From 8afbb8e1180dce3cb33a14fc3ec5afcf501104e6 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Fri, 11 Jan 2013 00:21:06 +0100 Subject: unit: allow extension of unit files with .d/*.conf drop-ins For all unit files foobar.service we will now read foobar.service.d/*.conf, too. This may be used to override certain unit settings without having to edit unit files directly. This makes it really easy to change specific settings for services without having to edit any unit file: mkdir /etc/systemd/system/avahi-daemon.service.d/ echo -e '[Service]\nNice=99' > /etc/systemd/system/avahi-daemon.service.d/nice.conf systemctl daemon-reload --- man/systemd.unit.xml | 284 ++++++++++++++++++++++++++----------------------- src/core/load-dropin.c | 63 +++++++---- src/core/unit.c | 20 ++-- 3 files changed, 207 insertions(+), 160 deletions(-) diff --git a/man/systemd.unit.xml b/man/systemd.unit.xml index 54671e7f19..bba0f5d29f 100644 --- a/man/systemd.unit.xml +++ b/man/systemd.unit.xml @@ -81,7 +81,7 @@ sections of the unit files. In addition to the generic [Unit] and [Install] - sections described here, each unit should have a + sections described here, each unit may have a type-specific section, e.g. [Service] for a service unit. See the respective man pages for more information. @@ -106,12 +106,14 @@ Time span values encoded in unit files can be written in various formats. A stand-alone number specifies a time in seconds. If suffixed with a time - unit, the unit is honored. A concatenation of - multiple values with units is supported, in which case - the values are added up. Example: "50" refers to 50 + unit, the unit is honored. A concatenation of multiple + values with units is supported, in which case the + values are added up. Example: "50" refers to 50 seconds; "2min 200ms" refers to 2 minutes plus 200 milliseconds, i.e. 120200ms. The following time units - are understood: s, min, h, d, w, ms, us. For details see systemd.time7. + are understood: s, min, h, d, w, ms, us. For details + see + systemd.time7. Empty lines and lines starting with # or ; are ignored. This may be used for commenting. Lines ending @@ -119,32 +121,42 @@ line while reading and the backslash is replaced by a space character. This may be used to wrap long lines. - If a line starts with - followed by a file name, the specified file will be - parsed at this point. Make sure that the file that is - included has the appropriate section headers before - any directives. - Along with a unit file - foo.service a directory + foo.service the directory foo.service.wants/ may exist. All - units symlinked from such a directory are implicitly - added as dependencies of type + unit files symlinked from such a directory are + implicitly added as dependencies of type Wanted= to the unit. This is useful to hook units into the start-up of other units, - without having to modify their unit configuration - files. For details about the semantics of - Wanted= see below. The preferred - way to create symlinks in the - .wants/ directory of a service is - with the enable command of the + without having to modify their unit files. For details + about the semantics of Wanted= see + below. The preferred way to create symlinks in the + .wants/ directory of a unit file + is with the enable command of the systemctl1 tool which reads information from the [Install] - section of unit files. (See below.) A similar + section of unit files (see below). A similar functionality exists for Requires= type dependencies as well, the directory suffix is .requires/ in this case. + Along with a unit file + foo.service a directory + foo.service.d/ may exist. All + files with the suffix .conf from + this directory will be parsed after the file itself is + parsed. This is useful to alter or add configuration + settings to a unit, without having to modify their + unit files. Make sure that the file that is included + has the appropriate section headers before any + directive. + + If a line starts with + followed by a file name, the specified file will be + parsed at this point. Make sure that the file that is + included has the appropriate section headers before + any directives. + Note that while systemd offers a flexible dependency system between units it is recommended to use this functionality only sparsely and instead rely @@ -186,116 +198,7 @@ To refer to the instance string from within the configuration file you may use the special %i specifier in many of the - configuration options. Other specifiers exist, the - full list is: - - - Specifiers available in unit files - - - - - - - Specifier - Meaning - Details - - - - - %n - Full unit name - - - - %N - Unescaped full unit name - - - - %p - Prefix name - This refers to the string before the @, i.e. "getty" in the example above, where "tty3" is the instance name. - - - %P - Unescaped prefix name - - - - %i - Instance name - This is the string between the @ character and the suffix. - - - %I - Unescaped instance name - - - - %f - Unescaped file name - This is either the unescaped instance name (if set) with / prepended (if necessary), or the prefix name similarly prepended with /. - - - %c - Control group path of the unit - - - - %r - Root control group path of systemd - - - - %R - Parent directory of the root control group path of systemd - - - - %t - Runtime socket dir - This is either /run (for the system manager) or $XDG_RUNTIME_DIR (for user managers). - - - %u - User name - This is the name of the configured user of the unit, or (if none is set) the user running the systemd instance. - - - %U - User uid - This is the uid of the configured user of the unit, or (if none is set) the user running the systemd instance. - - - %h - User home directory - This is the home directory of the configured user of the unit, or (if none is set) the user running the systemd instance. - - - %s - User shell - This is the shell of the configured user of the unit, or (if none is set) the user running the systemd instance. - - - %m - Machine ID - The machine ID of the running system, formatted as string. See machine-id5 for more information. - - - %b - Boot ID - The boot ID of the running system, formatted as string. See random4 for more information. - - - %H - Host name - The host name of the running system. - - - -
+ configuration options. See below for details. If a unit file is empty (i.e. has the file size 0) or is symlinked to /dev/null @@ -309,6 +212,7 @@ Interface Stability Promise. + @@ -1084,6 +988,124 @@ + + Specifiers + + Many settings resolve specifiers which may be + used to write generic unit files referring to runtime + or unit parameters that are replaced when the unit + files are loaded. The following specifiers are + understood: + + + Specifiers available in unit files + + + + + + + Specifier + Meaning + Details + + + + + %n + Full unit name + + + + %N + Unescaped full unit name + + + + %p + Prefix name + For instantiated units this refers to the string before the @. For non-instantiated units this refers to to the name of the unit with the type suffix removed. + + + %P + Unescaped prefix name + + + + %i + Instance name + For instantiated units: this is the string between the @ character and the suffix. + + + %I + Unescaped instance name + + + + %f + Unescaped file name + This is either the unescaped instance name (if applicable) with / prepended (if applicable), or the prefix name similarly prepended with /. + + + %c + Control group path of the unit + + + + %r + Root control group path of systemd + + + + %R + Parent directory of the root control group path of systemd + + + + %t + Runtime socket dir + This is either /run (for the system manager) or $XDG_RUNTIME_DIR (for user managers). + + + %u + User name + This is the name of the configured user of the unit, or (if none is set) the user running the systemd instance. + + + %U + User UID + This is the UID of the configured user of the unit, or (if none is set) the user running the systemd instance. + + + %h + User home directory + This is the home directory of the configured user of the unit, or (if none is set) the user running the systemd instance. + + + %s + User shell + This is the shell of the configured user of the unit, or (if none is set) the user running the systemd instance. + + + %m + Machine ID + The machine ID of the running system, formatted as string. See machine-id5 for more information. + + + %b + Boot ID + The boot ID of the running system, formatted as string. See random4 for more information. + + + %H + Host name + The host name of the running system. + + + +
