Add support for rc versions in upgrader (#15424)

services/upgrader/upgrader_linux.go

@@ -16,6 +16,7 @@ import (
 	"path"
 	"runtime"
 	"strconv"
+	"strings"
 	"sync/atomic"
 	"syscall"
 
@@ -69,7 +70,12 @@ func (wc *writeCounter) Write(p []byte) (int, error) {
 }
 
 func getCurrentVersionTgzUrl() string {
-	return "https://releases.mattermost.com/" + model.CurrentVersion + "/mattermost-" + model.CurrentVersion + "-linux-amd64.tar.gz"
+	version := model.CurrentVersion
+	if strings.HasPrefix(model.BuildNumber, version+"-rc") {
+		version = model.BuildNumber
+	}
+
+	return "https://releases.mattermost.com/" + version + "/mattermost-" + version + "-linux-amd64.tar.gz"
 }
 
 func verifySignature(filename string, sigfilename string, publicKey string) error {

services/upgrader/upgrader_linux_test.go

@@ -35,12 +35,41 @@ func TestCanIUpgradeToE0(t *testing.T) {
 }
 
 func TestGetCurrentVersionTgzUrl(t *testing.T) {
+	t.Run("get release version in regular version", func(t *testing.T) {
 		currentVersion := model.CurrentVersion
+		buildNumber := model.CurrentVersion
 		model.CurrentVersion = "5.22.0"
+		model.BuildNumber = "5.22.0"
 		defer func() {
 			model.CurrentVersion = currentVersion
+			model.BuildNumber = buildNumber
 		}()
 		require.Equal(t, "https://releases.mattermost.com/5.22.0/mattermost-5.22.0-linux-amd64.tar.gz", getCurrentVersionTgzUrl())
+	})
+
+	t.Run("get release version in dev version", func(t *testing.T) {
+		currentVersion := model.CurrentVersion
+		buildNumber := model.CurrentVersion
+		model.CurrentVersion = "5.22.0"
+		model.BuildNumber = "5.22.0-dev"
+		defer func() {
+			model.CurrentVersion = currentVersion
+			model.BuildNumber = buildNumber
+		}()
+		require.Equal(t, "https://releases.mattermost.com/5.22.0/mattermost-5.22.0-linux-amd64.tar.gz", getCurrentVersionTgzUrl())
+	})
+
+	t.Run("get release version in rc version", func(t *testing.T) {
+		currentVersion := model.CurrentVersion
+		buildNumber := model.CurrentVersion
+		model.CurrentVersion = "5.22.0"
+		model.BuildNumber = "5.22.0-rc2"
+		defer func() {
+			model.CurrentVersion = currentVersion
+			model.BuildNumber = buildNumber
+		}()
+		require.Equal(t, "https://releases.mattermost.com/5.22.0-rc2/mattermost-5.22.0-rc2-linux-amd64.tar.gz", getCurrentVersionTgzUrl())
+	})
 }
 
 func TestExtractBinary(t *testing.T) {