From e5a790753dee985d76bbea58686c689ceb47472e Mon Sep 17 00:00:00 2001
From: Jonathan Ballet <jballet@edgelab.ch>
Date: Fri, 27 Oct 2017 17:45:06 +0200
Subject: [PATCH 1/2] docker: log that a container has been killed by the OOM
 killer

Fix: #2203 (at least for Docker tasks)
---
 client/driver/docker.go      |  7 +++++
 client/driver/docker_test.go | 50 ++++++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/client/driver/docker.go b/client/driver/docker.go
index 9bc8554ba536..1597a36b6aec 100644
--- a/client/driver/docker.go
+++ b/client/driver/docker.go
@@ -1609,6 +1609,13 @@ func (h *DockerHandle) run() {
 		werr = fmt.Errorf("Docker container exited with non-zero exit code: %d", exitCode)
 	}
 
+	container, ierr := h.waitClient.InspectContainer(h.containerID)
+	if ierr != nil {
+		h.logger.Printf("[ERR] driver.docker: failed to inspect container %s: %v", h.containerID, ierr)
+	} else if container.State.OOMKilled {
+		werr = fmt.Errorf("Docker container killed by OOM killer")
+	}
+
 	close(h.doneCh)
 
 	// Shutdown the syslog collector
diff --git a/client/driver/docker_test.go b/client/driver/docker_test.go
index 1f2e63223dcf..65a4246e75d3 100644
--- a/client/driver/docker_test.go
+++ b/client/driver/docker_test.go
@@ -1753,3 +1753,53 @@ func TestDockerDriver_AuthConfiguration(t *testing.T) {
 		}
 	}
 }
+
+func TestDockerDriver_OOMKilled(t *testing.T) {
+	if !tu.IsTravis() {
+		t.Parallel()
+	}
+	if !testutil.DockerIsConnected(t) {
+		t.Skip("Docker not connected")
+	}
+
+	task := &structs.Task{
+		Name:   "oom-killed",
+		Driver: "docker",
+		Config: map[string]interface{}{
+			"image":   "busybox",
+			"load":    "busybox.tar",
+			"command": "sh",
+			// Incrementally creates a bigger and bigger variable.
+			"args": []string{"-c", "x=a; while true; do eval x='$x$x'; done"},
+		},
+		LogConfig: &structs.LogConfig{
+			MaxFiles:      10,
+			MaxFileSizeMB: 10,
+		},
+		Resources: &structs.Resources{
+			CPU:      250,
+			MemoryMB: 10,
+			DiskMB:   20,
+			Networks: []*structs.NetworkResource{},
+		},
+	}
+
+	_, handle, cleanup := dockerSetup(t, task)
+	defer cleanup()
+
+	select {
+	case res := <-handle.WaitCh():
+		if res.Successful() {
+			t.Fatalf("expected error, but container exited successfull")
+		}
+
+		if !strings.Contains(res.Err.Error(), "killed by OOM killer") {
+			t.Fatalf("not killed by OOM killer: %s", res.Err)
+		}
+
+		t.Logf("Successfully killed by OOM killer")
+
+	case <-time.After(time.Duration(tu.TestMultiplier()*5) * time.Second):
+		t.Fatalf("timeout")
+	}
+}

From 15114e448e1048715dcf02c338d34195bf9271db Mon Sep 17 00:00:00 2001
From: Jonathan Ballet <jballet@edgelab.ch>
Date: Fri, 27 Oct 2017 20:30:52 +0200
Subject: [PATCH 2/2] docker: changed OOM killed error message

---
 client/driver/docker.go      | 2 +-
 client/driver/docker_test.go | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/client/driver/docker.go b/client/driver/docker.go
index 1597a36b6aec..4dc6ae08f62e 100644
--- a/client/driver/docker.go
+++ b/client/driver/docker.go
@@ -1613,7 +1613,7 @@ func (h *DockerHandle) run() {
 	if ierr != nil {
 		h.logger.Printf("[ERR] driver.docker: failed to inspect container %s: %v", h.containerID, ierr)
 	} else if container.State.OOMKilled {
-		werr = fmt.Errorf("Docker container killed by OOM killer")
+		werr = fmt.Errorf("OOM Killed")
 	}
 
 	close(h.doneCh)
diff --git a/client/driver/docker_test.go b/client/driver/docker_test.go
index 65a4246e75d3..962c0efdf359 100644
--- a/client/driver/docker_test.go
+++ b/client/driver/docker_test.go
@@ -1793,7 +1793,7 @@ func TestDockerDriver_OOMKilled(t *testing.T) {
 			t.Fatalf("expected error, but container exited successfull")
 		}
 
-		if !strings.Contains(res.Err.Error(), "killed by OOM killer") {
+		if res.Err.Error() != "OOM Killed" {
 			t.Fatalf("not killed by OOM killer: %s", res.Err)
 		}