cmd/fpkg: app bundle helper

This helper program creates fortify configuration for running an application bundle. The activate action wraps a home-manager activation package and ensures each generation gets activated once.

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

cmd/fpkg/bundle.go

@@ -0,0 +1,79 @@
+package main
+
+import (
+	"encoding/json"
+	"os"
+
+	"git.gensokyo.uk/security/fortify/dbus"
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
+	"git.gensokyo.uk/security/fortify/internal/system"
+)
+
+type bundleInfo struct {
+	Name    string `json:"name"`
+	Version string `json:"version"`
+
+	// passed through to [fst.Config]
+	ID string `json:"id"`
+	// passed through to [fst.Config]
+	AppID int `json:"app_id"`
+	// passed through to [fst.Config]
+	Groups []string `json:"groups,omitempty"`
+	// passed through to [fst.Config]
+	UserNS bool `json:"userns,omitempty"`
+	// passed through to [fst.Config]
+	Net bool `json:"net,omitempty"`
+	// passed through to [fst.Config]
+	Dev bool `json:"dev,omitempty"`
+	// passed through to [fst.Config]
+	NoNewSession bool `json:"no_new_session,omitempty"`
+	// passed through to [fst.Config]
+	MapRealUID bool `json:"map_real_uid,omitempty"`
+	// passed through to [fst.Config]
+	DirectWayland bool `json:"direct_wayland,omitempty"`
+	// passed through to [fst.Config]
+	SystemBus *dbus.Config `json:"system_bus,omitempty"`
+	// passed through to [fst.Config]
+	SessionBus *dbus.Config `json:"session_bus,omitempty"`
+	// passed through to [fst.Config]
+	Enablements system.Enablements `json:"enablements"`
+
+	// allow gpu access within sandbox
+	GPU bool `json:"gpu"`
+	// inner nix store path to activate-and-exec script
+	Launcher string `json:"launcher"`
+	// store path to /run/current-system
+	CurrentSystem string `json:"current_system"`
+	// home-manager activation package
+	ActivationPackage string `json:"activation_package"`
+}
+
+func loadBundleInfo(name string, beforeFail func()) *bundleInfo {
+	bundle := new(bundleInfo)
+	if f, err := os.Open(name); err != nil {
+		beforeFail()
+		fmsg.Fatalf("cannot open bundle: %v", err)
+	} else if err = json.NewDecoder(f).Decode(&bundle); err != nil {
+		beforeFail()
+		fmsg.Fatalf("cannot parse bundle metadata: %v", err)
+	} else if err = f.Close(); err != nil {
+		fmsg.Printf("cannot close bundle metadata: %v", err)
+		// not fatal
+	}
+
+	if bundle.ID == "" {
+		beforeFail()
+		fmsg.Fatal("application identifier must not be empty")
+	}
+
+	return bundle
+}
+
+func formatHostname(name string) string {
+	if h, err := os.Hostname(); err != nil {
+		fmsg.Printf("cannot get hostname: %v", err)
+		return "fortify-" + name
+	} else {
+		return h + "-" + name
+	}
+}