(s[:]) / 128

func main() {
 println(a, b)
}

A: 0 0
B: 0 4
C: 4 0
D: 4 4

Answer

Try it
A

Map

Mon, 01 Jan 0001 00:00:00 +0000

map

package main

import "fmt"

type Student struct {
 Name string
}

var list map[string]Student

func main() {

 list = make(map[string]Student)

 student := Student{"Aceld"}

 list["student"] = student
 list["student"].Name = "LDB"

 fmt.Println(list["student"])
}

Answer

Try it
compilation error
cannot assign to struct field list["student"].Name in map

map1

package main

func main() {
 m := make(map[int]int, 3)
 x := len(m)
 m[1] = m[1]
 y := len(m)
 println(x, y)
}

Answer

Try it
0 1

Print

Mon, 01 Jan 0001 00:00:00 +0000

print

package main

import "fmt"

type T struct {
 x int
}

func (t T) String() string { return "boo" }

func main() {
 t := T{123}
 fmt.Printf("%v\n", t)
 fmt.Printf("%#v\n", t)
}

Answer

Try it
boo
main.T{x:123}

print1

package main

import (
 "fmt"
)

func f(a ...int) {
 fmt.Printf("%#v\n", a)
}

func main() {
 f()
}

Answer

Try it
[]int(nil)

Race

Mon, 01 Jan 0001 00:00:00 +0000

race

type Stats struct {
 mutex sync.Mutex

 counters map[string]int
}

func (s *Stats) Snapshot() map[string]int {
 s.mutex.Lock()
 defer s.mutex.Unlock()

 return s.counters
}

func (s *Stats) Add(name string, num int) {
 s.mutex.Lock()
 defer s.mutex.Unlock()
 s.counters[name] = num
}

Answer

func (s *Stats) Snapshot() map[string]int {
s.mutex.Lock()
defer s.mutex.Unlock()
result := make(map[string]int, len(s.counters))
for k, v := range s.counters {
result[k] = v
}
return result
}

Select

Mon, 01 Jan 0001 00:00:00 +0000

select

package main

import "sync"

func main() {
 var wg sync.WaitGroup
 foo := make(chan int)
 bar := make(chan int)
 wg.Add(1)
 go func() {
 defer wg.Done()
 select {
 case foo <- <-bar:
 default:
 println("default")
 }
 }()
 wg.Wait()
}

Answer

Try it
fatal error: all goroutines are asleep - deadlock!

select1

package main

import "fmt"

func main() {
 ch1 := make(chan int)
 ch2 := make(chan int)
 go func() {
 ch1 <- 1
 }()

 go func() {
 select {
 case <-ch1:
 case ch2 <- 2:
 }
 }()

 fmt.Println(<-ch2)
}

A. 1
B. 2
C. No output, program is deadlocked
D. No output, program has finished execution.
E. else

Answer

Try it
B

Slice

Mon, 01 Jan 0001 00:00:00 +0000

slice

package main

import (
 "fmt"
)

func main() {
 var s1 []int
 var s2 = []int{}
 if __ == nil {
 fmt.Println("nil slice")
 }
 if __ != nil {
 fmt.Println("empty slice")
 }
}

A. s1, s2
B. s2, s1
C. s1, s1
D. s2, s2

Answer

Try it
A

slice1

package main

import (
 "fmt"
)

func main() {
 s := [3]int{1, 2, 3}
 a := s[:0]
 b := s[:2]
 c := s[1:2:cap(s)]
 fmt.Println(len(a), cap(a))
 fmt.Println(len(b), cap(b))
 fmt.Println(len(c), cap(c))
}

Answer

Try it
0 3
2 3
1 2

slice2

package main

import "fmt"

func main() {
 s1 := []int{1, 2, 3}
 s2 := s1[1:]
 s2[1] = 4
 fmt.Println(s1)
 s2 = append(s2, 5, 6, 7)
 fmt.Println(s1)
}

Answer

Try it
[1 2 4]
[1 2 4]

