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Merge pull request #59125 from verb/pid-annotation

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Automatic merge from submit-queue (batch tested with PRs 60148, 60022, 59125, 60068, 60154). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Adding support for per-pod process namespace sharing in kubelet

**What this PR does / why we need it**: This enables process namespace sharing between containers in a pod as described in the [Shared PID Namespace](https://github.com/kubernetes/community/blob/master/contributors/design-proposals/node/pod-pid-namespace.md#container-runtime-interface-changes) proposal but leaves it disconnected pending merge of #58716.

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
WIP #1615

**Special notes for your reviewer**: 

**Release note**:

```release-note
NONE
```
This commit is contained in:
Kubernetes Submit Queue 2018-02-21 18:09:43 -08:00 committed by GitHub
commit 30a7bad884
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6 changed files with 100 additions and 42 deletions
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2
pkg/kubelet/dockershim/helpers_linux.go
View File

@ -118,7 +118,7 @@ func (ds *dockerService) updateCreateConfig(
if err := applyContainerSecurityContext(lc, podSandboxID, createConfig.Config, createConfig.HostConfig, securityOptSep); err != nil {
return fmt.Errorf("failed to apply container security context for container %q: %v", config.Metadata.Name, err)
}
modifyPIDNamespaceOverrides(ds.disableSharedPID, apiVersion, createConfig.HostConfig)
modifyContainerPIDNamespaceOverrides(ds.disableSharedPID, apiVersion, createConfig.HostConfig, podSandboxID)
}
// Apply cgroupsParent derived from the sandbox config.

25
pkg/kubelet/dockershim/security_context.go
View File

@ -122,13 +122,16 @@ func modifyHostConfig(sc *runtimeapi.LinuxContainerSecurityContext, hostConfig *
// modifySandboxNamespaceOptions apply namespace options for sandbox
func modifySandboxNamespaceOptions(nsOpts *runtimeapi.NamespaceOption, hostConfig *dockercontainer.HostConfig, network *knetwork.PluginManager) {
// The sandbox's PID namespace is the one that's shared, so CONTAINER and POD are equivalent for it
modifyCommonNamespaceOptions(nsOpts, hostConfig)
modifyHostOptionsForSandbox(nsOpts, network, hostConfig)
}
// modifyContainerNamespaceOptions apply namespace options for container
func modifyContainerNamespaceOptions(nsOpts *runtimeapi.NamespaceOption, podSandboxID string, hostConfig *dockercontainer.HostConfig) {
hostConfig.PidMode = dockercontainer.PidMode(fmt.Sprintf("container:%v", podSandboxID))
if nsOpts.GetPid() == runtimeapi.NamespaceMode_POD {
hostConfig.PidMode = dockercontainer.PidMode(fmt.Sprintf("container:%v", podSandboxID))
}
modifyCommonNamespaceOptions(nsOpts, hostConfig)
modifyHostOptionsForContainer(nsOpts, podSandboxID, hostConfig)
}
@ -181,14 +184,16 @@ func modifyHostOptionsForContainer(nsOpts *runtimeapi.NamespaceOption, podSandbo
// 1. Docker engine prior to API Version 1.24 doesn't support attaching to another container's
// PID namespace, and it didn't stabilize until 1.26. This check can be removed when Kubernetes'
// minimum Docker version is at least 1.13.1 (API version 1.26).
// 2. The administrator has overridden the default behavior by means of a kubelet flag. This is an
// "escape hatch" to return to previous behavior of isolated namespaces and should be removed once
// no longer needed.
func modifyPIDNamespaceOverrides(disableSharedPID bool, version *semver.Version, hc *dockercontainer.HostConfig) {
if !strings.HasPrefix(string(hc.PidMode), "container:") {
return
}
if disableSharedPID || version.LT(semver.Version{Major: 1, Minor: 26}) {
hc.PidMode = ""
// 2. The administrator can override the API behavior by using the deprecated --docker-disable-shared-pid=false
// flag. Until this flag is removed, this causes pods to use NamespaceMode_POD instead of
// NamespaceMode_CONTAINER regardless of pod configuration.
// TODO(verb): remove entirely once these two conditions are satisfied
func modifyContainerPIDNamespaceOverrides(disableSharedPID bool, version *semver.Version, hc *dockercontainer.HostConfig, podSandboxID string) {
if version.LT(semver.Version{Major: 1, Minor: 26}) {
if strings.HasPrefix(string(hc.PidMode), "container:") {
hc.PidMode = ""
}
} else if !disableSharedPID && hc.PidMode == "" {
hc.PidMode = dockercontainer.PidMode(fmt.Sprintf("container:%v", podSandboxID))
}
}

