Add workaround for flannel issue 1044

Author: Daniel Lipovetsky

cmd/nodeinit.go

@@ -102,6 +102,11 @@ func networkInit(config *apis.InitConfiguration) error {
 		log.Fatalf("failed to run %q: %s", strings.Join(cmd.Args, " "), err)
 	}
 
+	log.Infoln("Applying workaround for https://github.com/coreos/flannel/issues/1044")
+	if err := ensureFlannelDaemonSetToleratesAllNoScheduleTaints(); err != nil {
+		log.Fatalf("Failed to apply workaround: %v", err)
+	}
+
 	return nil
 }
 

cmd/workaround_flannel_issue_1044.go

@@ -0,0 +1,38 @@
+package cmd
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/platform9/nodeadm/constants"
+)
+
+// ensureFlannelDaemonSetTolerations patches the flannel daemonset so that it
+// tolerates all NoSchedule taints. See https://github.com/coreos/flannel/issues/1044
+func ensureFlannelDaemonSetToleratesAllNoScheduleTaints() error {
+	return patchFlannelDaemonSet()
+}
+
+// patchFlannelDaemonSet is idempotent; kubectl patch has a zero exit code if
+// the patch has already been applied.
+func patchFlannelDaemonSet() error {
+	name := "/bin/sh"
+	arg := fmt.Sprintf(`%s --kubeconfig=%s --namespace=kube-system patch daemonset kube-flannel-ds --patch='{"spec":{"template":{"spec":{"tolerations":[{"effect":"NoSchedule","operator":"Exists"}]}}}}'`, filepath.Join(constants.BaseInstallDir, constants.KubectlFilename), constants.AdminKubeconfigFile)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+	var stdout, stderr bytes.Buffer
+	cmd := exec.CommandContext(ctx, name, "-c", arg)
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+	if err := cmd.Run(); err != nil {
+		return fmt.Errorf("error running %q: %v (stdout: %s) (stderr: %s)", strings.Join(cmd.Args, " "), err, string(stdout.Bytes()), string(stderr.Bytes()))
+	}
+
+	return nil
+}