Add support for pgbouncer (#62)

* Add support for pgbouncer

* restart pgbouncer on config change

Co-authored-by: Colin Copeland <copelco@caktusgroup.com>

* support k8s_pgbouncer_replicas

Co-authored-by: Ronard <ronardcaktus@users.noreply.github.com>
Co-authored-by: Joel Sleppy <Jdsleppy@users.noreply.github.com>

---------

Co-authored-by: Colin Copeland <copelco@caktusgroup.com>
Co-authored-by: Ronard <ronardcaktus@users.noreply.github.com>
Co-authored-by: Joel Sleppy <Jdsleppy@users.noreply.github.com>

defaults/main.yml

@@ -84,6 +84,20 @@ k8s_redis_service_type: ClusterIP
 # load balancer (if suppported by the provider):
 # k8s_redis_load_balancer_ip: w.x.y.z
 
+k8s_pgbouncer_enabled: false
+k8s_pgbouncer_repo: "edoburu/pgbouncer"
+k8s_pgbouncer_version: "1.18.0"
+k8s_pgbouncer_replicas: 1
+k8s_pgbouncer_service_type: ClusterIP
+# If service_type is LoadBalancer, you can optionally assign a fixed IP for your
+# load balancer (if suppported by the provider):
+# k8s_pgbouncer_load_balancer_ip: w.x.y.z
+# To use pgbouncer, you must define a k8s_pgbouncer_environment variable with
+# at minimum the DATABASE_URL and any other settings you wish to customize.
+# See: https://hub.docker.com/r/edoburu/pgbouncer/
+# k8s_pgbouncer_environment:
+#   DATABASE_URL: postgres://...
+
 k8s_elasticsearch_enabled: false
 k8s_elasticsearch_cluster_name: "app-elasticsearch-cluster"
 k8s_elasticsearch_version: "7.5.2"
@@ -246,6 +260,8 @@ k8s_templates:
     state: "{{ k8s_dockerconfigjson | ternary('present', 'absent') }}"
   - name: redis.yaml.j2
     state: "{{ k8s_redis_enabled | ternary('present', 'absent') }}"
+  - name: pgbouncer.yaml.j2
+    state: "{{ k8s_pgbouncer_enabled | ternary('present', 'absent') }}"
   - name: elasticsearch.yaml.j2
     state: "{{ k8s_elasticsearch_enabled | ternary('present', 'absent') }}"
   - name: memcached.yaml.j2

templates/pgbouncer.yaml.j2

@@ -0,0 +1,77 @@
+apiVersion: v1
+kind: Secret
+metadata:
+  name: "pgbouncer-secrets"
+  labels:
+    app: "pgbouncer"
+  namespace: "{{ k8s_namespace }}"
+type: Opaque
+{% if k8s_pgbouncer_enabled %}
+{# fail loudly if k8s_pgbouncer_environment not defined when enabled (see defaults/main.yml) #}
+stringData: {{ k8s_pgbouncer_environment | to_json }}
+{% else %}
+stringData: {{ k8s_pgbouncer_environment | default({}) | to_json }}
+{% endif %}
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: "pgbouncer"
+  namespace: "{{ k8s_namespace }}"
+spec:
+  selector:
+    matchLabels:
+      app: "pgbouncer"
+  replicas: {{ k8s_pgbouncer_replicas }}
+  template:
+    metadata:
+      labels:
+        app: "pgbouncer"
+    spec:
+      affinity:
+        podAntiAffinity:
+          preferredDuringSchedulingIgnoredDuringExecution:
+          - weight: 100
+            podAffinityTerm:
+              labelSelector:
+                matchExpressions:
+                - key: app
+                  operator: In
+                  values:
+                  - pgbouncer
+              topologyKey: kubernetes.io/hostname
+      containers:
+      - name: "pgbouncer"
+        image: "{{ k8s_pgbouncer_repo }}:{{ k8s_pgbouncer_version }}"
+        imagePullPolicy: IfNotPresent
+        env:
+        - name: GET_HOSTS_FROM
+          value: dns
+        - name: PGBOUNCER_SECRETS_HASH
+          value: "{{ k8s_pgbouncer_environment | default({}) | to_json | hash('sha256') }}"
+        envFrom:
+        - secretRef:
+            name: "pgbouncer-secrets"
+        ports:
+        - containerPort: 5432
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: "pgbouncer"
+  labels:
+    app: "pgbouncer"
+  namespace: "{{ k8s_namespace }}"
+spec:
+  type: "{{ k8s_pgbouncer_service_type }}"
+{% if k8s_pgbouncer_load_balancer_ip is defined %}
+  loadBalancerIP: "{{ k8s_pgbouncer_load_balancer_ip }}"
+{% endif %}
+  ports:
+  - protocol: TCP
+    # Where other things in the cluster should try to connect to our application
+    port: 5432
+    # Where our application is listening:
+    targetPort: 5432
+  selector:
+    app: "pgbouncer"