util: check for instances file in app dir

It is possible to have an application without init.lua script.
Script names can be specified using instances file. So if the directory
contains instances file, it must be treated as a multi-instance
application.

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ### Changed
 
 - Set `compat.fiber_slice_default` to `new` by default in cartridge application template.
+- Treat the directory containing the instances file (instances.y[a]ml) as an application.
 
 ### Added
 

cli/running/running.go

@@ -225,13 +225,17 @@ func findInstSeparator(inst string) int {
 func getInstancesFromYML(dirPath string, selectedInstName string) ([]InstanceCtx,
 	error) {
 	instances := []InstanceCtx{}
-	instCfgPath := path.Join(dirPath, "instances.yml")
+
 	defAppPath := path.Join(dirPath, "init.lua")
 	defAppExist := false
 	if _, err := os.Stat(defAppPath); err == nil {
 		defAppExist = true
 	}
 
+	instCfgPath, err := util.GetYamlFileName(path.Join(dirPath, "instances.yml"), true)
+	if err != nil {
+		return nil, err
+	}
 	ymlData, err := ioutil.ReadFile(instCfgPath)
 	if err != nil {
 		return nil, err
@@ -282,7 +286,6 @@ func getInstancesFromYML(dirPath string, selectedInstName string) ([]InstanceCtx
 
 // CollectInstances searches all instances available in application.
 func CollectInstances(appName string, appDir string) ([]InstanceCtx, error) {
-	var err error
 	var appPath string
 
 	// The user can select a specific instance from the application.
@@ -320,9 +323,8 @@ func CollectInstances(appName string, appDir string) ([]InstanceCtx, error) {
 		}
 		appPath = luaPath
 	} else if dirStatErr == nil && dirInfo.IsDir() {
-		// Search for instances.yml
-		instCfgPath := path.Join(dirPath, "instances.yml")
-		if _, err = os.Stat(instCfgPath); err == nil {
+		// Search for instances.yml.
+		if _, err := util.GetYamlFileName(path.Join(dirPath, "instances.yml"), true); err == nil {
 			return getInstancesFromYML(dirPath, selectedInstName)
 		} else {
 			appPath = path.Join(dirPath, "init.lua")

cli/util/util.go

@@ -691,19 +691,22 @@ func IsApp(path string) bool {
 		return false
 	}
 
-	if !entry.IsDir() && filepath.Ext(entry.Name()) != ".lua" {
-		return false
-	} else if !entry.IsDir() && filepath.Ext(entry.Name()) == ".lua" {
-		return true
-	}
-
-	if _, err = os.Stat(filepath.Join(path, "init.lua")); err == nil && entry.IsDir() {
-		return true
-	} else if entry.IsDir() {
-		return false
+	if entry.IsDir() {
+		// Check if the directory contains init.lua script or instances.yml file.
+		for _, fileTocheck := range [...]string{"init.lua", "instances.yml", "instances.yaml"} {
+			if fileInfo, err := os.Stat(filepath.Join(path, fileTocheck)); err == nil {
+				if !fileInfo.IsDir() {
+					return true
+				}
+			}
+		}
+	} else {
+		if filepath.Ext(entry.Name()) == ".lua" {
+			return true
+		}
 	}
 
-	return true
+	return false
 }
 
 // CheckRequiredBinaries returns an error if some binaries not found in PATH

cli/util/util_test.go

@@ -229,7 +229,7 @@ func TestIsApp(t *testing.T) {
 		isApp      bool
 	}{
 		{
-			testName: "Application is directory",
+			testName: "Application is a directory with init.lua",
 			createFunc: func() (string, error) {
 				baseDir := t.TempDir()
 				filePath := filepath.Join(baseDir, "init.lua")
@@ -241,6 +241,32 @@ func TestIsApp(t *testing.T) {
 			},
 			isApp: true,
 		},
+		{
+			testName: "Application is a directory, no init.lua, instances.yml exists",
+			createFunc: func() (string, error) {
+				baseDir := t.TempDir()
+				filePath := filepath.Join(baseDir, "instances.yml")
+				_, err := os.Create(filePath)
+				if err != nil {
+					return "", err
+				}
+				return baseDir, nil
+			},
+			isApp: true,
+		},
+		{
+			testName: "Application is a directory, no init.lua, instances.yaml exists",
+			createFunc: func() (string, error) {
+				baseDir := t.TempDir()
+				filePath := filepath.Join(baseDir, "instances.yaml")
+				_, err := os.Create(filePath)
+				if err != nil {
+					return "", err
+				}
+				return baseDir, nil
+			},
+			isApp: true,
+		},
 		{
 			testName: "Application is file",
 			createFunc: func() (string, error) {

test/integration/running/multi_inst_app_no_init/instances.enabled/mi_app/instances.yml

