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[teleport-update] Add unlink-package command (#49250)
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* unlink

* test

* lock type

* comments

* cleanup

* Update lib/autoupdate/agent/installer.go

Co-authored-by: Hugo Shaka <hugo.hervieux@goteleport.com>

---------

Co-authored-by: Hugo Shaka <hugo.hervieux@goteleport.com>
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@sclevine @hugoShaka
sclevine and hugoShaka authored Nov 21, 2024
1 parent b123bd6 commit 1989776
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Showing 5 changed files with 342 additions and 23 deletions.
115 changes: 99 additions & 16 deletions lib/autoupdate/agent/installer.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -39,6 +39,7 @@ import (
"github.com/google/renameio/v2"
"github.com/gravitational/trace"

"github.com/gravitational/teleport"
"github.com/gravitational/teleport/lib/utils"
)

Expand Down Expand Up @@ -443,6 +444,46 @@ func (li *LocalInstaller) LinkSystem(ctx context.Context) (revert func(context.C
return revert, trace.Wrap(err)
}

// TryLink links the specified version, but only in the case that
// no installation of Teleport is already linked or partially linked.
// See Installer interface for additional specs.
func (li *LocalInstaller) TryLink(ctx context.Context, version string) error {
versionDir, err := li.versionDir(version)
if err != nil {
return trace.Wrap(err)
}
return trace.Wrap(li.tryLinks(ctx,
filepath.Join(versionDir, "bin"),
filepath.Join(versionDir, serviceDir),
))
}

// TryLinkSystem links the system installation, but only in the case that
// no installation of Teleport is already linked or partially linked.
// See Installer interface for additional specs.
func (li *LocalInstaller) TryLinkSystem(ctx context.Context) error {
return trace.Wrap(li.tryLinks(ctx, li.SystemBinDir, li.SystemServiceDir))
}

// Unlink unlinks a version from LinkBinDir and LinkServiceDir.
// See Installer interface for additional specs.
func (li *LocalInstaller) Unlink(ctx context.Context, version string) error {
versionDir, err := li.versionDir(version)
if err != nil {
return trace.Wrap(err)
}
return trace.Wrap(li.removeLinks(ctx,
filepath.Join(versionDir, "bin"),
filepath.Join(versionDir, serviceDir),
))
}

// UnlinkSystem unlinks the system (package) version from LinkBinDir and LinkServiceDir.
// See Installer interface for additional specs.
func (li *LocalInstaller) UnlinkSystem(ctx context.Context) error {
return trace.Wrap(li.removeLinks(ctx, li.SystemBinDir, li.SystemServiceDir))
}

// symlink from oldname to newname
type symlink struct {
oldname, newname string
Expand Down Expand Up @@ -640,25 +681,67 @@ func readFileN(name string, n int64) ([]byte, error) {
return data, trace.Wrap(err)
}

// TryLink links the specified version, but only in the case that
// no installation of Teleport is already linked or partially linked.
// See Installer interface for additional specs.
func (li *LocalInstaller) TryLink(ctx context.Context, version string) error {
versionDir, err := li.versionDir(version)
func (li *LocalInstaller) removeLinks(ctx context.Context, binDir, svcDir string) error {
removeService := false
entries, err := os.ReadDir(binDir)
if err != nil {
return trace.Errorf("failed to find Teleport binary directory: %w", err)
}
for _, entry := range entries {
if entry.IsDir() {
continue
}
oldname := filepath.Join(binDir, entry.Name())
newname := filepath.Join(li.LinkBinDir, entry.Name())
v, err := os.Readlink(newname)
if errors.Is(err, os.ErrNotExist) ||
errors.Is(err, os.ErrInvalid) ||
errors.Is(err, syscall.EINVAL) {
li.Log.DebugContext(ctx, "Link not present.", "oldname", oldname, "newname", newname)
continue
}
if err != nil {
return trace.Errorf("error reading link for %s: %w", filepath.Base(newname), err)
}
if v != oldname {
li.Log.DebugContext(ctx, "Skipping link to different binary.", "oldname", oldname, "newname", newname)
continue
}
if err := os.Remove(newname); err != nil {
li.Log.ErrorContext(ctx, "Unable to remove link.", "oldname", oldname, "newname", newname, errorKey, err)
continue
}
if filepath.Base(newname) == teleport.ComponentTeleport {
removeService = true
}
}
// only remove service if teleport was removed
if !removeService {
li.Log.DebugContext(ctx, "Teleport binary not unlinked. Skipping removal of teleport.service.")
return nil
}
src := filepath.Join(svcDir, serviceName)
srcBytes, err := readFileN(src, maxServiceFileSize)
if err != nil {
return trace.Wrap(err)
}
return trace.Wrap(li.tryLinks(ctx,
filepath.Join(versionDir, "bin"),
filepath.Join(versionDir, serviceDir),
))
}

