feat(controller): add database replica support

Author: duanhongyi

charts/controller/templates/_helpers.tpl

@@ -49,8 +49,15 @@ env:
 - name: DRYCC_DATABASE_URL
   valueFrom:
     secretKeyRef:
-      name: controller-creds
-      key: databaseUrl
+      name: passport-creds
+      key: database-url
+{{- if (.Values.databaseReplicaUrl) }}
+- name: DRYCC_DATABASE_REPLICA_URL
+  valueFrom:
+    secretKeyRef:
+      name: passport-creds
+      key: database-replica-url
+{{- end }}
 {{- else if eq .Values.global.databaseLocation "on-cluster"  }}
 - name: DRYCC_DATABASE_USER
   valueFrom:
@@ -63,7 +70,9 @@ env:
       name: database-creds
       key: password
 - name: DRYCC_DATABASE_URL
-  value: "postgres://$(DRYCC_DATABASE_USER):$(DRYCC_DATABASE_PASSWORD)@$(DRYCC_DATABASE_SERVICE_HOST):$(DRYCC_DATABASE_SERVICE_PORT)/controller"
+  value: "postgres://$(DRYCC_DATABASE_USER):$(DRYCC_DATABASE_PASSWORD)@drycc-database.{{.Release.Namespace}}.svc.{{.Values.global.clusterDomain}}:5432/controller"
+- name: DRYCC_DATABASE_REPLICA_URL
+  value: "postgres://$(DRYCC_DATABASE_USER):$(DRYCC_DATABASE_PASSWORD)@drycc-database-replica.{{.Release.Namespace}}.svc.{{.Values.global.clusterDomain}}:5432/controller"
 {{- end }}
 - name: WORKFLOW_NAMESPACE
   valueFrom:

charts/controller/templates/controller-secret-creds.yaml

@@ -10,5 +10,8 @@ data:
   {{- if (.Values.databaseUrl) }}
   database-url: {{ .Values.databaseUrl | b64enc }}
   {{- end }}
+  {{- if (.Values.databaseReplicaUrl) }}
+  database-replica-url: {{ .Values.databaseReplicaUrl | b64enc }}
+  {{- end }}
   django-secret-key: {{ randAscii 64 | b64enc }}
   deploy-hook-secret-key: {{ randAscii 64 | b64enc }}

charts/controller/values.yaml

@@ -29,8 +29,9 @@ webhookReplicas: 1
 # Forbid: The cron job does not allow concurrent runs; if it is time for a new job run and the previous job run hasn't finished yet, the cron job skips the new job run
 # Replace: If it is time for a new job run and the previous job run hasn't finished yet, the cron job replaces the currently running job run with a new job run
 concurrencyPolicy: "Replace"
-# Configuring this will no longer use the built-in database component
+# databaseUrl and databaseReplicaUrl are will no longer use the built-in database component
 databaseUrl: ""
+databaseReplicaUrl: ""
 # Configuring this will no longer use the built-in rabbitmq component
 rabbitmqUrl: ""
 # Service

rootfs/api/routers.py

@@ -0,0 +1,18 @@
+from django.conf import settings
+
+
+class DefaultReplicaRouter(object):
+
+    def db_for_read(self, model, **hints):
+        if 'replica' in settings.DATABASES:
+            return 'replica'
+        return 'default'
+
+    def db_for_write(self, model, **hints):
+        return 'default'
+
+    def allow_relation(self, obj1, obj2, **hints):
+        return True
+
+    def allow_migrate(self, db, app_label, model_name=None, **hints):
+        return True

rootfs/api/settings/production.py

@@ -405,6 +405,15 @@
     'default': dj_database_url.config(default=DRYCC_DATABASE_URL, conn_max_age=600)
 }
 
+# database replica setting
+DRYCC_DATABASE_REPLICA_URL = os.environ.get('DRYCC_DATABASE_REPLICA_URL', None)
+if DRYCC_DATABASE_REPLICA_URL is not None:
+    DATABASES["replica"] = dj_database_url.config(
+        default=DRYCC_DATABASE_REPLICA_URL, conn_max_age=600)
+
+# database routers
+DATABASE_ROUTERS = ['api.routers.DefaultReplicaRouter', ]
+
 APP_URL_REGEX = '[a-z0-9-]+'
 
 # Oauth settings