Create /etc/passwd *after* figuring out the sandbox uid/gid

Fixes build failures like

  # nix log /nix/store/gjaa0psfcmqvw7ivggsncx9w364p3s8s-sshd.conf-validated.drv
  No user exists for uid 30012
This commit is contained in:
Eelco Dolstra 2020-10-14 12:20:58 +02:00
parent 2653801939
commit 11882d7c7c

View file

@ -1420,12 +1420,6 @@ void DerivationGoal::startBuilder()
Samba-in-QEMU. */
createDirs(chrootRootDir + "/etc");
writeFile(chrootRootDir + "/etc/passwd", fmt(
"root:x:0:0:Nix build user:%3%:/noshell\n"
"nixbld:x:%1%:%2%:Nix build user:%3%:/noshell\n"
"nobody:x:65534:65534:Nobody:/:/noshell\n",
sandboxUid(), sandboxGid(), settings.sandboxBuildDir));
/* Declare the build user's group so that programs get a consistent
view of the system (e.g., "id -gn"). */
writeFile(chrootRootDir + "/etc/group",
@ -1730,6 +1724,14 @@ void DerivationGoal::startBuilder()
throw Error("cannot perform a sandboxed build because user namespaces are not enabled; check /proc/sys/user/max_user_namespaces");
}
/* Now that we now the sandbox uid, we can write
/etc/passwd. */
writeFile(chrootRootDir + "/etc/passwd", fmt(
"root:x:0:0:Nix build user:%3%:/noshell\n"
"nixbld:x:%1%:%2%:Nix build user:%3%:/noshell\n"
"nobody:x:65534:65534:Nobody:/:/noshell\n",
sandboxUid(), sandboxGid(), settings.sandboxBuildDir));
/* Save the mount namespace of the child. We have to do this
*before* the child does a chroot. */
sandboxMountNamespace = open(fmt("/proc/%d/ns/mnt", (pid_t) pid).c_str(), O_RDONLY);