Variable

Mon, 01 Jan 0001 00:00:00 +0000

variable

A. p.name
B. (&p).name
C. (*p).name
D. p->name

Answer

AC

variable1

package main

import (
 "fmt"
)

func main() {
 var ans float64 = 15 + 25 + 5.2
 fmt.Println(ans)
}

A. 45
B. 45.0
C. 45.2
D. compliation error

Answer

Try it
C

variable2

package main

import (
 "fmt"
)

func main() {
 var ans float64 = 3 / 2
 fmt.Println(ans)
}

A. 1.5
B. 1
C. 0
D. compliation error

Answer

Try it
B

variable3

package main

func main() {
 const a int8 = -1
 var b int8 = -128 / a

 println(b)
}

Answer

Try it
compliation error
-128 / a (constant 128 of type int8) overflows int8

variable4

package main

func main() {
 var a int8 = -1
 var b int8 = -128 / a

 println(b)
}

Answer

Try it
-128

variable5

package main

import "fmt"

type MyInt1 int
type MyInt2 = int

func main() {
 var i int =0
 var i1 MyInt1 = i
 var i2 MyInt2 = i
 fmt.Println(i1, i2)
}

Answer

Try it
compilation error
cannot use i (variable of type int) as MyInt1 value in variable declaration

variable6

package main

import "fmt"

func main() {
 const X = 7.0
 var x any = X
 if y, ok := x.(int); ok {
 fmt.Println(y)
 } else {
 fmt.Println(int(y))
 }
}

A. 7
B. 7.0
C. 0
D. compilation error

Answer

Try it
C

Elasticsearch Notes

Mon, 01 Jan 0001 00:00:00 +0000

Data too large

[parent] Data too large, data for [<http_request>] would be [123848638/118.1mb], which is larger than the limit of [123273216/117.5mb], real usage: [120182112/114.6mb], new bytes reserved: [3666526/3.4mb]

https://www.elastic.co/guide/en/elasticsearch/reference/7.14/fix-common-cluster-issues.html#circuit-breaker-errors

Go Libraries

Mon, 01 Jan 0001 00:00:00 +0000

Data

Input-Method Notes

Mon, 01 Jan 0001 00:00:00 +0000

類別	名稱	說明
PC	weasel 小狼毫	適用於 Windows 係統的開源輸入法
PC	squirrel 鼠須管	適用於 macOS 的開源輸入法
PC	ibus-rime	適用於 Linux 係統的開源輸入法
PC	openvanilla	專門針對 macOS 開發的開源輸入法
Mobile	fcitx5-android	適用於 Android 係統的開源輸入法，從 Fcitx 5 移植而來。
Mobile	trime 同文	適用於 Android 係統的開源輸入法，給予 rime 開發而來。
Mobile	YuyanIme 雨燕	適用於 Android 係統的開源輸入法，基於 rime 定製開發。
Mobile	Hamster	適用於 iOS 係統的開源輸入法，基於 rime 定製開發。
拚音	rime-ice	霧凇拚音，目前知名度最廣的拚音方案之一
拚音	rime-frost	白霜詞庫，基於霧凇拚音進行詞頻調整的拚音方案
拚音	oh-my-rime	薄荷拚音，基於霧凇拚音進行調整的輕量級拚音方案

Server-Configs Notes

Mon, 01 Jan 0001 00:00:00 +0000

Kafka

consumer.properties

max.partition.fetch.bytes=104857600

server.properties

socket.send.buffer.bytes=1048576000
socket.receive.buffer.bytes=1048576000
log.retention.bytes=-1
group.initial.rebalance.delay.ms=0
max.message.bytes=1048576000
fetch.message.max.bytes=1048576000
replica.fetch.max.bytes=1048576000
socket.request.max.bytes=1048576000
# 单个索引文件最大 10 MB
log.index.size.max.bytes=10485760
# 日志段大小 512 MB（根据需要再调小）
log.segment.bytes=536870912
# 避免過多 client 連進來撐爆 broker
max.connections=50000
max.connections.per.ip=20000
# 逾時
connections.max.idle.ms=300000
request.timeout.ms=60000

# —— 高并发优化配置 ——
# 若需要更高吞吐、能接受更高的调度开销
# num.network.threads=2 # 网络线程数 → CPU 核心数
# num.io.threads=4 # I/O 线程数 → 核心数×2
# 一般num.network.threads主要处理网络io，读写缓冲区数据，基本没有io等待，配置线程数量为cpu核数加1
# num.io.threads主要进行磁盘io操作，高峰期可能有些io等待，因此配置需要大些。配置线程数量为cpu核数2倍，最大不超过3倍.

