docs: add example configs for kubernetes; resolves #327

README.md

@@ -25,12 +25,9 @@ Its goal is to be a part of the developer's toolbox where [Linked Data](http://l
   * [GraphQL](./docs/GraphQL.md)-inspired\* query language.
   * (simplified) [MQL](./docs/MQL.md), for [Freebase](https://en.wikipedia.org/wiki/Freebase) fans
 * Plays well with multiple backend stores:
-  * [LevelDB](https://github.com/google/leveldb)
-  * [Bolt](https://github.com/boltdb/bolt)
-  * [PostgreSQL](http://www.postgresql.org)
-  * [MySQL](https://www.mysql.com)
-  * [MongoDB](https://www.mongodb.org) for distributed stores
-  * [CockroachDB](https://www.cockroachlabs.com)
+  * KVs: [Bolt](https://github.com/boltdb/bolt), [LevelDB](https://github.com/google/leveldb)
+  * NoSQL: [MongoDB](https://www.mongodb.org)
+  * SQL: [PostgreSQL](http://www.postgresql.org), [CockroachDB](https://www.cockroachlabs.com), [MySQL](https://www.mysql.com)
   * In-memory, ephemeral
 * Modular design; easy to extend with new languages and backends
 * Good test coverage

cmd/cayley/command/http.go

@@ -9,6 +9,7 @@ import (
 	"github.com/spf13/viper"
 
 	"github.com/cayleygraph/cayley/clog"
+	"github.com/cayleygraph/cayley/graph"
 	"github.com/cayleygraph/cayley/internal"
 	chttp "github.com/cayleygraph/cayley/internal/http"
 	"github.com/cayleygraph/cayley/quad"
@@ -27,7 +28,9 @@ func NewHttpCmd() *cobra.Command {
 			if init, err := cmd.Flags().GetBool("init"); err != nil {
 				return err
 			} else if init {
-				if err = initDatabase(); err != nil {
+				if err = initDatabase(); err == graph.ErrDatabaseExists {
+					clog.Infof("database already initialized, skipping init")
+				} else if err != nil {
 					return err
 				}
 			}

docs/Container.md

@@ -1,3 +1,7 @@
+# Running in Kubernetes
+
+To run Cayley in K8S check [this docs section](./k8s/k8s.md).
+
 # Running in a container
 
 A container exposing the HTTP API of Cayley is available.

docs/k8s/cayley-mongo.yml

@@ -0,0 +1,114 @@
+kind: Namespace
+apiVersion: v1
+metadata:
+  name: cayley
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: mongo
+  namespace: cayley
+  labels:
+    name: mongo
+spec:
+  ports:
+  - name: mgo
+    port: 27017
+    targetPort: mgo
+  clusterIP: None
+  selector:
+    role: mongo
+---
+apiVersion: apps/v1beta1
+kind: StatefulSet
+metadata:
+  name: mongo
+  namespace: cayley
+spec:
+  serviceName: "mongo"
+  replicas: 3
+  template:
+    metadata:
+      namespace: cayley
+      labels:
+        role: mongo
+        environment: test
+    spec:
+      terminationGracePeriodSeconds: 10
+      containers:
+        - name: mongo
+          image: mongo:3
+          command:
+            - mongod
+            - "--replSet"
+            - rs0
+            - "--smallfiles"
+            - "--noprealloc"
+          ports:
+            - name: mgo
+              containerPort: 27017
+          volumeMounts:
+            - name: mongo-pvc
+              mountPath: /data/db
+        - name: mongo-sidecar
+          image: cvallance/mongo-k8s-sidecar
+          env:
+            - name: MONGO_SIDECAR_POD_LABELS
+              value: "role=mongo,environment=test"
+  volumeClaimTemplates:
+  - metadata:
+      name: mongo-pvc
+    spec:
+      accessModes: [ "ReadWriteOnce" ]
+      storageClassName: standard
+      resources:
+        requests:
+          storage: 20Gi
+---
+kind: Service
+apiVersion: v1
+metadata:
+  name: cayley
+  namespace: cayley
+spec:
+  selector:
+    app: cayley
+  ports:
+  - protocol: TCP
+    port: 80
+    targetPort: http
+---
+apiVersion: extensions/v1beta1
+kind: Deployment
+metadata:
+  name: cayley
+  namespace: cayley
+spec:
+  replicas: 1
+  template:
+    metadata:
+      namespace: cayley
+      labels:
+        app: cayley
+    spec:
+      initContainers:
+      - name: cayley-init
+        image: quay.io/cayleygraph/cayley:v0.7.0-alpha
+        command:
+        - cayley
+        - init
+        - -d=mongo
+        - -a=mongo
+      containers:
+      - name: cayley
+        image: quay.io/cayleygraph/cayley:v0.7.0-alpha
+        command:
+        - cayley
+        - http
+        - --init # TODO: remove once initContainers works properly
+        - -d=mongo
+        - -a=mongo
+        - --host=:64210
+        ports:
+        - name: http
+          containerPort: 64210

