AWS CLI command completion with fish shell

Question

Has anybody been able to set up auto-complete for the AWS CLI with fish shell? The AWS documentation only offers the guide for bash, tcsh, and zsh.

Bash exports the variables COMP_LINE and COMP_POINT that is used by the aws_completer script provided by the Amazon. Is there any equivalent for fish? I'm new with the fish shell and I'm giving it a try.

Answer 1

It's actually possible to map bash's completion to fish's.

See the npm completions.

However it's probably still better to write a real fish script (it's not hard!).

Answer 2

While the provided answer doesn't answer the question directly about the using fish; I intend to provide an answer to help in the context of auto-completion & shell.

Amazon has launched a new CLI based tool forked from AWSCLI.

aws-shell is a command-line shell program that provides convenience and productivity features to help both new and advanced users of the AWS Command Line Interface. Key features include the following.

Fuzzy auto-completion

• Commands (e.g. ec2, describe-instances, sms, create-queue)
• Options (e.g. --instance-ids, --queue-url)
• Resource identifiers (e.g. Amazon EC2 instance IDs, Amazon SQS queue URLs, Amazon SNS topic names)

Dynamic in-line documentation

• Documentation for commands and options are displayed as you type

Execution of OS shell commands

• Use common OS commands such as cat, ls, and cp and pipe inputs and outputs without leaving the shell
• Export executed commands to a text editor To find out more, check out the related blog post on AWS Command Line Interface blog.

Answer 3

I also want to get his to work, and I've made some progress, but it's not perfect.

First I look some advise from here which helps to seem how to emulate the bash environment variables that as_completer expects.

Putting it together I get this:

complete -c aws -f -a '(begin; set -lx COMP_SHELL fish; set -lx COMP_LINE (commandline); /usr/local/bin/aws_completer; end)'

That mostly works but I get spurious extra slashes, so if I try to complete "aws ec2 describe-instances --" I get:

dave@retino ~> aws ec2 describe-instances --
--ca-bundle\             --color\          --filters\               --no-dry-run\        --output\      --region\
--cli-connect-timeout\   --debug\          --generate-cli-skeleton  --no-paginate\       --page-size\   --starting-token\
--cli-input-json\        --dry-run\        --instance-ids\          --no-sign-request\   --profile\     --version\
--cli-read-timeout\      --endpoint-url\   --max-items\             --no-verify-ssl\     --query\

It looks to me like there is a trailing whitespace char, but I tried to remove it using sed:

complete -c aws -f -a '(begin; set -lx COMP_SHELL fish; set -lx COMP_LINE (commandline); echo (/usr/local/bin/aws_completer | sed -e \'s/[ ]*//\') ; end)'

But this doesn't seem to help. It seems that fish expects a different output format than bash for it's completer. And indeed the fish decimation for the complete builtin doe say that it expects a space separated list.

So I tried joining the lines with xargs:

complete -c aws -f -a '(begin; set -lx COMP_SHELL fish; set -lx COMP_LINE (commandline); echo (/usr/local/bin/aws_completer | sed -e \'s/[ ]*//\') | xargs echo ; end)'

But this doesn't work either. I just get one completion

This is annoying, I'm so close, but it doesn't work!

Answer 4

The command I use in my virtualenv/bin/activate is this:

complete -C aws_completer aws

Looks like aws-cli has fish support too. There is a bundled installer provided with aws-cli that might be worth checking out: activate.fish. I found it in the same bin directory as the aws command.

For example:

ubuntu@ip-xxx-xx-x-xx:/data/src$ tail -n1 ~/venv/bin/activate
complete -C aws_completer aws
ubuntu@ip-xxx-xx-x-xx:/data/src$ source ~/venv/bin/activate
(venv) ubuntu@ip-xxx-xx-x-xx:/data/src$ aws s3         <- hitting TAB here
cp        ls        mb        mv        presign   rb        rm        sync      website
(venv) ubuntu@ip-xxx-xx-x-xx:/data/src$ aws s3

Answer 5

Building upon David Roussel's answers I cooked up the following:

function __fish_complete_aws
    env COMP_LINE=(commandline -pc) aws_completer | tr -d ' '
end

complete -c aws -f -a "(__fish_complete_aws)"

Put this in a file $HOME/.config/fish/completions/aws.fish so fish can autoload it when necessary.

aws_completer appends a space after every option it prints and that gets escaped as \ so trimming it solves the trailing backslashes.

Now we can test the completion with the following:

> complete -C'aws co'
codebuild
codecommit
codepipeline
codestar
cognito-identity
cognito-idp
cognito-sync
comprehend
comprehendmedical
connect
configure
configservice

Using the commandline -c helps if you move back the cursor since it cuts the command line at the cursor so aws_completer can offer the right completions.

Answer 6

Add this line to your .config/fish/config.fish

complete --command aws --no-files --arguments '(begin; set --local --export COMP_SHELL fish; set --local --export COMP_LINE (commandline); aws_completer | sed \'s/ $//\'; end)'

In case you want to make sure that aws-cli is installed:

test -x (which aws_completer); and complete --command aws --no-files --arguments '(begin; set --local --export COMP_SHELL fish; set --local --export COMP_LINE (commandline); aws_completer | sed \'s/ $//\'; end)'

All credits belong to this issue thread and a comment by an awesome SO contributor @scooter-dangle.