SUBMARINE-366. Support submarine link database in k8s

### What is this PR for?
We need to make the submarine database run in k8s, and let the submarine server connect to the database.

### What type of PR is it?
[Feature]

### Todos
* [ ] - Task

### What is the Jira issue?
* https://issues.apache.org/jira/browse/SUBMARINE-366

### How should this be tested?
* https://travis-ci.org/liuxunorg/submarine/builds/643813734

### Screenshots (if appropriate)

![image](https://user-images.githubusercontent.com/3677382/73445852-97d9a500-4396-11ea-86be-dbed4bdf0e1d.png)

### Questions:
* Does the licenses files need update? No
* Is there breaking changes for older versions? No
* Does this needs documentation? No

Author: Xun Liu <liuxun@apache.org>

Closes #169 from liuxunorg/SUBMARINE-366 and squashes the following commits:

e741833 [Xun Liu] SUBMARINE-366. Support submarine link database in k8s

submarine-cloud/hack/kind-cluster-build.sh

@@ -76,7 +76,7 @@ esac
 done
 
 clusterName=${clusterName:-kind}
-nodeNum=${nodeNum:-3}
+nodeNum=${nodeNum:-1}
 k8sVersion=${k8sVersion:-v1.12.8}
 volumeNum=${volumeNum:-1}
 
@@ -269,13 +269,16 @@ docker-image <image>' command to load images into nodes.
 EOF
 
 # Run submarine in kind cluster
+echo ""
 echo -n "Do you want to run submarine in kind cluster now? [y/n]"
 read myselect
 if [[ "$myselect" == "y" || "$myselect" == "Y" ]]; then
     docker pull apache/submarine:operator-0.3.0-SNAPSHOT
     kind load docker-image apache/submarine:operator-0.3.0-SNAPSHOT
     kubectl apply -f $ROOT/manifests/submarine-operator/
 
+    docker pull apache/submarine:database-0.3.0-SNAPSHOT
+    kind load docker-image apache/submarine:database-0.3.0-SNAPSHOT
     docker pull apache/submarine:server-0.3.0-SNAPSHOT
     kind load docker-image apache/submarine:server-0.3.0-SNAPSHOT
     kubectl apply -f $ROOT/manifests/submarine-cluster/

submarine-cloud/manifests/submarine-cluster/deployment.yaml

@@ -68,3 +68,40 @@ spec:
             periodSeconds: 10
             successThreshold: 1
             failureThreshold: 3
+
+---
+apiVersion: apps/v1beta1
+kind: Deployment
+metadata:
+  name: submarine-database
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: submarine-database
+  template:
+    metadata:
+      labels:
+        app: submarine-database
+    spec:
+      containers:
+        - name: submarine-database
+          image: apache/submarine:database-0.3.0-SNAPSHOT
+          ports:
+            - containerPort: 3306
+          env:
+            - name: MYSQL_ROOT_PASSWORD
+              value: "password" # Same submarine-site.xml mysql password
+
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: submarine-database
+spec:
+  ports:
+    - name: submarine-database
+      port: 3306
+      targetPort: 3306
+  selector:
+    app: submarine-database