docs/k8s/cayley-single.yml

@@ -0,0 +1,73 @@
+kind: Namespace
+apiVersion: v1
+metadata:
+  name: cayley
+---
+kind: Service
+apiVersion: v1
+metadata:
+  name: cayley
+  namespace: cayley
+spec:
+  selector:
+    app: cayley
+  ports:
+  - protocol: TCP
+    port: 80
+    targetPort: http
+---
+kind: PersistentVolumeClaim
+apiVersion: v1
+metadata:
+  name: cayley-pvc
+  namespace: cayley
+spec:
+  accessModes:
+  - ReadWriteOnce
+  resources:
+    requests:
+      storage: 20Gi
+  storageClassName: standard
+---
+apiVersion: extensions/v1beta1
+kind: Deployment
+metadata:
+  name: cayley
+  namespace: cayley
+spec:
+  replicas: 1 # cannot be really scaled because of local backend
+  template:
+    metadata:
+      namespace: cayley
+      labels:
+        app: cayley
+    spec:
+      initContainers:
+      - name: cayley-init
+        image: quay.io/cayleygraph/cayley:v0.7.0-alpha
+        command:
+        - cayley
+        - init
+        - -c=/etc/cayley.json
+        volumeMounts:
+        - mountPath: /data
+          name: database
+      containers:
+      - name: cayley
+        image: quay.io/cayleygraph/cayley:v0.7.0-alpha
+        command:
+        - cayley
+        - http
+        - --init # TODO: remove once initContainers is out of beta
+        - -c=/etc/cayley.json
+        - --host=:64210
+        ports:
+        - name: http
+          containerPort: 64210
+        volumeMounts:
+        - mountPath: /data
+          name: database
+      volumes:
+      - name: database
+        persistentVolumeClaim:
+          claimName: cayley-pvc

docs/k8s/k8s.md

@@ -0,0 +1,25 @@
+# Running in Kubernetes
+
+Most examples requires Kubernetes 1.5+ and PersistentVolumes are configured.
+
+After running scripts namespace `cayley` will be created and service with the same name will be available in cluster. Service is of type `ClusterIP` by default. If you want to expose it, consider changing type to `LoadBalancer`.
+
+## Single instance (Bolt)
+
+This is a simplest possible configuration: single Cayley instance with persistent storage, using Bolt as a backend.
+
+```bash
+kubectl create -f ./docs/k8s/cayley-single.yml
+```
+
+## Distributed (MongoDB cluster)
+
+This example is based on [thesandlord/mongo-k8s-sidecar](https://github.com/thesandlord/mongo-k8s-sidecar) and runs Cayley on top of 3-node Mongo cluster.
+
+```bash
+kubectl create -f ./docs/k8s/cayley-mongo.yml
+```
+
+## Distributed
+
+*TODO: PostgreSQL, CockroachDB*