Matomo

nginx.conf

user www-data;
worker_processes auto;
pid /run/nginx.pid;
include /etc/nginx/modules-enabled/*.conf;

events {
 worker_connections 768;
 # multi_accept on;
}

http {

 ##
 # Basic Settings
 ##

 sendfile on;
 tcp_nopush on;
 types_hash_max_size 2048;
 server_tokens off;
 # 同時調高打開的檔案數
 open_file_cache max=1000 inactive=20s;
 open_file_cache_valid 30s;
 open_file_cache_min_uses 2;

 # server_names_hash_bucket_size 64;
 # server_name_in_redirect off;

 include /etc/nginx/mime.types;
 default_type application/octet-stream;

 ##
 # SSL Settings
 ##

 ssl_protocols TLSv1 TLSv1.1 TLSv1.2 TLSv1.3; # Dropping SSLv3, ref: POODLE
 ssl_prefer_server_ciphers on;

 ##
 # Logging Settings
 ##

 access_log /var/log/nginx/access.log;
 error_log /var/log/nginx/error.log;

 ##
 # Gzip Settings
 ##

 gzip on;
 gzip_min_length 1024;
 gzip_comp_level 5;
 gzip_proxied any;
 gzip_types text/plain text/css application/javascript application/json image/svg+xml;

 # 全域 expires 規則
 expires 1d;
 add_header Cache-Control "public";

 # gzip_vary on;
 # gzip_proxied any;
 # gzip_comp_level 6;
 # gzip_buffers 16 8k;
 # gzip_http_version 1.1;
 # gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;

 ##
 # Virtual Host Configs
 ##

 include /etc/nginx/conf.d/*.conf;
 include /etc/nginx/sites-enabled/*;
}

matomo.conf

server {
 listen 80;
 server_name analytics.matomo.cc;
 root /var/www/html/matomo;

 index index.php index.html;
 access_log /var/log/nginx/matomo.access.log;
 error_log /var/log/nginx/matomo.error.log warn;

 location / {
 try_files $uri $uri/ =404;
 }

 # Matomo Rewrite for pretty URLs
 location ~ ^/(index|piwik|matomo)\.php(/|$) {
 fastcgi_split_path_info ^(.+\.php)(/.*)$;
 fastcgi_pass unix:/run/php/php8.1-fpm.sock;
 include fastcgi_params;
 fastcgi_param PATH_INFO $fastcgi_path_info;
 fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
 fastcgi_param HTTPS off;
 # 緩衝區
 fastcgi_buffers 16 16k;
 fastcgi_buffer_size 32k;
 fastcgi_busy_buffers_size 64k;
 fastcgi_temp_file_write_size 64k;
 # 逾時
 fastcgi_read_timeout 300;
 fastcgi_connect_timeout 60;
 fastcgi_send_timeout 60;

 # 加速 HEAD 請求
 fastcgi_ignore_headers X-Accel-Buffering;
 }

 # 靜態檔案快取
 location ~* \.(js|woff2?|ttf|css|png|jpg|jpeg|gif|ico|svg)$ {
 expires max;
 access_log off;
 log_not_found off;
 }

 # 安全：拒絕存取 .ht*
 location ~ /\.ht {
 deny all;
 }
}

crontab

*/5 * * * * php /var/www/html/matomo/console core:archive --force-all-websites > /var/log/matomo-archive.log 2>&1

MySQL

# 臨時表大小 - 可以設定更大
tmp_table_size = 2147483648 # 2GB (約記憶體的3-4%)
max_heap_table_size = 2147483648 # 2GB (必須與 tmp_table_size 相同)

# 排序緩衝區 - 每個連線獨立使用
sort_buffer_size = 4194304 # 4MB (不要太大，會佔用過多記憶體)

# 讀取緩衝區
read_buffer_size = 2097152 # 2MB (你的設定已經合適)
read_rnd_buffer_size = 8388608 # 8MB (可以稍微增大)

# 連線緩衝區
join_buffer_size = 8388608 # 8MB
bulk_insert_buffer_size = 67108864 # 64MB

# InnoDB 相關
innodb_buffer_pool_size = 42949672960 # 40GB (約記憶體的60-65%)
innodb_log_file_size = 2147483648 # 2GB
innodb_log_buffer_size = 67108864 # 64MB


