Add sysctls for dockershim

pkg/kubelet/dockershim/docker_container.go

@@ -122,6 +122,13 @@ func (ds *dockerService) CreateContainer(podSandboxID string, config *runtimeApi
 		Privileged:     config.GetPrivileged(),
 	}
 
+	// Set sysctls if requested
+	sysctls, err := getSysctlsFromAnnotations(config.Annotations)
+	if err != nil {
+		return "", fmt.Errorf("failed to get sysctls from annotations %v for container %q: %v", config.Annotations, config.Metadata.GetName(), err)
+	}
+	hc.Sysctls = sysctls
+
 	// Apply options derived from the sandbox config.
 	if lc := sandboxConfig.GetLinux(); lc != nil {
 		// Apply Cgroup options.
@@ -166,7 +173,6 @@ func (ds *dockerService) CreateContainer(podSandboxID string, config *runtimeApi
 		// Note: ShmSize is handled in kube_docker_client.go
 	}
 
-	var err error
 	hc.SecurityOpt, err = getContainerSecurityOpts(config.Metadata.GetName(), sandboxConfig, ds.seccompProfileRoot)
 	if err != nil {
 		return "", fmt.Errorf("failed to generate container security options for container %q: %v", config.Metadata.GetName(), err)

pkg/kubelet/dockershim/docker_sandbox.go

@@ -224,6 +224,13 @@ func (ds *dockerService) makeSandboxDockerConfig(c *runtimeApi.PodSandboxConfig,
 		HostConfig: hc,
 	}
 
+	// Set sysctls if requested
+	sysctls, err := getSysctlsFromAnnotations(c.Annotations)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get sysctls from annotations %v for sandbox %q: %v", c.Annotations, c.Metadata.GetName(), err)
+	}
+	hc.Sysctls = sysctls
+
 	// Apply linux-specific options.
 	if lc := c.GetLinux(); lc != nil {
 		// Apply Cgroup options.
@@ -265,7 +272,6 @@ func (ds *dockerService) makeSandboxDockerConfig(c *runtimeApi.PodSandboxConfig,
 	setSandboxResources(hc)
 
 	// Set security options.
-	var err error
 	hc.SecurityOpt, err = getSandboxSecurityOpts(c, ds.seccompProfileRoot)
 	if err != nil {
 		return nil, fmt.Errorf("failed to generate sandbox security options for sandbox %q: %v", c.Metadata.GetName(), err)

pkg/kubelet/dockershim/helpers.go

@@ -27,6 +27,7 @@ import (
 	dockernat "github.com/docker/go-connections/nat"
 	"github.com/golang/glog"
 
+	"k8s.io/kubernetes/pkg/api"
 	runtimeApi "k8s.io/kubernetes/pkg/kubelet/api/v1alpha1/runtime"
 	"k8s.io/kubernetes/pkg/kubelet/dockertools"
 	"k8s.io/kubernetes/pkg/kubelet/types"
@@ -216,6 +217,27 @@ func getNetworkNamespace(c *dockertypes.ContainerJSON) string {
 	return fmt.Sprintf(dockerNetNSFmt, c.State.Pid)
 }
 
+// getSysctlsFromAnnotations gets sysctls from annotations.
+func getSysctlsFromAnnotations(annotations map[string]string) (map[string]string, error) {
+	var results map[string]string
+
+	sysctls, unsafeSysctls, err := api.SysctlsFromPodAnnotations(annotations)
+	if err != nil {
+		return nil, err
+	}
+	if len(sysctls)+len(unsafeSysctls) > 0 {
+		results = make(map[string]string, len(sysctls)+len(unsafeSysctls))
+		for _, c := range sysctls {
+			results[c.Name] = c.Value
+		}
+		for _, c := range unsafeSysctls {
+			results[c.Name] = c.Value
+		}
+	}
+
+	return results, nil
+}
+
 // dockerFilter wraps around dockerfilters.Args and provides methods to modify
 // the filter easily.
 type dockerFilter struct {

pkg/kubelet/dockershim/helpers_test.go

@@ -147,3 +147,43 @@ func TestGetSandboxSecurityOpts(t *testing.T) {
 		}
 	}
 }
+
+// TestGetSystclsFromAnnotations tests the logic of getting sysctls from annotations.
+func TestGetSystclsFromAnnotations(t *testing.T) {
+	tests := []struct {
+		annotations     map[string]string
+		expectedSysctls map[string]string
+	}{{
+		annotations: map[string]string{
+			api.SysctlsPodAnnotationKey:       "kernel.shmmni=32768,kernel.shmmax=1000000000",
+			api.UnsafeSysctlsPodAnnotationKey: "knet.ipv4.route.min_pmtu=1000",
+		},
+		expectedSysctls: map[string]string{
+			"kernel.shmmni":            "32768",
+			"kernel.shmmax":            "1000000000",
+			"knet.ipv4.route.min_pmtu": "1000",
+		},
+	}, {
+		annotations: map[string]string{
+			api.SysctlsPodAnnotationKey: "kernel.shmmni=32768,kernel.shmmax=1000000000",
+		},
+		expectedSysctls: map[string]string{
+			"kernel.shmmni": "32768",
+			"kernel.shmmax": "1000000000",
+		},
+	}, {
+		annotations: map[string]string{
+			api.UnsafeSysctlsPodAnnotationKey: "knet.ipv4.route.min_pmtu=1000",
+		},
+		expectedSysctls: map[string]string{
+			"knet.ipv4.route.min_pmtu": "1000",
+		},
+	}}
+
+	for i, test := range tests {
+		actual, err := getSysctlsFromAnnotations(test.annotations)
+		assert.NoError(t, err, "TestCase[%d]", i)
+		assert.Len(t, actual, len(test.expectedSysctls), "TestCase[%d]", i)
+		assert.Equal(t, test.expectedSysctls, actual, "TestCase[%d]", i)
+	}
+}