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only relabel cri managed host mounts
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Co-authored-by: Samuel Karp <skarp@amazon.com>
Signed-off-by: Michael Crosby <michael@thepasture.io>
Signed-off-by: Samuel Karp <skarp@amazon.com>
(cherry picked from commit 9b03039)
Signed-off-by: Samuel Karp <skarp@amazon.com>
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@crosbymichael @samuelkarp
crosbymichael and samuelkarp committed Dec 9, 2021
1 parent 312af27 commit a41213f
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Showing 3 changed files with 57 additions and 67 deletions.
24 changes: 0 additions & 24 deletions pkg/cri/opts/spec_linux.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -225,30 +225,6 @@ func WithMounts(osi osinterface.OS, config *runtime.ContainerConfig, extra []*ru
}
}

const (
etcHosts = "/etc/hosts"
etcHostname = "/etc/hostname"
resolvConfPath = "/etc/resolv.conf"
)

// WithRelabeledContainerMounts relabels the default container mounts for files in /etc
func WithRelabeledContainerMounts(mountLabel string) oci.SpecOpts {
return func(ctx context.Context, client oci.Client, _ *containers.Container, s *runtimespec.Spec) (err error) {
if mountLabel == "" {
return nil
}
for _, m := range s.Mounts {
switch m.Destination {
case etcHosts, etcHostname, resolvConfPath:
if err := label.Relabel(m.Source, mountLabel, false); err != nil {
return err
}
}
}
return nil
}
}

// Ensure mount point on which path is mounted, is shared.
func ensureShared(path string, lookupMount func(string) (mount.Info, error)) error {
mountInfo, err := lookupMount(path)
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23 changes: 13 additions & 10 deletions pkg/cri/server/container_create_linux.go
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Original file line number Diff line number Diff line change
Expand Up @@ -68,28 +68,31 @@ func (c *criService) containerMounts(sandboxID string, config *runtime.Container
hostpath := c.getSandboxHostname(sandboxID)
if _, err := c.os.Stat(hostpath); err == nil {
mounts = append(mounts, &runtime.Mount{
ContainerPath: etcHostname,
HostPath: hostpath,
Readonly: securityContext.GetReadonlyRootfs(),
ContainerPath: etcHostname,
HostPath: hostpath,
Readonly: securityContext.GetReadonlyRootfs(),
SelinuxRelabel: true,
})
}
}

if !isInCRIMounts(etcHosts, config.GetMounts()) {
mounts = append(mounts, &runtime.Mount{
ContainerPath: etcHosts,
HostPath: c.getSandboxHosts(sandboxID),
Readonly: securityContext.GetReadonlyRootfs(),
ContainerPath: etcHosts,
HostPath: c.getSandboxHosts(sandboxID),
Readonly: securityContext.GetReadonlyRootfs(),
SelinuxRelabel: true,
})
}

// Mount sandbox resolv.config.
// TODO: Need to figure out whether we should always mount it as read-only
if !isInCRIMounts(resolvConfPath, config.GetMounts()) {
mounts = append(mounts, &runtime.Mount{
ContainerPath: resolvConfPath,
HostPath: c.getResolvPath(sandboxID),
Readonly: securityContext.GetReadonlyRootfs(),
ContainerPath: resolvConfPath,
HostPath: c.getResolvPath(sandboxID),
Readonly: securityContext.GetReadonlyRootfs(),
SelinuxRelabel: true,
})
}

Expand Down Expand Up @@ -192,7 +195,7 @@ func (c *criService) containerSpec(
}
}()

specOpts = append(specOpts, customopts.WithMounts(c.os, config, extraMounts, mountLabel), customopts.WithRelabeledContainerMounts(mountLabel))
specOpts = append(specOpts, customopts.WithMounts(c.os, config, extraMounts, mountLabel))

