Unbreak 'sudo' inside toolbox containers with Podman 2.0.5

Since Podman 2.0.5, containers that were created with
'podman create --userns=keep-id ...' automatically get the user added
to /etc/passwd [1]. However, this user isn't as fully configured as it
needs to be. The home directory is specified as '/' and the shell is
/bin/sh.

Note that Podman doesn't add the user's login group to /etc/group [2].
This leads to the following error message when entering the container:
  /usr/bin/id: cannot find name for group ID 1000

It's expected that this will be fixed in Podman itself.

Therefore, the entry point needs to call usermod(8) to update the user,
instead of using useradd(8) to create it.

[1] Podman commit 6c6670f12a3e6b91
    https://github.com/containers/podman/pull/6829

[2] https://github.com/containers/podman/issues/7389

https://github.com/containers/toolbox/issues/523
This commit is contained in:
Debarshi Ray 2020-08-30 16:26:07 +02:00
parent 59f4a79251
commit 9ea6fe5852
2 changed files with 50 additions and 17 deletions

View file

@ -161,6 +161,7 @@ Tools:
* `touch(1)`
* `unlink(1)`
* `useradd(8)`
* `usermod(8)`
Paths:
* `/etc/host.conf`: optional, if present not a bind mount

View file

@ -238,7 +238,17 @@ func initContainer(cmd *cobra.Command, args []string) error {
initContainerFlags.user,
initContainerFlags.home,
initContainerFlags.shell,
initContainerFlags.homeLink); err != nil {
initContainerFlags.homeLink,
false); err != nil {
return err
}
} else {
if err := configureUsers(initContainerFlags.uid,
initContainerFlags.user,
initContainerFlags.home,
initContainerFlags.shell,
initContainerFlags.homeLink,
true); err != nil {
return err
}
}
@ -337,7 +347,7 @@ func initContainerHelp(cmd *cobra.Command, args []string) {
func configureUsers(targetUserUid int,
targetUser, targetUserHome, targetUserShell string,
homeLink bool) error {
homeLink, targetUserExists bool) error {
if homeLink {
if err := redirectPath("/home", "/var/home", true); err != nil {
return err
@ -349,6 +359,27 @@ func configureUsers(targetUserUid int,
return fmt.Errorf("failed to get group for sudo: %w", err)
}
if targetUserExists {
logrus.Debugf("Modifying user %s with UID %d:", targetUser, targetUserUid)
usermodArgs := []string{
"--append",
"--groups", sudoGroup,
"--home", targetUserHome,
"--shell", targetUserShell,
"--uid", fmt.Sprint(targetUserUid),
targetUser,
}
logrus.Debug("usermod")
for _, arg := range usermodArgs {
logrus.Debugf("%s", arg)
}
if err := shell.Run("usermod", nil, nil, nil, usermodArgs...); err != nil {
return fmt.Errorf("failed to modify user %s with UID %d", targetUser, targetUserUid)
}
} else {
logrus.Debugf("Adding user %s with UID %d:", targetUser, targetUserUid)
useraddArgs := []string{
@ -368,6 +399,7 @@ func configureUsers(targetUserUid int,
if err := shell.Run("useradd", nil, nil, nil, useraddArgs...); err != nil {
return fmt.Errorf("failed to add user %s with UID %d", targetUser, targetUserUid)
}
}
logrus.Debugf("Removing password for user %s", targetUser)