Merge pull request #34718 from taimir/kubeadm-disco-wait

Automatic merge from submit-queue kubeadm join: polling discovery service API **What this PR does / why we need it**: Enhance kubeadm to allow for parallel provisioning of API endpoints and slave nodes, in addition to https://github.com/kubernetes/kubernetes/pull/33543. This PR let's `kubeadm join` poll the discovery service API and retry connecting to it every couple of seconds. That way `kubeadm init` and `kubeadm join` can be executed in parallel. **Fixes**: https://github.com/kubernetes/kubernetes/issues/33542 **Special notes for your reviewer**: @pires @errordeveloper last part of the discussed changes, in addition to https://github.com/kubernetes/kubernetes/pull/33543 and https://github.com/kubernetes/kubernetes/pull/34703

Merge pull request #34718 from taimir/kubeadm-disco-wait
7e6fda2e · Kubernetes Submit Queue · GitHub · c526657a · 32edc87e · 7e6fda2e
Commit 7e6fda2e authored Oct 15, 2016 by Kubernetes Submit Queue Committed by GitHub Oct 15, 2016
Hide whitespace changes
Inline Side-by-side

Showing with 15 additions and 4 deletions

discovery.go cmd/kubeadm/app/node/discovery.go +15 -4

No files found.
--- a/cmd/kubeadm/app/node/discovery.go
+++ b/cmd/kubeadm/app/node/discovery.go
@@ -22,11 +22,16 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"time"
 	jose "github.com/square/go-jose"
 	kubeadmapi "k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm"
+	"k8s.io/kubernetes/pkg/util/wait"
 )
+// the amount of time to wait between each request to the discovery API
+const discoveryRetryTimeout = 5 * time.Second
 func RetrieveTrustedClusterInfo(s *kubeadmapi.NodeConfiguration) (*kubeadmapi.ClusterInfo, error) {
 	host, port := s.MasterAddresses[0], 9898
 	requestURL := fmt.Sprintf("http://%s:%d/cluster-info/v1/?token-id=%s", host, port, s.Secrets.TokenID)
@@ -37,10 +42,16 @@ func RetrieveTrustedClusterInfo(s *kubeadmapi.NodeConfiguration) (*kubeadmapi.Cl
 	fmt.Printf("<node/discovery> created cluster info discovery client, requesting info from %q\n", requestURL)
-	res, err := http.DefaultClient.Do(req)
+	var res *http.Response
-	if err != nil {
+	wait.PollInfinite(discoveryRetryTimeout, func() (bool, error) {
-		return nil, fmt.Errorf("<node/discovery> failed to request cluster info [%v]", err)
+		res, err = http.DefaultClient.Do(req)
-	}
+		if err != nil {
+			fmt.Printf("<node/discovery> failed to request cluster info, will try again: [%s]\n", err)
+			return false, nil
+		}
+		return true, nil
+	})
 	buf := new(bytes.Buffer)
 	io.Copy(buf, res.Body)
 	res.Body.Close()