feat: add Semaphore deployment, database, services, and persistent volume claim

cluster/apps/semaphore/semaphore-db.yml

@@ -0,0 +1,39 @@
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: semaphore-db
+  namespace: default
+spec:
+  selector:
+    matchLabels:
+      app: semaphore-db
+  template:
+    metadata:
+      labels:
+        app: semaphore-db
+    spec:
+      containers:
+      - name: mysql
+        image: mysql:8.4
+        ports:
+        - containerPort: 3306
+        env:
+        - name: MYSQL_RANDOM_ROOT_PASSWORD
+          value: "'yes'"
+        - name: MYSQL_DATABASE
+          value: "semaphore"
+        - name: MYSQL_USER
+          value: "semaphore"
+        - name: MYSQL_PASSWORD
+          valueFrom:
+            secretKeyRef:
+              name: semaphore-secrets
+              key: mysql_password
+        volumeMounts:
+        - name: db
+          mountPath: /var/lib/mysql
+      volumes:
+      - name: db
+        persistentVolumeClaim:
+          claimName: longhorn-semaphore