Move Git hook logic to Opengist (#213)

internal/hooks/post-receive.go

@@ -0,0 +1,43 @@
+package hooks
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"strings"
+)
+
+func PostReceive(in io.Reader, out, er io.Writer) error {
+	scanner := bufio.NewScanner(in)
+	for scanner.Scan() {
+		line := scanner.Text()
+		parts := strings.Fields(line)
+		if len(parts) != 3 {
+			_, _ = fmt.Fprintln(er, "Invalid input")
+			return fmt.Errorf("invalid input")
+		}
+		oldrev, _, refname := parts[0], parts[1], parts[2]
+
+		if err := verifyHEAD(); err != nil {
+			setSymbolicRef(refname)
+		}
+
+		if oldrev == BaseHash {
+			_, _ = fmt.Fprintf(out, "\nYour new repository has been created here: %s\n\n", os.Getenv("OPENGIST_REPOSITORY_URL_INTERNAL"))
+			_, _ = fmt.Fprintln(out, "If you want to keep working with your gist, you could set the remote URL via:")
+			_, _ = fmt.Fprintf(out, "git remote set-url origin %s\n\n", os.Getenv("OPENGIST_REPOSITORY_URL_INTERNAL"))
+		}
+	}
+
+	return nil
+}
+
+func verifyHEAD() error {
+	return exec.Command("git", "rev-parse", "--verify", "--quiet", "HEAD").Run()
+}
+
+func setSymbolicRef(refname string) {
+	_ = exec.Command("git", "symbolic-ref", "HEAD", refname).Run()
+}