Add s6-svc -l and reload-signal

7 files changed, 47 insertions, 12 deletions

diff --git a/NEWS b/NEWS
index 89b9bd0..ad24466 100644
--- a/NEWS
+++ b/NEWS
@@ -6,6 +6,9 @@ In 2.15.1.0
  - Bugfixes.
  - New command: s6-svscanboot, for a self-logging s6-svscan
 that is not pid 1.
+ - New service directory file: reload-signal
+ - New s6-svc control: s6-svc -l, to send the signal defined
+in reload-signal, or a SIGHUP by default.
 
 
 In 2.15.0.0
diff --git a/doc/s6-svc.html b/doc/s6-svc.html
index a8a5192..5bdbcb1 100644
--- a/doc/s6-svc.html
+++ b/doc/s6-svc.html
@@ -29,7 +29,7 @@ knowing their PIDs, and without using horrible hacks such as .pid files.
 <h2> Interface </h2>
 
 <pre>
-     s6-svc [ -wu | -wU | -wd | -wD | -wr | -wR ] [ -T <em>timeout</em> ] [ -s <em>signal</em> | -abqhkti12pcyrPCK ] [ -oduDUxO ] <em>servicedirs...</em>
+     s6-svc [ -wu | -wU | -wd | -wD | -wr | -wR ] [ -T <em>timeout</em> ] [ -s <em>signal</em> | -abqhkti12pcyrlPCK ] [ -oduDUxO ] <em>servicedirs...</em>
 </pre>
 
 <p>
@@ -100,6 +100,13 @@ signal to kill it and letting <a href="s6-supervise.html">s6-supervise</a>
 start it again. By default, the signal is a SIGTERM; this can be configured
 via the <tt>./down-signal</tt> file in the <a href="servicedir.html">service
 directory</a>. </li>
+ <li> <tt>-l</tt>&nbsp;: If the service is up, reload it, by sending it a
+signal that should make it reload its configuration. (Not all services support
+this feature, in which case <tt>-l</tt> will be equivalent to <tt>-r</tt>.)
+By default, the signal is a SIGHUP; this can be configured
+via the <tt>./reload-signal</tt> file in the <a href="servicedir.html">service
+directory</a>. </li>
+
  <li> <tt>-T&nbsp;<em>timeout</em></tt>&nbsp;: if the <tt>-w<em>state</em></tt>
 option has been given, <tt>-T</tt> specifies a timeout
 (in milliseconds) after which s6-svc will exit 1 with an error message if
diff --git a/doc/servicedir.html b/doc/servicedir.html
index ced24d6..6824559 100644
--- a/doc/servicedir.html
+++ b/doc/servicedir.html
@@ -214,6 +214,12 @@ newline. This signal will be used to kill the supervised process when a
 <a href="s6-svc.html">s6-svc -d</a> or <a href="s6-svc.html">s6-svc -r</a>
 command is used. If the file does not exist, SIGTERM will be used by default. </li>
 
+ <li style="margin-bottom:1em"> An optional regular file named <tt>reload-signal</tt>. If such a file
+exists, it must only contain the name or number of a signal, followed by a
+newline. This signal will be sent to the supervised process when a
+<a href="s6-svc.html">s6-svc -l</a> command is used. If the file does not exist,
+SIGHUP will be used by default. </li>
+
  <li style="margin-bottom:1em"> An optional regular file named <tt>flag-newpidns</tt>.
 If such a file exists:
   <ul>
diff --git a/doc/upgrade.html b/doc/upgrade.html
index 43bd3f4..cd2d648 100644
--- a/doc/upgrade.html
+++ b/doc/upgrade.html
@@ -27,6 +27,9 @@ dependency bumped to 2.15.0.1. </li>
  <li> <a href="//skarnet.org/software/execline/">execline</a>
 recommended dependency bumped to 2.9.9.2. </li>
  <li> New <a href="s6-svscanboot.html">s6-svscanboot</a> binary. </li>
+ <li> New -l option to <a href="s6-svc.html">s6-svc</a>. </li>
+ <li> New optional <tt>reload-signal</tt> file in a
+<a href="servicedir.html">service directory</a>. </li>
 </ul>
 
 <h2> in 2.15.0.0 </h2>
diff --git a/src/libs6/s6_servicedir_file_list.c b/src/libs6/s6_servicedir_file_list.c
index bbbb68a..2483b40 100644
--- a/src/libs6/s6_servicedir_file_list.c
+++ b/src/libs6/s6_servicedir_file_list.c
@@ -13,6 +13,7 @@ static s6_servicedir_desc const s6_servicedir_file_list_[] =
   { .name = "timeout-finish", .type = S6_FILETYPE_UINT, .options = 0 },
   { .name = "max-death-tally", .type = S6_FILETYPE_UINT, .options = 0 },
   { .name = "down-signal", .type = S6_FILETYPE_NORMAL, .options = 0 },
+  { .name = "reload-signal", .type = S6_FILETYPE_NORMAL, .options = 0 },
   { .name = "flag-newpidns", .type = S6_FILETYPE_EMPTY, .options = 0 },
   { .name = "template", .type = S6_FILETYPE_DIR, .options = 0 },
   { .name = "data", .type = S6_FILETYPE_DIR, .options = 0 },
diff --git a/src/supervision/s6-supervise.c b/src/supervision/s6-supervise.c
index d9c47c1..6c8391e 100644
--- a/src/supervision/s6-supervise.c
+++ b/src/supervision/s6-supervise.c
@@ -43,7 +43,7 @@ typedef enum trans_e trans_t, *trans_t_ref ;
 enum trans_e
 {
   V_TIMEOUT, V_CHLD, V_TERM, V_HUP, V_QUIT, V_INT,
-  V_a, V_b, V_q, V_h, V_k, V_t, V_i, V_1, V_2, V_p, V_c, V_y, V_r, V_P, V_C, V_K,
+  V_a, V_b, V_q, V_h, V_k, V_t, V_i, V_1, V_2, V_p, V_c, V_y, V_r, V_l, V_P, V_C, V_K,
   V_o, V_d, V_u, V_D, V_U, V_x, V_O, V_Q
 } ;
 
