wireplumber.conf: add systemwide, embedded and split-instance profiles

Revamp the profiles section, making use of the inherits feature
and add commonly used profiles for systemwide & embedded use cases,
as well as profiles for a split-instance configuration where the
policy hooks run in a separate instance from the alsa, bluetooth
and camera monitors (which run in 3 separate instances respectively)

Also add an example on how to configure the loaded profile using
a config file instead of the CLI switch.

Fixes: #608

lib/wp/private/internal-comp-loader.c

@@ -942,6 +942,8 @@ wp_internal_comp_loader_load (WpComponentLoader * self, WpCore * core,
       g_autoptr (GError) error = NULL;
       const gchar *profile_name = component;
 
+      wp_notice ("Loading profile '%s'", profile_name);
+
       all_profiles_j = wp_conf_get_section (conf, "wireplumber.profiles");
 
       if (!parse_profile_description (profile, all_profiles_j, profile_name,

src/config/wireplumber.conf

@@ -57,6 +57,7 @@ context.modules = [
 wireplumber.profiles = {
   ## Syntax:
   ## <profile> = {
+  ##   inherits = [ other, profile, names ]   # optional
   ##   # optional is the default
   ##   <feature name> = [ required | optional | disabled ]
   ##   ...
@@ -64,29 +65,94 @@ wireplumber.profiles = {
 
   # The default profile
   main = {
-    check.no-media-session = required
+    inherits = [ base ]
+
     metadata.sm-settings = required
-    support.settings = required
-    support.log-settings = required
     metadata.sm-objects = required
+
+    policy.standard = required
+
     hardware.audio = required
     hardware.bluetooth = required
     hardware.video-capture = required
-    policy.standard = required
+  }
+
+  # Profile for running on a systemwide level
+  main-systemwide = {
+    inherits = [ main, mixin.systemwide-session ]
+  }
+
+  # Typical profile for embedded use cases, systemwide without maintaining state
+  main-embedded = {
+    inherits = [ main, mixin.systemwide-session, mixin.stateless ]
   }
 
   # Profile for video-only use cases (camera & screen sharing)
   video-only = {
-    check.no-media-session = required
-    metadata.sm-settings = required
-    support.settings = required
-    support.log-settings = required
-    metadata.sm-objects = required
+    inherits = [ main ]
     hardware.audio = disabled
     hardware.bluetooth = disabled
-    hardware.video-capture = required
+  }
+
+  ##
+  ## Profiles for multi-instance setup
+  ##
+
+  policy = {
+    inherits = [ base ]
+    metadata.sm-settings = required
+    metadata.sm-objects = required
     policy.standard = required
   }
+
+  audio = {
+    inherits = [ base ]
+    hardware.audio = required
+  }
+
+  bluetooth = {
+    inherits = [ base ]
+    hardware.bluetooth = required
+  }
+
+  video-capture = {
+    inherits = [ base ]
+    hardware.video-capture = required
+  }
+
+  ##
+  ## The following are not complete profiles, but blocks that can be inherited
+  ##
+
+  # The bare minimum that all instances should have by default
+  base = {
+    check.no-media-session = required
+    support.settings = required
+    support.log-settings = required
+  }
+
+  # Disable features that are meant only for user sessions
+  mixin.systemwide-session = {
+    support.reserve-device = disabled
+    monitor.alsa.reserve-device = disabled
+
+    support.portal-permissionstore = disabled
+    script.client.access-portal = disabled
+
+    support.logind = disabled
+    monitor.bluez.seat-monitoring = disabled
+  }
+
+  # Disable storing/restoring runtime state information regarding
+  # default nodes selection, profiles, routes and stream volume / properties
+  # This makes sense for embedded systems that should always reboot to a default
+  # state, not remembering any of the user's runtime changes
+  mixin.stateless = {
+    hooks.device.profile.state = disabled
+    hooks.device.routes.state = disabled
+    hooks.default-nodes.state = disabled
+    hooks.stream.state = disabled
+  }
 }
 
 wireplumber.components = [
@@ -167,7 +233,9 @@ wireplumber.components = [
   }
 
   ## Activates a global WpSettings instance, providing settings from
-  ## the sm-settings metadata object
+  ## the sm-settings metadata object. Note that this blocks and waits for the
+  ## sm-settings metadata object to become available, so one instance must
+  ## provide that, while others should only load this to access settings
   {
     name = settings-instance, type = built-in
     arguments = { metadata.name = sm-settings }

src/config/wireplumber.conf.d.examples/profile.conf

@@ -0,0 +1,9 @@
+# This example configuration fragment shows how to permanently instruct
+# WirePlumber to load with a specific profile. Note that this overrides the
+# `-p, --profile` command line switch, rendering it useless. If you intend to
+# run WirePlumber with multiple profiles based on its command line arguments,
+# do not use this
+
+context.properties = {
+  wireplumber.profile = main-embedded
+}