env_file object format in compose.yaml causes error on Docker Compose < v2.24.0: 'env_file.0 must be a string

[sidhant-shr]

🚨 Issue: env_file.0 must be a string error on Docker Compose < v2.24.0

📋 Summary

The current compose.yaml uses the object-based syntax for the env_file section, which causes an error on Docker Compose versions older than v2.24.0. These versions only accept env_file as a string or a list of strings, not objects.

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🧪 Steps to Reproduce

1. Use Docker Compose CLI version older than v2.24.0
2. Run the command:

   docker compose -f compose.yaml up -d

You will see the following error:

services.supra_cli.env_file.0 must be a string

💣 Problem Details

This snippet from compose.yaml:

env_file:
  - path: ./supra-cli.env
    required: false

is only supported on Docker Compose CLI v2.24.0 and above.

Older versions do not support the object format for env_file. They expect a string or list of strings, like this:

env_file:
  - ./supra-cli.env

✅ Universal Solution (Compatible with All Docker Compose Versions)

Change the env_file section in your compose.yaml to:

env_file:
  - ./supra-cli.env

This syntax works on all Docker Compose versions, including older ones.

🔧 Additional Information

• Affected versions: Docker Compose CLI < v2.24.0
• Root cause: Object-based env_file syntax introduced in v2.24.0
• Impact: Prevents container startup on older Docker Compose versions
• Solution: Use string-based syntax for backward compatibility

📚 References

• [Docker Compose env_file documentation](https://docs.docker.com/compose/environment-variables/set-environment-variables/#substitute-with-an-env-file)
• [Docker Compose release notes v2.24.0](https://github.com/docker/compose/releases/tag/v2.24.0)