[systemd-devel] [PATCH] systemctl: add add-wants and add-requires verbs
Zbigniew Jędrzejewski-Szmek
zbyszek at in.waw.pl
Tue Sep 23 19:17:20 PDT 2014
On Fri, Sep 19, 2014 at 04:33:46PM +0200, Lukas Nykryn wrote:
> ---
> TODO | 1 -
> man/systemctl.xml | 27 ++++++++++
> src/core/dbus-manager.c | 85 +++++++++++++++++++++++++----
> src/core/org.freedesktop.systemd1.conf | 8 +++
> src/shared/install.c | 87 +++++++++++++++++++++++++++---
> src/shared/install.h | 8 +++
> src/systemctl/systemctl.c | 99 +++++++++++++++++++++++++++++++++-
> 7 files changed, 295 insertions(+), 20 deletions(-)
>
> diff --git a/TODO b/TODO
> index 9ac6fac..923cbb8 100644
> --- a/TODO
> +++ b/TODO
> @@ -450,7 +450,6 @@ Features:
> - "systemctl mask" should find all names by which a unit is accessible
> (i.e. by scanning for symlinks to it) and link them all to /dev/null
> - systemctl list-unit-files should list generated files (and probably with a new state "generated" for them, or so)
> - - systemctl: maybe add "systemctl add-wants" or so...
Thank you for looking into this.
>
> * timer units:
> - timer units should get the ability to trigger when:
> diff --git a/man/systemctl.xml b/man/systemctl.xml
> index b28a3b7..73dfa87 100644
> --- a/man/systemctl.xml
> +++ b/man/systemctl.xml
> @@ -1098,6 +1098,33 @@ kobject-uevent 1 systemd-udevd-kernel.socket systemd-udevd.service
> </varlistentry>
>
> <varlistentry>
> + <term><command>add-wants|add-requires <replaceable>TARGET</replaceable>
> + <replaceable>NAME</replaceable>...</command>
> + </term>
> +
> + <listitem>
> + <para>Enables one or more units similarly to <command>enable</command>,
> + but instead of looking to <literal>[Install]</literal> section of
> + the unit file, adds <literal>Wants</literal>
> + resp. <literal>Requires</literal> dependency to the specified
> + <replaceable>TARGET</replaceable>.
> + </para>
> +
> + <para>This command will print the actions executed. This
> + output may be suppressed by passing <option>--quiet</option>.
> + </para>
> +
> + <para>Depending on whether <option>--system</option>,
> + <option>--user</option>, <option>--runtime</option>,
> + or <option>--global</option> is specified, this enables the unit
> + for the system, for the calling user only, for only this boot of
> + the system, or for all future logins of all users, or only this
> + boot. Note that in the last case, no systemd daemon
> + configuration is reloaded.</para>
> + </listitem>
I think that the description of --system/--user and --global and
--runtime should be split into separate paragraphs. (--runtime can be
used with any of those, no?). It's just not clear what those options
mean as it is written now. You should also mention that --system is
the default.
> + </varlistentry>
> +
> + <varlistentry>
> <term><command>link <replaceable>FILENAME</replaceable>...</command></term>
>
> <listitem>
> diff --git a/src/core/dbus-manager.c b/src/core/dbus-manager.c
> index 533ce43..9335e94 100644
> --- a/src/core/dbus-manager.c
> +++ b/src/core/dbus-manager.c
> @@ -1562,9 +1562,6 @@ static int method_enable_unit_files_generic(
> sd_bus_error *error) {
>
> _cleanup_strv_free_ char **l = NULL;
> -#ifdef HAVE_SELINUX
> - char **i;
> -#endif
> UnitFileChange *changes = NULL;
> unsigned n_changes = 0;
> UnitFileScope scope;
> @@ -1589,14 +1586,17 @@ static int method_enable_unit_files_generic(
> return r;
>
> #ifdef HAVE_SELINUX
> - STRV_FOREACH(i, l) {
> - Unit *u;
> -
> - u = manager_get_unit(m, *i);
> - if (u) {
> - r = selinux_unit_access_check(u, message, verb, error);
> - if (r < 0)
> - return r;
> + {
> + char **i;
> + STRV_FOREACH(i, l) {
> + Unit *u;
> +
> + u = manager_get_unit(m, *i);
> + if (u) {
> + r = selinux_unit_access_check(u, message, verb, error);
> + if (r < 0)
> + return r;
> + }
This should become a helper function. The code should become clearer, and
also the HAVE_SELINUX check can be hidden inside of the function.
