Merge pull request #10059 from yuwata/env-exec-directory

core: introduce $RUNTIME_DIRECTORY= or friends

TODO

@@ -249,15 +249,6 @@ Features:
   for all units. It should be both a way to pin units into memory as well as a
   wait to retrieve their exit data.
 
-* maybe set a new set of env vars for services, based on RuntimeDirectory=,
-  StateDirectory=, LogsDirectory=, CacheDirectory= and ConfigurationDirectory=
-  automatically. For example, there could be $RUNTIME_DIRECTORY,
-  $STATE_DIRECTORY, $LOGS_DIRECTORY=, $CACHE_DIRECTORY and
-  $CONFIGURATION_DIRECTORY or so. This could be useful to write services that
-  can adapt to varying directories for these purposes. Special care has to be
-  taken if multiple dirs are configured. Maybe avoid setting the env vars in
-  that case?
-
 * expose IO accounting data on the bus, show it in systemd-run --wait and log
   about it in the resource log message
 

man/systemd.exec.xml

@@ -814,15 +814,18 @@ CapabilityBoundingSet=~CAP_B CAP_C</programlisting>
         <listitem><para>These options take a whitespace-separated list of directory names. The specified directory
         names must be relative, and may not include <literal>..</literal>. If set, one or more
         directories by the specified names will be created (including their parents) below the locations
-        defined in the following table, when the unit is started.</para>
+        defined in the following table, when the unit is started. Also, the corresponding environment variable
+        is defined with the full path of directories. If multiple directories are set, then int the environment variable
+        the paths are concatenated with colon (<literal>:</literal>).</para>
         <table>
-          <title>Automatic directory creation</title>
+          <title>Automatic directory creation and environment variables</title>
-          <tgroup cols='3'>
+          <tgroup cols='4'>
             <thead>
               <row>
                 <entry>Locations</entry>
                 <entry>for system</entry>
                 <entry>for users</entry>
+                <entry>Environment variable</entry>
               </row>
             </thead>
             <tbody>
@@ -830,26 +833,31 @@ CapabilityBoundingSet=~CAP_B CAP_C</programlisting>
                 <entry><varname>RuntimeDirectory=</varname></entry>
                 <entry><filename>/run</filename></entry>
                 <entry><varname>$XDG_RUNTIME_DIR</varname></entry>
+                <entry><varname>$RUNTIME_DIRECTORY</varname></entry>
               </row>
               <row>
                 <entry><varname>StateDirectory=</varname></entry>
                 <entry><filename>/var/lib</filename></entry>
                 <entry><varname>$XDG_CONFIG_HOME</varname></entry>
+                <entry><varname>$STATE_DIRECTORY</varname></entry>
               </row>
               <row>
                 <entry><varname>CacheDirectory=</varname></entry>
                 <entry><filename>/var/cache</filename></entry>
                 <entry><varname>$XDG_CACHE_HOME</varname></entry>
+                <entry><varname>$CACHE_DIRECTORY</varname></entry>
               </row>
               <row>
                 <entry><varname>LogsDirectory=</varname></entry>
                 <entry><filename>/var/log</filename></entry>
                 <entry><varname>$XDG_CONFIG_HOME</varname><filename>/log</filename></entry>
+                <entry><varname>$LOGS_DIRECTORY</varname></entry>
               </row>
               <row>
                 <entry><varname>ConfigurationDirectory=</varname></entry>
                 <entry><filename>/etc</filename></entry>
                 <entry><varname>$XDG_CONFIG_HOME</varname></entry>
+                <entry><varname>$CONFIGURATION_DIRECTORY</varname></entry>
               </row>
             </tbody>
           </tgroup>
@@ -899,7 +907,13 @@ CapabilityBoundingSet=~CAP_B CAP_C</programlisting>
         <filename>/run/foo/bar</filename>, and <filename>/run/baz</filename>. The directories
         <filename>/run/foo/bar</filename> and <filename>/run/baz</filename> except <filename>/run/foo</filename> are
         owned by the user and group specified in <varname>User=</varname> and <varname>Group=</varname>, and removed
-        when the service is stopped.</para></listitem>
+        when the service is stopped.</para>
+
+        <para>Example: if a system service unit has the following,
+        <programlisting>RuntimeDirectory=foo/bar
+StateDirectory=aaa/bbb ccc</programlisting>
+        then the environment variable <literal>RUNTIME_DIRECTORY</literal> is set with <literal>/run/foo/bar</literal>, and
+        <literal>STATE_DIRECTORY</literal> is set with <literal>/var/lib/aaa/bbb:/var/lib/ccc</literal>.</para></listitem>
       </varlistentry>
 
