internal/app: modularise outcome finalise

This is the initial effort of splitting up host and container side of finalisation for params to shim. The new layout also enables much finer grained unit testing of each step, as well as partition access to per-app state for each step.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/app/spdbus.go

@@ -0,0 +1,50 @@
+package app
+
+import (
+	"hakurei.app/container"
+	"hakurei.app/hst"
+	"hakurei.app/system/acl"
+	"hakurei.app/system/dbus"
+)
+
+// spDBusOp maintains an xdg-dbus-proxy instance for the container.
+type spDBusOp struct {
+	// Whether to bind the system bus socket.
+	// Populated during toSystem.
+	ProxySystem bool
+}
+
+func (s *spDBusOp) toSystem(state *outcomeStateSys, config *hst.Config) error {
+	if config.SessionBus == nil {
+		config.SessionBus = dbus.NewConfig(config.ID, true, true)
+	}
+
+	// downstream socket paths
+	sessionPath, systemPath := state.instance().Append("bus"), state.instance().Append("system_bus_socket")
+
+	if err := state.sys.ProxyDBus(
+		config.SessionBus, config.SystemBus,
+		sessionPath, systemPath,
+	); err != nil {
+		return err
+	}
+
+	state.sys.UpdatePerm(sessionPath, acl.Read, acl.Write)
+	if config.SystemBus != nil {
+		s.ProxySystem = true
+		state.sys.UpdatePerm(systemPath, acl.Read, acl.Write)
+	}
+	return nil
+}
+
+func (s *spDBusOp) toContainer(state *outcomeStateParams) error {
+	sessionInner := state.runtimeDir.Append("bus")
+	state.env["DBUS_SESSION_BUS_ADDRESS"] = "unix:path=" + sessionInner.String()
+	state.params.Bind(state.instancePath().Append("bus"), sessionInner, 0)
+	if s.ProxySystem {
+		systemInner := container.AbsFHSRun.Append("dbus/system_bus_socket")
+		state.env["DBUS_SYSTEM_BUS_ADDRESS"] = "unix:path=" + systemInner.String()
+		state.params.Bind(state.instancePath().Append("system_bus_socket"), systemInner, 0)
+	}
+	return nil
+}