OCPBUGS-48469: GCP: Update /etc/hosts file when ClusterHostedDNS is enabled

pkg/controller/template/render.go

@@ -352,6 +352,7 @@ func renderTemplate(config RenderConfig, path string, b []byte) ([]byte, error)
 	funcs["cloudPlatformAPIIntLoadBalancerIPs"] = cloudPlatformAPIIntLoadBalancerIPs
 	funcs["cloudPlatformAPILoadBalancerIPs"] = cloudPlatformAPILoadBalancerIPs
 	funcs["cloudPlatformIngressLoadBalancerIPs"] = cloudPlatformIngressLoadBalancerIPs
+	funcs["cloudPlatformLBIPAvailable"] = cloudPlatformLBIPAvailable
 	funcs["join"] = strings.Join
 	tmpl, err := template.New(path).Funcs(funcs).Parse(string(b))
 	if err != nil {
@@ -777,6 +778,33 @@ func cloudPlatformIngressLoadBalancerIPs(cfg RenderConfig) (interface{}, error)
 	}
 }
 
+// cloudPlatformLBIPAvailable returns true when DNSType is set to `ClusterHosted`
+// and LB IPs are provided as part of `PlatformStatus`.
+func cloudPlatformLBIPAvailable(cfg RenderConfig) bool {
+	if cfg.Infra.Status.PlatformStatus != nil {
+		switch cfg.Infra.Status.PlatformStatus.Type {
+		case configv1.GCPPlatformType:
+			switch cloudPlatformLoadBalancerIPState(cfg) {
+			case availableLBIPState:
+				return true
+			default:
+				return false
+			}
+		case configv1.AWSPlatformType:
+			switch cloudPlatformLoadBalancerIPState(cfg) {
+			case availableLBIPState:
+				return true
+			default:
+				return false
+			}
+		default:
+			return false
+		}
+	} else {
+		return false
+	}
+}
+
 // cloudPlatformLoadBalancerIPState is a helper function that determines if
 // LoadBalancer config has been set.
 func cloudPlatformLoadBalancerIPState(cfg RenderConfig) LoadBalancerIPState {

pkg/controller/template/render_test.go

@@ -216,6 +216,8 @@ var (
 		"nutanix":                "./test_data/controller_config_nutanix.yaml",
 		"network-forwarding-sdn": "./test_data/controller_config_forwarding_sdn.yaml",
 		"network-forwarding-ovn": "./test_data/controller_config_forwarding_ovn.yaml",
+		"gcp-custom-dns":         "./test_data/controller_config_gcp_custom_dns.yaml",
+		"gcp-platform-default":   "./test_data/controller_config_gcp_platform_default.yaml",
 	}
 )
 

pkg/controller/template/test_data/controller_config_gcp_custom_dns.yaml

@@ -0,0 +1,33 @@
+apiVersion: "machineconfigurations.openshift.io/v1"
+kind: "ControllerConfig"
+spec:
+  clusterDNSIP: "10.3.0.10"
+  cloudProviderConfig: ""
+  etcdInitialCount: 3
+  etcdCAData: ZHVtbXkgZXRjZC1jYQo=
+  rootCAData: ZHVtbXkgcm9vdC1jYQo=
+  pullSecret:
+    data: ZHVtbXkgZXRjZC1jYQo=
+  images:
+    etcd: image/etcd:1
+    setupEtcdEnv: image/setupEtcdEnv:1
+    infraImage: image/infraImage:1
+    kubeClientAgentImage: image/kubeClientAgentImage:1
+  infra:
+    apiVersion: config.openshift.io/v1
+    kind: Infrastructure
+    status:
+      apiServerInternalURI: https://api-int.my-test-cluster.installer.team.coreos.systems:6443
+      apiServerURL: https://api.my-test-cluster.installer.team.coreos.systems:6443
+      etcdDiscoveryDomain: my-test-cluster.installer.team.coreos.systems
+      infrastructureName: my-test-cluster
+      platformStatus:
+        type: "GCP"
+        gcp:
+          cloudLoadBalancerConfig:
+            dnsType: "ClusterHosted"
+            clusterHosted:
+              apiLoadBalancerIPs:
+              - 20.20.20.20
+              apiIntLoadBalancerIPs:
+              - 10.10.10.10

pkg/controller/template/test_data/controller_config_gcp_platform_default.yaml

@@ -0,0 +1,28 @@
+apiVersion: "machineconfigurations.openshift.io/v1"
+kind: "ControllerConfig"
+spec:
+  clusterDNSIP: "10.3.0.10"
+  cloudProviderConfig: ""
+  etcdInitialCount: 3
+  etcdCAData: ZHVtbXkgZXRjZC1jYQo=
+  rootCAData: ZHVtbXkgcm9vdC1jYQo=
+  pullSecret:
+    data: ZHVtbXkgZXRjZC1jYQo=
+  images:
+    etcd: image/etcd:1
+    setupEtcdEnv: image/setupEtcdEnv:1
+    infraImage: image/infraImage:1
+    kubeClientAgentImage: image/kubeClientAgentImage:1
+  infra:
+    apiVersion: config.openshift.io/v1
+    kind: Infrastructure
+    status:
+      apiServerInternalURI: https://api-int.my-test-cluster.installer.team.coreos.systems:6443
+      apiServerURL: https://api.my-test-cluster.installer.team.coreos.systems:6443
+      etcdDiscoveryDomain: my-test-cluster.installer.team.coreos.systems
+      infrastructureName: my-test-cluster
+      platformStatus:
+        type: "GCP"
+        gcp:
+          cloudLoadBalancerConfig:
+            dnsType: "PlatformDefault"

