Merge "Use sequential forward policy in coredns"

controllerconfig/controllerconfig/upgrade-scripts/25-coredns-configmap.sh

@@ -0,0 +1,89 @@
+#!/bin/bash
+# Copyright (c) 2020 Wind River Systems, Inc.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+# This script will update subcloud_status table in dcmanager database
+# in preparation for upgrade to release 20.06.
+#
+# Subcloud load audit, introduced in release 20.06, entails creating
+# load status record when a subcloud is added to the database and
+# having the subcloud load status updated by dcmanager audit task.
+# The script adds a load status record for each of the existing
+# subclouds to ensure successful startup and operation of dcmanager
+# when the system controller hosts are upgraded to 20.06.
+#
+# This script can be removed in the release that follows 20.06.
+#
+
+NAME=$(basename $0)
+
+# The migration scripts are passed these parameters:
+FROM_RELEASE=$1
+TO_RELEASE=$2
+ACTION=$3
+
+# This will log to /var/log/platform.log
+function log {
+    logger -p local1.info $1
+}
+
+function create_configmap {
+    cat > /etc/kubernetes/coredns.yaml <<EOF
+# Based on https://github.com/kubernetes/kubernetes/blob/master/cluster/addons/dns/coredns/coredns.yaml.sed#L54-L82
+# Hardcode dns_domain to cluster.local.
+# Change policy from default of random to sequential, in order to attempt to
+# resolve domain names with dnsmasq first.
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: coredns
+  namespace: kube-system
+  labels:
+      addonmanager.kubernetes.io/mode: EnsureExists
+data:
+  Corefile: |
+    .:53 {
+        errors
+        health {
+            lameduck 5s
+        }
+        ready
+        kubernetes cluster.local in-addr.arpa ip6.arpa {
+            pods insecure
+            fallthrough in-addr.arpa ip6.arpa
+            ttl 30
+        }
+        prometheus :9153
+        forward . /etc/resolv.conf {
+            policy sequential
+        }
+        cache 30
+        loop
+        reload
+        loadbalance
+    }
+EOF
+
+}
+
+function apply_configmap {
+    kubectl --kubeconfig=/etc/kubernetes/admin.conf apply -f /etc/kubernetes/coredns.yaml
+    ret=$?
+    return $ret
+}
+
+
+if [ "$TO_RELEASE" == "20.06" ] && [ "$ACTION" == "activate" ]; then
+    log "$NAME: Migrating FROM release $FROM_RELEASE"
+    create_configmap
+    apply_configmap
+    ret=$?
+    if [ $ret -ne 0 ]; then
+        log "$NAME: Applying CoreDNS ConfigMap failed"
+        exit 1
+    fi
+
+fi
+
+exit 0