Better permissions request (#16)

* add more app metadata fields
* add pkexec policy template
* add command logger
* embed and write pkexec policy config when run as root
* add option to delay menu request for permission and pass desktop env as cmdline flag and add out/err logging
* add missing docs

.devcontainer/devcontainer.json

@@ -26,7 +26,8 @@
 	"extensions": [
 		"golang.Go",
 		"redhat.vscode-yaml",
-		"esbenp.prettier-vscode"
+		"esbenp.prettier-vscode",
+		"redhat.vscode-xml"
 	],
 
 	// Use 'forwardPorts' to make a list of ports inside the container available locally.

.github/workflows/build.yml

@@ -42,5 +42,5 @@ jobs:
         env:
           DISCORD_WEBHOOK_URL: ${{ secrets.DISCORD_WEBHOOK_URL }}
           GITHUB_ACTOR: ${{ github.actor }}
-          GITHUB_JOB_NAME: "${{ steps.release.outputs.id }}: ${{ steps.release.outputs.url }}"
+          GITHUB_JOB_NAME: "${{ steps.release.outputs.url }}"
           GITHUB_JOB_STATUS: ${{ job.status }}

buildinfo/app.yml

@@ -1,4 +1,7 @@
 name: huekeys
+reverse_dns: com.bitpony.huekeys
+url: https://github.com/BitPonyLLC/huekeys
+vendor: BitPony, LLC
 description: Control the keyboard backlight on System76 laptops
 full_description: >
   Huekeys is a fun application that makes it easy to adjust your System76

buildinfo/buildinfo.go

@@ -3,6 +3,7 @@ package buildinfo
 import (
 	_ "embed"
 	"fmt"
+	"os"
 	"time"
 
 	"github.com/rs/zerolog/log"
@@ -13,7 +14,12 @@ import (
 type AppInfo struct {
 	buildInfo
 
+	ExePath string `yaml:"-"`
+
 	Name            string `yaml:"name"`
+	URL             string `yaml:"url"`
+	ReverseDNS      string `yaml:"reverse_dns"`
+	Vendor          string `yaml:"vendor"`
 	Description     string `yaml:"description"`
 	FullDescription string `yaml:"full_description"`
 }
@@ -36,7 +42,14 @@ var app []byte
 var build []byte
 
 func init() {
-	err := yaml.Unmarshal(app, &App)
+	var err error
+
+	App.ExePath, err = os.Executable()
+	if err != nil {
+		log.Fatal().Err(err).Msg("unable to determine executable pathname")
+	}
+
+	err = yaml.Unmarshal(app, &App)
 	if err != nil {
 		log.Fatal().Err(err).Msg("unable to parse embedded app info")
 	}

cmd/menu.go

@@ -23,6 +23,7 @@ import (
 
 var patternName string
 var menuPidPath *pidpath.PidPath
+var delay = time.Duration(0)
 var restarting = false
 
 func init() {
@@ -33,6 +34,8 @@ func init() {
 	menuCmd.Flags().String("pidpath", defaultPidPath, "pathname of the menu pidfile")
 	viper.BindPFlag("menu.pidpath", menuCmd.Flags().Lookup("pidpath"))
 
+	menuCmd.Flags().DurationVar(&delay, "delay", delay, "delay before asking for sudo permission")
+
 	rootCmd.AddCommand(menuCmd)
 }
 
@@ -114,11 +117,14 @@ func ensureWaitRunning(cmd *cobra.Command) error {
 		return nil
 	}
 
-	exe, err := os.Executable()
-	if err != nil {
-		return fmt.Errorf("unable to determine executable pathname: %w", err)
+	if delay > time.Second {
+		log.Debug().Dur("delay", delay).Msg("waiting")
 	}
 
+	// this is useful when launching at start of X session to let the
+	// windowing env get set up
+	time.Sleep(delay)
+
 	dpEnv, err := patterns.DesktopPatternEnv()
 	if err != nil {
 		if util.IsTTY(os.Stderr) {
@@ -141,27 +147,50 @@ func ensureWaitRunning(cmd *cobra.Command) error {
 		execArgs = []string{"--user", "root"}
 	}
 
+	execArgs = append(execArgs, buildinfo.App.ExePath)
+
 	config := viper.GetViper().ConfigFileUsed()
 	if config != "" {
-		config = " --config " + config
+		execArgs = append(execArgs, "--config", config)
 	}
 
-	// use sh exec to let parent processes exit
-	hkCmd := fmt.Sprint("export ", dpEnv, "; exec ", exe, config, " run wait &")
-	execArgs = append(execArgs, "sh", "-c", hkCmd)
+	execArgs = append(execArgs, "run", "wait", "--env", dpEnv)
 
 	execStr := fmt.Sprint(execName, " ", strings.Join(execArgs, " "))
 	log.Debug().Str("cmd", execStr).Msg("")
 
