docker/secrets-0002-SUSE-implement-SUSE-container-secrets.patch
2019-05-03 16:22:55 +00:00

442 lines
14 KiB
Diff

From 3eabc382912eeb475013b5514412968dfa300d63 Mon Sep 17 00:00:00 2001
From: Aleksa Sarai <asarai@suse.de>
Date: Wed, 8 Mar 2017 11:43:29 +1100
Subject: [PATCH 2/2] SUSE: implement SUSE container secrets
This allows for us to pass in host credentials to a container, allowing
for SUSEConnect to work with containers.
THIS PATCH IS NOT TO BE UPSTREAMED, DUE TO THE FACT THAT IT IS
SUSE-SPECIFIC, AND UPSTREAM DOES NOT APPROVE OF THIS CONCEPT BECAUSE IT
MAKES BUILDS NOT ENTIRELY REPRODUCIBLE.
SUSE-Bugs: bsc#1057743 bsc#1055676 bsc#1030702
Signed-off-by: Aleksa Sarai <asarai@suse.de>
---
components/engine/daemon/start.go | 5 +
components/engine/daemon/suse_secrets.go | 396 +++++++++++++++++++++++
2 files changed, 401 insertions(+)
create mode 100644 components/engine/daemon/suse_secrets.go
diff --git a/components/engine/daemon/start.go b/components/engine/daemon/start.go
index e2265a4faeca..31b60e5621c6 100644
--- a/components/engine/daemon/start.go
+++ b/components/engine/daemon/start.go
@@ -151,6 +151,11 @@ func (daemon *Daemon) containerStart(container *container.Container, checkpoint
return err
}
+ // SUSE:secrets -- inject the SUSE secret store
+ if err := daemon.injectSuseSecretStore(container); err != nil {
+ return errdefs.System(err)
+ }
+
spec, err := daemon.createSpec(container)
if err != nil {
return errdefs.System(err)
diff --git a/components/engine/daemon/suse_secrets.go b/components/engine/daemon/suse_secrets.go
new file mode 100644
index 000000000000..087c877015a7
--- /dev/null
+++ b/components/engine/daemon/suse_secrets.go
@@ -0,0 +1,396 @@
+/*
+ * suse-secrets: patch for Docker to implement SUSE secrets
+ * Copyright (C) 2017 SUSE LLC.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package daemon
+
+import (
+ "archive/tar"
+ "bytes"
+ "fmt"
+ "io"
+ "io/ioutil"
+ "os"
+ "path/filepath"
+ "strings"
+ "syscall"
+
+ "github.com/docker/docker/container"
+ "github.com/docker/docker/pkg/archive"
+ "github.com/docker/docker/pkg/idtools"
+ "github.com/opencontainers/go-digest"
+ "github.com/sirupsen/logrus"
+
+ swarmtypes "github.com/docker/docker/api/types/swarm"
+ swarmexec "github.com/docker/swarmkit/agent/exec"
+ swarmapi "github.com/docker/swarmkit/api"
+)
+
+func init() {
+ // Output to tell us in logs that SUSE:secrets is enabled.
+ logrus.Infof("SUSE:secrets :: enabled")
+}
+
+// Creating a fake file.
+type SuseFakeFile struct {
+ Path string
+ Uid int
+ Gid int
+ Mode os.FileMode
+ Data []byte
+}
+
+func (s SuseFakeFile) id() string {
+ // NOTE: It is _very_ important that this string always has a prefix of
+ // "suse". This is how we can ensure that we can operate on
+ // SecretReferences with a confidence that it was made by us.
+ return fmt.Sprintf("suse_%s_%s", digest.FromBytes(s.Data).Hex(), s.Path)
+}
+
+func (s SuseFakeFile) toSecret() *swarmapi.Secret {
+ return &swarmapi.Secret{
+ ID: s.id(),
+ Internal: true,
+ Spec: swarmapi.SecretSpec{
+ Data: s.Data,
+ },
+ }
+}
+
+func (s SuseFakeFile) toSecretReference(idMaps *idtools.IdentityMapping) *swarmtypes.SecretReference {
+ // Figure out the host-facing {uid,gid} based on the provided maps. Fall
+ // back to root if the UID/GID don't match (we are guaranteed that root is
+ // mapped).