@@ -131,7 +131,16 @@ static inline int read_downsig (void)
   int sig = SIGTERM ;
   char buf[16] ;
   if (read_file("down-signal", buf, 15) && !sig0_scan(buf, &sig))
-    strerr_warnw1x("invalid down-signal") ;
+    strerr_warnw("invalid ", "down-signal") ;
+  return sig ;
+}
+
+static inline int read_reloadsig (void)
+{
+  int sig = SIGHUP ;
+  char buf[16] ;
+  if (read_file("reload-signal", buf, 15) && !sig0_scan(buf, &sig))
+    strerr_warnw("invalid ", "reload-signal") ;
   return sig ;
 }
 
@@ -264,6 +273,11 @@ static void killr (void)
   kill(status.pid, read_downsig()) ;
 }
 
+static void killl (void)
+{
+  kill(status.pid, read_reloadsig()) ;
+}
+
 static void killP (void)
 {
   killpg(status.pid, SIGSTOP) ;
@@ -602,22 +616,22 @@ static void lastfinish_z (void)
   bail() ;
 }
 
-static action_t_ref const actions[5][30] =
+static action_t_ref const actions[5][31] =
 {
   { &downtimeout, &nop, &bail, &bail, &bail, &bail,
-    &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop,
+    &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop,
     &down_o, &wantdown, &down_u, &wantDOWN, &down_U, &bail, &wantdown, &wantDOWN },
   { &uptimeout, &up_z, &up_term, &up_x, &bail, &sigint,
-    &killa, &killb, &killq, &killh, &killk, &killt, &killi, &kill1, &kill2, &killp, &killc, &killy, &killr, &killP, &killC, &killK,
+    &killa, &killb, &killq, &killh, &killk, &killt, &killi, &kill1, &kill2, &killp, &killc, &killy, &killr, &killl, &killP, &killC, &killK,
     &wantdown, &up_d, &wantup, &up_D, &wantUP, &up_x, &wantdown, &wantDOWN },
   { &finishtimeout, &finish_z, &finish_x, &finish_x, &bail, &sigint,
-    &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop,
+    &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop,
     &wantdown, &wantdown, &wantup, &wantDOWN, &wantUP, &finish_x, &wantdown, &wantDOWN },
   { &uptimeout, &lastup_z, &up_d, &closethem, &bail, &sigint,
-    &killa, &killb, &killq, &killh, &killk, &killt, &killi, &kill1, &kill2, &killp, &killc, &killy, &killr, &killP, &killC, &killK,
+    &killa, &killb, &killq, &killh, &killk, &killt, &killi, &kill1, &kill2, &killp, &killc, &killy, &killr, &killl, &killP, &killC, &killK,
     &wantdown, &up_d, &wantup, &up_D, &wantUP, &closethem, &wantdown, &wantDOWN },
   { &finishtimeout, &lastfinish_z, &nop, &closethem, &bail, &sigint,
-    &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop,
+    &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop, &nop,
     &wantdown, &wantdown, &wantup, &wantDOWN, &wantUP, &closethem, &wantdown, &wantDOWN }
 } ;
 
@@ -702,7 +716,7 @@ static inline void handle_control (int fd)
     else if (!r) break ;
     else
     {
-      size_t pos = byte_chr("abqhkti12pcyrPCKoduDUxOQ", 24, c) ;
+      size_t pos = byte_chr("abqhkti12pcyrlPCKoduDUxOQ", 25, c) ;
       if (pos < 24) (*actions[state][V_a + pos])() ;
     }
   }
diff --git a/src/supervision/s6-svc.c b/src/supervision/s6-svc.c
index c13b73b..0ddc760 100644
--- a/src/supervision/s6-svc.c
+++ b/src/supervision/s6-svc.c
@@ -18,7 +18,7 @@
 #include <s6/config.h>
 #include <s6/supervise.h>
 
-#define USAGE "s6-svc [ -wu | -wU | -wd | -wD | -wr | -wR ] [ -T timeout ] [ -s signal | -abqhkti12pcyrPCK ] [ -oduDUxOQ ] servicedirs..."
+#define USAGE "s6-svc [ -wu | -wU | -wd | -wD | -wr | -wR ] [ -T timeout ] [ -s signal | -abqhkti12pcyrlPCK ] [ -oduDUxOQ ] servicedirs..."
 #define dieusage() strerr_dieusage(100, USAGE)
 
 #define DATASIZE 63
@@ -50,7 +50,7 @@ int main (int argc, char const *const *argv)
     subgetopt l = SUBGETOPT_ZERO ;
     for (;;)
     {
-      int opt = subgetopt_r(argc, argv, "s:abqhkti12pcyrPCKoduDUxOQT:w:", &l) ;
+      int opt = subgetopt_r(argc, argv, "s:abqhkti12pcyrlPCKoduDUxOQT:w:", &l) ;
       if (opt == -1) break ;
       switch (opt)
       {
@@ -74,6 +74,7 @@ int main (int argc, char const *const *argv)
         case 'c' :
         case 'y' :
         case 'r' :
+        case 'l' :
         case 'P' :
         case 'C' :
         case 'K' :