swh: Support the deployment of a memcached instance

It will be used by graphq >= 0.0.8.1 and later by the webapp

Related to swh/infra/sysadm-environment#4785

swh/templates/memcached/deployment.yaml

+{{ if .Values.memcached.enabled -}}
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: memcached
+  namespace: {{ .Values.namespace }}
+  labels:
+    chart: "{{ .Chart.Name }}-{{ .Chart.Version | replace "+" "_" }}"
+    app: memcached
+
+spec:
+  selector:
+    matchLabels:
+      app: memcached
+  # TODO: allow to deploy clustered memcached
+  replicas: 1
+  template:
+    metadata:
+      labels:
+        app: memcached
+    spec:
+      containers:
+      - name: memcached
+        image: "{{ .Values.memcached.image }}"
+        args:
+          - -m
+          - {{ .Values.memcached.memory }}
+        imagePullPolicy: IfNotPresent
+        resources:
+          requests:
+            memory: {{ .Values.memcached.requestedMemory | default "300Mi" }}
+            cpu: {{ .Values.memcached.requestedCpu | default "100m" }}
+        readinessProbe:
+            tcpSocket:
+                port: 11211
+            initialDelaySeconds: 5
+            periodSeconds: 10
+        livenessProbe:
+            tcpSocket:
+                port: 11211
+            initialDelaySeconds: 15
+            periodSeconds: 20
+        {{- if .Values.memcached.prometheus.enabled }}
+      - name: metrics-exporter
+        image: {{ .Values.memcached.prometheus.image }}
+        readinessProbe:
+            httpGet:
+                path: /metrics
+                port: 9150
+            initialDelaySeconds: 5
+            periodSeconds: 10
+        livenessProbe:
+            httpGet:
+                path: /metrics
+                port: 9150
+            initialDelaySeconds: 5
+            periodSeconds: 10
+        {{- end }}
+{{- end -}}

swh/templates/memcached/service.yaml

+{{ if .Values.memcached.enabled -}}
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: memcached
+  namespace: {{ .Values.namespace }}
+  labels:
+    app: memcached
+    chart: "{{ .Chart.Name }}-{{ .Chart.Version | replace "+" "_" }}"
+spec:
+  type: ClusterIP
+  selector:
+    app: memcached
+  ports:
+    - name: memcached
+      port: 11211
+      targetPort: 11212
+    {{- if .Values.memcached.prometheus.enabled }}
+    - name: metrics
+      port: 9150
+      targetPort: 9150
+    {{- end }}
+{{- end -}}

swh/templates/memcached/servicemonitor.yaml

+{{ if and .Values.memcached.enabled .Values.memcached.prometheus.enabled -}}
+---
+apiVersion: monitoring.coreos.com/v1
+kind: ServiceMonitor
+metadata:
+  name: memcached
+  namespace: {{ .Values.namespace }}
+  labels:
+    chart: "{{ .Chart.Name }}-{{ .Chart.Version | replace "+" "_" }}"
+spec:
+  endpoints:
+  - path: /metrics
+    port: metrics
+    interval: 10s
+  selector:
+    matchLabels:
+      app: memcached
+  namespaceSelector:
+    any: true
+{{- end -}}

