postgresql plugin ignores PGPORT environment variable

[restblake]

Description

The postgresql plugin's process-compose.yaml does not respect the PGPORT environment variable when starting postgres:

# Current (plugins/postgresql/process-compose.yaml)
command: "pg_ctl start -o \"-k '$PGHOST'\""

This means postgres always starts on port 5432, even if PGPORT is set in the environment or via devbox.json.

Use Case

Running multiple devbox projects or worktrees simultaneously requires each instance to use different ports to avoid conflicts. Currently, there's no way to configure the postgres port through devbox's standard mechanisms.

Expected Behavior

The plugin should respect PGPORT like it respects PGHOST:

# Proposed fix
command: "pg_ctl start -o \"-k $PGHOST -p $PGPORT\""

And the readiness probe should also use the port:

readiness_probe:
  exec:
    command: "pg_isready -p $PGPORT"

Additional Context

• The valkey plugin correctly uses $VALKEY_PORT in its process-compose.yaml, so this pattern already exists in other plugins
• This is a one-line fix that would enable parallel development workflows
• Current workaround requires bypassing devbox services entirely and starting postgres manually

[mohsenari]

this seems like an easy fix. I just need to make sure when $PGPORT doesn't have a value , does pg_ctl falls back to a default or errors complaining about -p not having a corresponding value.

[mohsenari]

based on my testing your changes causes the following error:

waiting for server to start....
2026-02-02 23:02:15.033 GMT [43662] FATAL:  invalid value for parameter "port": ""
pg_ctl: could not start server
Examine the log output.
 stopped waiting

so I have to make it conditional and expand $PGPORT only if the env var is set.
So it will look like:
${PGPORT:+-p "$PGPORT"}
With this change I was able to run 2 postgres processes (in 2 different directories with different devbox.json files) side by side one with no PGPORT specified running on 5432 and the other with "env": { "PGPORT": "5433"} in its devbox.json