+ default credentials support

https://googleapis.dev/python/google-auth/latest/reference/google.auth.html#google.auth.default

https://developers.google.com/identity/protocols/application-default-credentials

README.md

@@ -1,11 +1,86 @@
 # sync_ics2gcal
 
+[![PyPI version](https://badge.fury.io/py/sync-ics2gcal.svg)](https://badge.fury.io/py/sync-ics2gcal)
 [![Build Status](https://travis-ci.org/b4tman/sync_ics2gcal.svg?branch=master)](https://travis-ci.org/b4tman/sync_ics2gcal)
-[![Dependabot Status](https://api.dependabot.com/badges/status?host=github&repo=b4tman/sync_ics2gcal)](https://dependabot.com)
+[![Dependabot Status](https://api.dependabot.com/badges/status?host=github&repo=b4tman/sync_ics2gcal)](https://dependabot.com)
+[![FOSSA Status](https://app.fossa.io/api/projects/git%2Bgithub.com%2Fb4tman%2Fsync_ics2gcal.svg?type=shield)](https://app.fossa.io/projects/git%2Bgithub.com%2Fb4tman%2Fsync_ics2gcal?ref=badge_shield)
 ![Python package status](https://github.com/b4tman/sync_ics2gcal/workflows/Python%20package/badge.svg)
 
 Python scripts for sync .ics file with Google calendar
 
+## Installation
+
+To install from [PyPI](https://pypi.org/project/sync-ics2gcal/) with [pip](https://pypi.python.org/pypi/pip), run:
+
+```
+pip install sync-ics2gcal
+```
+
+
+Or download source code and install:
+
+```
+python setup.py install
+```
+
+## Configuration
+
+### Create application in Google API Console
+1. Create a new project: https://console.developers.google.com/project
+2. Choose the new project from the top right project dropdown (only if another project is selected)
+3. In the project Dashboard, choose "Library"
+4. Find and Enable "Google Calendar API"
+5. In the project Dashboard, choose "Credentials"
+6. In the "Service Accounts" group, click to "Manage service accounts"
+7. Click "Create service account"
+8. Choose service account name and ID
+9. Go back to "Service Accounts" group in "Credentials"
+10. Edit service account and click "Create key", choose JSON and download key file.
+
+### Create working directory
+For example: `/home/user/myfolder`.
+1. Save service account key in file `service-account.json`.
+2. Download [sample config](https://github.com/b4tman/sync_ics2gcal/blob/develop/sample-config.yml) and save to file `config.yml`. For example:
+```
+wget https://raw.githubusercontent.com/b4tman/sync_ics2gcal/develop/sample-config.yml -O config.yml
+```
+3. *(Optional)* Place source `.ics` file, `my-calendar.ics` for example.
+
+### Configuration parameters
+* `start_from` - start date:
+  * full format datetime, `2018-04-03T13:23:25.000001Z` for example
+  * or just `now`
+* *(Optional)* `service_account` - service account filename, remove it from config to use [default credentials](https://developers.google.com/identity/protocols/application-default-credentials)
+* *(Optional)* `logging` - [config](https://docs.python.org/3.8/library/logging.config.html#dictionary-schema-details) to setup logging
+* `google_id` - target google calendar id, `my-calendar@group.calendar.google.com` for example
+* `source` - source `.ics` filename, `my-calendar.ics` for example
+
+
+## Usage
+
+### Manage calendars
+
+```
+manage-ics2gcal <subcommand> [-h] [options]
+```
+
+subcomands:
+* **list** - list calendars
+* **create** - create calendar
+* **add_owner** - add owner to calendar
+* **remove** - remove calendar
+* **rename** - rename calendar
+
+Use **-h** for more info.
+
+### Sync calendar
+
+just type:
+```
+sync-ics2gcal
+```
+
+
 ## How it works
 
 ![How it works](how-it-works.png)

sync_ics2gcal/gcal.py

@@ -14,6 +14,21 @@ class GoogleCalendarService():
         service Resource
     """
 
+    @staticmethod
+    def default():
+        """make service Resource from default credentials (authorize)
+        ( https://developers.google.com/identity/protocols/application-default-credentials )
+        ( https://googleapis.dev/python/google-auth/latest/reference/google.auth.html#google.auth.default )
+
+        Returns:
+            service Resource
+        """
+
+        scopes = ['https://www.googleapis.com/auth/calendar']
+        credentials, _ = google.auth.default(scopes=scopes)
+        service = discovery.build('calendar', 'v3', credentials=credentials)
+        return service
+    
     @staticmethod
     def from_srv_acc_file(service_account_file):
         """make service Resource from service account filename (authorize)
@@ -27,6 +42,26 @@ class GoogleCalendarService():
         scoped_credentials = credentials.with_scopes(scopes)
         service = discovery.build('calendar', 'v3', credentials=scoped_credentials)
         return service
+    
+    @staticmethod
+    def from_config(config):
+        """make service Resource from config dict
+
+        Arguments:
+        config -- dict() config with keys:
+                    (optional) service_account: - service account filename
+                    if key not in dict then default credentials will be used
+                    ( https://developers.google.com/identity/protocols/application-default-credentials )
+
+        Returns:
+            service Resource
+        """
+
+        if 'service_account' in config:
+            service = GoogleCalendarService.from_srv_acc_file(config['service_account'])
+        else:
+            service = GoogleCalendarService.default()
+        return service
 
 def select_event_key(event):
     """select event key for logging

sync_ics2gcal/manage_calendars.py

@@ -86,8 +86,7 @@ def main():
     if 'logging' in config:
         logging.config.dictConfig(config['logging'])
 
-    srv_acc_file = config['service_account']
-    service = GoogleCalendarService.from_srv_acc_file(srv_acc_file)
+    service = GoogleCalendarService.from_config(config)
 
     if 'list' == args.command:
         list_calendars(service)

sync_ics2gcal/sync_calendar.py

@@ -34,14 +34,13 @@ def main():
 
     calendarId = config['calendar']['google_id']
     ics_filepath = config['calendar']['source']
-    srv_acc_file = config['service_account']
 
     start = get_start_date(config['start_from'])
 
     converter = CalendarConverter()
     converter.load(ics_filepath)
 
-    service = GoogleCalendarService.from_srv_acc_file(srv_acc_file)
+    service = GoogleCalendarService.from_config(config)
     gcalendar = GoogleCalendar(service, calendarId)
 
     sync = CalendarSync(gcalendar, converter)