> }
> }
> #endif
> @@ -1828,6 +1828,67 @@ static int method_preset_all_unit_files(sd_bus *bus, sd_bus_message *message, vo
> return reply_unit_file_changes_and_free(m, bus, message, -1, changes, n_changes);
> }
>
> +static int method_add_install_dependency_unit_files(sd_bus *bus, sd_bus_message *message, void *userdata, UnitFileInstallDependency dep, sd_bus_error *error) {
> + _cleanup_strv_free_ char **l = NULL;
> + Manager *m = userdata;
> + UnitFileChange *changes = NULL;
> + unsigned n_changes = 0;
> + UnitFileScope scope;
> + int runtime, force, r;
> + char *target;
> +
> + assert(bus);
> + assert(message);
> + assert(m);
> +
> + r = bus_verify_manage_unit_files_async(m, message, error);
> + if (r < 0)
> + return r;
> + if (r == 0)
> + return 1; /* No authorization for now, but the async polkit stuff will call us again when it has it */
> +
> + r = sd_bus_message_read_strv(message, &l);
> + if (r < 0)
> + return r;
> +
> + r = sd_bus_message_read(message, "sbb", &target, &runtime, &force);
> + if (r < 0)
> + return r;
> +
> +#ifdef HAVE_SELINUX
> + {
> + char **i;
> + STRV_FOREACH(i, l) {
> + Unit *u;
> +
> + u = manager_get_unit(m, *i);
> + if (u) {
> + //for purposes of selinux, this should be same as enabling unit files
> + r = selinux_unit_access_check(u, message, "enable", error);
> + if (r < 0)
> + return r;
> + }
> + }
> + }
> +#endif
> +
> + scope = m->running_as == SYSTEMD_SYSTEM ? UNIT_FILE_SYSTEM : UNIT_FILE_USER;
> +
> + r = unit_file_add_install_dependency(scope, runtime, NULL, l, target, dep, force, &changes, &n_changes);
> + if (r < 0)
> + return r;
> +
> + return reply_unit_file_changes_and_free(m, bus, message, -1, changes, n_changes);
> +}
> +
> +static int method_add_wants_unit_files(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
> + return method_add_install_dependency_unit_files(bus, message, userdata, UNIT_FILE_INSTALL_DEPENDENCY_WANTS, error);
> +}
> +
> +static int method_add_requires_unit_files(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
> + return method_add_install_dependency_unit_files(bus, message, userdata, UNIT_FILE_INSTALL_DEPENDENCY_REQUIRES, error);
> +}
> +
> const sd_bus_vtable bus_manager_vtable[] = {
> SD_BUS_VTABLE_START(0),
>
> @@ -1918,6 +1979,8 @@ const sd_bus_vtable bus_manager_vtable[] = {
> SD_BUS_METHOD("SetDefaultTarget", "sb", "a(sss)", method_set_default_target, SD_BUS_VTABLE_UNPRIVILEGED),
> SD_BUS_METHOD("GetDefaultTarget", NULL, "s", method_get_default_target, SD_BUS_VTABLE_UNPRIVILEGED),
> SD_BUS_METHOD("PresetAllUnitFiles", "sbb", "a(sss)", method_preset_all_unit_files, SD_BUS_VTABLE_UNPRIVILEGED),
> + SD_BUS_METHOD("AddWantsUnitFiles", "assbb", "a(sss)", method_add_wants_unit_files, SD_BUS_VTABLE_UNPRIVILEGED),
> + SD_BUS_METHOD("AddRequiresUnitFiles", "assbb", "a(sss)", method_add_requires_unit_files, SD_BUS_VTABLE_UNPRIVILEGED),
>
> SD_BUS_SIGNAL("UnitNew", "so", 0),
> SD_BUS_SIGNAL("UnitRemoved", "so", 0),
> diff --git a/src/core/org.freedesktop.systemd1.conf b/src/core/org.freedesktop.systemd1.conf
> index 3e13825..0b95fe6 100644
> --- a/src/core/org.freedesktop.systemd1.conf
> +++ b/src/core/org.freedesktop.systemd1.conf
> @@ -199,6 +199,14 @@
> send_member="PresetAllUnitFiles"/>
>
> <allow send_destination="org.freedesktop.systemd1"
> + send_interface="org.freedesktop.systemd1.Manager"
> + send_member="AddWantsUnitFiles"/>
> +
> + <allow send_destination="org.freedesktop.systemd1"
> + send_interface="org.freedesktop.systemd1.Manager"
> + send_member="AddRequiresUnitFiles"/>
> +
> + <allow send_destination="org.freedesktop.systemd1"
> send_interface="org.freedesktop.systemd1.Job"
> send_member="Cancel"/>
Hm, maybe it would be better to make the relationship type a parameter
("requires", "wants", maybe other ones further down the road). This way
it will not be necessary to add further methods if we want to support
RequiresOverridable / Before / After at some point.
