knowledge/categories/devops.md

AWS

• EC2
• EC2 container
• Cloudfront
• S3
• RDS

CI

• Jenkins
• Gitlab CI
• Travis

Linux

• ssh
• IP table
• Cron job
• ps aux
• tail
• nohup
• df -h
• free
• Tips
  • Change timezone
    • TZ=Asia/Shanghai;ln -snf /usr/share/zoneinfo/$TZ /etc/localtime
  • Check release
    • cat /etc/*-release
• Packages
  • htop
    • like top, but more
  • mosh
    • auto reconnect ssh

Everything is code

• Infrastructure as code
• CI config as code
• Dockerfile

CD

Capistrano

Ansible

Puppet

Terraform

Terraform use a declarative language to describe the current state of infrastructure, and there is no server side agent installed.

Basic steps

# go to the folder which stores the environment credentials
terraform init # Initialize a new or existing Terraform working directory by creating initial files, loading any remote state, downloading modules, etc.
terraform get # Downloads and installs modules that defined by configuration files
terraform plan # Kind of try run, you will what kind of changes you will have
terraform apply # Apply changes to cluster

HA High Availability

• LB - haproxy
• Keepalived -- vrrp
  • Nginx + Keepalived
• Heartbeat

Network

• IP
  • Private IP Addresses
    • 10.0.0.0 – 10.255.255.255
    • 172.16.0.0 – 172.31.255.255
    • 192.168.0.0 – 192.168.255.255

OSI Model( 7 layers network)

tools

• git

  • cherrypick

  • rebase

  • commit

  • checkout

    • checkout -b br com

  • push

    • --tags
      • push tags
    • —all
      • push all branchs
    • -f
      • force push

  • branch -d xx

    • delete a local branch

  • remote

    • show xxx
      • show info of a remote branch
    • add xxx
      • add a remote repo

  • branch

    • list all the branchs

  • mv Rename/move files and folder with git history records

    e.g. git mv -k ./a/b ./c/d option k would avoid the "can not move directory into itself" error.

• oh-my-zsh
• IDE/tools
  • Intellij
  • vscode