[PATCH] image-account-extension: configure adduser UID/GID pools

[Cedric Hombourger]

For users and groups with an explicit uid/gid set, generate adduser pool
files so that maintainer scripts calling adduser/addgroup during package
installation will reserve the expected IDs.

A new 'reserve-only' flag allows entries to exist solely for pool
reservation without being explicitly created during image postprocessing.

Work-around: /etc/adduser.conf is pre-created with UID_POOL/GID_POOL
directives and --force-confold is passed to dpkg so that our version is
kept when the adduser package is installed. This is needed because
adduser does not support loading configuration fragments from a .d
directory or from environment variables. We want to discuss this!
Do we want to create images from a template richer than bootstrap
so adduser could be pre-installed and possibly its configuration
already patched to use UID_POOL / GID_POOL?

Signed-off-by: Cedric Hombourger <cedric.h...@siemens.com>
---
doc/user_manual.md | 44 +++++--
.../image-account-extension.bbclass | 113 +++++++++++++++++-
2 files changed, 145 insertions(+), 12 deletions(-)

diff --git a/doc/user_manual.md b/doc/user_manual.md
index 69e8dfef..3bd2e767 100644
--- a/doc/user_manual.md
+++ b/doc/user_manual.md
@@ -737,7 +737,8 @@ The `GROUP_<groupname>` variable contains the settings of a group named `groupna

- `gid` - The numeric group id.
- `flags` - A list of additional flags of the group. Those are the currently recognized flags:
- - `system` - The group is created using the `--system` parameter.
+ - `system` - The group is created using the `--system` parameter.
+ - `reserve-only` - The group is not explicitly created during image postprocessing. Instead, its `gid` is reserved in the adduser GID pool so that packages creating this group via maintainer scripts will use the specified ID.

The `USERS` and `USER:<username>` variable works similar to the `GROUPS` and `GROUP:<groupname>` variable. The difference are the accepted flags of the `USER:<username>` variable. It accepts the following flags:

@@ -750,13 +751,14 @@ The `USERS` and `USER:<username>` variable works similar to the `GROUPS` and `GR
- `home` - This changes the default home directory of the user with `usermod --move-home`. Only takes effect when used together with the `create-home` flag.
- `shell` - This users login shell
- `groups` - A space separated list of groups this user is a member of.
- - `flags` - A list of additional flags of the user:
- - `no-create-home` - `useradd` will be called with `-M` to prevent creation of the users home directory.
- - `create-home` - `useradd` will be called with `-m` to force creation of the users home directory.
- - `system` - `useradd` will be called with `--system`.
- - `allow-empty-password` - Even if the `password` flag is empty, it will still be set. This results in a login without password.
- - `clear-text-password` - The `password` flag of the given user contains a clear-text password and not an encrypted version of it.
- - `force-passwd-change` - Force the user to change to password on first login.
+ - `flags` - A list of additional flags of the user:
+ - `no-create-home` - `useradd` will be called with `-M` to prevent creation of the users home directory.
+ - `create-home` - `useradd` will be called with `-m` to force creation of the users home directory.
+ - `system` - `useradd` will be called with `--system`.
+ - `allow-empty-password` - Even if the `password` flag is empty, it will still be set. This results in a login without password.
+ - `clear-text-password` - The `password` flag of the given user contains a clear-text password and not an encrypted version of it.
+ - `force-passwd-change` - Force the user to change to password on first login.
+ - `reserve-only` - The user is not explicitly created during image postprocessing. Instead, its `uid` is reserved in the adduser UID pool so that packages creating this user via maintainer scripts will use the specified ID.

#### Example

@@ -779,6 +781,32 @@ USER_root[flags] = "create-home system force-passwd-change"

Some examples can be also found in `meta-isar/conf/local.conf.sample`.