98
pkg/kubelet/dockershim/security_context_test.go
View File

@ -328,51 +328,93 @@ func TestModifyContainerNamespacePIDOverride(t *testing.T) {
input, expected dockercontainer.PidMode
}{
{
name: "SharedPID.Enable",
disable: false,
version: &semver.Version{Major: 1, Minor: 26},
input: "container:sandbox",
expected: "container:sandbox",
},
{
name: "SharedPID.Disable",
name: "mode:CONTAINER docker:NEW flag:UNSET",
disable: true,
version: &semver.Version{Major: 1, Minor: 26},
input: "container:sandbox",
input: "",
expected: "",
},
{
name: "SharedPID.OldDocker",
name: "mode:CONTAINER docker:NEW flag:SET",
disable: false,
version: &semver.Version{Major: 1, Minor: 25},
input: "container:sandbox",
expected: "",
},
{
name: "SharedPID.HostPid",
disable: true,
version: &semver.Version{Major: 1, Minor: 27},
input: "host",
expected: "host",
},
{
name: "SharedPID.DistantFuture",
disable: false,
version: &semver.Version{Major: 2, Minor: 10},
input: "container:sandbox",
version: &semver.Version{Major: 1, Minor: 26},
input: "",
expected: "container:sandbox",
},
{
name: "SharedPID.EmptyPidMode",
name: "mode:CONTAINER docker:OLD flag:UNSET",
disable: true,
version: &semver.Version{Major: 1, Minor: 25},
input: "",
expected: "",
},
{
name: "mode:CONTAINER docker:OLD flag:SET",
disable: false,
version: &semver.Version{Major: 1, Minor: 25},
input: "",
expected: "",
},
{
name: "mode:HOST docker:NEW flag:UNSET",
disable: true,
version: &semver.Version{Major: 1, Minor: 26},
input: "host",
expected: "host",
},
{
name: "mode:HOST docker:NEW flag:SET",
disable: false,
version: &semver.Version{Major: 1, Minor: 26},
input: "host",
expected: "host",
},
{
name: "mode:HOST docker:OLD flag:UNSET",
disable: true,
version: &semver.Version{Major: 1, Minor: 25},
input: "host",
expected: "host",
},
{
name: "mode:HOST docker:OLD flag:SET",
disable: false,
version: &semver.Version{Major: 1, Minor: 25},
input: "host",
expected: "host",
},
{
name: "mode:POD docker:NEW flag:UNSET",
disable: true,
version: &semver.Version{Major: 1, Minor: 26},
input: "container:sandbox",
expected: "container:sandbox",
},
{
name: "mode:POD docker:NEW flag:SET",
disable: false,
version: &semver.Version{Major: 1, Minor: 26},
input: "container:sandbox",
expected: "container:sandbox",
},
{
name: "mode:POD docker:OLD flag:UNSET",
disable: true,
version: &semver.Version{Major: 1, Minor: 25},
input: "container:sandbox",
expected: "",
},
{
name: "mode:POD docker:OLD flag:SET",
disable: false,
version: &semver.Version{Major: 1, Minor: 25},
input: "container:sandbox",
expected: "",
},
}
for _, tc := range cases {
dockerCfg := &dockercontainer.HostConfig{PidMode: tc.input}
modifyPIDNamespaceOverrides(tc.disable, tc.version, dockerCfg)
modifyContainerPIDNamespaceOverrides(tc.disable, tc.version, dockerCfg, "sandbox")
assert.Equal(t, tc.expected, dockerCfg.PidMode, "[Test case %q]", tc.name)
}
}

2
pkg/kubelet/kuberuntime/BUILD
View File

@ -84,6 +84,7 @@ go_test(
embed = [":go_default_library"],
deps = [
"//pkg/credentialprovider:go_default_library",
"//pkg/features:go_default_library",
"//pkg/kubelet/apis/cri/runtime/v1alpha2:go_default_library",
"//pkg/kubelet/apis/cri/testing:go_default_library",
"//pkg/kubelet/container:go_default_library",
@ -101,6 +102,7 @@ go_test(
"//vendor/k8s.io/apimachinery/pkg/util/intstr:go_default_library",
"//vendor/k8s.io/apimachinery/pkg/util/sets:go_default_library",
"//vendor/k8s.io/apiserver/pkg/util/feature:go_default_library",
"//vendor/k8s.io/apiserver/pkg/util/feature/testing:go_default_library",
"//vendor/k8s.io/client-go/util/flowcontrol:go_default_library",
],
)

9
pkg/kubelet/kuberuntime/helpers.go
View File

@ -294,10 +294,13 @@ func networkNamespaceForPod(pod *v1.Pod) runtimeapi.NamespaceMode {
}
func pidNamespaceForPod(pod *v1.Pod) runtimeapi.NamespaceMode {
if pod != nil && pod.Spec.HostPID {
return runtimeapi.NamespaceMode_NODE
if pod != nil {
if pod.Spec.HostPID {
return runtimeapi.NamespaceMode_NODE
}
// TODO(verb): set NamespaceMode_POD based on ShareProcessNamespace after #58716 is merged
}
// Note that PID does not default to the zero value
// Note that PID does not default to the zero value for v1.Pod
return runtimeapi.NamespaceMode_CONTAINER
}

6
pkg/kubelet/kuberuntime/helpers_test.go
View File

@ -25,6 +25,9 @@ import (
"k8s.io/api/core/v1"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
utilfeature "k8s.io/apiserver/pkg/util/feature"
utilfeaturetesting "k8s.io/apiserver/pkg/util/feature/testing"
"k8s.io/kubernetes/pkg/features"
runtimeapi "k8s.io/kubernetes/pkg/kubelet/apis/cri/runtime/v1alpha2"
runtimetesting "k8s.io/kubernetes/pkg/kubelet/apis/cri/testing"
kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
@ -307,6 +310,8 @@ func TestGetSeccompProfileFromAnnotations(t *testing.T) {
}
func TestNamespacesForPod(t *testing.T) {
defer utilfeaturetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, features.PodShareProcessNamespace, true)()
for desc, test := range map[string]struct {
input *v1.Pod
expected *runtimeapi.NamespaceOption
@ -341,6 +346,7 @@ func TestNamespacesForPod(t *testing.T) {
Pid: runtimeapi.NamespaceMode_NODE,
},
},
// TODO(verb): add test cases for ShareProcessNamespace true (after #58716 is merged)
} {
t.Logf("TestCase: %s", desc)
actual := namespacesForPod(test.input)