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kubectl debug: add netadmin profile #115712
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Original file line number | Diff line number | Diff line change |
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@@ -52,6 +52,8 @@ const ( | |
// ProfileRestricted is identical to "baseline" but adds configuration that's required | ||
// under the restricted security profile, such as requiring a non-root user and dropping all capabilities. | ||
ProfileRestricted = "restricted" | ||
// ProfileNetadmin offers elevated privileges for network debugging. | ||
ProfileNetadmin = "netadmin" | ||
) | ||
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||
type ProfileApplier interface { | ||
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@@ -70,6 +72,8 @@ func NewProfileApplier(profile string) (ProfileApplier, error) { | |
return &baselineProfile{}, nil | ||
case ProfileRestricted: | ||
return &restrictedProfile{}, nil | ||
case ProfileNetadmin: | ||
return &netadminProfile{}, nil | ||
} | ||
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||
return nil, fmt.Errorf("unknown profile: %s", profile) | ||
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@@ -87,6 +91,9 @@ type baselineProfile struct { | |
type restrictedProfile struct { | ||
} | ||
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type netadminProfile struct { | ||
} | ||
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func (p *legacyProfile) Apply(pod *corev1.Pod, containerName string, target runtime.Object) error { | ||
switch target.(type) { | ||
case *corev1.Pod: | ||
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@@ -183,6 +190,26 @@ func (p *restrictedProfile) Apply(pod *corev1.Pod, containerName string, target | |
return nil | ||
} | ||
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func (p *netadminProfile) Apply(pod *corev1.Pod, containerName string, target runtime.Object) error { | ||
style, err := getDebugStyle(pod, target) | ||
if err != nil { | ||
return fmt.Errorf("netadmin profile: %s", err) | ||
} | ||
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allowNetadminCapability(pod, containerName) | ||
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switch style { | ||
case node: | ||
useHostNamespaces(pod) | ||
setPrivileged(pod, containerName) | ||
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case podCopy, ephemeral: | ||
// no additional modifications needed | ||
} | ||
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return nil | ||
} | ||
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// removeLabelsAndProbes removes labels from the pod and remove probes | ||
// from all containers of the pod. | ||
func removeLabelsAndProbes(p *corev1.Pod) { | ||
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@@ -239,6 +266,20 @@ func clearSecurityContext(p *corev1.Pod, containerName string) { | |
}) | ||
} | ||
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// setPrivileged configures the containers as privileged. | ||
func setPrivileged(p *corev1.Pod, containerName string) { | ||
podutils.VisitContainers(&p.Spec, podutils.AllContainers, func(c *corev1.Container, _ podutils.ContainerType) bool { | ||
if c.Name != containerName { | ||
return true | ||
} | ||
if c.SecurityContext == nil { | ||
c.SecurityContext = &corev1.SecurityContext{} | ||
} | ||
c.SecurityContext.Privileged = pointer.BoolPtr(true) | ||
There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. nit: There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. followup PR: #115837 |
||
return false | ||
}) | ||
} | ||
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// disallowRoot configures the container to run as a non-root user. | ||
func disallowRoot(p *corev1.Pod, containerName string) { | ||
podutils.VisitContainers(&p.Spec, podutils.AllContainers, func(c *corev1.Container, _ podutils.ContainerType) bool { | ||
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@@ -274,13 +315,28 @@ func allowProcessTracing(p *corev1.Pod, containerName string) { | |
if c.Name != containerName { | ||
return true | ||
} | ||
if c.SecurityContext == nil { | ||
c.SecurityContext = &corev1.SecurityContext{} | ||
} | ||
if c.SecurityContext.Capabilities == nil { | ||
c.SecurityContext.Capabilities = &corev1.Capabilities{} | ||
addCapability(c, "SYS_PTRACE") | ||
return false | ||
}) | ||
} | ||
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// allowNetadminCapability grants NET_ADMIN capability to the container. | ||
func allowNetadminCapability(p *corev1.Pod, containerName string) { | ||
podutils.VisitContainers(&p.Spec, podutils.AllContainers, func(c *corev1.Container, _ podutils.ContainerType) bool { | ||
if c.Name != containerName { | ||
return true | ||
} | ||
c.SecurityContext.Capabilities.Add = append(c.SecurityContext.Capabilities.Add, "SYS_PTRACE") | ||
addCapability(c, "NET_ADMIN") | ||
return false | ||
}) | ||
} | ||
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||
func addCapability(c *corev1.Container, capability corev1.Capability) { | ||