+#### UID/GID pool reservation
+
+When a user or group entry has an explicit `uid` or `gid` set, it is added to
+the adduser UID/GID pool. This ensures that packages creating users or groups
+via their maintainer scripts (e.g. `adduser` or `addgroup`) will allocate the
+specified IDs. Combined with the `reserve-only` flag, this allows reserving IDs
+without explicitly creating the accounts:
+
+```
+USERS += "tss"
+USER_tss[uid] = "666"
+USER_tss[flags] = "reserve-only"
+
+GROUPS += "tss"
+GROUP_tss[gid] = "666"
+GROUP_tss[flags] = "reserve-only"
+
+GROUPS += "docker"
+GROUP_docker[gid] = "1234"
+GROUP_docker[flags] = "reserve-only"
+```
+
+In this example, when `tpm2-abrmd` or `docker.io` are installed, their
+maintainer scripts will create the `tss` and `docker` accounts using the
+reserved IDs rather than dynamically allocated ones.
+
#### Home directory contents prefilling

To cover all users simply use `/etc/skel`. Files in there will be available in every home directory under correct permissions.
diff --git a/meta/classes-recipe/image-account-extension.bbclass b/meta/classes-recipe/image-account-extension.bbclass
index e874f3c7..7dfcd8e0 100644
--- a/meta/classes-recipe/image-account-extension.bbclass
+++ b/meta/classes-recipe/image-account-extension.bbclass
@@ -14,16 +14,18 @@ python() {
for entry in (d.getVar("GROUPS") or "").split():
group_entry = "GROUP_{}".format(entry)
d.appendVarFlag("image_postprocess_accounts", "vardeps", " {}".format(group_entry))
+ d.appendVarFlag("image_configure_adduser_pools", "vardeps", " {}".format(group_entry))
d.appendVarFlag("do_rootfs_install", "vardeps", " {}".format(group_entry))

for entry in (d.getVar("USERS") or "").split():
user_entry = "USER_{}".format(entry)
d.appendVarFlag("image_postprocess_accounts", "vardeps", " {}".format(user_entry))
+ d.appendVarFlag("image_configure_adduser_pools", "vardeps", " {}".format(user_entry))
d.appendVarFlag("do_rootfs_install", "vardeps", " {}".format(user_entry))
}
do_rootfs_install[vardeps] += "GROUPS USERS"

-def image_create_groups(d: "DataSmart") -> None:
+def image_create_groups(d):
"""Creates the groups defined in the ``GROUPS`` bitbake variable.

Args:
@@ -40,6 +42,10 @@ def image_create_groups(d: "DataSmart") -> None:
args = []
group_entry = "GROUP_{}".format(entry)

+ flags = (d.getVarFlag(group_entry, "flags") or "").split()
+ if "reserve-only" in flags:
+ continue
+
with open("{}/etc/group".format(rootfsdir), "r") as group_file:
exists = any(line.startswith("{}:".format(entry)) for line in group_file)

@@ -59,7 +65,7 @@ def image_create_groups(d: "DataSmart") -> None:
bb.process.run([*chroot, "/usr/sbin/groupadd", *args, entry])


-def image_create_users(d: "DataSmart") -> None:
+def image_create_users(d):
"""Creates the users defined in the ``USERS`` bitbake variable.

Args:
@@ -78,6 +84,10 @@ def image_create_users(d: "DataSmart") -> None:
args = []
user_entry = "USER_{}".format(entry)

+ flags = (d.getVarFlag(user_entry, "flags") or "").split()
+ if "reserve-only" in flags:
+ continue
+
with open("{}/etc/passwd".format(rootfsdir), "r") as passwd_file:
exists = any(line.startswith("{}:".format(entry)) for line in passwd_file)

@@ -99,8 +109,6 @@ def image_create_users(d: "DataSmart") -> None:
args.append("--groups")
args.append(','.join(groups))

- flags = (d.getVarFlag(user_entry, "flags") or "").split()
-
if exists:
add_user_option("--home", "home")
if d.getVarFlag(user_entry, "home") or "":
@@ -143,6 +151,103 @@ def image_create_users(d: "DataSmart") -> None:
bb.process.run([*chroot, "/usr/bin/passwd", "--expire", entry])


