The cloud native way of configuring services is via environment variables, and they should be unified throughout the stack. We do have an issue with FLAGD_PORT, which is actually used twice, once for in-process and once for RPC mode on the provider. But flagd (to whom we connect) has two different environment variables. We should adapt to be compliant with the flagd way.

Most current test scenarios in the testbed rely on the default configuration, and only limited adaptation is required to address this issue.

What needs to change?

• Generate or add specific tests focused on configuration where the environment variable for the in-process provider port is relevant.
• Ensure these tests verify that both FLAGD_PORT and FLAGD_SYNC_PORT can be used as environment variables for in-process providers, to maintain backwards compatibility.
• Existing tests that use the default configuration do not need to be changed.

Tagging for backwards compatibility

• Add the @legacy-sync-port tag to all backwards compatibility scenarios relating to the in-process sync port.
• This will enable us to easily deactivate these tests in the future if backwards compatibility support is no longer required.

Context

This issue is a sub-issue of open-feature/flagd#1573 and helps ensure correct and maintainable usage of environment variables in provider configuration tests.