Make your own docker command!

I saw this post about a custom cli app to make it just a little nicer to quickly shell in to a local docker container:

Docket : connect to your docker's container easily !

pob ・ Mar 5 ・ 2 min read

#docker #container #bash #ruby

And I thought, what if instead of a brand new command, it was part of the docker cli? It's not well advertised, but you can! So I installed it as a custom docker command. Official docs here.

There are a couple rules.

1. Where does the script go? I wanted to run docker goto. The easiest choice for me was ~/.docker/cli-plugins/docker-goto. Whatever subcommand name you want, just prefix it with "docker-"

2. You must have a subcommand called "docker-cli-plugin-metadata". When I run docker goto docker-cli-plugin-metadata, it has to output specific json. This block is enough:
   

   if [[ "$1" == "docker-cli-plugin-metadata" ]]; then
   cat << HERE
   {
     "SchemaVersion": "0.1.0",
     "Vendor": "example.com",
   }
   HERE
   exit
   fi
   

3. Make it executable: chmod +x ~/.docker/cli-plugins/docker-goto

Now you can make it do whatever you want! Full code in this gist.