+def configure_adduser_pools(d):
+ """Configures adduser UID/GID pools for users and groups with explicit IDs.
+
+ Creates pool files and a minimal /etc/adduser.conf with UID_POOL/GID_POOL
+ directives before package installation.
+
+ Args:
+ d (DataSmart): The bitbake datastore.
+
+ Returns:
+ None
+ """
+ import os
+ import tempfile
+
+ rootfsdir = d.getVar("ROOTFSDIR")
+ adduser_conf = "{}/etc/adduser.conf".format(rootfsdir)
+ uid_pool_path = "/etc/adduser-uid.pool"
+ gid_pool_path = "/etc/adduser-gid.pool"
+
+ uid_pool_entries = []
+ seen_users = set()
+ for entry in (d.getVar("USERS") or "").split():
+ if entry in seen_users:
+ continue
+ seen_users.add(entry)
+ user_entry = "USER_{}".format(entry)
+ uid = d.getVarFlag(user_entry, "uid") or ""
+ if uid:
+ uid_pool_entries.append("{}:{}".format(entry, uid))
+
+ gid_pool_entries = []
+ seen_groups = set()
+ for entry in (d.getVar("GROUPS") or "").split():
+ if entry in seen_groups:
+ continue
+ seen_groups.add(entry)
+ group_entry = "GROUP_{}".format(entry)
+ gid = d.getVarFlag(group_entry, "gid") or ""
+ if gid:
+ gid_pool_entries.append("{}:{}".format(entry, gid))
+
+ if not uid_pool_entries and not gid_pool_entries:
+ return
+
+ if uid_pool_entries:
+ with tempfile.NamedTemporaryFile(mode="w", delete=False) as f:
+ f.write("\n".join(uid_pool_entries) + "\n")
+ tmp = f.name
+ bb.process.run(
+ ["sudo", "cp", tmp, "{}{}".format(rootfsdir, uid_pool_path)])
+ bb.process.run(
+ ["sudo", "chmod", "644", "{}{}".format(rootfsdir, uid_pool_path)])
+ os.unlink(tmp)
+
+ if gid_pool_entries:
+ with tempfile.NamedTemporaryFile(mode="w", delete=False) as f:
+ f.write("\n".join(gid_pool_entries) + "\n")
+ tmp = f.name
+ bb.process.run(
+ ["sudo", "cp", tmp, "{}{}".format(rootfsdir, gid_pool_path)])
+ bb.process.run(
+ ["sudo", "chmod", "644", "{}{}".format(rootfsdir, gid_pool_path)])
+ os.unlink(tmp)
+
+ # Create /etc/adduser.conf with the upstream default content plus pool
+ # directives. We use --force-confold during package installation so that
+ # dpkg keeps this version when the adduser package is installed.
+ conf_lines = []
+ conf_lines.append("# /etc/adduser.conf: `adduser' configuration.")
+ conf_lines.append("# See adduser(8) and adduser.conf(5) for full documentation.")
+ conf_lines.append("")
+ if uid_pool_entries:
+ conf_lines.append("UID_POOL={}".format(uid_pool_path))
+ if gid_pool_entries:
+ conf_lines.append("GID_POOL={}".format(gid_pool_path))
+
+ with tempfile.NamedTemporaryFile(mode="w", delete=False) as f:
+ f.write("\n".join(conf_lines) + "\n")
+ tmp = f.name
+ bb.process.run(["sudo", "cp", tmp, adduser_conf])
+ bb.process.run(["sudo", "chmod", "644", adduser_conf])
+ os.unlink(tmp)
+
+
+# Work-around: pre-create /etc/adduser.conf with pool directives and use
+# --force-confold so dpkg keeps our version when the adduser package is
+# installed. This is needed because adduser does not support loading
+# configuration from /etc/adduser.conf.d/ or from environment variables.
+ROOTFS_APT_ARGS += "-o DPkg::Options::=--force-confold"
+
+ROOTFS_CONFIGURE_COMMAND += "image_configure_adduser_pools"
+image_configure_adduser_pools[vardeps] += "USERS GROUPS"
+python image_configure_adduser_pools() {
+ configure_adduser_pools(d)
+}
+
ROOTFS_POSTPROCESS_COMMAND += "image_postprocess_accounts"
image_postprocess_accounts[vardeps] += "USERS GROUPS"
python image_postprocess_accounts() {
--
2.47.3

[Jan Kiszka]

On 21.05.26 18:21, 'Cedric Hombourger' via isar-users wrote:
> For users and groups with an explicit uid/gid set, generate adduser pool
> files so that maintainer scripts calling adduser/addgroup during package
> installation will reserve the expected IDs.
>
> A new 'reserve-only' flag allows entries to exist solely for pool
> reservation without being explicitly created during image postprocessing.
>
> Work-around: /etc/adduser.conf is pre-created with UID_POOL/GID_POOL
> directives and --force-confold is passed to dpkg so that our version is
> kept when the adduser package is installed. This is needed because
> adduser does not support loading configuration fragments from a .d
> directory or from environment variables. We want to discuss this!
> Do we want to create images from a template richer than bootstrap
> so adduser could be pre-installed and possibly its configuration
> already patched to use UID_POOL / GID_POOL?
>

This is a valuable starting point for (public) discussions, thanks!