# 設定原則
# tmp_table_size & max_heap_table_size：
# 這兩個參數必須相同
# 建議設定為記憶體的 2-4%
# 64GB 機器建議 1-2GB

# sort_buffer_size：
# 每個連線都會分配，不要設太大
# 建議 2-8MB，你的 2MB 其實已經合適


# innodb_buffer_pool_size：
# 最重要的參數
# 建議設定為記憶體的 60-70%
# 64GB 機器建議 38-42GB

# TempTable Storage Engine 參數（MySQL 8.0 關鍵）
temptable_max_ram = 4294967296 # 4GB（記憶體中臨時表）
temptable_max_mmap = 42949672960 # 40GB（記憶體映射檔案）
temptable_use_mmap = 1 # 啟用記憶體映射

v2ray

supervisord.conf

; supervisor config file

[unix_http_server]
file=/var/run/supervisor.sock ; (the path to the socket file)
chmod=0700 ; sockef file mode (default 0700)

[supervisord]
logfile=/var/log/supervisor/supervisord.log ; (main log file;default $CWD/supervisord.log)
pidfile=/var/run/supervisord.pid ; (supervisord pidfile;default supervisord.pid)
childlogdir=/var/log/supervisor ; ('AUTO' child log dir, default $TEMP)
logfileMaxbytes=100MB
logfileBackups=50
loglevel=debug

; the below section must remain in the config file for RPC
; (supervisorctl/web interface) to work, additional interfaces may be
; added by defining them in separate rpcinterface: sections
[rpcinterface:supervisor]
supervisor.rpcinterface_factory = supervisor.rpcinterface:make_main_rpcinterface

[supervisorctl]
serverurl=unix:///var/run/supervisor.sock ; use a unix:// URL for a unix socket

; The [include] section can just contain the "files" setting. This
; setting can list multiple files (separated by whitespace or
; newlines). It can also contain wildcards. The filenames are
; interpreted as relative to this file. Included files *cannot*
; include files themselves.

[include]
files = /etc/supervisor/conf.d/*.conf

conf.d/v2ray.conf

[program:v2ray]
command = /etc/v2ray/bin/v2ray run -config /etc/v2ray/config.json -confdir /etc/v2ray/conf
process_name = v2ray
stdout_logfile = /var/log/supervisor/v2ray.log
stderr_logfile = /var/log/supervisor/v2ray.log
autostart=true
startsecs=3
startretries=3
autorestart=true
exitcodes=0
stopsignal=TERM
stopwaitsecs=10
stopasgroup=true
killasgroup=true

[program:caddy]
command = /usr/local/bin/caddy run --environ --config /etc/caddy/Caddyfile --adapter caddyfile
process_name = caddy
stdout_logfile = /var/log/supervisor/caddy.log
stderr_logfile = /var/log/supervisor/caddy.log
autostart=true
startsecs=3
startretries=3
autorestart=true
exitcodes=0
stopsignal=TERM
stopwaitsecs=10
stopasgroup=true
killasgroup=true

Notes on Ricky

Ansible Command

Lookup

winrm

- console output

- /etc/ansible/hosts

AWS Command

CloudFront

EC2

ECR

S3

snapshot

sns

WAF

Mount S3 Bucket on EC2

AWS Configure

S3 Bucket Policy

S3 CORS

ECR Lifecycle Policy

ECR Lifecycle Policy1

ECR Lifecycle Policy2

AWS Terraform

tf

Provider

EC2

Elastic IP

MQ

RDS

Security Group

VPC

WAF

Cloudflare docs

Setting CloudFlare Worker for CORS

Terraform_create_record

Terraform_create_page_rule

Terraform_create_rate_limit_rule

API Document

Common Command

ab

age

awk

caffeinate

certbot

cutycapt

dmesg

dnscontrol

ffmpeg

go

k6

kafka

hey

openfortivpn

openssl

prlimit

siege

tr

vegeta

wrk

Vagrant with hyper-v provider

Common

Gitbook

Diagrams

Diagrams

Docker Command

Build with secret

Compose

Create buildx instance

Create Network

Multiple build-arg

Multiple platform

Run container in different platform

Docker docs

docker-compose

cAdvisor

Elasticsearch

local dev

NodeJS

rstudio

rsyncd

Dockerfile