Add git commmand helper

1 files changed, 53 insertions, 0 deletions

diff --git a/internal/helper/command.go b/internal/helper/command.go
new file mode 100644
index 000000000..c9c0cdf94
--- /dev/null
+++ b/internal/helper/command.go
@@ -0,0 +1,53 @@
+package helper
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"syscall"
+)
+
+// Command encapsulates operations with commands creates with NewCommand
+type Command struct {
+	io.Reader
+	*exec.Cmd
+}
+
+// Kill cleans the subprocess group of the command. Callers should defer a call
+// to kill after they get the command from NewCommand
+func (c *Command) Kill() {
+	CleanUpProcessGroup(c.Cmd)
+}
+
+// GitCommand creates a git Command with the given args
+func GitCommand(args ...string) (*Command, error) {
+	return NewCommand(exec.Command("git", args...))
+}
+
+// NewCommand creates a Command from an exec.Cmd
+func NewCommand(cmd *exec.Cmd) (*Command, error) {
+	// Explicitly set the environment for the command
+	cmd.Env = []string{
+		fmt.Sprintf("HOME=%s", os.Getenv("HOME")),
+		fmt.Sprintf("PATH=%s", os.Getenv("PATH")),
+		fmt.Sprintf("LD_LIBRARY_PATH=%s", os.Getenv("LD_LIBRARY_PATH")),
+	}
+
+	// Start the command in its own process group (nice for signalling)
+	cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
+
+	// If we don't do something with cmd.Stderr, Git errors will be lost
+	cmd.Stderr = os.Stderr
+
+	stdout, err := cmd.StdoutPipe()
+	if err != nil {
+		return nil, fmt.Errorf("GitCommand: stdout: %v", err)
+	}
+
+	if err := cmd.Start(); err != nil {
+		return nil, fmt.Errorf("GitCommand: start %v: %v", cmd.Args, err)
+	}
+
+	return &Command{Reader: stdout, Cmd: cmd}, nil
+}