       <varlistentry>

src/basic/strv.c

@@ -339,21 +339,22 @@ int strv_split_extract(char ***t, const char *s, const char *separators, Extract
         return (int) n;
 }
 
-char *strv_join(char **l, const char *separator) {
+char *strv_join_prefix(char **l, const char *separator, const char *prefix) {
         char *r, *e;
         char **s;
-        size_t n, k;
+        size_t n, k, m;
 
         if (!separator)
                 separator = " ";
 
         k = strlen(separator);
+        m = strlen_ptr(prefix);
 
         n = 0;
         STRV_FOREACH(s, l) {
                 if (s != l)
                         n += k;
-                n += strlen(*s);
+                n += m + strlen(*s);
         }
 
         r = new(char, n+1);
@@ -365,6 +366,9 @@ char *strv_join(char **l, const char *separator) {
                 if (s != l)
                         e = stpcpy(e, separator);
 
+                if (prefix)
+                        e = stpcpy(e, prefix);
+
                 e = stpcpy(e, *s);
         }
 

src/basic/strv.h

@@ -71,7 +71,10 @@ char **strv_split_newlines(const char *s);
 
 int strv_split_extract(char ***t, const char *s, const char *separators, ExtractFlags flags);
 
-char *strv_join(char **l, const char *separator);
+char *strv_join_prefix(char **l, const char *separator, const char *prefix);
+static inline char *strv_join(char **l, const char *separator) {
+        return strv_join_prefix(l, separator, NULL);
+}
 
 char **strv_parse_nulstr(const char *s, size_t l);
 char **strv_split_nulstr(const char *s);

src/core/execute.c

@@ -1602,6 +1602,8 @@ static void do_idle_pipe_dance(int idle_pipe[4]) {
         idle_pipe[3] = safe_close(idle_pipe[3]);
 }
 
+static const char *exec_directory_env_name_to_string(ExecDirectoryType t);
+
 static int build_environment(
                 const Unit *u,
                 const ExecContext *c,
@@ -1615,14 +1617,16 @@ static int build_environment(
                 char ***ret) {
 
         _cleanup_strv_free_ char **our_env = NULL;
+        ExecDirectoryType t;
         size_t n_env = 0;
         char *x;
 
         assert(u);
         assert(c);
+        assert(p);
         assert(ret);
 
-        our_env = new0(char*, 14);
+        our_env = new0(char*, 14 + _EXEC_DIRECTORY_TYPE_MAX);
         if (!our_env)
                 return -ENOMEM;
 
@@ -1727,8 +1731,37 @@ static int build_environment(
                 our_env[n_env++] = x;
         }
 
+        for (t = 0; t < _EXEC_DIRECTORY_TYPE_MAX; t++) {
+                _cleanup_free_ char *pre = NULL, *joined = NULL;
+                const char *n;
+
+                if (!p->prefix[t])
+                        continue;
+
+                if (strv_isempty(c->directories[t].paths))
+                        continue;
+
+                n = exec_directory_env_name_to_string(t);
+                if (!n)
+                        continue;
+
+                pre = strjoin(p->prefix[t], "/");
+                if (!pre)
+                        return -ENOMEM;
+
+                joined = strv_join_prefix(c->directories[t].paths, ":", pre);
+                if (!joined)
+                        return -ENOMEM;
+
+                x = strjoin(n, "=", joined);
+                if (!x)
+                        return -ENOMEM;
+
+                our_env[n_env++] = x;
+        }
+
         our_env[n_env++] = NULL;
-        assert(n_env <= 12);
+        assert(n_env <= 14 + _EXEC_DIRECTORY_TYPE_MAX);
 
         *ret = TAKE_PTR(our_env);
 
@@ -5121,6 +5154,16 @@ static const char* const exec_directory_type_table[_EXEC_DIRECTORY_TYPE_MAX] = {
 
 DEFINE_STRING_TABLE_LOOKUP(exec_directory_type, ExecDirectoryType);
 