There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. Thank you for factoring this out into its own function. 👍 There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. +1 I'm wondering if we even need |
||
if c.SecurityContext == nil { | ||
c.SecurityContext = &corev1.SecurityContext{} | ||
} | ||
if c.SecurityContext.Capabilities == nil { | ||
c.SecurityContext.Capabilities = &corev1.Capabilities{} | ||
} | ||
c.SecurityContext.Capabilities.Add = append(c.SecurityContext.Capabilities.Add, capability) | ||
} |
Original file line number | Diff line number | Diff line change |
---|---|---|
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@@ -17,6 +17,7 @@ limitations under the License. | |
package debug | ||
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import ( | ||
"fmt" | ||
"testing" | ||
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"github.com/google/go-cmp/cmp" | ||
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@@ -430,3 +431,140 @@ func TestRestrictedProfile(t *testing.T) { | |
}) | ||
} | ||
} | ||
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func TestNetAdminProfile(t *testing.T) { | ||
pod := &corev1.Pod{ | ||
ObjectMeta: metav1.ObjectMeta{Name: "pod"}, | ||
Spec: corev1.PodSpec{EphemeralContainers: []corev1.EphemeralContainer{ | ||
{ | ||
EphemeralContainerCommon: corev1.EphemeralContainerCommon{ | ||
Name: "dbg", Image: "dbgimage", | ||
}, | ||
}, | ||
}}, | ||
} | ||
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tests := []struct { | ||
name string | ||
pod *corev1.Pod | ||
containerName string | ||
target runtime.Object | ||
expectPod *corev1.Pod | ||
expectErr error | ||
}{ | ||
{ | ||
name: "nil target", | ||
pod: pod, | ||
containerName: "dbg", | ||
target: nil, | ||
expectErr: fmt.Errorf("netadmin profile: objects of type <nil> are not supported"), | ||
}, | ||
{ | ||
name: "debug by ephemeral container", | ||
pod: pod, | ||
containerName: "dbg", | ||
target: pod, | ||
expectPod: &corev1.Pod{ | ||
ObjectMeta: metav1.ObjectMeta{Name: "pod"}, | ||
Spec: corev1.PodSpec{EphemeralContainers: []corev1.EphemeralContainer{ | ||
{ | ||
EphemeralContainerCommon: corev1.EphemeralContainerCommon{ | ||
Name: "dbg", Image: "dbgimage", | ||
SecurityContext: &corev1.SecurityContext{ | ||
Capabilities: &corev1.Capabilities{ | ||
Add: []corev1.Capability{"NET_ADMIN"}, | ||
}, | ||
}, | ||
}, | ||
}, | ||
}}, | ||
}, | ||
}, | ||
{ | ||
name: "debug by pod copy", | ||
pod: &corev1.Pod{ | ||
ObjectMeta: metav1.ObjectMeta{Name: "podcopy"}, | ||
Spec: corev1.PodSpec{ | ||
Containers: []corev1.Container{ | ||
{Name: "app", Image: "appimage"}, | ||
{Name: "dbg", Image: "dbgimage"}, | ||
}, | ||
}, | ||
}, | ||
containerName: "dbg", | ||
target: &corev1.Pod{ | ||
ObjectMeta: metav1.ObjectMeta{Name: "podcopy"}, | ||
Spec: corev1.PodSpec{ | ||
Containers: []corev1.Container{ | ||
{Name: "app", Image: "appimage"}, | ||
}, | ||
}, | ||
}, | ||
expectPod: &corev1.Pod{ | ||
ObjectMeta: metav1.ObjectMeta{Name: "podcopy"}, | ||
Spec: corev1.PodSpec{ | ||
Containers: []corev1.Container{ | ||
{Name: "app", Image: "appimage"}, | ||
{ | ||
Name: "dbg", | ||
Image: "dbgimage", | ||
SecurityContext: &corev1.SecurityContext{ | ||
Capabilities: &corev1.Capabilities{ | ||
Add: []corev1.Capability{"NET_ADMIN"}, | ||
}, | ||
}, | ||
}, | ||
}, | ||
}, | ||
}, | ||
}, | ||
{ | ||
name: "debug by node", | ||
pod: &corev1.Pod{ | ||
ObjectMeta: metav1.ObjectMeta{Name: "pod"}, | ||
Spec: corev1.PodSpec{ | ||
Containers: []corev1.Container{ | ||
{Name: "dbg", Image: "dbgimage"}, | ||
}, | ||
}, | ||
}, | ||
containerName: "dbg", | ||
target: testNode, | ||
expectPod: &corev1.Pod{ | ||
ObjectMeta: metav1.ObjectMeta{Name: "pod"}, | ||
Spec: corev1.PodSpec{ | ||
HostNetwork: true, | ||
HostPID: true, | ||
HostIPC: true, | ||
Containers: []corev1.Container{ | ||
{ | ||
Name: "dbg", | ||
Image: "dbgimage", | ||
SecurityContext: &corev1.SecurityContext{ | ||
Privileged: pointer.BoolPtr(true), | ||
Capabilities: &corev1.Capabilities{ | ||
Add: []corev1.Capability{"NET_ADMIN"}, | ||
There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. nit: Could you please add a test case to cover that already existed capability in the container is also shown. There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. added in followup PR: #115839 |
||
}, | ||
}, | ||
}, | ||
}, | ||
}, | ||
}, | ||
}, | ||
} | ||
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for _, test := range tests { | ||
t.Run(test.name, func(t *testing.T) { | ||
err := (&netadminProfile{}).Apply(test.pod, test.containerName, test.target) | ||
if (err == nil) != (test.expectErr == nil) || (err != nil && test.expectErr != nil && err.Error() != test.expectErr.Error()) { | ||
t.Fatalf("expect error: %v, got error: %v", test.expectErr, err) | ||
} | ||
if err != nil { | ||
return | ||
} | ||
if diff := cmp.Diff(test.expectPod, test.pod); diff != "" { | ||
t.Error("unexpected diff in generated object: (-want +got):\n", diff) | ||
} | ||
}) | ||
} | ||
} |
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nit: I think we need to add unit tests also in
TestGenerateNodeDebugPod
andTestGeneratePodCopyWithDebugContainer
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added in followup PR: #115839