Merge pull request #22705 from mrc0mmand/pretty_hostname_specifier

core: introduce %R specifier for pretty hostname

man/standard-specifiers.xml

@@ -34,6 +34,11 @@
     <entry>Short host name</entry>
     <entry>The hostname of the running system, truncated at the first dot to remove any domain component.</entry>
   </row>
+  <row id='R'>
+    <entry><literal>%R</literal></entry>
+    <entry>Pretty host name</entry>
+    <entry>The pretty hostname of the running system, as read from the <varname>PRETTY_HOSTNAME=</varname> field of <filename>/etc/machine-info</filename>. If not set, resolves to the short hostname. See <citerefentry><refentrytitle>machine-info</refentrytitle><manvolnum>5</manvolnum></citerefentry> for more information.</entry>
+  </row>
   <row id='m'>
     <entry><literal>%m</literal></entry>
     <entry>Machine ID</entry>

man/systemd.unit.xml

@@ -2031,6 +2031,8 @@ Note that this setting is <emphasis>not</emphasis> influenced by the <varname>Us
           </row>
           <row>
             <entry><literal>%l</literal></entry>
+            <!-- We do not use the common definition from standard-specifiers.xml here since we want a
+                 slightly more verbose explanation here, referring to the reload cycle. -->
             <entry>Short host name</entry>
             <entry>The hostname of the running system at the point in time the unit configuration is loaded, truncated at the first dot to remove any domain component.</entry>
           </row>
@@ -2062,6 +2064,13 @@ Note that this setting is <emphasis>not</emphasis> influenced by the <varname>Us
             <entry>Unescaped prefix name</entry>
             <entry>Same as <literal>%p</literal>, but with escaping undone.</entry>
           </row>
+          <row>
+            <!-- We do not use the common definition from standard-specifiers.xml here since we want a
+                 slightly more verbose explanation here, referring to the reload cycle. -->
+            <entry><literal>%R</literal></entry>
+            <entry>Pretty host name</entry>
+            <entry>The pretty hostname of the running system at the point in time the unit configuration is loaded, as read from the <varname>PRETTY_HOSTNAME=</varname> field of <filename>/etc/machine-info</filename>. If not set, resolves to the short hostname. See <citerefentry><refentrytitle>machine-info</refentrytitle><manvolnum>5</manvolnum></citerefentry> for more information.</entry>
+          </row>
           <row>
             <entry><literal>%s</literal></entry>
             <entry>User shell</entry>

src/shared/specifier.c

@@ -40,6 +40,7 @@ int specifier_printf(const char *text, size_t max_length, const Specifier table[
         char *t;
         int r;
 
+        assert(ret);
         assert(text);
         assert(table);
 
@@ -112,6 +113,8 @@ int specifier_printf(const char *text, size_t max_length, const Specifier table[
 int specifier_string(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
         char *n = NULL;
 
+        assert(ret);
+
         if (!isempty(data)) {
                 n = strdup(data);
                 if (!n)
@@ -125,6 +128,8 @@ int specifier_string(char specifier, const void *data, const char *root, const v
 int specifier_real_path(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
         const char *path = data;
 
+        assert(ret);
+
         if (!path)
                 return -ENOENT;
 
@@ -135,6 +140,8 @@ int specifier_real_directory(char specifier, const void *data, const char *root,
         _cleanup_free_ char *path = NULL;
         int r;
 
+        assert(ret);
+
         r = specifier_real_path(specifier, data, root, userdata, &path);
         if (r < 0)
                 return r;
@@ -148,6 +155,8 @@ int specifier_machine_id(char specifier, const void *data, const char *root, con
         char *n;
         int r;
 
+        assert(ret);
+
         if (root) {
                 _cleanup_close_ int fd = -1;
 
@@ -174,6 +183,8 @@ int specifier_boot_id(char specifier, const void *data, const char *root, const
         char *n;
         int r;
 
+        assert(ret);
+
         r = sd_id128_get_boot(&id);
         if (r < 0)
                 return r;
@@ -189,6 +200,8 @@ int specifier_boot_id(char specifier, const void *data, const char *root, const
 int specifier_host_name(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
         char *n;
 
+        assert(ret);
+
         n = gethostname_malloc();
         if (!n)
                 return -ENOMEM;
@@ -200,6 +213,8 @@ int specifier_host_name(char specifier, const void *data, const char *root, cons
 int specifier_short_host_name(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
         char *n;
 
+        assert(ret);
+
         n = gethostname_short_malloc();
         if (!n)
                 return -ENOMEM;
@@ -208,10 +223,27 @@ int specifier_short_host_name(char specifier, const void *data, const char *root
         return 0;
 }
 
+int specifier_pretty_host_name(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
+        char *n = NULL;
+
+        assert(ret);
+
+        if (get_pretty_hostname(&n) < 0) {
+                n = gethostname_short_malloc();
+                if (!n)
+                        return -ENOMEM;
+        }
+
+        *ret = n;
+        return 0;
+}
+
 int specifier_kernel_release(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
         struct utsname uts;
         char *n;
 
+        assert(ret);
+
         if (uname(&uts) < 0)
                 return -errno;
 
@@ -226,6 +258,8 @@ int specifier_kernel_release(char specifier, const void *data, const char *root,
 int specifier_architecture(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
         char *t;
 