+static const char* const exec_directory_env_name_table[_EXEC_DIRECTORY_TYPE_MAX] = {
+        [EXEC_DIRECTORY_RUNTIME] = "RUNTIME_DIRECTORY",
+        [EXEC_DIRECTORY_STATE] = "STATE_DIRECTORY",
+        [EXEC_DIRECTORY_CACHE] = "CACHE_DIRECTORY",
+        [EXEC_DIRECTORY_LOGS] = "LOGS_DIRECTORY",
+        [EXEC_DIRECTORY_CONFIGURATION] = "CONFIGURATION_DIRECTORY",
+};
+
+DEFINE_PRIVATE_STRING_TABLE_LOOKUP_TO_STRING(exec_directory_env_name, ExecDirectoryType);
+
 static const char* const exec_keyring_mode_table[_EXEC_KEYRING_MODE_MAX] = {
         [EXEC_KEYRING_INHERIT] = "inherit",
         [EXEC_KEYRING_PRIVATE] = "private",

src/test/test-cgroup-util.c

@@ -297,7 +297,7 @@ static void test_shift_path(void) {
         test_shift_path_one("/foobar/waldo", "/", "/foobar/waldo");
         test_shift_path_one("/foobar/waldo", "", "/foobar/waldo");
         test_shift_path_one("/foobar/waldo", "/foobar", "/waldo");
-        test_shift_path_one("/foobar/waldo", "/fuckfuck", "/foobar/waldo");
+        test_shift_path_one("/foobar/waldo", "/hogehoge", "/foobar/waldo");
 }
 
 static void test_mask_supported(void) {

src/test/test-strv.c

@@ -144,6 +144,38 @@ static void test_strv_join(void) {
         assert_se(streq(w, ""));
 }
 
+static void test_strv_join_prefix(void) {
+        _cleanup_free_ char *p = NULL, *q = NULL, *r = NULL, *s = NULL, *t = NULL, *v = NULL, *w = NULL;
+
+        p = strv_join_prefix((char **)input_table_multiple, ", ", "foo");
+        assert_se(p);
+        assert_se(streq(p, "fooone, footwo, foothree"));
+
+        q = strv_join_prefix((char **)input_table_multiple, ";", "foo");
+        assert_se(q);
+        assert_se(streq(q, "fooone;footwo;foothree"));
+
+        r = strv_join_prefix((char **)input_table_multiple, NULL, "foo");
+        assert_se(r);
+        assert_se(streq(r, "fooone footwo foothree"));
+
+        s = strv_join_prefix((char **)input_table_one, ", ", "foo");
+        assert_se(s);
+        assert_se(streq(s, "fooone"));
+
+        t = strv_join_prefix((char **)input_table_none, ", ", "foo");
+        assert_se(t);
+        assert_se(streq(t, ""));
+
+        v = strv_join_prefix((char **)input_table_two_empties, ", ", "foo");
+        assert_se(v);
+        assert_se(streq(v, "foo, foo"));
+
+        w = strv_join_prefix((char **)input_table_one_empty, ", ", "foo");
+        assert_se(w);
+        assert_se(streq(w, "foo"));
+}
+
 static void test_strv_unquote(const char *quoted, char **list) {
         _cleanup_strv_free_ char **s;
         _cleanup_free_ char *j;
@@ -252,18 +284,18 @@ static void test_strv_split_nulstr(void) {
 
 static void test_strv_parse_nulstr(void) {
         _cleanup_strv_free_ char **l = NULL;
-        const char nulstr[] = "fuck\0fuck2\0fuck3\0\0fuck5\0\0xxx";
+        const char nulstr[] = "hoge\0hoge2\0hoge3\0\0hoge5\0\0xxx";
 
         l = strv_parse_nulstr(nulstr, sizeof(nulstr)-1);
         assert_se(l);
         puts("Parse nulstr:");
         strv_print(l);
 
