Add systemd resource budgets with TOML profiles

internal/budget/launch.go

@@ -0,0 +1,52 @@
+package budget
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"syscall"
+)
+
+func systemctl(args ...string) error {
+	cmd := exec.Command("systemctl", append([]string{"--user"}, args...)...)
+	cmd.Stdout, cmd.Stderr = os.Stdout, os.Stderr
+	return cmd.Run()
+}
+
+func runArgs(c config, name, id string, command []string) ([]string, error) {
+	if len(command) > 0 && command[0] == "--" {
+		command = command[1:]
+	}
+	if len(command) == 0 {
+		return nil, fmt.Errorf("a command is required")
+	}
+	values, err := c.assignments(name)
+	if err != nil {
+		return nil, err
+	}
+	slice := "app.slice"
+	if name == "search" {
+		slice = "search.slice"
+	}
+	args := []string{"systemd-run", "--user", "--scope", "--collect", "--quiet", "--unit=work-" + id, "--slice=" + slice}
+	for _, value := range values {
+		args = append(args, "--property="+value)
+	}
+	return append(append(args, "--"), command...), nil
+}
+
+func launch(c config, name string, command []string) error {
+	id, err := randomID()
+	if err != nil {
+		return err
+	}
+	args, err := runArgs(c, name, id, command)
+	if err != nil {
+		return err
+	}
+	path, err := exec.LookPath(args[0])
+	if err != nil {
+		return err
+	}
+	return syscall.Exec(path, args, os.Environ())
+}