@@ -0,0 +1,4 @@
+router:                                                                                         
+
+storage:                                                                                         
+

test/integration/running/multi_inst_app_no_init/instances.enabled/mi_app/router.init.lua

@@ -0,0 +1,12 @@
+local inst_name = os.getenv('TARANTOOL_INSTANCE_NAME')                                          
+local app_name = os.getenv('TARANTOOL_APP_NAME')                                                
+
+while true do                                                                                   
+    print("custom init file...")                                                                
+    if app_name ~= nil and inst_name ~= nil then                                                
+        print(app_name .. ":" .. inst_name)                                                     
+    else                                                                                        
+        print("unknown instance")                                                               
+    end                                                                                         
+    require("fiber").sleep(1)                                                                   
+end

test/integration/running/multi_inst_app_no_init/instances.enabled/mi_app/storage.init.lua

@@ -0,0 +1,11 @@
+local inst_name = os.getenv('TARANTOOL_INSTANCE_NAME')                                          
+local app_name = os.getenv('TARANTOOL_APP_NAME')                                                
+
+while true do                                                                                   
+    if app_name ~= nil and inst_name ~= nil then                                                
+        print(app_name .. ":" .. inst_name)                                                     
+    else                                                                                        
+        print("unknown instance")                                                               
+    end                                                                                         
+    require("fiber").sleep(1)                                                                   
+end 

test/integration/running/multi_inst_app_no_init/tt.yaml

@@ -0,0 +1,3 @@
+tt:
+  app:
+    instances_enabled: instances.enabled

test/integration/running/test_running.py

@@ -729,3 +729,63 @@ def test_running_start(tt_cmd):
             # Check that the process was terminated correctly.
             instance_process_rc = instance_process.wait(1)
             assert instance_process_rc == 0
+
+
+def test_running_instance_from_multi_inst_app_no_init_script(tt_cmd):
+    test_app_path_src = os.path.join(os.path.dirname(__file__), "multi_inst_app_no_init")
+
+    # Default temporary directory may have very long path. This can cause socket path buffer
+    # overflow. Create our own temporary directory.
+    with tempfile.TemporaryDirectory() as tmpdir:
+        test_env_path = os.path.join(tmpdir, "tt_env")
+        shutil.copytree(test_app_path_src, test_env_path)
+
+        def empty():
+            pass
+
+        def rename():
+            os.rename(os.path.join(test_env_path, "instances.enabled", "mi_app", "instances.yml"),
+                      os.path.join(test_env_path, "instances.enabled", "mi_app", "instances.yaml"))
+
+        for modify_func in [empty, rename]:
+            modify_func()
+
+            # Start the application.
+            start_cmd = [tt_cmd, "start", "mi_app"]
+            instance_process = subprocess.Popen(
+                start_cmd,
+                cwd=test_env_path,
+                stderr=subprocess.STDOUT,
+                stdout=subprocess.PIPE,
+                text=True
+            )
+            start_output = instance_process.stdout.readline()
+            assert "Starting an instance [mi_app:" in start_output
+            assert "Starting an instance [mi_app:" in start_output
+            # Check that the process was terminated correctly.
+            instance_process_rc = instance_process.wait(5)
+            assert instance_process_rc == 0
+
+            # Check status.
+            file = wait_file(os.path.join(test_env_path, run_path, "mi_app", "router"),
+                             "router.pid", [])
+            assert file != ""
+            file = wait_file(os.path.join(test_env_path, run_path, "mi_app", "storage"),
+                             "storage.pid", [])
+            assert file != ""
+
+            for inst in ["router", "storage"]:
+                status_cmd = [tt_cmd, "status", "mi_app:" + inst]
+                status_rc, status_out = run_command_and_get_output(status_cmd, cwd=test_env_path)
+                assert status_rc == 0
+                status_out = extract_status(status_out)
+                assert status_out[f"mi_app:{inst}"]["STATUS"] == "RUNNING"
+
+            # Stop the Instance.
+            stop_cmd = [tt_cmd, "stop", "mi_app"]
+            stop_rc, stop_out = run_command_and_get_output(stop_cmd, cwd=test_env_path)
+            assert stop_rc == 0
+            assert re.search(r"The Instance mi_app:router \(PID = \d+\) has been terminated.",
+                             stop_out)
+            assert re.search(r"The Instance mi_app:storage \(PID = \d+\) has been terminated.",
+                             stop_out)