> diff --git a/src/shared/install.c b/src/shared/install.c
> index 5d3fcf5..6ff278e 100644
> --- a/src/shared/install.c
> +++ b/src/shared/install.c
> @@ -1089,7 +1089,8 @@ static int unit_file_search(
> InstallInfo *info,
> LookupPaths *paths,
> const char *root_dir,
> - bool allow_symlink) {
> + bool allow_symlink,
> + bool load) {
>
> char **p;
> int r;
> @@ -1110,7 +1111,11 @@ static int unit_file_search(
> if (!path)
> return -ENOMEM;
>
> - r = unit_file_load(c, info, path, root_dir, allow_symlink);
> + if (load)
> + r = unit_file_load(c, info, path, root_dir, allow_symlink);
> + else
> + r = access(path, F_OK) ? -errno : 0;
> +
> if (r >= 0) {
> info->path = path;
> path = NULL;
> @@ -1139,7 +1144,11 @@ static int unit_file_search(
> if (!path)
> return -ENOMEM;
>
> - r = unit_file_load(c, info, path, root_dir, allow_symlink);
> + if (load)
> + r = unit_file_load(c, info, path, root_dir, allow_symlink);
> + else
> + r = access(path, F_OK) ? -errno : 0;
> +
> if (r >= 0) {
> info->path = path;
> path = NULL;
> @@ -1172,7 +1181,7 @@ static int unit_file_can_install(
>
> assert_se(i = hashmap_first(c.will_install));
>
> - r = unit_file_search(&c, i, paths, root_dir, allow_symlink);
> + r = unit_file_search(&c, i, paths, root_dir, allow_symlink, true);
>
> if (r >= 0)
> r =
> @@ -1399,7 +1408,7 @@ static int install_context_apply(
>
> assert_se(hashmap_move_one(c->have_installed, c->will_install, i->name) == 0);
>
> - q = unit_file_search(c, i, paths, root_dir, false);
> + q = unit_file_search(c, i, paths, root_dir, false, true);
> if (q < 0) {
> if (r >= 0)
> r = q;
> @@ -1440,7 +1449,7 @@ static int install_context_mark_for_removal(
>
> assert_se(hashmap_move_one(c->have_installed, c->will_install, i->name) == 0);
>
> - q = unit_file_search(c, i, paths, root_dir, false);
> + q = unit_file_search(c, i, paths, root_dir, false, true);
> if (q == -ENOENT) {
> /* do nothing */
> } else if (q < 0) {
> @@ -1486,6 +1495,70 @@ static int install_context_mark_for_removal(
> return r;
> }
>
> +int unit_file_add_install_dependency(
> + UnitFileScope scope,
> + bool runtime,
> + const char *root_dir,
> + char **files,
> + char *target,
> + UnitFileInstallDependency dep,
> + bool force,
> + UnitFileChange **changes,
> + unsigned *n_changes) {
> +
> + _cleanup_lookup_paths_free_ LookupPaths paths = {};
> + _cleanup_(install_context_done) InstallContext c = {};
> + _cleanup_free_ char *config_path = NULL;
> + char **i;
> + int r;
> + InstallInfo *info;
> +
> + assert(scope >= 0);
> + assert(scope < _UNIT_FILE_SCOPE_MAX);
> +
> + r = lookup_paths_init_from_scope(&paths, scope, root_dir);
> + if (r < 0)
> + return r;
> +
> + r = get_config_path(scope, runtime, root_dir, &config_path);
> + if (r < 0)
> + return r;
> +
> + STRV_FOREACH(i, files) {
> + r = install_info_add_auto(&c, *i);
> + if (r < 0)
> + return r;
> + }
> +
> + while ((info = hashmap_first(c.will_install))) {
> + r = hashmap_ensure_allocated(&(c.have_installed), &string_hash_ops);
^ you can lose the parentheses here,
we usually don't add them in such situations.