swh/tests/memcached_deployment_test.yaml

+suite: test memcached deployment
+templates:
+  - memcached/deployment.yaml
+tests:
+  - it: memcached deployment is deployed with default values when activated
+    set:
+      memcached.enabled: true
+      memcached.image: myimage:myversion
+    asserts:
+      - containsDocument:
+          kind: Deployment
+          apiVersion: apps/v1
+      - equal:
+          path: metadata.namespace
+          value: swh
+      - equal:
+          path: spec.replicas
+          value: 1
+      - equal:
+          path: spec.template.spec.containers[0].image
+          value: myimage:myversion
+      - equal:
+          path: spec.template.spec.containers[0].args[1]
+          value: 256m
+      - equal:
+          path: spec.template.spec.containers[0].resources.requests.cpu
+          value: 100m
+      - equal:
+          path: spec.template.spec.containers[0].resources.requests.memory
+          value: 300Mi
+      - lengthEqual:
+          path: spec.template.spec.containers
+          count: 2
+  - it: memcached memory check
+    set:
+      namespace: mynamespace
+      memcached.enabled: true
+      memcached.memory: 128m
+      memcached.requestedCpu: 1
+      memcached.requestedMemory: 2
+    asserts:
+      - equal:
+          path: .metadata.namespace
+          value: mynamespace
+      -  equal:
+          path: spec.template.spec.containers[0].args[1]
+          value: 128m
+      - equal:
+          path: spec.template.spec.containers[0].resources.requests.cpu
+          value: 1
+      - equal:
+          path: spec.template.spec.containers[0].resources.requests.memory
+          value: 2
+  - it: memcached prometheus disabled
+    set:
+      memcached.enabled: true
+      memcached.prometheus.enabled: true
+    asserts:
+      - lengthEqual:
+          path: spec.template.spec.containers
+          count: 2
+  - it: memcached prometheus properties
+    set:
+      memcached.enabled: true
+      memcached.prometheus.enabled: true
+      memcached.prometheus.image: myimage:myversion
+    asserts:
+      - lengthEqual:
+          path: spec.template.spec.containers
+          count: 2
+      - equal:
+          path: spec.template.spec.containers[1].image
+          value: myimage:myversion

swh/tests/memcached_global_test.yaml

+suite: test memcached deployment
+templates:
+  - memcached/deployment.yaml
+  - memcached/service.yaml
+  - memcached/servicemonitor.yaml
+tests:
+  - it: memcached service is not deployed by default
+    values:
+      - ../values.yaml
+    asserts:
+      - hasDocuments:
+          count: 0

swh/tests/memcached_service_test.yaml

+suite: test memcached service
+templates:
+  - memcached/service.yaml
+tests:
+  - it: memcached service is deployed with default values when activated
+    set:
+      memcached.enabled: true
+    asserts:
+      - containsDocument:
+          kind: Service
+          apiVersion: v1
+      - equal:
+          path: metadata.namespace
+          value: swh
+      - lengthEqual:
+          path: spec.ports
+          count: 2
+  - it: metrics port disabled when prometheus is disabled
+    set:
+      namespace: mynamespace
+      memcached.enabled: true
+      memcached.prometheus.enabled: false
+    asserts:
+      - equal:
+          path: metadata.namespace
+          value: mynamespace
+      - lengthEqual:
+          path: spec.ports
+          count: 1

swh/tests/memcached_servicemonitor_test.yaml

+suite: test memcached ServiceMonitor
+templates:
+  - memcached/servicemonitor.yaml
+tests:
+  - it: memcached servicemonitor is deployed with default values when activated
+    set:
+      memcached.enabled: true
+    asserts:
+      - containsDocument:
+          kind: ServiceMonitor
+          apiVersion: monitoring.coreos.com/v1
+      - equal:
+          path: metadata.namespace
+          value: swh
+  - it: memcached servicemonitor namespace
+    set:
+      memcached.enabled: true
+      namespace: mynamespace
+    asserts:
+      - equal:
+          path: metadata.namespace
+          value: mynamespace
+  - it: memcached servicemonitor not deployed when prometheus is disabled
+    set:
+      memcached.enabled: true
+      memcached.prometheus.enabled: false
+    asserts:
+      - hasDocuments:
+          count: 0

swh/values.yaml

@@ -126,3 +126,15 @@ statsd_exporter:
   enabled: false
   image: prom/statsd-exporter
   imageVersion: "v0.22.7"
+
+memcached:
+  # Deploy a memcached instance used by the webapp and graphql for sessions caching
+  enabled: false
+  image: memcached:1.6.18
+  memory: 256m
+  requestedCpu: 100m
+  requestedMemory: 300Mi
+  prometheus:
+    # Activate the deployment of the memcached exporter and ServiceMonitor
+    enabled: true
+    image: quay.io/prometheus/memcached-exporter:v0.11.1