Docker ENV Private Registry parse error... about amazon-ecs-agent HOT 2 CLOSED

What you're observing is a bash/zsh expansion really. It's common enough to see something like ls *.{csv,tsv}, where the braces expand before the ls program ever sees them. What the Docker run command actually sees is the following:

--env=ECS_ENGINE_AUTH_DATA={https://index.docker.io/v1/:username:my_name} --env=ECS_ENGINE_AUTH_DATA={https://index.docker.io/v1/:password:my_password} --env=ECS_ENGINE_AUTH_DATA={https://index.docker.io/v1/:email:[email protected]}

You notice, bash also destructively removed the double quotes because those also need to be escaped.

If you were to use the /etc/ecs/ecs.config file on an ECS Optimized AMI, I do not believe this issue would manifest because bash doesn't enter into the picture there. Similarly, if you used the --env-file option and specified these in a file, bash again would not alter these. I also don't think there'd be an issue with the values in a systemd unit file.

Finally, for the 'good' option, it would really be better to use single quotes as they allow bash to escape less. Unless I'm mistaken, the current 'good' one would still strip the double quotes and thus still be invalid JSON.

I see an opportunity for documentation improvement here, but I don't think the agent needs to understand and revert preprocessing done outside of its, and Docker's, control and knowledge.

Does the above make sense, or do you think there is a better option agent-side? I definitely agree this can be a bit confusing and documentation improvements would be helpful.

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Howdy,

It 100% does make sense and I agree about the single quotes. This was mainly raised to see if the agent could / would handle it. Closing. :)

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