I don't really know any details, but all I can tell you is that this is the output of running it in a fresh environment (masked out the instance details and snipped some output..):

  $ docker rmi amazon/aws-cli
  <snip>
  $ cd /tmp
  $ python3 -m venv venv
  <snip>
  $ . venv/bin/activate
  $ pip install awscliv2
  <snip>
  $ ssh -i mykey.pem ec2-user@i-masked     -o ProxyCommand='awsv2 ec2-instance-connect open-tunnel --instance-id i-masked'
  Unable to find image 'amazon/aws-cli:latest' locally
  latest: Pulling from amazon/aws-cli
  6ebddf7084e9: Pull complete 
  eb7d160dbc3b: Pull complete 
  af71d24e41d0: Pull complete 
  cf26adf9ea98: Pull complete 
  2491adb1df28: Pull complete 
  Digest: sha256:a8c8edb4641672d9ef61873594aa02d1c493341ca30f96e257fdc4d3da17ef9c
  Status: Downloaded newer image for amazon/aws-cli:latest
  
  A newer release of "Amazon Linux" is available.
  <snip>

And now I am logged into the machine. You can clearly see that it downloaded an AWS docker image. Exit from ssh, back to local terminal, and now there is an image on my machine:

  $ docker images | grep aws-cli

amazon/aws-cli latest 817d1061df76 3 hours ago 384MB

So I don't know if I agree that aws ec2-instance-connect doesn't use docker. And also, I don't necessarily have a problem that it does, it just surprised me a bit.

You're confusing `awscliv2`[1], a third-party Python wrapper around AWS CLI v2[2], with instance connect. From its package page:

- This is not an official AWS CLI v2 application

- By default this app uses amazon/aws-cli Docker image

The only official macOS distribution of AWS CLI v2 is via a macOS installer package:

https://docs.aws.amazon.com/cli/latest/userguide/getting-sta...

It's also available in Homebrew[3] but the packaging is maintained by a third-party, not Amazon.

[1] https://pypi.org/project/awscliv2/

[2] https://awscli.amazonaws.com/v2/documentation/api/latest/ind...

[3] https://formulae.brew.sh/formula/awscli

Oh I see. I installed awscliv2 after discovering that awscli did not have the ec2-instance-connect command, so I could not follow the documentation and went searching to see if there was an updated package and discovered that one. So I guess you are not supposed to install it using pip anymore. Good to know.

Update: and now I've read through the github issue, oh my I've missed quite some drama.

I agree it's confusing and I think Amazon's reasons for dropping PyPI support are pretty lame:

https://github.com/aws/aws-cli/issues/4947#issuecomment-5860...

They also have't provided a reason for why they don't distribute via Homebrew:

https://github.com/aws/aws-cli/issues/727