Internally, we already thought about this, also considering to add a way
for deriving this preceeding of the UIDs/GIDs from a "version 1" run of
a build so that you do not have to collect and encode all the data
manually. This would also emulate a normal Debian system lifecycle:
Install a blank version, then add or upgrade packages, thus,
users/groups while maintaining the assignments of the initial installation.

Jan

Siemens AG, Foundational Technologies
Linux Expert Center

[Cedric Hombourger]

For users and groups with an explicit uid/gid set, generate adduser pool
files so that maintainer scripts calling adduser/addgroup during package
installation will reserve the expected IDs.

Pool directories (/etc/adduser-uid.pool.d/ and /etc/adduser-gid.pool.d/)
are used, with a numbered fragment (00-image-accounts.conf) generated
from USERS/GROUPS entries. Additional .uid/.gid files from SRC_URI are
installed as numbered fragments, following the same pattern as .list
files for apt sources. Duplicates across fragments are filtered out
(USERS/GROUPS wins) with build warnings for traceability.

A new 'reserve-only' flag allows entries to exist solely for pool
reservation without being explicitly created during image postprocessing.

After postprocessing, ${IMAGE_FULLNAME}.uid and ${IMAGE_FULLNAME}.gid
are deployed to DEPLOY_DIR_IMAGE with all users/groups from the final
rootfs in adduser pool format.

Work-around: /etc/adduser.conf is pre-created with UID_POOL/GID_POOL
directives and --force-confold is passed to dpkg so that our version is
kept when the adduser package is installed. This is needed because
adduser does not support loading configuration fragments from a .d
directory or from environment variables.

Signed-off-by: Cedric Hombourger <cedric.h...@siemens.com>
---

doc/user_manual.md | 73 ++++-
.../image-account-extension.bbclass | 282 +++++++++++++++++-
2 files changed, 343 insertions(+), 12 deletions(-)

diff --git a/doc/user_manual.md b/doc/user_manual.md
index 69e8dfef..b5b54f64 100644

@@ -779,6 +781,61 @@ USER_root[flags] = "create-home system force-passwd-change"

+#### UID/GID pool files from SRC_URI
+
+Pool entries can also be provided via `.uid` and `.gid` files in `SRC_URI`.
+These files use the adduser pool format (`name:id`, one per line) and are
+installed as numbered fragments in `/etc/adduser-uid.pool.d/` and
+`/etc/adduser-gid.pool.d/` respectively.
+
+```
+SRC_URI += "file://my-accounts.uid file://my-accounts.gid"
+```
+
+Where `my-accounts.uid` might contain:
+
+```
+# Reserve UIDs for package-created users
+tss:666
+sshd:800
+```
+
+Entries from `USERS`/`GROUPS` (placed in `00-image-accounts.conf`) take
+priority over SRC_URI pool files. Duplicates are automatically filtered
+with a build warning indicating which entries were dropped and from which
+file.
+
+After image postprocessing, `${IMAGE_FULLNAME}.uid` and
+`${IMAGE_FULLNAME}.gid` files are deployed to `DEPLOY_DIR_IMAGE` containing
+all users and groups from the final rootfs. These files can be used as pool
+inputs for other images to maintain consistent UID/GID allocation.

+
#### Home directory contents prefilling

To cover all users simply use `/etc/skel`. Files in there will be available in every home directory under correct permissions.
diff --git a/meta/classes-recipe/image-account-extension.bbclass b/meta/classes-recipe/image-account-extension.bbclass

index e874f3c7..52eeec1b 100644

@@ -143,9 +151,275 @@ def image_create_users(d: "DataSmart") -> None:

bb.process.run([*chroot, "/usr/bin/passwd", "--expire", entry])

+def account_pool_files(d):
+ """Returns lists of .uid and .gid files found in SRC_URI."""
+ uid_files = []
+ gid_files = []
+ sources = d.getVar("SRC_URI").split()
+ for s in sources:
+ _, _, local, _, _, _ = bb.fetch.decodeurl(s)
+ base, ext = os.path.splitext(os.path.basename(local))
+ if ext == ".uid":
+ uid_files.append(local)
+ elif ext == ".gid":
+ gid_files.append(local)
+ return uid_files, gid_files
+
+

