homedir: remove idtools and libcontainer's user package dependencies
About github.com/opencontainers/runc/libcontainer/user:
According to https://github.com/opencontainers/runc/commit/195d8d544aca731301d8116821c75e1244dd5a0c
this package has two functions:
- Have a static implementation of user lookup, which is now supported in the
os/user stdlib package with the osusergo build tag, but wasn't at the time.
- Have extra functions that os/user doesn't have, but none of those are used
in homedir.
Since https://github.com/moby/moby/pull/11287, homedir depended directly on
libcontainer's user package for CurrentUser().
This is being replaced with os/user.Current(), because all of our static
binaries are compiled with the osusergo tag, and for dynamic libraries it
is more correct to use libc's implementation than parsing /etc/passwd.
About github.com/docker/docker/pkg/idtools:
Only dependency was from GetStatic() which uses idtools.LookupUID(uid).
The implementation of idtools.LookupUID just calls to
github.com/opencontainers/runc/libcontainer/user.LookupUid or fallbacks
to exec-ing to getent (since https://github.com/moby/moby/pull/27599).
This patch replaces calls to homedir.GetStatic by homedir.Get(), opting out
of supporting nss lookups in static binaries via exec-ing to getent for
the homedir package.
If homedir package users need to support nss lookups, they are advised
to compile dynamically instead.
Signed-off-by: Tibor Vass <tibor@docker.com>
Tibor Vass authored on 2019/09/24 07:16:38Showing 4 changed files
- daemon/logger/gcplogs/gcplogging_linux.go
- pkg/homedir/homedir_linux.go
- pkg/homedir/homedir_others.go
- pkg/homedir/homedir_unix.go
| ... | ... |
@@ -11,17 +11,15 @@ import ( |
| 11 | 11 |
// ensureHomeIfIAmStatic ensure $HOME to be set if dockerversion.IAmStatic is "true". |
| 12 | 12 |
// See issue #29344: gcplogs segfaults (static binary) |
| 13 | 13 |
// If HOME is not set, logging.NewClient() will call os/user.Current() via oauth2/google. |
| 14 |
-// However, in static binary, os/user.Current() leads to segfault due to a glibc issue that won't be fixed |
|
| 15 |
-// in a short term. (golang/go#13470, https://sourceware.org/bugzilla/show_bug.cgi?id=19341) |
|
| 14 |
+// If compiling statically, make sure osusergo build tag is also used to prevent a segfault |
|
| 15 |
+// due to a glibc issue that won't be fixed in a short term |
|
| 16 |
+// (see golang/go#13470, https://sourceware.org/bugzilla/show_bug.cgi?id=19341). |
|
| 16 | 17 |
// So we forcibly set HOME so as to avoid call to os/user/Current() |
| 17 | 18 |
func ensureHomeIfIAmStatic() error {
|
| 18 |
- // Note: dockerversion.IAmStatic and homedir.GetStatic() is only available for linux. |
|
| 19 |
+ // Note: dockerversion.IAmStatic is only available for linux. |
|
| 19 | 20 |
// So we need to use them in this gcplogging_linux.go rather than in gcplogging.go |
| 20 | 21 |
if dockerversion.IAmStatic == "true" && os.Getenv("HOME") == "" {
|
| 21 |
- home, err := homedir.GetStatic() |
|
| 22 |
- if err != nil {
|
|
| 23 |
- return err |
|
| 24 |
- } |
|
| 22 |
+ home := homedir.Get() |
|
| 25 | 23 |
logrus.Warnf("gcplogs requires HOME to be set for static daemon binary. Forcibly setting HOME to %s.", home)
|
| 26 | 24 |
os.Setenv("HOME", home)
|
| 27 | 25 |
} |
| ... | ... |
@@ -5,24 +5,8 @@ import ( |
| 5 | 5 |
"os" |
| 6 | 6 |
"path/filepath" |
| 7 | 7 |
"strings" |
| 8 |
- |
|
| 9 |
- "github.com/docker/docker/pkg/idtools" |
|
| 10 | 8 |
) |
| 11 | 9 |
|
| 12 |
-// GetStatic returns the home directory for the current user without calling |
|
| 13 |
-// os/user.Current(). This is useful for static-linked binary on glibc-based |
|
| 14 |
-// system, because a call to os/user.Current() in a static binary leads to |
|
| 15 |
-// segfault due to a glibc issue that won't be fixed in a short term. |
|
| 16 |
-// (#29344, golang/go#13470, https://sourceware.org/bugzilla/show_bug.cgi?id=19341) |
|
| 17 |
-func GetStatic() (string, error) {
|
|
| 18 |
- uid := os.Getuid() |
|
| 19 |
- usr, err := idtools.LookupUID(uid) |
|
| 20 |
- if err != nil {
|
|
| 21 |
- return "", err |
|
| 22 |
- } |
|
| 23 |
- return usr.Home, nil |
|
| 24 |
-} |
|
| 25 |
- |
|
| 26 | 10 |
// GetRuntimeDir returns XDG_RUNTIME_DIR. |
| 27 | 11 |
// XDG_RUNTIME_DIR is typically configured via pam_systemd. |
| 28 | 12 |
// GetRuntimeDir returns non-nil error if XDG_RUNTIME_DIR is not set. |
| ... | ... |
@@ -6,12 +6,6 @@ import ( |
| 6 | 6 |
"errors" |
| 7 | 7 |
) |
| 8 | 8 |
|
| 9 |
-// GetStatic is not needed for non-linux systems. |
|
| 10 |
-// (Precisely, it is needed only for glibc-based linux systems.) |
|
| 11 |
-func GetStatic() (string, error) {
|
|
| 12 |
- return "", errors.New("homedir.GetStatic() is not supported on this system")
|
|
| 13 |
-} |
|
| 14 |
- |
|
| 15 | 9 |
// GetRuntimeDir is unsupported on non-linux system. |
| 16 | 10 |
func GetRuntimeDir() (string, error) {
|
| 17 | 11 |
return "", errors.New("homedir.GetRuntimeDir() is not supported on this system")
|
| ... | ... |
@@ -4,8 +4,7 @@ package homedir // import "github.com/docker/docker/pkg/homedir" |
| 4 | 4 |
|
| 5 | 5 |
import ( |
| 6 | 6 |
"os" |
| 7 |
- |
|
| 8 |
- "github.com/opencontainers/runc/libcontainer/user" |
|
| 7 |
+ "os/user" |
|
| 9 | 8 |
) |
| 10 | 9 |
|
| 11 | 10 |
// Key returns the env var name for the user's home dir based on |
| ... | ... |
@@ -17,11 +16,13 @@ func Key() string {
|
| 17 | 17 |
// Get returns the home directory of the current user with the help of |
| 18 | 18 |
// environment variables depending on the target operating system. |
| 19 | 19 |
// Returned path should be used with "path/filepath" to form new paths. |
| 20 |
+// If compiling statically, ensure the osusergo build tag is used. |
|
| 21 |
+// If needing to do nss lookups, do not compile statically. |
|
| 20 | 22 |
func Get() string {
|
| 21 | 23 |
home := os.Getenv(Key()) |
| 22 | 24 |
if home == "" {
|
| 23 |
- if u, err := user.CurrentUser(); err == nil {
|
|
| 24 |
- return u.Home |
|
| 25 |
+ if u, err := user.Current(); err == nil {
|
|
| 26 |
+ return u.HomeDir |
|
| 25 | 27 |
} |
| 26 | 28 |
} |
| 27 | 29 |
return home |