Implement workaround for kubernetes/kubeadm#857

workarounds/kubeadm_issue_857.go

@@ -0,0 +1,47 @@
+package workarounds
+
+import (
+	"fmt"
+	"io/ioutil"
+
+	"github.com/platform9/nodeadm/constants"
+	"github.com/platform9/nodeadm/utils"
+)
+
+// PatchKubeProxyDaemonSet patches the kube-proxy daemonset to ensure that
+// kube-proxy functions when Node names are not hostnames, but some other value,
+// e.g., the host IPs.
+// Upstream issue: https://github.com/kubernetes/kubeadm/issues/857
+// Workaround: https://kubernetes.io/docs/setup/independent/troubleshooting-kubeadm/#services-with-externaltrafficpolicy-local-are-not-reachable
+func PatchKubeProxyDaemonSet() error {
+	patch := `[
+		{
+			"op": "add",
+			"path": "/spec/template/spec/containers/0/env",
+			"value": [
+				{
+					"name": "NODE_NAME",
+					"valueFrom": {
+						"fieldRef": {
+							"apiVersion": "v1",
+							"fieldPath": "spec.nodeName"
+						}
+					}
+				}
+			]
+		},
+		{
+			"op": "add",
+			"path": "/spec/template/spec/containers/0/command/-",
+			"value": "--hostname-override=${NODE_NAME}"
+		}
+	]`
+	patchFile, err := ioutil.TempFile("", "nodeadm")
+	if err != nil {
+		return fmt.Errorf("unable to create temporary file: %v", err)
+	}
+	defer patchFile.Close()
+	patchFile.WriteString(patch)
+	utils.Run(constants.BASE_INSTALL_DIR, "kubectl", fmt.Sprintf("--kubeconfig=%s", constants.AdminKubeconfigFile), "--namepspace=kube-system", "patch", "--type=json", "daemonset", "kube-proxy", "-f", patchFile.Name())
+	return nil
+}