Using Docker Commands with Aliases and Bash Functions

We use Docker at work and so I find myself running the same commands over and over. To save time I saved frequent docker and docker-compose commands as aliases and functions.

Aliases #

These aliases save a few key strokes for running often used commands:

# general compose aliases
alias dcb="docker-compose build"
alias dcu="docker-compose up"
alias dcub="docker-compose up --build"
alias dcs="docker-compose stop"

# list all running containers
alias dps="docker ps"

# stop all running containers
alias dsa="docker ps -q | awk '{print $1}' | xargs -o docker stop"

# list dangling images
alias dlist="docker volume ls -qf dangling=true"

Functions #

Some commands are better saved as functions.

When developing and writing unit tests, I will often want to get to the bash prompt in the test container. I saved this function as dcbash.sh and aliased it as dcbash to save a few keystrokes:

#!/bin/bash

# Run a bash shell in the specified container (with docker-compose)

# a simple help menu: if no arg is passed in, the function usage is printed
if [ $# -ne 1 ]; then
  echo "Usage: $FUNCNAME CONTAINER_NAME"
  return 1
fi

# this echo is optional but I like to maintain familiarity with the actual command
echo "CMD: docker-compose run --entrypoint="" $1 /bin/bash";
docker-compose run --entrypoint="" $1 /bin/bash

For example dcbash pretend-service-test runs docker-compose run --entrypoint="" pretend-service-test /bin/bash.

Images take up space and are not auto removed. I’ve encountered errors before about lack of space so a periodic tidy up of unused images and containers is recommended.

I saved this as drmi.sh and it removes dangling Docker images:

#!/bin/bash

# remove docker dangling images
docker rmi $(docker images --filter "dangling=true" -q --no-trunc)

I saved this as drmc.sh and it removes all non-running containers:

#!/bin/bash

# removes all non-running containers
docker rm $(docker ps -q -a);

These aliases and functions help my productivity by saving a key strokes and saving time looking up the commands for a periodic tidy up of Docker images and containers. I hope they may prove useful to you too.