support lxc.execute.cmd container configuration option

Signed-off-by: Serge Hallyn <shallyn@cisco.com>

diff --git a/doc/lxc.container.conf.sgml.in b/doc/lxc.container.conf.sgml.in
index 287bc8e517cf5c92a71962ad962e4f71b4202ab9..3f05e52b6bef0359b47a22a81a9a49c0e7d64856 100644 (file)
--- a/doc/lxc.container.conf.sgml.in
+++ b/doc/lxc.container.conf.sgml.in
@@ -260,6 +260,19 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 
         Defaults to: /sbin/init
       </para>
+      <variablelist>
+        <varlistentry>
+          <term>
+            <option>lxc.execute.cmd</option>
+          </term>
+          <listitem>
+            <para>
+              Absolute path from container rootfs to the binary to run by default.  This
+             mostly makes sense for lxc-execute.
+            </para>
+          </listitem>
+        </varlistentry>
+      </variablelist>
       <variablelist>
         <varlistentry>
           <term>

diff --git a/src/lxc/conf.c b/src/lxc/conf.c
index 0b5a9e2600cdd4234b48eca12c2b3309e7556c8d..6871b83a0523cd9c913055c0bdf3f8b3aaed88bf 100644 (file)
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -3525,6 +3525,7 @@ void lxc_conf_free(struct lxc_conf *conf)
        free(conf->ttydir);
        free(conf->fstab);
        free(conf->rcfile);
+       free(conf->execute_cmd);
        free(conf->init_cmd);
        free(conf->unexpanded_config);
        free(conf->pty_names);

diff --git a/src/lxc/conf.h b/src/lxc/conf.h
index 1bc02dc4f3206c82dd289d0da8c3469e77d1f140..169857f2bb711c25f53503ce9aec969f934dbe4d 100644 (file)
--- a/src/lxc/conf.h
+++ b/src/lxc/conf.h
@@ -309,6 +309,9 @@ struct lxc_conf {
        char *unexpanded_config;
        size_t unexpanded_len, unexpanded_alloced;
 
+       /* default command for lxc-execute */
+       char *execute_cmd;
+
        /* init command */
        char *init_cmd;
 

diff --git a/src/lxc/confile.c b/src/lxc/confile.c
index 1beb9c7b4b1a851e7ff8d68084f6c28f6830842e..c9afcb01cf7782329c91cd94210eb01fe90087be 100644 (file)
--- a/src/lxc/confile.c
+++ b/src/lxc/confile.c
@@ -127,6 +127,7 @@ lxc_config_define(start);
 lxc_config_define(monitor);
 lxc_config_define(group);
 lxc_config_define(environment);
+lxc_config_define(execute_cmd);
 lxc_config_define(init_cmd);
 lxc_config_define(init_uid);
 lxc_config_define(init_gid);
@@ -149,6 +150,7 @@ static struct lxc_config_t config[] = {
        { "lxc.console.path",              false,                  set_config_console_path,                get_config_console_path,                clr_config_console_path,              },
        { "lxc.environment",               false,                  set_config_environment,                 get_config_environment,                 clr_config_environment,               },
        { "lxc.ephemeral",                 false,                  set_config_ephemeral,                   get_config_ephemeral,                   clr_config_ephemeral,                 },
+       { "lxc.execute.cmd",               false,                  set_config_execute_cmd,                 get_config_execute_cmd,                 clr_config_execute_cmd,                  },
        { "lxc.group",                     false,                  set_config_group,                       get_config_group,                       clr_config_group,                     },
        { "lxc.hook.autodev",              false,                  set_config_hooks,                       get_config_hooks,                       clr_config_hooks,                     },
        { "lxc.hook.clone",                false,                  set_config_hooks,                       get_config_hooks,                       clr_config_hooks,                     },
@@ -920,6 +922,12 @@ static int set_config_seccomp_profile(const char *key, const char *value,
        return set_config_path_item(&lxc_conf->seccomp, value);
 }
 
+static int set_config_execute_cmd(const char *key, const char *value,
+                              struct lxc_conf *lxc_conf, void *data)
+{
+       return set_config_path_item(&lxc_conf->execute_cmd, value);
+}
+
 static int set_config_init_cmd(const char *key, const char *value,
                               struct lxc_conf *lxc_conf, void *data)
 {
@@ -3095,6 +3103,12 @@ static int get_config_environment(const char *key, char *retv, int inlen,
        return fulllen;
 }
 
+static int get_config_execute_cmd(const char *key, char *retv, int inlen,
+                              struct lxc_conf *c, void *data)
+{
+       return lxc_get_conf_str(retv, inlen, c->execute_cmd);
+}
+
 static int get_config_init_cmd(const char *key, char *retv, int inlen,
                               struct lxc_conf *c, void *data)
 {
@@ -3450,6 +3464,14 @@ static inline int clr_config_environment(const char *key, struct lxc_conf *c,
        return lxc_clear_environment(c);
 }
 
+static inline int clr_config_execute_cmd(const char *key, struct lxc_conf *c,
+                                     void *data)
+{
+       free(c->execute_cmd);
+       c->execute_cmd = NULL;
+       return 0;
+}
+
 static inline int clr_config_init_cmd(const char *key, struct lxc_conf *c,
                                      void *data)
 {

diff --git a/src/lxc/tools/lxc_execute.c b/src/lxc/tools/lxc_execute.c
index 0b3309a30fccfa9c9b81582f1ac52759505a74dd..f69ab6a5145e4c8235d9859c199674ad85e5d233 100644 (file)
--- a/src/lxc/tools/lxc_execute.c
+++ b/src/lxc/tools/lxc_execute.c
@@ -46,16 +46,6 @@ lxc_log_define(lxc_execute_ui, lxc);
 
 static struct lxc_list defines;
 
-static int my_checker(const struct lxc_arguments* args)
-{
-       if (!args->argc) {
-               lxc_error(args, "missing command to execute !");
-               return -1;
-       }
-
-       return 0;
-}
-
 static int my_parser(struct lxc_arguments* args, int c, char* arg)
 {
        switch (c) {
@@ -100,9 +90,29 @@ Options :\n\
   -g, --gid=GID        Execute COMMAND with GID inside the container\n",
        .options  = my_longopts,
        .parser   = my_parser,
-       .checker  = my_checker,
 };
 
+static bool set_argv(struct lxc_conf *conf, struct lxc_arguments *args)
+{
+       char **components, **p;
+
+       if (!conf->execute_cmd)
+               return false;
+
+       /* TODO -
+          we should honor '"' etc; This seems worth a new helper in utils.c.
+        */
+       components = lxc_string_split(conf->execute_cmd, ' ');
+       if (!components)
+               return false;
+
+       args->argv = components;
+       for (p = components; *p; p++)
+               args->argc++;
+
+       return true;
+}
+
 int main(int argc, char *argv[])
 {
        struct lxc_container *c;
@@ -150,6 +160,14 @@ int main(int argc, char *argv[])
                }
        }
 
+       if (my_args.argc == 0) {
+               if (!set_argv(c->lxc_conf, &my_args)) {
+                       ERROR("missing command to execute!");
+                       lxc_container_put(c);
+                       exit(EXIT_FAILURE);
+               }
+       }
+
        if (my_args.uid)
                c->lxc_conf->init_uid = my_args.uid;