Add a script to download SA keys in case user looses them

Signed-off-by: lzzy12 <jhashivam2020@gmail.com>

README.md

@@ -54,6 +54,8 @@ Fill up rest of the fields. Meaning of each fields are discussed below:
 - AUTO_DELETE_MESSAGE_DURATION : Interval of time (in seconds), after which the bot deletes it's message (and command message) which is expected to be viewed instantly. Note: Set to -1 to never automatically delete messages
 - IS_TEAM_DRIVE : (Optional field) Set to "True" if GDRIVE_FOLDER_ID is from a Team Drive else False or Leave it empty. 
 - INDEX_URL : (Optional field) Refer to https://github.com/maple3142/GDIndex/ The URL should not have any trailing '/'
+- API_KEY : This is to authenticate to your telegram account for downloading Telegram files. You can get this from https://my.telegram.org DO NOT put this in quotes.
+- API_HASH : This is to authenticate to your telegram account for downloading Telegram files. You can get this from https://my.telegram.org
 - USER_SESSION_STRING : Session string generated by running:
 ```
 python3 generate_string_session.py
@@ -106,6 +108,9 @@ Note: 1 service account can copy around 750gb a day, 1 project makes 100 service
 A folder named accounts will be created which will contain keys for the service accounts created
 ```
 We highly recommend to zip this folder and store it somewhere safe, so that you do not have to create a new project everytime you want to deploy the bot
+
+**However** If you lose it anyway, you can redownload it by running script:
+python3 download_service_accounts.py project_id
 ```
 ### Adding service accounts to Google Groups:
 We use Google Groups to manager our service accounts considering the  

download_service_accounts.py

@@ -0,0 +1,62 @@
+import os
+import sys
+import pickle
+
+from google_auth_oauthlib.flow import InstalledAppFlow
+from google.auth.transport.requests import Request
+from googleapiclient import discovery
+
+OAUTH_SCOPE = ['https://www.googleapis.com/auth/cloud-platform']
+
+
+# noinspection DuplicatedCode
+def authorize():
+    # Get credentials
+    credentials = None
+    if os.path.exists('token-iam.pickle'):
+        with open('token-iam.pickle', 'rb') as f:
+            credentials = pickle.load(f)
+    if credentials is None or not credentials.valid:
+        if credentials and credentials.expired and credentials.refresh_token:
+            credentials.refresh(Request())
+        else:
+            flow = InstalledAppFlow.from_client_secrets_file(
+                'credentials.json', OAUTH_SCOPE)
+            credentials = flow.run_console(port=0)
+
+        # Save the credentials for the next run
+        with open('token-iam.pickle', 'wb') as token:
+            pickle.dump(credentials, token)
+    return discovery.build('iam', 'v1', credentials=credentials)
+
+
+def get_service_accounts(project_id):
+    """Returns a list of service accounts in project with id == project_id"""
+    accounts = service.projects().serviceAccounts().list(
+        name=f'projects/{project_id}').execute()
+    return accounts['accounts']
+
+
+def download_keys(project_id):
+    accounts = get_service_accounts(project_id)
+    print(f'{len(accounts)} service accounts found! Dumping now')
+    i = 0
+    for acc in accounts:
+        if not os.path.exists('accounts/'):
+            os.mkdir('accounts/')
+        if os.path.isfile('accounts/'):
+            os.remove('accounts')
+            os.mkdir('accounts/')
+        print("Dumping " + acc['email'])
+        key = service.projects().serviceAccounts().keys().create(
+            name='projects/-/serviceAccounts/' + acc['email'], body={}
+        ).execute()
+        with open(f'accounts/{i}.json', 'w') as f:
+            f.write(str(key))
+        i += 1
+
+
+service = authorize()
+
+if __name__ == '__main__':
+    download_keys(sys.argv[1])