+def configure_adduser_pools(d):
+ """Configures adduser UID/GID pools for users and groups with explicit IDs.
+

+ Creates pool directories (/etc/adduser-uid.pool.d/ and
+ /etc/adduser-gid.pool.d/) containing:
+ - A numbered fragment (00-image-accounts.conf) generated from
+ USERS/GROUPS entries with explicit uid/gid.
+ - Additional .uid/.gid files from SRC_URI copied as numbered fragments.
+
+ A minimal /etc/adduser.conf is pre-created pointing UID_POOL and GID_POOL
+ at the respective directories.

+
+ Args:
+ d (DataSmart): The bitbake datastore.
+
+ Returns:
+ None
+ """
+ import os
+ import tempfile
+
+ rootfsdir = d.getVar("ROOTFSDIR")

+ workdir = d.getVar("WORKDIR")

+ adduser_conf = "{}/etc/adduser.conf".format(rootfsdir)

+ uid_pool_dir = "/etc/adduser-uid.pool.d"
+ gid_pool_dir = "/etc/adduser-gid.pool.d"

+
+ uid_pool_entries = []
+ seen_users = set()
+ for entry in (d.getVar("USERS") or "").split():
+ if entry in seen_users:
+ continue
+ seen_users.add(entry)
+ user_entry = "USER_{}".format(entry)
+ uid = d.getVarFlag(user_entry, "uid") or ""
+ if uid:
+ uid_pool_entries.append("{}:{}".format(entry, uid))
+
+ gid_pool_entries = []
+ seen_groups = set()
+ for entry in (d.getVar("GROUPS") or "").split():
+ if entry in seen_groups:
+ continue
+ seen_groups.add(entry)
+ group_entry = "GROUP_{}".format(entry)
+ gid = d.getVarFlag(group_entry, "gid") or ""
+ if gid:
+ gid_pool_entries.append("{}:{}".format(entry, gid))
+

+ # Collect .uid/.gid files from SRC_URI
+ src_uid_files, src_gid_files = account_pool_files(d)
+
+ has_uid_pool = uid_pool_entries or src_uid_files
+ has_gid_pool = gid_pool_entries or src_gid_files
+
+ if not has_uid_pool and not has_gid_pool:
+ return
+
+ # Create pool directories
+ if has_uid_pool:
+ bb.process.run(
+ ["sudo", "mkdir", "-p", "{}{}".format(rootfsdir, uid_pool_dir)])
+ if has_gid_pool:
+ bb.process.run(
+ ["sudo", "mkdir", "-p", "{}{}".format(rootfsdir, gid_pool_dir)])
+
+ # Track seen names and IDs to detect duplicates across fragments.
+ # 00-image-accounts.conf (from USERS/GROUPS) has highest priority.
+ uid_seen_names = set()
+ uid_seen_ids = set()
+ gid_seen_names = set()
+ gid_seen_ids = set()
+
+ # Install fragment from USERS/GROUPS as 00-image-accounts.conf
+ if uid_pool_entries:
+ for e in uid_pool_entries:
+ name, uid = e.split(":")
+ uid_seen_names.add(name)
+ uid_seen_ids.add(uid)

+ with tempfile.NamedTemporaryFile(mode="w", delete=False) as f:
+ f.write("\n".join(uid_pool_entries) + "\n")
+ tmp = f.name
+ bb.process.run(
+ ["sudo", "cp", tmp,

+ "{}{}/00-image-accounts.conf".format(rootfsdir, uid_pool_dir)])

+ os.unlink(tmp)
+
+ if gid_pool_entries:

+ for e in gid_pool_entries:
+ name, gid = e.split(":")
+ gid_seen_names.add(name)
+ gid_seen_ids.add(gid)

+ with tempfile.NamedTemporaryFile(mode="w", delete=False) as f:
+ f.write("\n".join(gid_pool_entries) + "\n")
+ tmp = f.name
+ bb.process.run(
+ ["sudo", "cp", tmp,