pkg/operator/render.go

@@ -80,6 +80,7 @@ func (a *assetRenderer) addTemplateFuncs() {
 	funcs["cloudPlatformAPIIntLoadBalancerIPs"] = cloudPlatformAPIIntLoadBalancerIPs
 	funcs["cloudPlatformAPILoadBalancerIPs"] = cloudPlatformAPILoadBalancerIPs
 	funcs["cloudPlatformIngressLoadBalancerIPs"] = cloudPlatformIngressLoadBalancerIPs
+	funcs["cloudPlatformLBIPAvailable"] = cloudPlatformLBIPAvailable
 	funcs["join"] = strings.Join
 
 	a.tmpl = a.tmpl.Funcs(funcs)
@@ -461,6 +462,33 @@ func cloudPlatformIngressLoadBalancerIPs(cfg mcfgv1.ControllerConfigSpec) (inter
 	}
 }
 
+// cloudPlatformLBIPAvailable returns true when DNSType is set to `ClusterHosted`
+// and LB IPs are provided as part of `PlatformStatus`.
+func cloudPlatformLBIPAvailable(cfg mcfgv1.ControllerConfigSpec) bool {
+	if cfg.Infra.Status.PlatformStatus != nil {
+		switch cfg.Infra.Status.PlatformStatus.Type {
+		case configv1.GCPPlatformType:
+			switch cloudPlatformLoadBalancerIPState(cfg) {
+			case availableLBIPState:
+				return true
+			default:
+				return false
+			}
+		case configv1.AWSPlatformType:
+			switch cloudPlatformLoadBalancerIPState(cfg) {
+			case availableLBIPState:
+				return true
+			default:
+				return false
+			}
+		default:
+			return false
+		}
+	} else {
+		return false
+	}
+}
+
 // cloudPlatformLoadBalancerIPState is a helper function that determines if
 // LoadBalancer config has been set.
 func cloudPlatformLoadBalancerIPState(cfg mcfgv1.ControllerConfigSpec) LoadBalancerIPState {

templates/common/gcp/files/usr-local-bin-update-etc-hosts.yaml

@@ -0,0 +1,20 @@
+mode: 0755
+path: "/usr/local/bin/update-etc-hosts"
+contents:
+  inline: |
+    #!/bin/bash
+    apiLBIP=${1}
+    apiURL=${2}
+    apiIntLBIP=${3}
+    apiIntURL=${4}
+    if [ -z "$apiLBIP" ]; then
+      # apiLBIPs are not expected to be set on private clusters
+      apiLBIP=$apiIntLBIP
+    fi
+    mkdir -p /etc/conf.d
+    etc_hosts_config_filename="/etc/conf.d/etc-hosts.conf"
+    echo "${apiLBIP}    ${apiURL%:*}" >> ${etc_hosts_config_filename}
+    echo "${apiIntLBIP}    ${apiIntURL%:*}" >> ${etc_hosts_config_filename}
+    cat /etc/conf.d/etc-hosts.conf
+    cat /etc/conf.d/etc-hosts.conf >> /etc/hosts
+    echo "Done updating /etc/hosts"

templates/common/gcp/units/gcp-update-etc-hosts.service.yaml

@@ -0,0 +1,28 @@
+name: gcp-update-etc-hosts.service
+enabled: {{if and (eq .Infra.Status.PlatformStatus.Type "GCP") (.Infra.Status.PlatformStatus.GCP) (.Infra.Status.PlatformStatus.GCP.CloudLoadBalancerConfig) (eq .Infra.Status.PlatformStatus.GCP.CloudLoadBalancerConfig.DNSType "ClusterHosted") }}true{{else}}false{{end}}
+contents: |
+  [Unit]
+  Description=Update Default GCP /etc/hosts
+  # We don't need to do this on the firstboot
+  After=firstboot-osupdate.target
+  # Wait for NetworkManager to report it's online
+  After=NetworkManager-wait-online.service
+  # Run before kubelet
+  Before=kubelet-dependencies.target
+
+  [Service]
+  # Need oneshot to delay kubelet
+  Type=oneshot
+  ExecStart=/bin/bash -c " \
+  {{ if and (cloudPlatformLBIPAvailable .) (gt (len (cloudPlatformAPIIntLoadBalancerIPs .)) 0) }} \
+  apiIntLBIP={{ index (cloudPlatformAPIIntLoadBalancerIPs .) 0 }} \
+  {{ end }} \
+  {{ if and (cloudPlatformLBIPAvailable .) (gt (len (cloudPlatformAPILoadBalancerIPs .)) 0) }} \
+  apiLBIP={{ index (cloudPlatformAPILoadBalancerIPs .) 0 }} \
+  {{ end }} \
+  apiServerURL={{ .Infra.Status.APIServerURL }} \
+  apiServerIntURL={{ .Infra.Status.APIServerInternalURL }} \
+  /usr/local/bin/update-etc-hosts ${apiLBIP} ${apiServerURL} ${apiIntLBIP} ${apiServerIntURL}"
+
+  [Install]
+  RequiredBy=kubelet-dependencies.target