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_` 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:` variable works similar to the `GROUPS` and `GROUP:` variable. The difference are the accepted flags of the `USER:` variable. It accepts the following flags: @@ -750,13 +751,14 @@ The `USERS` and `USER:` 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() {