// TryLinkSystem links the system installation, but only in the case that
// no installation of Teleport is already linked or partially linked.
// See Installer interface for additional specs.
func (li *LocalInstaller) TryLinkSystem(ctx context.Context) error {
return trace.Wrap(li.tryLinks(ctx, li.SystemBinDir, li.SystemServiceDir))
dst := filepath.Join(li.LinkServiceDir, serviceName)
dstBytes, err := readFileN(dst, maxServiceFileSize)
if errors.Is(err, os.ErrNotExist) {
li.Log.DebugContext(ctx, "Service not present.", "path", dst)
return nil
}
if err != nil {
return trace.Wrap(err)
}
if !bytes.Equal(srcBytes, dstBytes) {
li.Log.WarnContext(ctx, "Removed teleport binary link, but skipping removal of custom teleport.service: the service file does not match the reference file for this version. The file might have been manually edited.")
return nil
}
if err := os.Remove(dst); err != nil {
return trace.Errorf("error removing copy of %s: %w", filepath.Base(dst), err)
}
return nil
}

// tryLinks create binary and service links for files in binDir and svcDir if links are not already present.
Expand Down
188 changes: 184 additions & 4 deletions lib/autoupdate/agent/installer_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,7 @@ import (
"os"
"path/filepath"
"runtime"
"slices"
"strconv"
"strings"
"testing"
Expand Down Expand Up @@ -393,7 +394,7 @@ func TestLocalInstaller_Link(t *testing.T) {
installer := &LocalInstaller{
InstallDir: versionsDir,
LinkBinDir: filepath.Join(linkDir, "bin"),
LinkServiceDir: filepath.Join(linkDir, "lib/systemd/system"),
LinkServiceDir: filepath.Join(linkDir, serviceDir),
Log: slog.Default(),
}
ctx := context.Background()
Expand Down Expand Up @@ -635,7 +636,7 @@ func TestLocalInstaller_TryLink(t *testing.T) {
installer := &LocalInstaller{
InstallDir: versionsDir,
LinkBinDir: filepath.Join(linkDir, "bin"),
LinkServiceDir: filepath.Join(linkDir, "lib/systemd/system"),
LinkServiceDir: filepath.Join(linkDir, serviceDir),
Log: slog.Default(),
}
ctx := context.Background()
Expand Down Expand Up @@ -773,8 +774,8 @@ func TestLocalInstaller_Remove(t *testing.T) {

installer := &LocalInstaller{
InstallDir: versionsDir,
LinkBinDir: linkDir,
LinkServiceDir: linkDir,
LinkBinDir: filepath.Join(linkDir, "bin"),
LinkServiceDir: filepath.Join(linkDir, serviceDir),
Log: slog.Default(),
}
ctx := context.Background()
Expand All @@ -796,6 +797,185 @@ func TestLocalInstaller_Remove(t *testing.T) {
}
}

func TestLocalInstaller_Unlink(t *testing.T) {
t.Parallel()
const version = "existing-version"
servicePath := filepath.Join(serviceDir, serviceName)