+ ctrUser := idtools.Identity{UID: s.Uid, GID: s.Gid}
+ hostUser := idMaps.RootPair()
+ if user, err := idMaps.ToHost(ctrUser); err == nil {
+ hostUser = user
+ }
+
+ // Return the secret reference as a file target.
+ return &swarmtypes.SecretReference{
+ SecretID: s.id(),
+ SecretName: s.id(),
+ File: &swarmtypes.SecretReferenceFileTarget{
+ Name: s.Path,
+ UID: fmt.Sprintf("%d", hostUser.UID),
+ GID: fmt.Sprintf("%d", hostUser.GID),
+ Mode: s.Mode,
+ },
+ }
+}
+
+// readDir will recurse into a directory prefix/dir, and return the set of
+// secrets in that directory (as a tar archive that is packed inside the "data"
+// field). The Path attribute of each has the prefix stripped. Symlinks are
+// dereferenced.
+func readDir(prefix, dir string) ([]*SuseFakeFile, error) {
+ var suseFiles []*SuseFakeFile
+
+ path := filepath.Join(prefix, dir)
+ fi, err := os.Stat(path)
+ if err != nil {
+ // Ignore dangling symlinks.
+ if os.IsNotExist(err) {
+ logrus.Warnf("SUSE:secrets :: dangling symlink: %s", path)
+ return nil, nil
+ }
+ return nil, err
+ } else if !fi.IsDir() {
+ // Just to be safe.
+ logrus.Warnf("SUSE:secrets :: expected %q to be a directory, but was a file", path)
+ return readFile(prefix, dir)
+ }
+ path, err = filepath.EvalSymlinks(path)
+ if err != nil {
+ return nil, err
+ }
+
+ // Construct a tar archive of the source directory. We tar up the prefix
+ // directory and add dir as an IncludeFiles specifically so that we
+ // preserve the name of the directory itself.
+ tarStream, err := archive.TarWithOptions(path, &archive.TarOptions{
+ Compression: archive.Uncompressed,
+ IncludeSourceDir: true,
+ })
+ if err != nil {
+ return nil, fmt.Errorf("SUSE:secrets :: failed to tar source directory %q: %v", path, err)
+ }
+ tarStreamBytes, err := ioutil.ReadAll(tarStream)
+ if err != nil {
+ return nil, fmt.Errorf("SUSE:secrets :: failed to read full tar archive: %v", err)
+ }
+
+ // Get a list of the symlinks in the tar archive.
+ var symlinks []string
+ tmpTr := tar.NewReader(bytes.NewBuffer(tarStreamBytes))
+ for {
+ hdr, err := tmpTr.Next()
+ if err == io.EOF {
+ break
+ }
+ if err != nil {
+ return nil, fmt.Errorf("SUSE:secrets :: failed to read through tar reader: %v", err)
+ }
+ if hdr.Typeflag == tar.TypeSymlink {
+ symlinks = append(symlinks, hdr.Name)
+ }
+ }
+
+ // Symlinks aren't dereferenced in the above archive, so we explicitly do a
+ // rewrite of the tar archive to include all symlinks to files. We cannot
+ // do directories here, but lower-level directory symlinks aren't supported
+ // by zypper so this isn't an issue.
+ symlinkModifyMap := map[string]archive.TarModifierFunc{}
+ for _, sym := range symlinks {
+ logrus.Debugf("SUSE:secrets: archive(%q) %q is a need-to-rewrite symlink", path, sym)
+ symlinkModifyMap[sym] = func(tarPath string, hdr *tar.Header, r io.Reader) (*tar.Header, []byte, error) {
+ logrus.Debugf("SUSE:secrets: archive(%q) mapping for symlink %q", path, tarPath)
+ tarFullPath := filepath.Join(path, tarPath)
+
+ // Get a copy of the original byte stream.
+ oldContent, err := ioutil.ReadAll(r)
+ if err != nil {
+ return nil, nil, fmt.Errorf("suse_rewrite: failed to read archive entry %q: %v", tarPath, err)
+ }
+
+ // Check that the file actually exists.
+ fi, err := os.Stat(tarFullPath)
+ if err != nil {
+ logrus.Warnf("suse_rewrite: failed to stat archive entry %q: %v", tarFullPath, err)
+ return hdr, oldContent, nil
+ }
+
+ // Read the actual contents.
