feat: control systemd Docker daemon target

cmd/proxyctl/main.go

@@ -9,6 +9,7 @@ import (
 	tea "github.com/charmbracelet/bubbletea"
 
 	"proxyctl/internal/app"
+	"proxyctl/internal/dockerdaemon"
 	"proxyctl/internal/profile"
 	"proxyctl/internal/shell"
 	"proxyctl/internal/target"
@@ -23,11 +24,17 @@ func main() {
 }
 
 func run(args []string, input io.Reader, output io.Writer) error {
+	return runWithSystemTargets(args, input, output, nil)
+}
+
+// runWithSystemTargets keeps process smoke tests hermetic. A nil slice selects
+// production system Targets; a non-nil slice supplies fakes (or no Targets).
+func runWithSystemTargets(args []string, input io.Reader, output io.Writer, systemTargets []target.Target) error {
 	executable, err := os.Executable()
 	if err != nil {
 		return fmt.Errorf("locate proxyctl executable: %w", err)
 	}
-	return runWithEnvironment(args, input, output, processEnvironment{}, nil, executable)
+	return runWithEnvironmentAndTargets(args, input, output, processEnvironment{}, nil, executable, systemTargets)
 }
 
 type processEnvironment struct{}
@@ -41,6 +48,10 @@ func (processEnvironment) LookupUser(name string) (profile.UserIdentity, error)
 func (processEnvironment) LookupEnv(name string) (string, bool) { return os.LookupEnv(name) }
 
 func runWithEnvironment(args []string, input io.Reader, output io.Writer, environment profile.IdentityEnvironment, files shell.FileSystem, executable string) error {
+	return runWithEnvironmentAndTargets(args, input, output, environment, files, executable, nil)
+}
+
+func runWithEnvironmentAndTargets(args []string, input io.Reader, output io.Writer, environment profile.IdentityEnvironment, files shell.FileSystem, executable string, systemTargets []target.Target) error {
 	profileConfiguration, err := profile.ResolveConfiguration(environment)
 	if err != nil {
 		return err
@@ -74,7 +85,11 @@ func runWithEnvironment(args []string, input io.Reader, output io.Writer, enviro
 	}
 
 	store := profile.NewOwnedFileStoreAt(profileConfiguration.Path, profileConfiguration.Owner, profileConfiguration.TrustedRoot)
-	application, err := app.NewWithTargets(store, []target.Target{shellTarget})
+	if systemTargets == nil {
+		systemTargets = []target.Target{dockerdaemon.New(dockerdaemon.DefaultConfiguration(), nil, nil)}
+	}
+	targets := append([]target.Target{shellTarget}, systemTargets...)
+	application, err := app.NewWithTargets(store, targets)
 	if err != nil {
 		return err
 	}