Pull down repository on receiving a webhook! (+ basic error checking)

main.go

@@ -2,19 +2,82 @@ package main
 
 import (
 	"encoding/json"
+	"fmt"
 	"log"
 	"net/http"
+	"os"
+	"github.com/gogs/git-module"
 )
 
+type DeployError struct {
+	code int
+	where string
+	details string
+}
+func newDeployError(code int, where string, details string) DeployError {
+	return DeployError{ code: code, where: where, details: details }
+}
+
+// fileExists returns whether the given file or directory exists.
+func fileExists(path string) (bool, error) {
+    _, err := os.Stat(path)
+    if err == nil { return true, nil }
+    if os.IsNotExist(err) { return false, nil }
+    return false, err
+}
+
+// startServer attempts to start a Lapis server in the given repository.
+func startServer(name string) DeployError {
+	
+	return DeployError{}
+}
+
+// pullRepo attempts to pull or clone a repository using the given name and url
+func pullRepo(url string, name string) DeployError  {	
+	exists, err := fileExists(name)
+	if err != nil {
+		return newDeployError(1, "fileExists",
+			fmt.Sprintf("Failed to check whether folder '%s' exists while pulling down repository '%s'!", name, name))
+	}
+	if !exists {	
+		if err = git.Clone(url, name); err != nil {
+			return newDeployError(1, "pullRepo", fmt.Sprintf("Failed to pull down repository '%s'", name))
+		}
+	} else {
+		repo,err := git.Open(name)	
+		if err != nil {
+			return newDeployError(1, "pullRepo", fmt.Sprintf("Failed to open git repository '%s'", name))
+		}
+		repo.Pull()
+	}
+	return DeployError{}
+}
+
+func handler(data map[string]interface{}) {
+	repository := data["repository"].(map[string]interface{})
+	log.Default().Printf("Repo: %s", repository["full_name"])
+	log.Default().Printf("Ref: %s", data["ref"])
+
+
+	deploy_error := pullRepo(repository["ssh_url"].(string), repository["name"].(string))
+	if deploy_error.code != 0 {
+		log.Default().Printf("Error in %s! [Code: %d] (%s)", deploy_error.where, deploy_error.code, deploy_error.details)
+	}
+	//syscall.Chdir(repository["name"].(string))
+	//syscall.Exec("lapis", []string{"serve"}, []string{"production"})
+}
+
 func main()  {
 	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request){
 		var data map[string]interface{}
 		err := json.NewDecoder(r.Body).Decode(&data)
 		if err != nil {
-			http.Error(w, err.Error(), http.StatusBadRequest)
+			log.Panic(err)
 			return
 		}
-		log.Default().Printf("Ref: %s", data["ref"])
+
+		go handler(data)
+		fmt.Fprint(w, "Received!")
 	})
-	log.Fatal(http.ListenAndServe(":8080", nil))
+	log.Fatal(http.ListenAndServe(":7575", nil))
 }