Detect user based on key, username or id

This allows gitlab-shell to be called with an argument of the format
`key-123` or `username-name`.

When called in this way, `gitlab-shell` will call the GitLab internal
API. If the API responds with user information, it will print a
welcome message including the username.

If the API responds with a successful but empty response, gitlab-shell
will print a welcome message for an anonymous user.

If the API response includes an error message in JSON, this message
will be printed to stderr.

If the API call fails, an error message including the status code will
be printed to stderr.

1 files changed, 56 insertions, 0 deletions

diff --git a/go/internal/gitlabnet/testserver/testserver.go b/go/internal/gitlabnet/testserver/testserver.go
new file mode 100644
index 0000000..9640fd7
--- /dev/null
+++ b/go/internal/gitlabnet/testserver/testserver.go
@@ -0,0 +1,56 @@
+package testserver
+
+import (
+	"io/ioutil"
+	"log"
+	"net"
+	"net/http"
+	"os"
+	"path"
+	"path/filepath"
+)
+
+var (
+	tempDir, _ = ioutil.TempDir("", "gitlab-shell-test-api")
+	TestSocket = path.Join(tempDir, "internal.sock")
+)
+
+type TestRequestHandler struct {
+	Path    string
+	Handler func(w http.ResponseWriter, r *http.Request)
+}
+
+func StartSocketHttpServer(handlers []TestRequestHandler) (func(), error) {
+	if err := os.MkdirAll(filepath.Dir(TestSocket), 0700); err != nil {
+		return nil, err
+	}
+
+	socketListener, err := net.Listen("unix", TestSocket)
+	if err != nil {
+		return nil, err
+	}
+
+	server := http.Server{
+		Handler: buildHandler(handlers),
+		// We'll put this server through some nasty stuff we don't want
+		// in our test output
+		ErrorLog: log.New(ioutil.Discard, "", 0),
+	}
+	go server.Serve(socketListener)
+
+	return cleanupSocket, nil
+}
+
+func cleanupSocket() {
+	os.RemoveAll(tempDir)
+}
+
+func buildHandler(handlers []TestRequestHandler) http.Handler {
+	h := http.NewServeMux()
+
+	for _, handler := range handlers {
+		h.HandleFunc(handler.Path, handler.Handler)
+	}
+
+	return h
+}