From 72ecf59c88553b5f222c0a99e16d0ee49ff79970 Mon Sep 17 00:00:00 2001
From: Sebastiaan van Stijn <github@gone.nl>
Date: Sun, 14 Mar 2021 19:38:37 +0100
Subject: [PATCH] libcontainer/user: fix windows compile error

Move the unix-specific code to a file that's not compiled on
Windows.

Some of the errors (ErrUnsupported, ErrNoPasswdEntries, ErrNoGroupEntries)
are used in other parts of the code, so are moved to a non-platform
specific file.

Most of "user" is probably not useful on Windows, although it's possible
that Windows code may have to parse a passwd file, so leaving that code
for now.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
---
 libcontainer/user/lookup.go      | 41 --------------------------------
 libcontainer/user/lookup_unix.go | 20 ++++++++++++----
 libcontainer/user/user.go        |  8 +++++++
 3 files changed, 24 insertions(+), 45 deletions(-)
 delete mode 100644 libcontainer/user/lookup.go

diff --git a/libcontainer/user/lookup.go b/libcontainer/user/lookup.go
deleted file mode 100644
index 6fd8dd0d4..000000000
--- a/libcontainer/user/lookup.go
+++ /dev/null
@@ -1,41 +0,0 @@
-package user
-
-import (
-	"errors"
-)
-
-var (
-	// The current operating system does not provide the required data for user lookups.
-	ErrUnsupported = errors.New("user lookup: operating system does not provide passwd-formatted data")
-	// No matching entries found in file.
-	ErrNoPasswdEntries = errors.New("no matching entries in passwd file")
-	ErrNoGroupEntries  = errors.New("no matching entries in group file")
-)
-
-// LookupUser looks up a user by their username in /etc/passwd. If the user
-// cannot be found (or there is no /etc/passwd file on the filesystem), then
-// LookupUser returns an error.
-func LookupUser(username string) (User, error) {
-	return lookupUser(username)
-}
-
-// LookupUid looks up a user by their user id in /etc/passwd. If the user cannot
-// be found (or there is no /etc/passwd file on the filesystem), then LookupId
-// returns an error.
-func LookupUid(uid int) (User, error) {
-	return lookupUid(uid)
-}
-
-// LookupGroup looks up a group by its name in /etc/group. If the group cannot
-// be found (or there is no /etc/group file on the filesystem), then LookupGroup
-// returns an error.
-func LookupGroup(groupname string) (Group, error) {
-	return lookupGroup(groupname)
-}
-
-// LookupGid looks up a group by its group id in /etc/group. If the group cannot
-// be found (or there is no /etc/group file on the filesystem), then LookupGid
-// returns an error.
-func LookupGid(gid int) (Group, error) {
-	return lookupGid(gid)
-}
diff --git a/libcontainer/user/lookup_unix.go b/libcontainer/user/lookup_unix.go
index 92b5ae8de..967717a1b 100644
--- a/libcontainer/user/lookup_unix.go
+++ b/libcontainer/user/lookup_unix.go
@@ -16,13 +16,19 @@ const (
 	unixGroupPath  = "/etc/group"
 )
 
-func lookupUser(username string) (User, error) {
+// LookupUser looks up a user by their username in /etc/passwd. If the user
+// cannot be found (or there is no /etc/passwd file on the filesystem), then
+// LookupUser returns an error.
+func LookupUser(username string) (User, error) {
 	return lookupUserFunc(func(u User) bool {
 		return u.Name == username
 	})
 }
 
-func lookupUid(uid int) (User, error) {
+// LookupUid looks up a user by their user id in /etc/passwd. If the user cannot
+// be found (or there is no /etc/passwd file on the filesystem), then LookupId
+// returns an error.
+func LookupUid(uid int) (User, error) {
 	return lookupUserFunc(func(u User) bool {
 		return u.Uid == uid
 	})
@@ -51,13 +57,19 @@ func lookupUserFunc(filter func(u User) bool) (User, error) {
 	return users[0], nil
 }
 
-func lookupGroup(groupname string) (Group, error) {
+// LookupGroup looks up a group by its name in /etc/group. If the group cannot
+// be found (or there is no /etc/group file on the filesystem), then LookupGroup
+// returns an error.
+func LookupGroup(groupname string) (Group, error) {
 	return lookupGroupFunc(func(g Group) bool {
 		return g.Name == groupname
 	})
 }
 
-func lookupGid(gid int) (Group, error) {
+// LookupGid looks up a group by its group id in /etc/group. If the group cannot
+// be found (or there is no /etc/group file on the filesystem), then LookupGid
+// returns an error.
+func LookupGid(gid int) (Group, error) {
 	return lookupGroupFunc(func(g Group) bool {
 		return g.Gid == gid
 	})
diff --git a/libcontainer/user/user.go b/libcontainer/user/user.go
index 90eb4b0bb..68da4400d 100644
--- a/libcontainer/user/user.go
+++ b/libcontainer/user/user.go
@@ -2,6 +2,7 @@ package user
 
 import (
 	"bufio"
+	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -15,6 +16,13 @@ const (
 )
 
 var (
+	// The current operating system does not provide the required data for user lookups.
+	ErrUnsupported = errors.New("user lookup: operating system does not provide passwd-formatted data")
+
+	// No matching entries found in file.
+	ErrNoPasswdEntries = errors.New("no matching entries in passwd file")
+	ErrNoGroupEntries  = errors.New("no matching entries in group file")
+
 	ErrRange = fmt.Errorf("uids and gids must be in range %d-%d", minId, maxId)
 )