# The API, as a blue-green Rollout.
#
# Same shape as a Deployment, but the new version comes up alongside the old,
# gets checked against Prometheus, and only then takes over the active Service.
apiVersion: argoproj.io/v1alpha1
kind: Rollout
metadata:
  name: nereus-api
  labels:
    app.kubernetes.io/name: nereus-api
    app.kubernetes.io/part-of: nereus
spec:
  replicas: 2
  revisionHistoryLimit: 3
  selector:
    matchLabels:
      app.kubernetes.io/name: nereus-api
  template:
    metadata:
      labels:
        app.kubernetes.io/name: nereus-api
        app.kubernetes.io/part-of: nereus
    spec:
      imagePullSecrets:
        - name: nereus-registry
      securityContext:
        # distroless nonroot.
        runAsUser: 65532
        runAsGroup: 65532
        runAsNonRoot: true
        seccompProfile:
          type: RuntimeDefault
      containers:
        - name: api
          image: nereus-api:0.1.0
          imagePullPolicy: IfNotPresent
          ports:
            - name: http
              containerPort: 8080
          envFrom:
            - configMapRef:
                name: nereus-api-config
          env:
            - name: DATABASE_URL
              valueFrom:
                secretKeyRef:
                  name: nereus-db
                  key: DATABASE_URL
          # /healthz ignores Postgres, so a database outage makes pods unready
          # without restarting them.
          livenessProbe:
            httpGet:
              path: /healthz
              port: http
            initialDelaySeconds: 3
            periodSeconds: 10
            timeoutSeconds: 2
            failureThreshold: 3
          # /readyz waits for migrations.
          readinessProbe:
            httpGet:
              path: /readyz
              port: http
            initialDelaySeconds: 3
            periodSeconds: 5
            timeoutSeconds: 3
            failureThreshold: 3
          securityContext:
            allowPrivilegeEscalation: false
            capabilities:
              drop: ["ALL"]
            readOnlyRootFilesystem: true
          volumeMounts:
            - name: tmp
              mountPath: /tmp
          resources:
            requests:
              cpu: 50m
              memory: 64Mi
            limits:
              memory: 256Mi
      volumes:
        - name: tmp
          emptyDir:
            medium: Memory
            sizeLimit: 16Mi
  strategy:
    blueGreen:
      activeService: nereus-api-active
      previewService: nereus-api-preview
      # Auto-promote only if the analysis passes; a failure aborts instead.
      autoPromotionEnabled: true
      # Keep the old ReplicaSet warm so an abort falls straight back.
      scaleDownDelaySeconds: 30
      prePromotionAnalysis:
        templates:
          - templateName: nereus-api-error-rate
        args:
          - name: service
            value: nereus-api-preview