service: add support for instances without command

This can be useful for maintaining active procd data for use in other
services, even when no helper process is active.

Signed-off-by: Felix Fietkau <nbd@nbd.name>

diff --git a/service/instance.c b/service/instance.c
index b7839660654a3548a6674a26b19a99f48c55edd9..10e35ca6f295dc21aa041e3ae3eedd6b67e07c55 100644 (file)
--- a/service/instance.c
+++ b/service/instance.c
@@ -386,7 +386,7 @@ instance_start(struct service_instance *in)
                return;
        }
 
-       if (in->proc.pending)
+       if (in->proc.pending || !in->command)
                return;
 
        instance_free_stdio(in);
@@ -753,31 +753,42 @@ instance_jail_parse(struct service_instance *in, struct blob_attr *attr)
 }
 
 static bool
-instance_config_parse(struct service_instance *in)
+instance_config_parse_command(struct service_instance *in, struct blob_attr **tb)
 {
-       struct blob_attr *tb[__INSTANCE_ATTR_MAX];
        struct blob_attr *cur, *cur2;
-       int argc = 0;
+       bool ret = false;
        int rem;
 
-       blobmsg_parse(instance_attr, __INSTANCE_ATTR_MAX, tb,
-               blobmsg_data(in->config), blobmsg_data_len(in->config));
-
        cur = tb[INSTANCE_ATTR_COMMAND];
-       if (!cur)
-               return false;
+       if (!cur) {
+               in->command = NULL;
+               return true;
+       }
 
        if (!blobmsg_check_attr_list(cur, BLOBMSG_TYPE_STRING))
                return false;
 
        blobmsg_for_each_attr(cur2, cur, rem) {
-               argc++;
+               ret = true;
                break;
        }
-       if (!argc)
-               return false;
 
        in->command = cur;
+       return ret;
+}
+
+static bool
+instance_config_parse(struct service_instance *in)
+{
+       struct blob_attr *tb[__INSTANCE_ATTR_MAX];
+       struct blob_attr *cur, *cur2;
+       int rem;
+
+       blobmsg_parse(instance_attr, __INSTANCE_ATTR_MAX, tb,
+               blobmsg_data(in->config), blobmsg_data_len(in->config));
+
+       if (!instance_config_parse_command(in, tb))
+               return false;
 
        if (tb[INSTANCE_ATTR_RESPAWN]) {
                int i = 0;
@@ -981,7 +992,8 @@ void instance_dump(struct blob_buf *b, struct service_instance *in, int verbose)
        blobmsg_add_u8(b, "running", in->proc.pending);
        if (in->proc.pending)
                blobmsg_add_u32(b, "pid", in->proc.pid);
-       blobmsg_add_blob(b, in->command);
+       if (in->command)
+               blobmsg_add_blob(b, in->command);
 
        if (!avl_is_empty(&in->errors.avl)) {
                struct blobmsg_list_node *var;