I don't know how I've managed without this for so long. Bash completion is a kind of plug-in for your terminal that lets you auto-complete or auto-suggest what to type in next by hitting tab.
Here's the kicker - it works for Docker too after running a few quick scripts.
If you are using a terminal every day then you probably hit tab after every few characters.. like this:
$ docker-com[tab] docker-compose $
I use this for laziness, so I get to type less and make fewer mistakes. You also have bash completion for when you're not sure what commands are available.
Do I have bzip? What was it called again?
$ bz[tab] bzcat bzdiff bzfgrep bzip2 bzless bzcmp bzegrep bzgrep bzip2recover bzmore
On to Docker
Now if you're running the Docker Mac beta and you have brew installed too, then it only takes a few moments. I learned this information by reading all the way to the bottom of the new Docker for Mac getting started page. This little nugget was hidden away there.
We will run through the instructions here and show a couple of examples of what it looks like when configured.
- Set up Bash competition through brew
$ brew install bash-completion $ brew tap homebrew/completions
- Update your .bashrc or .bash_profile
This snippet will update your .bashrc file that is executed every time you open a terminal.
If you don't have a
.bashrcfile already then you may want to use
chmod +xand to add an extra line at the top of the file
cat >> ~/.bashrc <<EOL if [ -f $(brew --prefix)/etc/bash_completion ]; then . $(brew --prefix)/etc/bash_completion fi EOL
- Add Docker-specific completions
cd /usr/local/etc/bash_completion.d ln -s /Applications/Docker.app/Contents/Resources/etc/docker.bash-completion ln -s /Applications/Docker.app/Contents/Resources/etc/docker-machine.bash-completion ln -s /Applications/Docker.app/Contents/Resources/etc/docker-compose.bash-completion
Now you can profit from doing things like this:
- Figuring out commands
$ docker [tab] attach events info network rename service unpause build exec inspect node restart start update commit export kill pause rm stats version cp help load port rmi stop volume create history login ps run swarm wait daemon images logout pull save tag diff import logs push search top
Having done this myself I saw
docker top - something brand new for me.
Display the running processes of a container
- Auto-completing container names
Here I run an nginx container and then forget to give it a name.
$ docker run -d -P nginx 99b9505c7c18e51b1154e7d95f0e034eac4c9264ff2196501208ffd35644c37c
docker inspect or
docker kill take an ID or name as an input, so if you're new to Docker you would probably copy/paste the whole container ID. Fortunately these commands also work with a few unique characters like below:
$ docker inspect 99b9 $ docker inspect fd3564
For when you want to be explicit about naming then tab-completion helps you out and will attempt to finish off the name or ID you started typing in.
Here I type just the first letter and hit tab. This even works with some of the crazy automatically generated container names that Docker can create.
$ docker inspect 9[tab] $ docker inspect 99b9505c7c18e51b1154e7d95f0e034eac4c9264ff2196501208ffd35644c37c
$ docker rm -f goof[tab] $ docker rm -f goofy_curie
So I hope you found this useful - and I'm sure there are lots more ways you can take advantage of this. If you have more hints and hacks for completion let me know in the comments.
See also - swarm mode:
In Docker 1.12RC we get a native, built-in orchestration model called Swarm Mode. Check out my quick tutorials below: