feat(ilf-app-backend): added support for redis url (#332)

This pull request adds support for configuring the Redis connection URL
via a secret reference in the backend Helm chart. The main changes
include introducing a new `redis_url_ref` configuration option and
wiring it up so both the `server` and `worker` deployments receive the
Redis URL from the referenced secret.

Redis URL configuration:

* Added `redis_url_ref` to the `config` section in
`charts/interledger-app/backend/values.yaml` to allow specifying the
secret key for the Redis connection URL.

Environment variable injection:

* Updated the `server` deployment to inject the `REDIS_URL` environment
variable using the value from the secret referenced by `redis_url_ref`.
* Updated the `worker` deployment to inject the `REDIS_URL` environment
variable using the value from the secret referenced by `redis_url_ref`.

Author: bosbaber

charts/interledger-app/backend/values.yaml

@@ -158,12 +158,13 @@ config:
 
   sentry:
     dsn_ref: "sentryDSN"
-
 
   pti: # FIANT configuration
     jwk_ref: "ptiJwk"
     client_id_ref: "ptiClientID"
 
+  redis_url_ref: "redisURL"
+
 server:
   enabled: true
   replicaCount: 2
@@ -396,6 +397,11 @@ server:
           secretKeyRef:
               name: '{{ include "common.fullname" . }}'
               key: "{{ .Values.config.admin.team_domain_ref }}"
+    -  name: REDIS_URL
+       valueFrom:
+          secretKeyRef:
+            name: '{{ include "common.fullname" . }}'
+            key: "{{ .Values.config.redis_url_ref }}"
   resources:
     requests:
       memory: 128Mi
@@ -677,6 +683,11 @@ worker:
           secretKeyRef:
               name: '{{ include "common.fullname" . }}'
               key: "{{ .Values.config.admin.team_domain_ref }}"
+    -  name: REDIS_URL
+       valueFrom:
+          secretKeyRef:
+            name: '{{ include "common.fullname" . }}'
+            key: "{{ .Values.config.redis_url_ref }}"
   resources:
     requests:
       memory: 128Mi