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Implement containerd environment variables whitelisting #2857

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Merged
merged 1 commit into from
May 9, 2021
Merged

Implement containerd environment variables whitelisting #2857

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5 changes: 4 additions & 1 deletion container/containerd/factory.go
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Original file line number Diff line number Diff line change
Expand Up @@ -41,6 +41,8 @@ const k8sContainerdNamespace = "containerd"
// --cgroup-parent have another prefix than 'containerd'
var containerdCgroupRegexp = regexp.MustCompile(`([a-z0-9]{64})`)

var containerdEnvWhitelist = flag.String("containerd_env_metadata_whitelist", "", "a comma-separated list of environment variable keys matched with specified prefix that needs to be collected for containerd containers")

type containerdFactory struct {
machineInfoFactory info.MachineInfoFactory
client ContainerdClient
Expand All @@ -62,7 +64,8 @@ func (f *containerdFactory) NewContainerHandler(name string, inHostNamespace boo
return
}

metadataEnvs := []string{}
metadataEnvs := strings.Split(*containerdEnvWhitelist, ",")

return newContainerdContainerHandler(
client,
name,
Expand Down
18 changes: 13 additions & 5 deletions container/containerd/handler.go
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Original file line number Diff line number Diff line change
Expand Up @@ -133,11 +133,19 @@ func newContainerdContainerHandler(
}
// Add the name and bare ID as aliases of the container.
handler.image = cntr.Image
for _, envVar := range spec.Process.Env {
if envVar != "" {
splits := strings.SplitN(envVar, "=", 2)
if len(splits) == 2 {
handler.envs[splits[0]] = splits[1]

for _, exposedEnv := range metadataEnvs {
if exposedEnv == "" {
// if no containerdEnvWhitelist provided, len(metadataEnvs) == 1, metadataEnvs[0] == ""
continue
}

for _, envVar := range spec.Process.Env {
if envVar != "" {
splits := strings.SplitN(envVar, "=", 2)
if len(splits) == 2 && strings.HasPrefix(splits[0], exposedEnv) {
handler.envs[splits[0]] = splits[1]
}
}
}
}
Expand Down
41 changes: 39 additions & 2 deletions container/containerd/handler_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,16 @@ func init() {
typeurl.Register(&specs.Spec{}, "types.contianerd.io/opencontainers/runtime-spec", "v1", "Spec")
}

type mockedMachineInfo struct{}

func (m *mockedMachineInfo) GetMachineInfo() (*info.MachineInfo, error) {
return &info.MachineInfo{}, nil
}

func (m *mockedMachineInfo) GetVersionInfo() (*info.VersionInfo, error) {
return &info.VersionInfo{}, nil
}

func TestHandler(t *testing.T) {
as := assert.New(t)
type testCase struct {
Expand All @@ -47,13 +57,14 @@ func TestHandler(t *testing.T) {
hasErr bool
errContains string
checkReference *info.ContainerReference
checkEnvVars map[string]string
}
testContainers := make(map[string]*containers.Container)
testContainer := &containers.Container{
ID: "40af7cdcbe507acad47a5a62025743ad3ddc6ab93b77b21363aa1c1d641047c9",
Labels: map[string]string{"io.cri-containerd.kind": "sandbox"},
}
spec := &specs.Spec{Root: &specs.Root{Path: "/test/"}, Process: &specs.Process{}}
spec := &specs.Spec{Root: &specs.Root{Path: "/test/"}, Process: &specs.Process{Env: []string{"TEST_REGION=FRA", "TEST_ZONE=A", "HELLO=WORLD"}}}
testContainer.Spec, _ = typeurl.MarshalAny(spec)
testContainers["40af7cdcbe507acad47a5a62025743ad3ddc6ab93b77b21363aa1c1d641047c9"] = testContainer
for _, ts := range []testCase{
Expand All @@ -69,11 +80,12 @@ func TestHandler(t *testing.T) {
true,
"unable to find container \"40af7cdcbe507acad47a5a62025743ad3ddc6ab93b77b21363aa1c1d641047c9\"",
nil,
nil,
},
{
mockcontainerdClient(testContainers, nil),
"/kubepods/pod068e8fa0-9213-11e7-a01f-507b9d4141fa/40af7cdcbe507acad47a5a62025743ad3ddc6ab93b77b21363aa1c1d641047c9",
nil,
&mockedMachineInfo{},
nil,
&containerlibcontainer.CgroupSubsystems{},
false,
Expand All @@ -87,6 +99,26 @@ func TestHandler(t *testing.T) {
Aliases: []string{"40af7cdcbe507acad47a5a62025743ad3ddc6ab93b77b21363aa1c1d641047c9", "/kubepods/pod068e8fa0-9213-11e7-a01f-507b9d4141fa/40af7cdcbe507acad47a5a62025743ad3ddc6ab93b77b21363aa1c1d641047c9"},
Namespace: k8sContainerdNamespace,
},
map[string]string{},
},
{
mockcontainerdClient(testContainers, nil),
"/kubepods/pod068e8fa0-9213-11e7-a01f-507b9d4141fa/40af7cdcbe507acad47a5a62025743ad3ddc6ab93b77b21363aa1c1d641047c9",
&mockedMachineInfo{},
nil,
&containerlibcontainer.CgroupSubsystems{},
false,
[]string{"TEST"},
nil,
false,
"",
&info.ContainerReference{
Id: "40af7cdcbe507acad47a5a62025743ad3ddc6ab93b77b21363aa1c1d641047c9",
Name: "/kubepods/pod068e8fa0-9213-11e7-a01f-507b9d4141fa/40af7cdcbe507acad47a5a62025743ad3ddc6ab93b77b21363aa1c1d641047c9",
Aliases: []string{"40af7cdcbe507acad47a5a62025743ad3ddc6ab93b77b21363aa1c1d641047c9", "/kubepods/pod068e8fa0-9213-11e7-a01f-507b9d4141fa/40af7cdcbe507acad47a5a62025743ad3ddc6ab93b77b21363aa1c1d641047c9"},
Namespace: k8sContainerdNamespace,
},
map[string]string{"TEST_REGION": "FRA", "TEST_ZONE": "A"},
},
} {
handler, err := newContainerdContainerHandler(ts.client, ts.name, ts.machineInfoFactory, ts.fsInfo, ts.cgroupSubsystems, ts.inHostNamespace, ts.metadataEnvs, ts.includedMetrics)
Expand All @@ -101,5 +133,10 @@ func TestHandler(t *testing.T) {
as.Nil(err)
as.Equal(*ts.checkReference, cr)
}
if ts.checkEnvVars != nil {
sp, err := handler.GetSpec()
as.Nil(err)
as.Equal(ts.checkEnvVars, sp.Envs)
}
}
}