apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: cockroachdb
spec:
  serviceName: "cockroachdb"
  replicas: 3
  selector:
    matchLabels:
      app: cockroachdb
  template:
    metadata:
      labels:
        app: cockroachdb
    spec:
      # Init containers are run only once in the lifetime of a pod, before
      # it's started up for the first time. It has to exit successfully
      # before the pod's main containers are allowed to start.
      # This particular init container does a DNS lookup for other pods in
      # the set to help determine whether or not a cluster already exists.
      # If any other pods exist, it creates a file in the cockroach-data
      # directory to pass that information along to the primary container that
      # has to decide what command-line flags to use when starting CockroachDB.
      # This only matters when a pod's persistent volume is empty - if it has
      # data from a previous execution, that data will always be used.
      initContainers:
      - name: bootstrap
        image: cockroachdb/cockroach-k8s-init:0.1
        imagePullPolicy: IfNotPresent
        args:
        - "-on-start=/on-start.sh"
        - "-service=cockroachdb"
        env:
        - name: POD_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace
        volumeMounts:
        - name: datadir
          mountPath: "/cockroach/cockroach-data"
      affinity:
        podAntiAffinity:
          preferredDuringSchedulingIgnoredDuringExecution:
          - weight: 100
            podAffinityTerm:
              labelSelector:
                matchExpressions:
                - key: app
                  operator: In
                  values:
                  - cockroachdb
              topologyKey: kubernetes.io/hostname
      containers:
      - name: cockroachdb
        image: cockroachdb/cockroach:v1.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 26257
          name: grpc
        - containerPort: 8080
          name: http
        volumeMounts:
        - name: datadir
          mountPath: /cockroach/cockroach-data
        command:
          - "/bin/bash"
          - "-ecx"
          - |
            # The use of qualified `hostname -f` is crucial:
            # Other nodes aren't able to look up the unqualified hostname.
            CRARGS=("start" "--logtostderr" "--insecure" "--host" "$(hostname -f)" "--http-host" "0.0.0.0")
            # We only want to initialize a new cluster (by omitting the join flag)
            # if we're sure that we're the first node (i.e. index 0) and that
            # there aren't any other nodes running as part of the cluster that
            # this is supposed to be a part of (which indicates that a cluster
            # already exists and we should make sure not to create a new one).
            # It's fine to run without --join on a restart if there aren't any
            # other nodes.
            if [ ! "$(hostname)" == "cockroachdb-0" ] || \
               [ -e "/cockroach/cockroach-data/cluster_exists_marker" ]
            then
              # We don't join cockroachdb in order to avoid a node attempting
              # to join itself, which currently doesn't work
              # (https://github.com/cockroachdb/cockroach/issues/9625).
              CRARGS+=("--join" "cockroachdb-0.cockroachdb,cockroachdb-1.cockroachdb,cockroachdb-2.cockroachdb")
            fi
            exec /cockroach/cockroach ${CRARGS[*]}
      # No pre-stop hook is required, a SIGTERM plus some time is all that's
      # needed for graceful shutdown of a node.
      terminationGracePeriodSeconds: 60
      volumes:
      - name: datadir
        persistentVolumeClaim:
          claimName: datadir
  volumeClaimTemplates:
  - metadata:
      name: datadir
    spec:
      accessModes:
        - "ReadWriteOnce"
      resources:
        requests:
          storage: 1Gi
