[kots]: add database to preflight checks

Author: Simon Emms

install/kots/manifests/kots-preflight.yaml

@@ -7,6 +7,34 @@ metadata:
   name: gitpod
 spec:
   collectors:
+    - run:
+        collectorName: database
+        image: bitnami/mysql:5.7
+        name: database
+        command:
+          - /bin/bash
+          - -c
+        args:
+          - |
+            set -e
+
+            if [ '{{repl (ConfigOptionEquals "db_incluster" "1") }}' = "true" ]; then
+              # In cluster database
+              echo "pass"
+              exit 0
+            elif [ '{{repl and (ConfigOptionEquals "db_incluster" "0") (ConfigOptionEquals "db_cloudsql_enabled" "0") }}' = "true" ]; then
+              # External database - suppress CLI output
+              result=$(mysql \
+                --connect-timeout=5 \
+                --user="{{repl ConfigOption "db_username" }}" \
+                --password="{{repl ConfigOption "db_password" }}" \
+                --host="{{repl ConfigOption "db_host" }}" \
+                --port="{{repl ConfigOption "db_port" }}" \
+                --execute="SELECT 1 + 1")
+
+              echo "pass"
+              exit 0
+            fi
     - run:
         collectorName: "kernel"
         image: alpine/semver
@@ -151,3 +179,13 @@ spec:
               message: No default storage class found
           - pass:
               message: Default storage class found
+    - textAnalyze:
+        checkName: Database connection is valid
+        fileName: database/database.log
+        regex: pass
+        outcomes:
+          - pass:
+              when: "true"
+              message: Database connection is valid
+          - fail:
+              message: Database connection is invalid. Please check your settings and that the database is accessible from your cluster