This is a pr to add support for reading the db connection string from a file, which is an alternative option to reading the connection string from an environment variable.

This is the first step in addressing a lack of support for rotating db credentials, as at present a rollout restart must be performed in order for the updated credentials to be picked up by the pod, i.e. env vars are not updated in a pod when the underlying secret is updated. Apgfileurl sql driver is also added to re-read the file on each connection attempt to support credential rotation.

This would be used by populating values.yaml with:

  env:    - name: CODER_PG_CONNECTION_URL_FILE      value: "/etc/coder/pg/pg-url.txt"  volumes:    - name: coder-pg-url-file      secret:        secretName: coder-pg-url-file  volumeMounts:    - name: coder-pg-url-file      mountPath: /etc/coder/pg      readOnly: true

With it referencing a secret created using:

kubectl create secret generic coder-pg-url-file \  -n pg-coder \  --from-file=pg-url.txt=./pg-url.txtcat pg-url.txt     postgres://coder_pg:coder_pg@my-local-db-host.tld:5432/coder_pg?sslmode=require

created with mux!