tests := []struct {
name string
bins []string
svcOrig []byte

links []symlink
svcCopy []byte

remaining []string
errMatch string
}{
{
name: "normal",
bins: []string{"teleport", "tsh"},
svcOrig: []byte("orig"),
links: []symlink{
{oldname: "bin/teleport", newname: "bin/teleport"},
{oldname: "bin/tsh", newname: "bin/tsh"},
},
svcCopy: []byte("orig"),
},
{
name: "different services",
bins: []string{"teleport", "tsh"},
svcOrig: []byte("orig"),
links: []symlink{
{oldname: "bin/teleport", newname: "bin/teleport"},
{oldname: "bin/tsh", newname: "bin/tsh"},
},
svcCopy: []byte("custom"),
remaining: []string{servicePath},
},
{
name: "missing target service",
bins: []string{"teleport", "tsh"},
svcOrig: []byte("orig"),
links: []symlink{
{oldname: "bin/teleport", newname: "bin/teleport"},
{oldname: "bin/tsh", newname: "bin/tsh"},
},
},
{
name: "missing source service",
bins: []string{"teleport", "tsh"},
links: []symlink{
{oldname: "bin/teleport", newname: "bin/teleport"},
{oldname: "bin/tsh", newname: "bin/tsh"},
},
svcCopy: []byte("custom"),
remaining: []string{servicePath},
errMatch: "no such",
},
{
name: "missing teleport link",
bins: []string{"teleport", "tsh"},
svcOrig: []byte("orig"),
links: []symlink{
{oldname: "bin/tsh", newname: "bin/tsh"},
},
svcCopy: []byte("orig"),
remaining: []string{servicePath},
},
{
name: "missing other link",
bins: []string{"teleport", "tsh"},
svcOrig: []byte("orig"),
links: []symlink{
{oldname: "bin/teleport", newname: "bin/teleport"},
},
svcCopy: []byte("orig"),
},
{
name: "wrong teleport link",
bins: []string{"teleport", "tsh"},
svcOrig: []byte("orig"),
links: []symlink{
{oldname: "other", newname: "bin/teleport"},
{oldname: "bin/tsh", newname: "bin/tsh"},
},
svcCopy: []byte("orig"),
remaining: []string{servicePath, "bin/teleport"},
},
{
name: "wrong other link",
bins: []string{"teleport", "tsh"},
svcOrig: []byte("orig"),
links: []symlink{
{oldname: "bin/teleport", newname: "bin/teleport"},
{oldname: "wrong", newname: "bin/tsh"},
},
svcCopy: []byte("orig"),
remaining: []string{"bin/tsh"},
},
}

for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
versionsDir := t.TempDir()
versionDir := filepath.Join(versionsDir, version)
err := os.MkdirAll(versionDir, 0o755)
require.NoError(t, err)
linkDir := t.TempDir()

var files []smallFile
for _, n := range tt.bins {
files = append(files, smallFile{
name: filepath.Join(versionDir, "bin", n),
data: []byte("binary"),
mode: os.ModePerm,
})
}
if tt.svcOrig != nil {
files = append(files, smallFile{
name: filepath.Join(versionDir, servicePath),
data: tt.svcOrig,
mode: os.ModePerm,
})
}
if tt.svcCopy != nil {
files = append(files, smallFile{
name: filepath.Join(linkDir, servicePath),
data: tt.svcCopy,
mode: os.ModePerm,
})
}

for _, n := range files {
err = os.MkdirAll(filepath.Dir(n.name), os.ModePerm)
require.NoError(t, err)
err = os.WriteFile(n.name, n.data, n.mode)
require.NoError(t, err)
}
for _, n := range tt.links {
newname := filepath.Join(linkDir, n.newname)
oldname := filepath.Join(versionDir, n.oldname)
err = os.MkdirAll(filepath.Dir(newname), os.ModePerm)
require.NoError(t, err)
err = os.Symlink(oldname, newname)
require.NoError(t, err)
}

installer := &LocalInstaller{
InstallDir: versionsDir,
LinkBinDir: filepath.Join(linkDir, "bin"),
LinkServiceDir: filepath.Join(linkDir, serviceDir),
Log: slog.Default(),
}
ctx := context.Background()
err = installer.Unlink(ctx, version)
if tt.errMatch != "" {
require.Error(t, err)
assert.Contains(t, err.Error(), tt.errMatch)
} else {
require.NoError(t, err)
}
for _, n := range tt.remaining {
_, err = os.Lstat(filepath.Join(linkDir, n))
require.NoError(t, err)
}
for _, n := range tt.links {
if slices.Contains(tt.remaining, n.newname) {
continue
}
_, err = os.Lstat(filepath.Join(linkDir, n.newname))
require.ErrorIs(t, err, os.ErrNotExist)
}
if !slices.Contains(tt.remaining, servicePath) {
_, err = os.Lstat(filepath.Join(linkDir, servicePath))
require.ErrorIs(t, err, os.ErrNotExist)
}
})
}
}

func TestLocalInstaller_List(t *testing.T) {
installDir := t.TempDir()
versions := []string{"v1", "v2"}
Expand Down
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