From 7679a84c6d63442b64f7aca30b197ba85e741b61 Mon Sep 17 00:00:00 2001
From: Aleksa Sarai <asarai@suse.de>
Date: Wed, 5 Apr 2017 00:11:53 +1000
Subject: [PATCH] server: issues.k8s.io/44043 workaround

Because kubelet will create broken symlinks for logPath it is necessary
to remove those symlinks before we attempt to write to them. This is a
temporary workaround while the issue is fixed upstream.

Ref: https://issues.k8s.io/44043
Signed-off-by: Aleksa Sarai <asarai@suse.de>
---
 server/container_create.go | 28 ++++++++++++++++++++++++++++
 server/sandbox_run.go      |  5 +++++
 2 files changed, 33 insertions(+)

diff --git a/server/container_create.go b/server/container_create.go
index cad91100..94f4b390 100644
--- a/server/container_create.go
+++ b/server/container_create.go
@@ -203,6 +203,29 @@ func setupContainerUser(specgen *generate.Generator, rootfs string, sc *pb.Linux
 	return nil
 }
 
+// ensureSaneLogPath is a hack to fix https://issues.k8s.io/44043 which causes
+// logPath to be a broken symlink to some magical Docker path. Ideally we
+// wouldn't have to deal with this, but until that issue is fixed we have to
+// remove the path if it's a broken symlink.
+func ensureSaneLogPath(logPath string) error {
+	// If the path exists but the resolved path does not, then we have a broken
+	// symlink and we need to remove it.
+	fi, err := os.Lstat(logPath)
+	if err != nil || fi.Mode()&os.ModeSymlink == 0 {
+		// Non-existant files and non-symlinks aren't our problem.
+		return nil
+	}
+
+	_, err = os.Stat(logPath)
+	if os.IsNotExist(err) {
+		err = os.RemoveAll(logPath)
+		if err != nil {
+			return fmt.Errorf("ensureSaneLogPath remove bad logPath: %s", err)
+		}
+	}
+	return nil
+}
+
 // CreateContainer creates a new container in specified PodSandbox
 func (s *Server) CreateContainer(ctx context.Context, req *pb.CreateContainerRequest) (res *pb.CreateContainerResponse, err error) {
 	logrus.Debugf("CreateContainerRequest %+v", req)
@@ -342,6 +365,11 @@ func (s *Server) createSandboxContainer(ctx context.Context, containerID string,
 		logPath = filepath.Join(sb.logDir, logPath)
 	}
 
+	// Handle https://issues.k8s.io/44043
+	if err := ensureSaneLogPath(logPath); err != nil {
+		return nil, err
+	}
+
 	logrus.WithFields(logrus.Fields{
 		"sbox.logdir": sb.logDir,
 		"ctr.logfile": containerConfig.LogPath,
diff --git a/server/sandbox_run.go b/server/sandbox_run.go
index c9169fe4..362419f0 100644
--- a/server/sandbox_run.go
+++ b/server/sandbox_run.go
@@ -255,6 +255,11 @@ func (s *Server) RunPodSandbox(ctx context.Context, req *pb.RunPodSandboxRequest
 	// set log path inside log directory
 	logPath := filepath.Join(logDir, id+".log")
 
+	// Handle https://issues.k8s.io/44043
+	if err := ensureSaneLogPath(logPath); err != nil {
+		return nil, err
+	}
+
 	privileged := s.privilegedSandbox(req)
 	g.AddAnnotation("ocid/metadata", string(metadataJSON))
 	g.AddAnnotation("ocid/labels", string(labelsJSON))