+ content, err := ioutil.ReadFile(tarFullPath)
+ if err != nil {
+ logrus.Warnf("suse_rewrite: failed to read %q: %v", tarFullPath, err)
+ return hdr, oldContent, nil
+ }
+
+ newHdr, err := tar.FileInfoHeader(fi, "")
+ if err != nil {
+ // Fake the header.
+ newHdr = &tar.Header{
+ Typeflag: tar.TypeReg,
+ Mode: 0644,
+ }
+ }
+
+ // Update the key fields.
+ hdr.Typeflag = newHdr.Typeflag
+ hdr.Mode = newHdr.Mode
+ hdr.Linkname = ""
+ return hdr, content, nil
+ }
+ }
+
+ // Create the rewritten tar stream.
+ tarStream = archive.ReplaceFileTarWrapper(ioutil.NopCloser(bytes.NewBuffer(tarStreamBytes)), symlinkModifyMap)
+ tarStreamBytes, err = ioutil.ReadAll(tarStream)
+ if err != nil {
+ return nil, fmt.Errorf("SUSE:secrets :: failed to read rewritten archive: %v", err)
+ }
+
+ // Add the tar stream as a "file".
+ suseFiles = append(suseFiles, &SuseFakeFile{
+ Path: dir,
+ Mode: fi.Mode(),
+ Data: tarStreamBytes,
+ })
+ return suseFiles, nil
+}
+
+// readFile returns a secret given a file under a given prefix.
+func readFile(prefix, file string) ([]*SuseFakeFile, error) {
+ path := filepath.Join(prefix, file)
+ fi, err := os.Stat(path)
+ if err != nil {
+ // Ignore dangling symlinks.
+ if os.IsNotExist(err) {
+ logrus.Warnf("SUSE:secrets :: dangling symlink: %s", path)
+ return nil, nil
+ }
+ return nil, err
+ } else if fi.IsDir() {
+ // Just to be safe.
+ logrus.Warnf("SUSE:secrets :: expected %q to be a file, but was a directory", path)
+ return readDir(prefix, file)
+ }
+
+ stat, ok := fi.Sys().(*syscall.Stat_t)
+ if !ok {
+ logrus.Warnf("SUSE:secrets :: failed to cast file stat_t: defaulting to owned by root:root: %s", path)
+ }
+
+ bytes, err := ioutil.ReadFile(path)
+ if err != nil {
+ return nil, err
+ }
+
+ var suseFiles []*SuseFakeFile
+ suseFiles = append(suseFiles, &SuseFakeFile{
+ Path: file,
+ Uid: int(stat.Uid),
+ Gid: int(stat.Gid),
+ Mode: fi.Mode(),
+ Data: bytes,
+ })
+ return suseFiles, nil
+}
+
+// getHostSuseSecretData returns the list of SuseFakeFiles the need to be added
+// as SUSE secrets.
+func getHostSuseSecretData() ([]*SuseFakeFile, error) {
+ secrets := []*SuseFakeFile{}
+
+ credentials, err := readDir("/etc/zypp", "credentials.d")
+ if err != nil {
+ if os.IsNotExist(err) {
+ credentials = []*SuseFakeFile{}
+ } else {
+ logrus.Errorf("SUSE:secrets :: error while reading zypp credentials: %s", err)
+ return nil, err
+ }
+ }
+ secrets = append(secrets, credentials...)
+
+ suseConnect, err := readFile("/etc", "SUSEConnect")
+ if err != nil {
+ if os.IsNotExist(err) {
+ suseConnect = []*SuseFakeFile{}
+ } else {
+ logrus.Errorf("SUSE:secrets :: error while reading /etc/SUSEConnect: %s", err)
+ return nil, err
+ }
+ }
+ secrets = append(secrets, suseConnect...)
+
+ return secrets, nil
+}
+
+// To fake an empty store, in the case where we are operating on a container
+// that was created pre-swarmkit. Otherwise segfaults and other fun things
+// happen. See bsc#1057743.
+type (
+ suseEmptyStore struct{}
+ suseEmptySecret struct{}
+ suseEmptyConfig struct{}
+)
+
+// In order to reduce the amount of code touched outside of this file, we
+// implement the swarm API for DependencyGetter. This asserts that this
+// requirement will always be matched. In addition, for the case of the *empty*
+// getters this reduces memory usage by having a global instance.
