Bug report: Composer home directory (i.e. /home/webapp/composer-home) on Elastic Beanstalk is not writable, breaks composer update and eb deploy

Question

On deployment, I get lots of errors like this:
`Cannot create cache directory /home/webapp/composer-home/cache/files/, or directory is not writable. Proceeding without cache. See also cache-read-only config if your filesystem is read-only.`

This leads to a failed deployment: `Instance deployment failed to install Composer dependencies specified in 'composer.json' in your source bundle. The deployment failed.`

This can be worked around but seems like a bug, given that composer installation is supposed to be handled automatically on the EB PHP platform. It also means these instructions don't work:
https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/php-configuration-composerupdate.html

Answer

Thank you for surfacing this issue with our docs. We have updated our docs https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/php-configuration-composerupdate.html to contain new sample commands for updating composer and setting the COMPOSER_HOME variable. Due to the changes related to composer introduced in the February 22, 2024, AL2023 platform release and the February 28, 2024, AL2 platform release, updating composer may fail if COMPOSER_HOME is set at the time of the self-update.

Pease try the following EB extension:

commands:
  01updateComposer:
    command: /usr/bin/composer.phar self-update 2.7.0

option_settings:
  - namespace: aws:elasticbeanstalk:application:environment
    option_name: COMPOSER_HOME
    value: /home/webapp/composer-home

Pease try the following EB extension:

```
commands:
  01updateComposer:
    command: /usr/bin/composer.phar self-update 2.7.0

option_settings:
  - namespace: aws:elasticbeanstalk:application:environment
    option_name: COMPOSER_HOME
    value: /home/webapp/composer-home
```

Bug report: Composer home directory (i.e. /home/webapp/composer-home) on Elastic Beanstalk is not writable, breaks composer update and eb deploy

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