+ "{}{}/00-image-accounts.conf".format(rootfsdir, gid_pool_dir)])
+ os.unlink(tmp)
+
+ # Install .uid files from SRC_URI as numbered fragments, filtering
+ # duplicates. Keeping original filenames provides traceability.
+ for idx, uid_file in enumerate(src_uid_files, start=1):
+ src = os.path.join(workdir, uid_file)
+ filtered_lines = []
+ with open(src, "r") as f:
+ for line in f:
+ stripped = line.strip()
+ if not stripped or stripped.startswith("#"):
+ filtered_lines.append(line)
+ continue
+ parts = stripped.split(":")
+ if len(parts) < 2:
+ filtered_lines.append(line)
+ continue
+ name, uid = parts[0], parts[1]
+ if name in uid_seen_names:
+ bb.warn("{}: dropping '{}' (name already in pool)"
+ .format(uid_file, stripped))
+ continue
+ if uid in uid_seen_ids:
+ bb.warn("{}: dropping '{}' (UID {} already in pool)"
+ .format(uid_file, stripped, uid))
+ continue
+ uid_seen_names.add(name)
+ uid_seen_ids.add(uid)
+ filtered_lines.append(line)
+
+ dst_name = "{:02d}-{}.conf".format(idx, os.path.splitext(uid_file)[0])

+ with tempfile.NamedTemporaryFile(mode="w", delete=False) as f:

+ f.writelines(filtered_lines)

+ tmp = f.name
+ bb.process.run(

+ ["sudo", "cp", tmp, "{}{}/{}".format(rootfsdir, uid_pool_dir, dst_name)])
+ os.unlink(tmp)
+
+ # Install .gid files from SRC_URI as numbered fragments, filtering
+ # duplicates.
+ for idx, gid_file in enumerate(src_gid_files, start=1):
+ src = os.path.join(workdir, gid_file)
+ filtered_lines = []
+ with open(src, "r") as f:
+ for line in f:
+ stripped = line.strip()
+ if not stripped or stripped.startswith("#"):
+ filtered_lines.append(line)
+ continue
+ parts = stripped.split(":")
+ if len(parts) < 2:
+ filtered_lines.append(line)
+ continue
+ name, gid = parts[0], parts[1]
+ if name in gid_seen_names:
+ bb.warn("{}: dropping '{}' (name already in pool)"
+ .format(gid_file, stripped))
+ continue
+ if gid in gid_seen_ids:
+ bb.warn("{}: dropping '{}' (GID {} already in pool)"
+ .format(gid_file, stripped, gid))
+ continue
+ gid_seen_names.add(name)
+ gid_seen_ids.add(gid)
+ filtered_lines.append(line)
+
+ dst_name = "{:02d}-{}.conf".format(idx, os.path.splitext(gid_file)[0])

+ with tempfile.NamedTemporaryFile(mode="w", delete=False) as f:

+ f.writelines(filtered_lines)

+ tmp = f.name
+ bb.process.run(

+ ["sudo", "cp", tmp, "{}{}/{}".format(rootfsdir, gid_pool_dir, dst_name)])
+ os.unlink(tmp)
+
+ # Ensure pool directories are world-readable
+ if has_uid_pool:
+ bb.process.run(
+ ["sudo", "chmod", "-R", "a+rX", "{}{}".format(rootfsdir, uid_pool_dir)])
+ if has_gid_pool:
+ bb.process.run(
+ ["sudo", "chmod", "-R", "a+rX", "{}{}".format(rootfsdir, gid_pool_dir)])
+
+ # Work-around: pre-create /etc/adduser.conf with pool directives and use
+ # --force-confold so dpkg keeps our version when the adduser package is
+ # installed. This is needed because adduser does not support loading
+ # configuration from /etc/adduser.conf.d/ or from environment variables.

+ conf_lines = []
+ conf_lines.append("# /etc/adduser.conf: `adduser' configuration.")
+ conf_lines.append("# See adduser(8) and adduser.conf(5) for full documentation.")
+ conf_lines.append("")

+ if has_uid_pool:
+ conf_lines.append("UID_POOL={}".format(uid_pool_dir))
+ if has_gid_pool:
+ conf_lines.append("GID_POOL={}".format(gid_pool_dir))

+
+ with tempfile.NamedTemporaryFile(mode="w", delete=False) as f:
+ f.write("\n".join(conf_lines) + "\n")
+ tmp = f.name
+ bb.process.run(["sudo", "cp", tmp, adduser_conf])
+ bb.process.run(["sudo", "chmod", "644", adduser_conf])
+ os.unlink(tmp)
+
+

+# Work-around: use --force-confold so dpkg keeps our pre-created
+# /etc/adduser.conf when the adduser package is installed.