+var (
+ _ swarmexec.DependencyGetter = &suseDependencyStore{}
+ emptyStore swarmexec.DependencyGetter = suseEmptyStore{}
+ emptySecret swarmexec.SecretGetter = suseEmptySecret{}
+ emptyConfig swarmexec.ConfigGetter = suseEmptyConfig{}
+)
+
+var errSuseEmptyStore = fmt.Errorf("SUSE:secrets :: tried to get a resource from empty store [this is a bug]")
+
+func (_ suseEmptyConfig) Get(_ string) (*swarmapi.Config, error) { return nil, errSuseEmptyStore }
+func (_ suseEmptySecret) Get(_ string) (*swarmapi.Secret, error) { return nil, errSuseEmptyStore }
+func (_ suseEmptyStore) Secrets() swarmexec.SecretGetter { return emptySecret }
+func (_ suseEmptyStore) Configs() swarmexec.ConfigGetter { return emptyConfig }
+
+type suseDependencyStore struct {
+ dfl swarmexec.DependencyGetter
+ secrets map[string]*swarmapi.Secret
+}
+
+// The following are effectively dumb wrappers that return ourselves, or the
+// default.
+func (s *suseDependencyStore) Secrets() swarmexec.SecretGetter { return s }
+func (s *suseDependencyStore) Configs() swarmexec.ConfigGetter { return s.dfl.Configs() }
+
+// Get overrides the underlying DependencyGetter with our own secrets (falling
+// through to the underlying DependencyGetter if the secret isn't present).
+func (s *suseDependencyStore) Get(id string) (*swarmapi.Secret, error) {
+ logrus.Debugf("SUSE:secrets :: id=%s requested from suseDependencyGetter", id)
+
+ secret, ok := s.secrets[id]
+ if !ok {
+ // fallthrough
+ return s.dfl.Secrets().Get(id)
+ }
+ return secret, nil
+}
+
+// removeSuseSecrets removes any SecretReferences which were added by us
+// explicitly (this is detected by checking that the prefix has a 'suse'
+// prefix). See bsc#1057743.
+func removeSuseSecrets(c *container.Container) {
+ var without []*swarmtypes.SecretReference
+ for _, secret := range c.SecretReferences {
+ if strings.HasPrefix(secret.SecretID, "suse") {
+ logrus.Warnf("SUSE:secrets :: removing 'old' suse secret %q from container %q", secret.SecretID, c.ID)
+ continue
+ }
+ without = append(without, secret)
+ }
+ c.SecretReferences = without
+}
+
+func (daemon *Daemon) injectSuseSecretStore(c *container.Container) error {
+ newDependencyStore := &suseDependencyStore{
+ dfl: c.DependencyStore,
+ secrets: make(map[string]*swarmapi.Secret),
+ }
+ // Handle old containers. See bsc#1057743.
+ if newDependencyStore.dfl == nil {
+ newDependencyStore.dfl = emptyStore
+ }
+
+ // We drop any "old" SUSE secrets, as it appears that old containers (when
+ // restarted) could still have references to old secrets. The .id() of all
+ // secrets have a prefix of "suse" so this is much easier. See bsc#1057743
+ // for details on why this could cause issues.
+ removeSuseSecrets(c)
+
+ secrets, err := getHostSuseSecretData()
+ if err != nil {
+ return err
+ }
+
+ idMaps := daemon.idMapping
+ for _, secret := range secrets {
+ newDependencyStore.secrets[secret.id()] = secret.toSecret()
+ c.SecretReferences = append(c.SecretReferences, secret.toSecretReference(idMaps))
+ }
+
+ c.DependencyStore = newDependencyStore
+
+ // bsc#1057743 -- In older versions of Docker we added volumes explicitly
+ // to the mount list. This causes clashes because of duplicate namespaces.
+ // If we see an existing mount that will clash with the in-built secrets
+ // mount we assume it's our fault.
+ intendedMounts, err := c.SecretMounts()
+ if err != nil {
+ logrus.Warnf("SUSE:secrets :: fetching old secret mounts: %v", err)
+ return err
+ }
+ for _, intendedMount := range intendedMounts {
+ mountPath := intendedMount.Destination
+ if volume, ok := c.MountPoints[mountPath]; ok {
+ logrus.Debugf("SUSE:secrets :: removing pre-existing %q mount: %#v", mountPath, volume)
+ delete(c.MountPoints, mountPath)
+ }
+ }
+ return nil
+}
--
2.21.0