+        assert(ret);
+
         t = strdup(architecture_to_string(uname_architecture()));
         if (!t)
                 return -ENOMEM;
@@ -238,32 +272,40 @@ int specifier_architecture(char specifier, const void *data, const char *root, c
  * otherwise. We'll return an empty value or NULL in that case from the functions below. */
 
 int specifier_os_id(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
+        assert(ret);
         return parse_os_release(root, "ID", ret);
 }
 
 int specifier_os_version_id(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
+        assert(ret);
         return parse_os_release(root, "VERSION_ID", ret);
 }
 
 int specifier_os_build_id(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
+        assert(ret);
         return parse_os_release(root, "BUILD_ID", ret);
 }
 
 int specifier_os_variant_id(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
+        assert(ret);
         return parse_os_release(root, "VARIANT_ID", ret);
 }
 
 int specifier_os_image_id(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
+        assert(ret);
         return parse_os_release(root, "IMAGE_ID", ret);
 }
 
 int specifier_os_image_version(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
+        assert(ret);
         return parse_os_release(root, "IMAGE_VERSION", ret);
 }
 
 int specifier_group_name(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
         char *t;
 
+        assert(ret);
+
         t = gid_to_name(getgid());
         if (!t)
                 return -ENOMEM;
@@ -273,6 +315,8 @@ int specifier_group_name(char specifier, const void *data, const char *root, con
 }
 
 int specifier_group_id(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
+        assert(ret);
+
         if (asprintf(ret, UID_FMT, getgid()) < 0)
                 return -ENOMEM;
 
@@ -282,6 +326,8 @@ int specifier_group_id(char specifier, const void *data, const char *root, const
 int specifier_user_name(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
         char *t;
 
+        assert(ret);
+
         /* If we are UID 0 (root), this will not result in NSS, otherwise it might. This is good, as we want to be able
          * to run this in PID 1, where our user ID is 0, but where NSS lookups are not allowed.
 
@@ -298,6 +344,8 @@ int specifier_user_name(char specifier, const void *data, const char *root, cons
 }
 
 int specifier_user_id(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
+        assert(ret);
+
         if (asprintf(ret, UID_FMT, getuid()) < 0)
                 return -ENOMEM;
 
@@ -305,6 +353,7 @@ int specifier_user_id(char specifier, const void *data, const char *root, const
 }
 
 int specifier_user_home(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
+        assert(ret);
 
         /* On PID 1 (which runs as root) this will not result in NSS,
          * which is good. See above */
@@ -313,6 +362,7 @@ int specifier_user_home(char specifier, const void *data, const char *root, cons
 }
 
 int specifier_user_shell(char specifier, const void *data, const char *root, const void *userdata, char **ret) {
+        assert(ret);
 
         /* On PID 1 (which runs as root) this will not result in NSS,
          * which is good. See above */
@@ -325,6 +375,8 @@ int specifier_tmp_dir(char specifier, const void *data, const char *root, const
         char *copy;
         int r;
 
+        assert(ret);
+
         if (root) /* If root dir is set, don't honour $TMP or similar */
                 p = "/tmp";
         else {
@@ -345,6 +397,8 @@ int specifier_var_tmp_dir(char specifier, const void *data, const char *root, co
         char *copy;
         int r;
 
+        assert(ret);
+
         if (root)
                 p = "/var/tmp";
         else {

src/shared/specifier.h

@@ -21,6 +21,7 @@ int specifier_machine_id(char specifier, const void *data, const char *root, con
 int specifier_boot_id(char specifier, const void *data, const char *root, const void *userdata, char **ret);
 int specifier_host_name(char specifier, const void *data, const char *root, const void *userdata, char **ret);
 int specifier_short_host_name(char specifier, const void *data, const char *root, const void *userdata, char **ret);
+int specifier_pretty_host_name(char specifier, const void *data, const char *root, const void *userdata, char **ret);
 int specifier_kernel_release(char specifier, const void *data, const char *root, const void *userdata, char **ret);
 int specifier_architecture(char specifier, const void *data, const char *root, const void *userdata, char **ret);
 int specifier_os_id(char specifier, const void *data, const char *root, const void *userdata, char **ret);
@@ -75,6 +76,7 @@ int specifier_var_tmp_dir(char specifier, const void *data, const char *root, co
         { 'B', specifier_os_build_id,     NULL }, \
         { 'H', specifier_host_name,       NULL }, \
         { 'l', specifier_short_host_name, NULL }, \
+        { 'R', specifier_pretty_host_name,NULL }, \
         { 'm', specifier_machine_id,      NULL }, \
         { 'M', specifier_os_image_id,     NULL }, \
         { 'o', specifier_os_id,           NULL }, \

src/test/test-specifier.c

@@ -73,7 +73,7 @@ TEST(specifier_printf) {
         assert_se(streq(w, "xxx a=AAAA b=BBBB e= yyy"));
 
         free(w);
-        r = specifier_printf("machine=%m, boot=%b, host=%H, version=%v, arch=%a, empty=%e", SIZE_MAX, table, NULL, NULL, &w);
+        r = specifier_printf("machine=%m, boot=%b, host=%H, pretty=%R, version=%v, arch=%a, empty=%e", SIZE_MAX, table, NULL, NULL, &w);
         assert_se(r >= 0);
         assert_se(w);
         puts(w);