Add probes for LanCache DNS. (#1434)

charts/incubator/lancache/Chart.yaml

@@ -2,7 +2,7 @@ apiVersion: v2
 appVersion: 1.0.0
 description: LanCache Monolithic - a caching proxy server for game download content
 name: lancache
-version: 0.3.0
+version: 0.4.0
 kubeVersion: ">=1.16.0-0"
 keywords:
   - lancache
@@ -21,5 +21,5 @@ dependencies:
     version: 4.3.0
 annotations:
   artifacthub.io/changes: |
-    - kind: changed
+    - kind: added
-      description: Upgraded `common` chart dependency to version `4.3.0`.
+      description: Added probes for LanCache DNS container.

charts/incubator/lancache/templates/common.yaml

@@ -44,6 +44,45 @@ additionalContainers:
       - name: dns
         containerPort: 53
         protocol: UDP
+    livenessProbe:
+      exec:
+        command:
+          - bash
+          - -c
+          - |
+            set -euo pipefail
+
+            # Check if LanCache DNS entries are set up.
+            dig @127.0.0.1 "${LANCACHE_DNSDOMAIN}" SOA | grep localhost
+
+            # Check if upstream DNS server is reachable.
+            dig "${LANCACHE_DNSDOMAIN}" SOA
+    readinessProbe:
+      exec:
+        command:
+          - bash
+          - -c
+          - |
+            set -euo pipefail
+
+            # Check if LanCache DNS entries are set up.
+            dig @127.0.0.1 "${LANCACHE_DNSDOMAIN}" SOA | grep localhost
+
+            # Check if upstream DNS server is reachable.
+            dig "${LANCACHE_DNSDOMAIN}" SOA
+    startupProbe:
+      exec:
+        command:
+          - bash
+          - -c
+          - |
+            set -euo pipefail
+
+            # Check if LanCache DNS entries are set up.
+            dig @127.0.0.1 "${LANCACHE_DNSDOMAIN}" SOA | grep localhost
+
+            # Check if upstream DNS server is reachable.
+            dig "${LANCACHE_DNSDOMAIN}" SOA
 
 service:
   dns:

charts/incubator/lancache/values.yaml

@@ -40,7 +40,7 @@ service:
         port: 53
 
 # -- LanCache uses custom upstream nameservers, overridable with the `UPSTREAM_DNS` variable.
-dnsPolicy: 'None'
+dnsPolicy: None
 dnsConfig:
   nameservers:
     - 127.0.0.1