if !c.config.DisableProcMount {
// Change the default masked/readonly paths to empty slices
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77 changes: 44 additions & 33 deletions pkg/cri/server/container_create_linux_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -450,19 +450,22 @@ func TestContainerMounts(t *testing.T) {
},
expectedMounts: []*runtime.Mount{
{
ContainerPath: "/etc/hostname",
HostPath: filepath.Join(testRootDir, sandboxesDir, testSandboxID, "hostname"),
Readonly: true,
ContainerPath: "/etc/hostname",
HostPath: filepath.Join(testRootDir, sandboxesDir, testSandboxID, "hostname"),
Readonly: true,
SelinuxRelabel: true,
},
{
ContainerPath: "/etc/hosts",
HostPath: filepath.Join(testRootDir, sandboxesDir, testSandboxID, "hosts"),
Readonly: true,
ContainerPath: "/etc/hosts",
HostPath: filepath.Join(testRootDir, sandboxesDir, testSandboxID, "hosts"),
Readonly: true,
SelinuxRelabel: true,
},
{
ContainerPath: resolvConfPath,
HostPath: filepath.Join(testRootDir, sandboxesDir, testSandboxID, "resolv.conf"),
Readonly: true,
ContainerPath: resolvConfPath,
HostPath: filepath.Join(testRootDir, sandboxesDir, testSandboxID, "resolv.conf"),
Readonly: true,
SelinuxRelabel: true,
},
{
ContainerPath: "/dev/shm",
Expand All @@ -476,19 +479,22 @@ func TestContainerMounts(t *testing.T) {
securityContext: &runtime.LinuxContainerSecurityContext{},
expectedMounts: []*runtime.Mount{
{
ContainerPath: "/etc/hostname",
HostPath: filepath.Join(testRootDir, sandboxesDir, testSandboxID, "hostname"),
Readonly: false,
ContainerPath: "/etc/hostname",
HostPath: filepath.Join(testRootDir, sandboxesDir, testSandboxID, "hostname"),
Readonly: false,
SelinuxRelabel: true,
},
{
ContainerPath: "/etc/hosts",
HostPath: filepath.Join(testRootDir, sandboxesDir, testSandboxID, "hosts"),
Readonly: false,
ContainerPath: "/etc/hosts",
HostPath: filepath.Join(testRootDir, sandboxesDir, testSandboxID, "hosts"),
Readonly: false,
SelinuxRelabel: true,
},
{
ContainerPath: resolvConfPath,
HostPath: filepath.Join(testRootDir, sandboxesDir, testSandboxID, "resolv.conf"),
Readonly: false,
ContainerPath: resolvConfPath,
HostPath: filepath.Join(testRootDir, sandboxesDir, testSandboxID, "resolv.conf"),
Readonly: false,
SelinuxRelabel: true,
},
{
ContainerPath: "/dev/shm",
Expand All @@ -504,19 +510,22 @@ func TestContainerMounts(t *testing.T) {
},
expectedMounts: []*runtime.Mount{
{
ContainerPath: "/etc/hostname",
HostPath: filepath.Join(testRootDir, sandboxesDir, testSandboxID, "hostname"),
Readonly: false,
ContainerPath: "/etc/hostname",
HostPath: filepath.Join(testRootDir, sandboxesDir, testSandboxID, "hostname"),
Readonly: false,
SelinuxRelabel: true,
},
{
ContainerPath: "/etc/hosts",
HostPath: filepath.Join(testRootDir, sandboxesDir, testSandboxID, "hosts"),
Readonly: false,
ContainerPath: "/etc/hosts",
HostPath: filepath.Join(testRootDir, sandboxesDir, testSandboxID, "hosts"),
Readonly: false,
SelinuxRelabel: true,
},
{
ContainerPath: resolvConfPath,
HostPath: filepath.Join(testRootDir, sandboxesDir, testSandboxID, "resolv.conf"),
Readonly: false,
ContainerPath: resolvConfPath,
HostPath: filepath.Join(testRootDir, sandboxesDir, testSandboxID, "resolv.conf"),
Readonly: false,
SelinuxRelabel: true,
},
{
ContainerPath: "/dev/shm",
Expand Down Expand Up @@ -555,14 +564,16 @@ func TestContainerMounts(t *testing.T) {
securityContext: &runtime.LinuxContainerSecurityContext{},
expectedMounts: []*runtime.Mount{
{
ContainerPath: "/etc/hosts",
HostPath: filepath.Join(testRootDir, sandboxesDir, testSandboxID, "hosts"),
Readonly: false,
ContainerPath: "/etc/hosts",
HostPath: filepath.Join(testRootDir, sandboxesDir, testSandboxID, "hosts"),
Readonly: false,
SelinuxRelabel: true,
},
{
ContainerPath: resolvConfPath,
HostPath: filepath.Join(testRootDir, sandboxesDir, testSandboxID, "resolv.conf"),
Readonly: false,
ContainerPath: resolvConfPath,
HostPath: filepath.Join(testRootDir, sandboxesDir, testSandboxID, "resolv.conf"),
Readonly: false,
SelinuxRelabel: true,
},
{
ContainerPath: "/dev/shm",
Expand Down

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