Resolve url for dstack login

src/dstack/_internal/cli/commands/login.py

@@ -7,7 +7,7 @@
 from typing import Optional
 
 from dstack._internal.cli.commands import BaseCommand
-from dstack._internal.cli.utils.common import console
+from dstack._internal.cli.utils.common import console, resolve_url
 from dstack._internal.core.errors import ClientError, CLIError
 from dstack._internal.core.models.users import UserWithCreds
 from dstack.api._public.runs import ConfigManager
@@ -202,19 +202,13 @@ def _create_server(self, handler: type[BaseHTTPRequestHandler]) -> HTTPServer:
 
 
 def _normalize_url_or_error(url: str) -> str:
-    if not url.startswith("http://") and not url.startswith("https://"):
-        url = "http://" + url
-    parsed = urllib.parse.urlparse(url)
-    if (
-        not parsed.scheme
-        or not parsed.hostname
-        or parsed.path not in ("", "/")
-        or parsed.params
-        or parsed.query
-        or parsed.fragment
-        or (parsed.port is not None and not (1 <= parsed.port <= 65535))
-    ):
-        raise CLIError("Invalid server URL format. Format: --url https://sky.dstack.ai")
+    try:
+        # Validate the URL and determine the URL scheme.
+        # Need to resolve the scheme before making first POST request
+        # since for some redirect codes (301), clients change POST to GET.
+        url = resolve_url(url)
+    except ValueError as e:
+        raise CLIError(e.args[0])
     return url
 
 

src/dstack/_internal/cli/utils/common.py

@@ -3,6 +3,7 @@
 from pathlib import Path
 from typing import Any, Dict, Optional, Union
 
+import requests
 from rich.console import Console
 from rich.prompt import Confirm
 from rich.table import Table
@@ -128,3 +129,20 @@ def get_start_time(since: Optional[str]) -> Optional[datetime]:
         return parse_since(since)
     except ValueError as e:
         raise CLIError(e.args[0])
+
+
+def resolve_url(url: str, timeout: float = 5.0) -> str:
+    """
+    Starts with http:// and follows redirects. Returns the final URL (including scheme).
+    """
+    if not url.startswith("http://") and not url.startswith("https://"):
+        url = "http://" + url
+    try:
+        response = requests.get(
+            url,
+            allow_redirects=True,
+            timeout=timeout,
+        )
+    except requests.exceptions.ConnectionError as e:
+        raise ValueError(f"Failed to resolve url {url}") from e
+    return response.url

src/tests/_internal/cli/commands/test_login.py

@@ -13,8 +13,12 @@ def test_login_no_projects(self, capsys: CaptureFixture, tmp_path: Path):
             patch("dstack._internal.cli.commands.login.webbrowser") as webbrowser_mock,
             patch("dstack._internal.cli.commands.login.APIClient") as APIClientMock,
             patch("dstack._internal.cli.commands.login._LoginServer") as LoginServerMock,
+            patch(
+                "dstack._internal.cli.commands.login._normalize_url_or_error"
+            ) as _normalize_url_or_error_mock,
         ):
             webbrowser_mock.open.return_value = True
+            _normalize_url_or_error_mock.return_value = "http://127.0.0.1:31313"
             APIClientMock.return_value.auth.list_providers.return_value = [
                 SimpleNamespace(name="github", enabled=True)
             ]
@@ -49,7 +53,11 @@ def test_login_configures_projects(self, capsys: CaptureFixture, tmp_path: Path)
             patch("dstack._internal.cli.commands.login.APIClient") as APIClientMock,
             patch("dstack._internal.cli.commands.login.ConfigManager") as ConfigManagerMock,
             patch("dstack._internal.cli.commands.login._LoginServer") as LoginServerMock,
+            patch(
+                "dstack._internal.cli.commands.login._normalize_url_or_error"
+            ) as _normalize_url_or_error_mock,
         ):
+            _normalize_url_or_error_mock.return_value = "http://127.0.0.1:31313"
             webbrowser_mock.open.return_value = True
             APIClientMock.return_value.auth.list_providers.return_value = [
                 SimpleNamespace(name="github", enabled=True)