-	err = exec.Command(execName, execArgs...).Run()
+	subCmd := exec.Command(execName, execArgs...)
+
+	// send out/err to logs...
+	subLogger := log.With().Str("cmd", execName).Logger()
+	subCmd.Stdout = &util.CommandLogger{Log: func(msg string) { subLogger.Info().Msg(msg) }}
+	subCmd.Stderr = &util.CommandLogger{Log: func(msg string) { subLogger.Error().Msg(msg) }}
+
+	err = subCmd.Start()
 	if err != nil {
 		return fmt.Errorf("unable to run %s: %w", execStr, err)
 	}
 
-	// wait a second for socket to be ready...
+	var subCmdErr error
+
+	go func() {
+		stat, err := subCmd.Process.Wait()
+		if err == nil {
+			subCmdErr = fmt.Errorf("wait process exited: %s", stat)
+		} else {
+			subCmdErr = fmt.Errorf("unable to stat the background wait process: %w", err)
+		}
+	}()
+
+	// wait for user to grant permission to run...
+	const delay = 50 * time.Millisecond
 	sockPath := waitSockPath()
-	for i := 0; i < 10; i += 1 {
-		time.Sleep(50 * time.Millisecond)
+	for timeout := time.Minute; timeout > 0; timeout -= delay {
+		if subCmdErr != nil {
+			return subCmdErr
+		}
+
+		time.Sleep(delay)
 		_, err := os.Stat(sockPath)
 		if err == nil {
 			return nil

cmd/pattern.go

@@ -34,6 +34,7 @@ func init() {
 	addPatternCmd("monitor the desktop picture and change the keyboard color to match", patterns.Get("desktop"))
 
 	//----------------------------------------
+	desktopEnv := ""
 	waitCmd := addPatternCmd("wait for remote commands", patterns.Get("wait"))
 	// wait needs to manage the pidpath and start the IPC server...
 	waitCmd.PreRunE = func(cmd *cobra.Command, args []string) error {
@@ -43,6 +44,12 @@ func init() {
 		if err := waitPidPath.CheckAndSet(); err != nil {
 			return fail(11, err)
 		}
+		if desktopEnv != "" {
+			desktopPattern := patterns.Get("desktop").(*patterns.DesktopPattern)
+			if err := desktopPattern.SetEnv(desktopEnv); err != nil {
+				return err
+			}
+		}
 		return ipcServer.Start(cmd.Context(), &log.Logger, waitSockPath(), rootCmd)
 	}
 	waitCmd.PostRun = func(cmd *cobra.Command, args []string) {
@@ -59,6 +66,9 @@ func init() {
 	waitCmd.Flags().String("sockpath", defaultSockPath, "pathname of the wait sockfile")
 	viper.BindPFlag("wait.sockpath", waitCmd.Flags().Lookup("sockpath"))
 
+	waitCmd.Flags().StringVar(&desktopEnv, "env", desktopEnv, "environment to set for desktop pattern")
+	waitCmd.Flags().MarkHidden("env") // only used by menu
+
 	//----------------------------------------
 	watchPattern := patterns.Get("watch").(*patterns.WatchPattern)
 	watchCmd := addPatternCmd("watch and report color, brightness, and pattern changes", watchPattern)

cmd/pkexec_policy.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE policyconfig PUBLIC "-//freedesktop//DTD PolicyKit Policy Configuration 1.0//EN" "https://specifications.freedesktop.org/PolicyKit/1.0/policyconfig.dtd">
+<policyconfig>
+
+  <vendor>{{ .Vendor }}</vendor>
+  <vendor_url>{{ .URL }}</vendor_url>
+
+  <action id="{{ .ReverseDNS }}">
+    <description>Access System76 keyboard color and brightness devices.</description>
+    <message>{{ .Name }} needs permission to change your keyboard brightness and colors</message>
+    <icon_name>gnome-settings-theme</icon_name>
+    <defaults>
+      <allow_any>no</allow_any>
+      <allow_inactive>no</allow_inactive>
+      <allow_active>auth_admin_keep</allow_active>
+    </defaults>
+    <annotate key="org.freedesktop.policykit.exec.path">{{ .ExePath }}</annotate>
+  </action>
+
+</policyconfig>

cmd/root.go

@@ -2,6 +2,7 @@ package cmd
 
 import (
 	"context"
+	_ "embed"
 	"errors"
 	"fmt"
 	"io"
@@ -10,6 +11,7 @@ import (
 	"os/signal"
 	"path/filepath"
 	"syscall"
+	"text/template"
 