> + if (r < 0)
> + return r;
> +
> + assert_se(hashmap_move_one(c.have_installed, c.will_install, info->name) == 0);
> +
> + r = unit_file_search(&c, info, &paths, root_dir, false, false);
> + if (r < 0)
> + return r;
> +
> + if (dep == UNIT_FILE_INSTALL_DEPENDENCY_WANTS)
> + r = strv_extend(&info->wanted_by, target);
> + else if (dep == UNIT_FILE_INSTALL_DEPENDENCY_REQUIRES)
> + r = strv_extend(&info->required_by, target);
> + else
> + r = -EINVAL;
> +
> + if (r < 0)
> + return r;
> +
> + r = install_info_apply(info, &paths, config_path, root_dir, force, changes, n_changes);
> + if (r < 0)
> + return r;
> + }
> +
> + return 0;
> +}
> +
> int unit_file_enable(
> UnitFileScope scope,
> bool runtime,
> @@ -1622,7 +1695,7 @@ int unit_file_set_default(
>
> assert_se(i = hashmap_first(c.will_install));
>
> - r = unit_file_search(&c, i, &paths, root_dir, false);
> + r = unit_file_search(&c, i, &paths, root_dir, false, true);
> if (r < 0)
> return r;
>
> diff --git a/src/shared/install.h b/src/shared/install.h
> index ff16d9f..9a67495 100644
> --- a/src/shared/install.h
> +++ b/src/shared/install.h
> @@ -53,6 +53,13 @@ typedef enum UnitFilePresetMode {
> _UNIT_FILE_PRESET_INVALID = -1
> } UnitFilePresetMode;
>
> +typedef enum UnitFileInstallDependency {
> + UNIT_FILE_INSTALL_DEPENDENCY_WANTS,
> + UNIT_FILE_INSTALL_DEPENDENCY_REQUIRES,
> + _UNIT_FILE_INSTALL_DEPENDENCY_MAX,
> + _UNIT_FILE_INSTALL_DEPENDENCY_INVALID = -1
> +} UnitFileInstallDependency;
> +
> typedef enum UnitFileChangeType {
> UNIT_FILE_SYMLINK,
> UNIT_FILE_UNLINK,
> @@ -93,6 +100,7 @@ int unit_file_mask(UnitFileScope scope, bool runtime, const char *root_dir, char
> int unit_file_unmask(UnitFileScope scope, bool runtime, const char *root_dir, char **files, UnitFileChange **changes, unsigned *n_changes);
> int unit_file_set_default(UnitFileScope scope, const char *root_dir, const char *file, bool force, UnitFileChange **changes, unsigned *n_changes);
> int unit_file_get_default(UnitFileScope scope, const char *root_dir, char **name);
> +int unit_file_add_install_dependency(UnitFileScope scope, bool runtime, const char *root_dir, char **files, char *target, UnitFileInstallDependency dep, bool force, UnitFileChange **changes, unsigned *n_changes);
>
> UnitFileState unit_file_get_state(UnitFileScope scope, const char *root_dir, const char *filename);
>
> diff --git a/src/systemctl/systemctl.c b/src/systemctl/systemctl.c
> index 88be871..1f45009 100644
> --- a/src/systemctl/systemctl.c
> +++ b/src/systemctl/systemctl.c
> @@ -5289,6 +5289,97 @@ finish:
> return r;
> }
>
> +static int add_install_dependency(sd_bus *bus, char **args) {
> + _cleanup_strv_free_ char **names = NULL;
> + _cleanup_free_ char *target = NULL;
> + const char *verb = args[0];
> + int r = 0;
> +
> + if (!args[1])
> + return 0;
> +
> + target = unit_name_mangle_with_suffix(args[1], MANGLE_NOGLOB, ".target");
> +
> + if (!target)
> + return log_oom();
> +
> + r = mangle_names(args+2, &names);
> + if (r < 0)
> + return r;
> +
> + if (!bus || avoid_bus()) {
> + UnitFileChange *changes = NULL;
> + unsigned n_changes = 0;
> +
> + if (streq(verb, "add-wants"))
> + r = unit_file_add_install_dependency(arg_scope, arg_runtime, arg_root, names, target, UNIT_FILE_INSTALL_DEPENDENCY_WANTS, arg_force, &changes, &n_changes);
> + else if (streq(verb, "add-requires"))