-        assert_se(streq(l[0], "fuck"));
+        assert_se(streq(l[0], "hoge"));
-        assert_se(streq(l[1], "fuck2"));
+        assert_se(streq(l[1], "hoge2"));
-        assert_se(streq(l[2], "fuck3"));
+        assert_se(streq(l[2], "hoge3"));
         assert_se(streq(l[3], ""));
-        assert_se(streq(l[4], "fuck5"));
+        assert_se(streq(l[4], "hoge5"));
         assert_se(streq(l[5], ""));
         assert_se(streq(l[6], "xxx"));
 }
@@ -726,6 +758,7 @@ int main(int argc, char *argv[]) {
         test_strv_find_prefix();
         test_strv_find_startswith();
         test_strv_join();
+        test_strv_join_prefix();
 
         test_strv_unquote("    foo=bar     \"waldo\"    zzz    ", STRV_MAKE("foo=bar", "waldo", "zzz"));
         test_strv_unquote("", STRV_MAKE_EMPTY);

test/test-execute/exec-dynamicuser-statedir-migrate-step1.service

@@ -10,6 +10,7 @@ ExecStart=test -d /var/lib/test-dynamicuser-migrate
 ExecStart=test -d /var/lib/test-dynamicuser-migrate2/hoge
 ExecStart=touch /var/lib/test-dynamicuser-migrate/yay
 ExecStart=touch /var/lib/test-dynamicuser-migrate2/hoge/yayyay
+ExecStart=/bin/sh -x -c 'test "$$STATE_DIRECTORY" = "%S/test-dynamicuser-migrate:%S/test-dynamicuser-migrate2/hoge"'
 
 Type=oneshot
 DynamicUser=no

test/test-execute/exec-dynamicuser-statedir-migrate-step2.service

@@ -18,6 +18,7 @@ ExecStart=touch /var/lib/test-dynamicuser-migrate/yay
 ExecStart=touch /var/lib/test-dynamicuser-migrate2/hoge/yayyay
 ExecStart=touch /var/lib/private/test-dynamicuser-migrate/yay
 ExecStart=touch /var/lib/private/test-dynamicuser-migrate2/hoge/yayyay
+ExecStart=/bin/sh -x -c 'test "$$STATE_DIRECTORY" = "%S/test-dynamicuser-migrate:%S/test-dynamicuser-migrate2/hoge"'
 
 Type=oneshot
 DynamicUser=yes

test/test-execute/exec-dynamicuser-statedir.service

@@ -10,6 +10,7 @@ ExecStart=test -f /var/lib/waldo/yay
 ExecStart=test -f /var/lib/quux/pief/yayyay
 ExecStart=test -f /var/lib/private/waldo/yay
 ExecStart=test -f /var/lib/private/quux/pief/yayyay
+ExecStart=/bin/sh -x -c 'test "$$STATE_DIRECTORY" = "%S/waldo:%S/quux/pief"'
 
 # Make sure that /var/lib/private/waldo is really the only writable directory besides the obvious candidates
 ExecStart=sh -x -c 'test $$(find / \( -path /var/tmp -o -path /tmp -o -path /proc -o -path /dev/mqueue -o -path /dev/shm -o -path /sys/fs/bpf \) -prune -o -type d -writable -print 2>/dev/null | sort -u | tr -d '\\\\n') = /var/lib/private/quux/pief/var/lib/private/waldo'

test/test-execute/exec-runtimedirectory-mode.service

@@ -3,6 +3,7 @@ Description=Test for RuntimeDirectoryMode
 
 [Service]
 ExecStart=/bin/sh -x -c 'mode=$$(stat -c %%a %t/test-exec_runtimedirectory-mode); test "$$mode" = "750"'
+ExecStart=/bin/sh -x -c 'test "$$RUNTIME_DIRECTORY" = "%t/test-exec_runtimedirectory-mode"'
 Type=oneshot
 RuntimeDirectory=test-exec_runtimedirectory-mode
 RuntimeDirectoryMode=0750

test/test-execute/exec-runtimedirectory.service

@@ -4,6 +4,7 @@ Description=Test for RuntimeDirectory
 [Service]
 ExecStart=/bin/sh -x -c 'test -d %t/test-exec_runtimedirectory'
 ExecStart=/bin/sh -x -c 'test -d %t/test-exec_runtimedirectory2/hogehoge'
+ExecStart=/bin/sh -x -c 'test "$$RUNTIME_DIRECTORY" = "%t/test-exec_runtimedirectory:%t/test-exec_runtimedirectory2/hogehoge"'
 Type=oneshot
 RuntimeDirectory=test-exec_runtimedirectory
 RuntimeDirectory=./test-exec_runtimedirectory2///./hogehoge/.