 	"github.com/BitPonyLLC/huekeys/buildinfo"
 	"github.com/BitPonyLLC/huekeys/pkg/ipc"
@@ -78,6 +80,10 @@ func Execute() int {
 
 const logDstLabel = "log-dst"
 const minimalTimeFormat = "15:04:05.000"
+const policyConfigPath = "/usr/share/polkit-1/actions"
+
+//go:embed pkexec_policy.xml
+var policyConfigTemplate string
 
 var failureCode = 1
 var initialized = false
@@ -143,7 +149,7 @@ func atStart(cmd *cobra.Command, _ []string) error {
 	}
 
 	log.Debug().Str("file", viper.ConfigFileUsed()).Msg("config")
-	return nil
+	return checkPolicyConfig()
 }
 
 func atExit() {
@@ -223,6 +229,54 @@ func setupLogging(cmd *cobra.Command, logDst string) error {
 	return nil
 }
 
+func checkPolicyConfig() error {
+	if os.Getuid() != 0 {
+		return nil
+	}
+
+	policyPath := filepath.Join(policyConfigPath, buildinfo.App.ReverseDNS+".policy")
+	cfgF, err := os.OpenFile(policyPath, os.O_RDWR|os.O_CREATE, 0644)
+	if err != nil {
+		return fmt.Errorf("unable to open %s: %w", policyPath, err)
+	}
+	defer cfgF.Close()
+
+	policyStat, err := cfgF.Stat()
+	if err != nil {
+		return fmt.Errorf("unable to stat %s: %w", policyPath, err)
+	}
+
+	if policyStat.Size() > 0 {
+		exeStat, err := os.Stat(buildinfo.App.ExePath)
+		if err != nil {
+			return fmt.Errorf("unable to stat %s: %w", buildinfo.App.ExePath, err)
+		}
+
+		if exeStat.ModTime().Before(policyStat.ModTime()) {
+			log.Debug().Str("policy", policyPath).Msg("unchanged")
+			return nil
+		}
+	}
+
+	err = cfgF.Truncate(0)
+	if err != nil {
+		return fmt.Errorf("unable to truncate %s: %w", policyPath, err)
+	}
+
+	tmpl, err := template.New("policy-config").Parse(policyConfigTemplate)
+	if err != nil {
+		return fmt.Errorf("unable to parse policy template: %w", err)
+	}
+
+	err = tmpl.Execute(cfgF, buildinfo.App)
+	if err != nil {
+		return fmt.Errorf("unable to execute policy template: %w", err)
+	}
+
+	log.Debug().Str("policy", policyPath).Msg("updated")
+	return nil
+}
+
 func fail(code int, formatOrErr interface{}, args ...interface{}) error {
 	failureCode = code
 	if len(args) == 0 {

pkg/patterns/desktop.go

@@ -67,6 +67,34 @@ func DesktopPatternEnv() (string, error) {
 	return desktopPatternKey + "=" + sVal, err
 }
 
+// SetEnv is invoked when the DesktopPattern needs additional environment values
+// to pass along to the gsettings process (e.g. to ensure it monitors the right
+// user desktop).
+func (p *DesktopPattern) SetEnv(env string) error {
+	p.env = &preservedEnv{}
+
+	if env == "" {
+		return nil
+	}
+
+	if strings.HasPrefix(env, desktopPatternKey) {
+		env = env[len(desktopPatternKey)+1:]
+	}
+
+	jVal, err := base64.RawStdEncoding.DecodeString(env)
+	if err != nil {
+		return fmt.Errorf("unable to decode %s (%s): %w", desktopPatternKey, env, err)
+	}
+
+	err = json.Unmarshal(jVal, p.env)
+	if err != nil {
+		return fmt.Errorf("unable to unmarshal %s (%s): %w", desktopPatternKey, env, err)
+	}
+
+	log.Debug().Interface("env", p.env).Msg("using")
+	return nil
+}
+
 //--------------------------------------------------------------------------------
 // private
 
@@ -87,21 +115,7 @@ func init() {
 
 func (p *DesktopPattern) run() error {
 	if p.env == nil {
-		p.env = &preservedEnv{}
-		dp := os.Getenv(desktopPatternKey)
-		if dp != "" {
-			jVal, err := base64.RawStdEncoding.DecodeString(dp)
-			if err != nil {
-				return fmt.Errorf("unable to decode %s (%s): %w", desktopPatternKey, dp, err)
-			}
-
-			err = json.Unmarshal(jVal, p.env)
-			if err != nil {
-				return fmt.Errorf("unable to unmarshal %s (%s): %w", desktopPatternKey, dp, err)
-			}
-
-			log.Debug().Interface("env", p.env).Msg("using")
-		}
+		p.SetEnv(os.Getenv(desktopPatternKey))
 	}
 
 	colorScheme, err := p.getDesktopSetting("interface", "color-scheme")