> + r = unit_file_add_install_dependency(arg_scope, arg_runtime, arg_root, names, target, UNIT_FILE_INSTALL_DEPENDENCY_REQUIRES, arg_force, &changes, &n_changes);
> + else
> + assert_not_reached("Unknown verb");
> +
> + if (!arg_quiet)
> + dump_unit_file_changes(changes, n_changes);
> +
> + unit_file_changes_free(changes, n_changes);
> +
> + } else {
> + _cleanup_bus_message_unref_ sd_bus_message *reply = NULL, *m = NULL;
> + _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
> + const char *method;
> +
> + if (streq(verb, "add-wants"))
> + method="AddWantsUnitFiles";
> + else if (streq(verb, "add-requires"))
> + method="AddRequiresUnitFiles";
> + else
> + assert_not_reached("Unknown verb");
> +
> + r = sd_bus_message_new_method_call(
> + bus,
> + &m,
> + "org.freedesktop.systemd1",
> + "/org/freedesktop/systemd1",
> + "org.freedesktop.systemd1.Manager",
> + method);
> + if (r < 0)
> + return bus_log_create_error(r);
> +
> + r = sd_bus_message_append_strv(m, names);
> + if (r < 0)
> + return bus_log_create_error(r);
> +
> + r = sd_bus_message_append(m, "s", target);
> + if (r < 0)
> + return bus_log_create_error(r);
> +
> + r = sd_bus_message_append(m, "b", arg_runtime);
> + if (r < 0)
> + return bus_log_create_error(r);
> +
> + r = sd_bus_message_append(m, "b", arg_force);
> + if (r < 0)
> + return bus_log_create_error(r);
> +
> + r = sd_bus_call(bus, m, 0, &error, &reply);
> + if (r < 0) {
> + log_error("Failed to execute operation: %s", bus_error_message(&error, r));
> + return r;
> + }
> +
> + r = deserialize_and_dump_unit_file_changes(reply);
> + if (r < 0)
> + return r;
> +
> + if (!arg_no_reload)
> + r = daemon_reload(bus, args);
> + else
> + r = 0;
> + }
> +
> + return r;
> +}
> +
> static int preset_all(sd_bus *bus, char **args) {
> UnitFileChange *changes = NULL;
> unsigned n_changes = 0;
> @@ -5526,7 +5617,6 @@ static void systemctl_help(void) {
> " disable NAME... Disable one or more unit files\n"
> " reenable NAME... Reenable one or more unit files\n"
> " preset NAME... Enable/disable one or more unit files\n"
> - " based on preset configuration\n"
Line removed by mistake?
> " preset-all Enable/disable all unit files based on\n"
> " preset configuration\n"
> " is-enabled NAME... Check whether unit files are enabled\n\n"
> @@ -5534,6 +5624,11 @@ static void systemctl_help(void) {
> " unmask NAME... Unmask one or more units\n"
> " link PATH... Link one or more units files into\n"
> " the search path\n"
> + " based on preset configuration\n"
> + " add-wants TARGET NAME... Add 'Wants' dependency for the target\n"
> + " on specified one or more units\n"
> + " add-requires TARGET NAME... Add 'Requires' dependency for the target\n"
> + " on specified one or more units\n"
> " get-default Get the name of the default target\n"
> " set-default NAME Set the default target\n\n"
> "Machine Commands:\n"
> @@ -6544,6 +6639,8 @@ static int systemctl_main(sd_bus *bus, int argc, char *argv[], int bus_error) {
> { "get-default", EQUAL, 1, get_default, NOBUS },
> { "set-property", MORE, 3, set_property },
> { "is-system-running", EQUAL, 1, is_system_running },
> + { "add-wants", MORE, 3, add_install_dependency, NOBUS },
> + { "add-requires", MORE, 3, add_install_dependency, NOBUS },
> {}
> }, *verb = verbs;
Patch looks OK, module the comments above.
Zbyszek
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