+ + See Also diff --git a/src/core/load-dropin.c b/src/core/load-dropin.c index 86f81c7484..8e10d8fb4c 100644 --- a/src/core/load-dropin.c +++ b/src/core/load-dropin.c @@ -27,10 +27,21 @@ #include "log.h" #include "strv.h" #include "unit-name.h" +#include "conf-parser.h" +#include "load-fragment.h" + +static int load_dropin_config_file(Unit *u, const char *path) { + assert(u); + assert(path); + + if (!endswith(path, ".conf")) + return 0; + + return config_parse(path, NULL, UNIT_VTABLE(u)->sections, config_item_perf_lookup, (void*) load_fragment_gperf_lookup, false, u); +} static int iterate_dir(Unit *u, const char *path, UnitDependency dependency) { - DIR *d; - struct dirent *de; + _cleanup_closedir_ DIR *d = NULL; int r; assert(u); @@ -38,37 +49,46 @@ static int iterate_dir(Unit *u, const char *path, UnitDependency dependency) { d = opendir(path); if (!d) { - if (errno == ENOENT) return 0; return -errno; } - while ((de = readdir(d))) { - char *f; + for (;;) { + struct dirent *de; + union dirent_storage buf; + _cleanup_free_ char *f = NULL; + int k; + + k = readdir_r(d, &buf.de, &de); + if (k != 0) { + log_error("Failed to read directory %s: %s", path, strerror(k)); + return -k; + } + + if (!de) + break; if (ignore_file(de->d_name)) continue; f = strjoin(path, "/", de->d_name, NULL); - if (!f) { - r = -ENOMEM; - goto finish; - } + if (!f) + return log_oom(); - r = unit_add_dependency_by_name(u, dependency, de->d_name, f, true); - free(f); - - if (r < 0) - log_error("Cannot add dependency %s to %s, ignoring: %s", de->d_name, u->id, strerror(-r)); + if (dependency >= 0) { + r = unit_add_dependency_by_name(u, dependency, de->d_name, f, true); + if (r < 0) + log_error("Cannot add dependency %s to %s, ignoring: %s", de->d_name, u->id, strerror(-r)); + } else { + r = load_dropin_config_file(u, f); + if (r < 0) + log_error("Cannot load drop-in configuration file %s for %s, ignoring: %s", f, u->id, strerror(-r)); + } } - r = 0; - -finish: - closedir(d); - return r; + return 0; } static int process_dir(Unit *u, const char *unit_path, const char *name, const char *suffix, UnitDependency dependency) { @@ -143,6 +163,11 @@ int unit_load_dropin(Unit *u) { r = process_dir(u, *p, t, ".requires", UNIT_REQUIRES); if (r < 0) return r; + + /* This loads the drop-in config snippets */ + r = process_dir(u, *p, t, ".d", _UNIT_TYPE_INVALID); + if (r < 0) + return r; } } diff --git a/src/core/unit.c b/src/core/unit.c index 45453dce64..f00cfedb89 100644 --- a/src/core/unit.c +++ b/src/core/unit.c @@ -1781,6 +1781,7 @@ static const char *resolve_template(Unit *u, const char *name, const char*path, assert(u); assert(name || path); + assert(p); if (!name) name = path_get_file_name(path); @@ -1795,7 +1796,8 @@ static const char *resolve_template(Unit *u, const char *name, const char*path, else { char *i; - if (!(i = unit_name_to_prefix(u->id))) + i = unit_name_to_prefix(u->id); + if (!i) return NULL; s = unit_name_replace_instance(name, i); @@ -1812,22 +1814,20 @@ static const char *resolve_template(Unit *u, const char *name, const char*path, int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name, const char *path, bool add_reference) { Unit *other; int r; - char *s; + _cleanup_free_ char *s = NULL; assert(u); assert(name || path); - if (!(name = resolve_template(u, name, path, &s))) + name = resolve_template(u, name, path, &s); + if (!name) return -ENOMEM; - if ((r = manager_load_unit(u->manager, name, path, NULL, &other)) < 0) - goto finish; - - r = unit_add_dependency(u, d, other, add_reference); + r = manager_load_unit(u->manager, name, path, NULL, &other); + if (r < 0) + return r; -finish: - free(s); - return r; + return unit_add_dependency(u, d, other, add_reference); } int unit_add_two_dependencies_by_name(Unit *u, UnitDependency d, UnitDependency e, const char *name, const char *path, bool add_reference) { -- cgit v1.2.3-54-g00ecf