Terminal magic with Fish shell functions

I have an issue: I have to login to AWS ECR and push images multiple times a day and I hate it. I always get the command wrong, mistype the path or forget to use the new --no-include-email flag — get-login docs.

This is why I decided to add a function that will do just that: get login credentials from ECR.

Simple!

The output of this command is actually another command, which is used to log me into my container registry. It looks like below:

That is the standard docker registry login command, and I need to execute it. I could just manually do a copy+paste with it, but I’m too lazy, so I pipe it through the fish shell interpreter.

ecr-login us-east-1 | fish

This way, when ecr-login finishes, and returns the docker login command, that automatically gets piped through the interpreter, which in turn, executes it.

Finally, here’s the whole “picture”.

Logging in to Amazon Elastic Container Registry using a custom alias function

P.S. There’s also an awesome collection of such “aliases”, courtesy of Jessie Frazelle.

Like the article? Found it useful? Follow me on Medium / Twitter.