+ROOTFS_APT_ARGS += "-o DPkg::Options::=--force-confold"
+
+ROOTFS_CONFIGURE_COMMAND += "image_configure_adduser_pools"
+image_configure_adduser_pools[vardeps] += "USERS GROUPS"
+python image_configure_adduser_pools() {
+ configure_adduser_pools(d)
+}
+
ROOTFS_POSTPROCESS_COMMAND += "image_postprocess_accounts"
image_postprocess_accounts[vardeps] += "USERS GROUPS"
python image_postprocess_accounts() {

image_create_groups(d)
image_create_users(d)
+ image_deploy_id_pools(d)
}
+
+
+def image_deploy_id_pools(d):
+ """Deploys UID/GID pool files from the final rootfs to DEPLOY_DIR_IMAGE.
+
+ Generates ${IMAGE_FULLNAME}.uid and ${IMAGE_FULLNAME}.gid files in
+ adduser pool format (name:id) from /etc/passwd and /etc/group.

+
+ Args:
+ d (DataSmart): The bitbake datastore.
+
+ Returns:
+ None
+ """
+ import os
+

+ rootfsdir = d.getVar("ROOTFSDIR")

+ deploy_dir = d.getVar("DEPLOY_DIR_IMAGE")
+ image_fullname = d.getVar("IMAGE_FULLNAME")
+
+ os.makedirs(deploy_dir, exist_ok=True)
+
+ # Generate .uid from /etc/passwd
+ uid_file = os.path.join(deploy_dir, "{}.uid".format(image_fullname))
+ with open("{}/etc/passwd".format(rootfsdir), "r") as f:
+ with open(uid_file, "w") as out:
+ for line in f:
+ fields = line.strip().split(":")
+ if len(fields) >= 3:
+ out.write("{}:{}\n".format(fields[0], fields[2]))
+
+ # Generate .gid from /etc/group
+ gid_file = os.path.join(deploy_dir, "{}.gid".format(image_fullname))
+ with open("{}/etc/group".format(rootfsdir), "r") as f:
+ with open(gid_file, "w") as out:
+ for line in f:
+ fields = line.strip().split(":")
+ if len(fields) >= 3:
+ out.write("{}:{}\n".format(fields[0], fields[2]))
--
2.47.3

[Jan Kiszka]

On 21.05.26 20:48, 'Cedric Hombourger' via isar-users wrote:
> For users and groups with an explicit uid/gid set, generate adduser pool
> files so that maintainer scripts calling adduser/addgroup during package
> installation will reserve the expected IDs.
>
> Pool directories (/etc/adduser-uid.pool.d/ and /etc/adduser-gid.pool.d/)
> are used, with a numbered fragment (00-image-accounts.conf) generated
> from USERS/GROUPS entries. Additional .uid/.gid files from SRC_URI are
> installed as numbered fragments, following the same pattern as .list
> files for apt sources. Duplicates across fragments are filtered out
> (USERS/GROUPS wins) with build warnings for traceability.
>

Didn't study all details yet, but this looks fairly appealing.

This signature change/alignment should be factored out and argued about
separately.

Would be a valuable follow-up task then to work with upstream adduser to
overcome this. Specifically as we cannot confine this workaround to the
package or even files that need it.

> +ROOTFS_CONFIGURE_COMMAND += "image_configure_adduser_pools"
> +image_configure_adduser_pools[vardeps] += "USERS GROUPS"
> +python image_configure_adduser_pools() {
> + configure_adduser_pools(d)
> +}
> +
> ROOTFS_POSTPROCESS_COMMAND += "image_postprocess_accounts"
> image_postprocess_accounts[vardeps] += "USERS GROUPS"
> python image_postprocess_accounts() {
> image_create_groups(d)
> image_create_users(d)
> + image_deploy_id_pools(d)
> }
> +
> +
> +def image_deploy_id_pools(d):

This is not C, but I think the pattern was so far defining functions
before they are used.

Hmm, should we filter out from those file the users/groups that are
coming from Isar itself? Our primary concern is about the
package-generated accounts.

Jan