chore(docs): add iwa sample script under samples/

Author: shajia-deshaw

sample/integrated_windows_authentication_sample.py

@@ -0,0 +1,87 @@
+"""
+The configuration file would look like this:
+
+{
+    "authority": "https://login.microsoftonline.com/organizations",
+    "client_id": "your_client_id",
+    "username": "your_username@your_tenant.com",
+    "scope": ["User.ReadBasic.All"],
+        // You can find the other permission names from this document
+        // https://docs.microsoft.com/en-us/graph/permissions-reference
+    "endpoint": "https://graph.microsoft.com/v1.0/users"
+        // You can find more Microsoft Graph API endpoints from Graph Explorer
+        // https://developer.microsoft.com/en-us/graph/graph-explorer
+}
+
+You can then run this sample with a JSON configuration file:
+
+    python sample.py parameters.json
+"""
+
+import sys  # For simplicity, we'll read config file from 1st CLI param sys.argv[1]
+import json
+import logging
+import time
+
+import requests
+import msal
+
+
+# Optional logging
+# logging.basicConfig(level=logging.DEBUG)  # Enable DEBUG log for entire script
+# logging.getLogger("msal").setLevel(logging.INFO)  # Optionally disable MSAL DEBUG logs
+
+config = json.load(open(sys.argv[1]))
+
+# If for whatever reason you plan to recreate same ClientApplication periodically,
+# you shall create one global token cache and reuse it by each ClientApplication
+global_token_cache = msal.TokenCache()  # The TokenCache() is in-memory.
+# See more options in https://msal-python.readthedocs.io/en/latest/#tokencache
+
+# Create a preferably long-lived app instance, to avoid the overhead of app creation
+global_app = msal.PublicClientApplication(
+    config["client_id"], authority=config["authority"],
+    client_credential=config.get("client_secret"),
+    token_cache=global_token_cache,  # Let this app (re)use an existing token cache.
+    # If absent, ClientApplication will create its own empty token cache
+)
+
+
+def acquire_and_use_token():
+    # The pattern to acquire a token looks like this.
+    result = None
+
+    # Firstly, check the cache to see if this end user has signed in before
+    accounts = global_app.get_accounts(username=config["username"])
+    if accounts:
+        logging.info("Account(s) exists in cache, probably with token too. Let's try.")
+        result = global_app.acquire_token_silent(config["scope"], account=accounts[0])
+
+    if not result:
+        logging.info("No suitable token exists in cache. Let's get a new one from AAD.")
+        # See this page for constraints of Username Password Flow.
+        # https://github.com/AzureAD/microsoft-authentication-library-for-python/wiki/Username-Password-Authentication
+        result = global_app.acquire_token_integrated_windows_auth(
+            config["username"], scopes=config["scope"])
+
+    if "access_token" in result:
+        print("Token was obtained from:", result["token_source"])  # Since MSAL 1.25
+        # Calling graph using the access token
+        graph_data = requests.get(  # Use token to call downstream service
+            config["endpoint"],
+            headers={'Authorization': 'Bearer ' + result['access_token']},).json()
+        print("Graph API call result: %s" % json.dumps(graph_data, indent=2))
+    else:
+        print("Token acquisition failed")  # Examine result["error_description"] etc. to diagnose error
+        print(result)
+        if 65001 in result.get("error_codes", []):  # Not mean to be coded programatically, but...
+            raise RuntimeError(
+                "AAD requires user consent for U/P flow to succeed. "
+                "Run acquire_token_interactive() instead.")
+
+
+while True:  # Here we mimic a long-lived daemon
+    acquire_and_use_token()
+    print("Press Ctrl-C to stop.")
+    time.sleep(5)  # Let's say your app would run a workload every X minutes.
+