Docker Cli Tips and Tricks
==========================

- bret@bretfisher.com
- https://twitter.com/BretFisher
- http://bretfisher.com

## My favorite command line options and best practices
 - Bash/zsh completion
   - use *Tab* to populate command line, narrows down options as you go, fills in container names, ID's, images, volumes. Huge time saver.
   - http://blog.alexellis.io/docker-mac-bash-completion/
   - https://github.com/docker/docker/blob/master/contrib/completion/bash/docker
   - https://docs.docker.com/compose/completion/
 - Even without auto complete: you don't need type full container ID's
   - just type enough of ID to be unique
   - Example: `docker rmi 7c9 2f 5cad` will remove three images
 - Name volumes to find/keep easier
   - Example: `docker run --name psql -d -p 5432:5432 -v psql:/var/lib/postgresql sameersbn/postgresql`
   - Then: `docker volume ls`
 - Use ONBUILD Versions for easy development of Node, Ruby, and others
   - https://docs.docker.com/engine/userguide/eng-image/dockerfile_best-practices/#/onbuild
   - https://hub.docker.com/_/ruby/
   - https://hub.docker.com/_/node/
 - Always use `docker-compose down` to cleanup properly (networks, containers)
   - To also remove unnamed containers and volumes: `docker-compose down -v --rmi local`

## My favorite command line aliases (quick container management, usually for local dev)
 - Only removes stopped containers, doesn't delete data volumes, mostly safe
   - `alias drma='docker rm $(docker ps -aq)'`
 - Remove all images, doesn't remove images in use by containers, mostly safe
   - `alias drmi='docker rmi $(docker images -q -f "dangling=true")'`
 - Remove all images, doesn't remove images in use by containers, mostly safe
   - `alias drmai='docker rmi $(docker images -q)'`
 - For Docker Machine users, set docker cli to use the default VM
   - `alias drdefault='eval "$(docker-machine env default)"'`
 - Execute interactive command in running container
   - `alias drit='docker exec -it'`
 - Get the IP for eth0 inside the container
   - `alias drip='docker inspect --format="{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}"'`

### Other lists/dotfiles/functions for less typing
  - [oh-my-zsh has a add-in](https://github.com/robbyrussell/oh-my-zsh/blob/master/plugins/docker/README.md), which I use always
  - [jessfraz](https://twitter.com/jessfraz) has [some next level shit](https://github.com/jfrazelle/dotfiles/blob/master/.dockerfunc) as bash functions
  - @tcnksm has [a good list to start with](https://github.com/tcnksm/docker-alias/blob/master/zshrc)

## Cli filters for managing lots of images/containers

### Filters
 - [Filtering the image list](https://docs.docker.com/engine/reference/commandline/images/#/filtering)
   - Only list dangling images (built with no name): `docker images --filter "dangling=true"`
 - [Filtering the containers list](https://docs.docker.com/engine/reference/commandline/ps/#/filtering)
   - Only list containers that have exited successfully (without error): `docker ps -a --filter 'exited=0'`
   - Only list containers coming from nginx image: `docker ps --filter ancestor=nginx`

### Formatting
 - [Change the columns shown in docker command](https://docs.docker.com/engine/reference/commandline/images/#/formatting), great for TPS Reports
 - `docker images --format "table {{.ID}}\t{{.Repository}}\t{{.Tag}}" > images.txt`

## Best list of all things Docker ecosystem
 - https://github.com/veggiemonk/awesome-docker