From 28a37d41bd40336c570fcf28c2f8eac4c9e48c2f Mon Sep 17 00:00:00 2001
From: Pavlo Shchelokovskyy <shchelokovskyy@gmail.com>
Date: Thu, 5 Dec 2019 18:13:14 +0200
Subject: [PATCH] Add http.login function

accepts optional path to kubeconfig file and optional name of a context
in the kubeconfig file.
If kubeconfig not specified, first tries to load kubeconfig from service
account. If that is not available too, tries to load configuration from
default local source.
Returns HTTPClient instance configured with loaded config.

Issue #24
---
 pykube/__init__.py  |  2 +-
 pykube/console.py   |  8 ++------
 pykube/http.py      | 28 ++++++++++++++++++++++++++++
 tests/test_login.py | 41 +++++++++++++++++++++++++++++++++++++++++
 tox.ini             |  9 +++++----
 5 files changed, 77 insertions(+), 11 deletions(-)
 create mode 100644 tests/test_login.py

diff --git a/pykube/__init__.py b/pykube/__init__.py
index 012592d..6d9fe4a 100644
--- a/pykube/__init__.py
+++ b/pykube/__init__.py
@@ -6,7 +6,7 @@
 
 from .config import KubeConfig  # noqa
 from .exceptions import KubernetesError, PyKubeError, ObjectDoesNotExist  # noqa
-from .http import HTTPClient  # noqa
+from .http import HTTPClient, login  # noqa
 from .objects import (  # noqa
     object_factory,
     ConfigMap,
diff --git a/pykube/console.py b/pykube/console.py
index 2ea46a6..1247b0b 100644
--- a/pykube/console.py
+++ b/pykube/console.py
@@ -20,12 +20,8 @@ def main(argv=None):
     parser.add_argument('-c', help='Python program passed in as string', metavar='SCRIPT')
     args = parser.parse_args(argv)
 
-    config = pykube.KubeConfig.from_file(args.kubeconfig)
-
-    if args.context:
-        config.set_current_context(args.context)
-
-    api = pykube.HTTPClient(config)
+    api = pykube.login(kubeconfig=args.kubeconfig, kubecontext=args.context)
+    config = api.config
 
     context = {
         '__name__': '__console__',
diff --git a/pykube/http.py b/pykube/http.py
index ccb5004..fdcee52 100644
--- a/pykube/http.py
+++ b/pykube/http.py
@@ -7,6 +7,7 @@
 import posixpath
 import shlex
 import subprocess
+from typing import Optional
 
 try:
     import google.auth
@@ -342,3 +343,30 @@ def delete(self, *args, **kwargs):
            - `kwargs`: Keyword arguments
         """
         return self.session.delete(*args, **self.get_kwargs(**kwargs))
+
+
+def login(
+    kubeconfig: Optional[str] = None,
+    kubecontext: Optional[str] = None,
+) -> HTTPClient:
+    """Make Kubernetes API client.
+
+    :param kubeconfig: (optional) path to kubeconfig,
+                       if not passed will use in-cluster config or
+                       default kubectl ones (in that order of preference)
+    :param kubecontext: (optional) name of the context in the kubeconfig file
+    :return: pykube.HTTPClient
+    """
+    if kubeconfig:
+        # if passed kubeconfig file explicitly - use it
+        config = KubeConfig.from_file(kubeconfig)
+    else:
+        try:
+            # running in cluster
+            config = KubeConfig.from_service_account()
+        except FileNotFoundError:
+            # not running in cluster => load default local KUBECONFIG
+            config = KubeConfig.from_file()
+    if kubecontext:
+        config.set_current_context(kubecontext)
+    return HTTPClient(config)
diff --git a/tests/test_login.py b/tests/test_login.py
new file mode 100644
index 0000000..b44c65c
--- /dev/null
+++ b/tests/test_login.py
@@ -0,0 +1,41 @@
+from unittest import mock
+
+from pykube.http import login
+from . import TestCase
+
+
+@mock.patch('pykube.http.KubeConfig')
+@mock.patch('pykube.http.HTTPClient')
+class TestLogin(TestCase):
+    def test_login_with_config(self, client, config):
+        api = login(kubeconfig='/path/to/file')
+        config.from_file.assert_called_once_with('/path/to/file')
+        config.from_service_account.assert_not_called()
+        config.from_file.return_value.set_current_context.assert_not_called()
+        client.assert_called_once_with(config.from_file.return_value)
+        assert api == client.return_value
+
+    def test_login_with_config_and_context(self, client, config):
+        api = login(kubeconfig='/path/to/file', kubecontext='fake')
+        config.from_file.assert_called_once_with('/path/to/file')
+        config.from_service_account.assert_not_called()
+        config.from_file.return_value.set_current_context.assert_called_once_with('fake')
+        client.assert_called_once_with(config.from_file.return_value)
+        assert api == client.return_value
+
+    def test_login_with_incluster(self, client, config):
+        api = login()
+        config.from_service_account.assert_called_once_with()
+        config.from_file.assert_not_called()
+        config.from_service_account.return_value.set_current_context.assert_not_called()
+        client.assert_called_once_with(config.from_service_account.return_value)
+        assert api == client.return_value
+
+    def test_login_with_default_config(self, client, config):
+        config.from_service_account.side_effect = FileNotFoundError
+        api = login()
+        config.from_service_account.assert_called_once_with()
+        config.from_file.assert_called_once_with()
+        config.from_file.return_value.set_current_context.assert_not_called()
+        client.assert_called_once_with(config.from_file.return_value)
+        assert api == client.return_value
diff --git a/tox.ini b/tox.ini
index 1cfaf28..0936372 100644
--- a/tox.ini
+++ b/tox.ini
@@ -8,10 +8,11 @@ envlist =
 
 [testenv]
 deps =
-    coverage == 4.0.3
-    flake8 == 2.5.4
-    pytest == 2.9.0
-    pytest-cov == 2.2.1
+    coverage == 4.5.4
+    flake8 == 3.7.8
+    pytest == 5.2.1
+    pytest-cov == 2.8.1
+    responses == 0.10.6
 usedevelop = True
 setenv =
    LANG=en_US.UTF-8