Chapter 4 - clean up code, switch to f-strings, remove tokens, and unwanted fluff

.gitignore

@@ -1,3 +1,3 @@
 **/*.pyc
-**/venv/*
+**/*venv/*
 **/.idea/*

source-code/chapter-4/exercise-1/docker-hello-world/Dockerfile

@@ -1,9 +1,8 @@
 FROM python:3-alpine
 
-LABEL author="sathyabhat"
 LABEL description="Dockerfile for Python script which prints Hello, Name"
 
 COPY hello-world.py /app/
-ENV NAME=Sathya
+ENV NAME=Readers
 CMD python3 /app/hello-world.py
 

source-code/chapter-4/exercise-1/docker-hello-world/hello-world.py

@@ -1,10 +1,8 @@
 #!/usr/bin/env python3
-
 from os import getenv
 
 if getenv('NAME') is None:
     name = 'World'
 else:
     name = getenv('NAME')
-
-print("Hello, {}!".format(name))
+print(f"Hello, {name}!")

source-code/chapter-4/exercise-2/README.md

@@ -1,3 +1,6 @@
 ### README
 
-This exercise contains the source code for the second exercise of chapter 4. In this exercise, you will build two Docker images, the first one using a standard build process using python:3 as the base image.
+This exercise contains the source code for the second exercise of chapter 4. In this exercise, you will build two Docker images
+
+ - Using the standard build process using python:3 as the base image (present in [docker-multi-stage/standard-build](docker-multi-stage/standard-build) directory. 
+ - Using Multi-Stage builds (present [docker-multi-stage/multistage-build](docker-multi-stage/multistage-build) directory. 

source-code/chapter-4/exercise-2/docker-multi-stage/multistage-build/requirements.txt

@@ -1 +1 @@
-praw
+praw==3.6.0

source-code/chapter-4/exercise-2/docker-multi-stage/standard-build/Dockerfile

@@ -1,4 +1,3 @@
 FROM python:3
 COPY requirements.txt .
 RUN pip install -r requirements.txt
-

source-code/chapter-4/exercise-2/docker-multi-stage/standard-build/requirements.txt

@@ -1 +1 @@
-praw
+praw==3.6.0

source-code/chapter-4/exercise-3/README.md

@@ -1,3 +1,20 @@
 ### README
 
-This exercise contains the source code for the third exercise of chapter 4. In this exercise, we’ll try writing the Dockerfile for the project.
+This exercise contains the source code for the third exercise of chapter 4. In this exercise, we compose a Dockerfile for Newsbot and then use the Dockerfile to build a Docker image and run the container.
+
+
+### Building the Docker image
+
+Build the image using the below command
+
+```
+docker build -t sathyabhat/newsbot
+```
+
+Run the container using 
+
+```
+docker run -e NBT_ACCESS_TOKEN=<token> sathyabhat/newsbot
+```
+
+Replace `<token>` with the Telegram API Token that was generated. 

source-code/chapter-4/exercise-3/docker-subreddit-fetcher/Dockerfile → source-code/chapter-4/exercise-3/newsbot/Dockerfile

@@ -1,9 +1,5 @@
 FROM python:3-alpine
-
-COPY * /apps/subredditfetcher/
 WORKDIR /apps/subredditfetcher/
+COPY . .
 RUN ["pip", "install", "-r", "requirements.txt"]
-
-ENV NBT_ACCESS_TOKEN="495637361:AAHIhiDTX1UeX17KJy0-FsMZEqEtCFYfcP8"
-
 CMD ["python", "newsbot.py"]

source-code/chapter-4/exercise-3/docker-subreddit-fetcher/constants.py → source-code/chapter-4/exercise-3/newsbot/constants.py

@@ -1,13 +1,15 @@
 __author__ = 'Sathyajith'
 
 from os import environ
+from sys import exit
 ERR_NO_SOURCE = 'No sources defined! Set a source using /source list, of, sub, reddits'
 skip_list = []
 sources_dict = {}
+UPDATE_PERIOD = 1
+FALSE_RESPONSE = {"ok": False}
 
 BOT_KEY = environ.get('NBT_ACCESS_TOKEN')
-REDDIT_CLIENT_ID = environ.get('REDDIT_CLIENT_ID')
-REDDIT_CLIENT_SECRET = environ.get('REDDIT_CLIENT_SECRET')
-API_BASE = 'https://api.telegram.org/bot'
-UPDATE_PERIOD = 6
-FALSE_RESPONSE = {"ok": False}
+if not BOT_KEY:
+    print("Telegram access token not set, exiting.")
+    exit(1)
+API_BASE = f'https://api.telegram.org/bot{BOT_KEY}'

source-code/chapter-4/exercise-3/docker-subreddit-fetcher/newsbot.py → source-code/chapter-4/exercise-3/newsbot/newsbot.py

@@ -12,15 +12,15 @@ def get_last_updated():
         f.close()
     except FileNotFoundError:
         last_updated = 0
-    log.debug('Last updated id: {0}'.format(last_updated))
+    log.debug(f"Last updated id: {last_updated}")
     return last_updated
 
 if __name__ == '__main__':
 
     try:
-        log.debug('Starting up')
+        log.info("Starting up")
         States.last_updated = get_last_updated()
         while True:
             handle_incoming_messages(States.last_updated)
     except KeyboardInterrupt:
-        log.info('Received KeybInterrupt, exiting')
+        log.info("Received KeybInterrupt, exiting")

source-code/chapter-4/exercise-3/newsbot/reddit.py

@@ -0,0 +1,32 @@
+import praw
+from states import log
+
+__author__ = 'Sathyajith'
+
+
+def get_latest_news(sub_reddits):
+    log.debug('Fetching news from reddit')
+    r = praw.Reddit(user_agent='Practical Docker With Python tutorial')
+    # Can change the subreddit or add more.
+    sub_reddits = clean_up_subreddits(sub_reddits)
+    log.debug(f"Fetching subreddits: {sub_reddits}")
+    submissions = r.get_subreddit(sub_reddits).get_top(limit=5)
+    submission_content = ''
+    try:
+        for post in submissions:
+            submission_content += f"{post.title} - {post.url} \n\n"
+    except praw.errors.Forbidden:
+            log.info(f"subreddit {sub_reddits} is private".format())
+            submission_content = "Sorry couldn't fetch; subreddit is private"
+    except praw.errors.InvalidSubreddit:
+            log.info(f"Subreddit {sub_reddits} is invalid or doesn''t exist.")
+            submission_content = "Sorry couldn't fetch; subreddit doesn't seem to exist"
+    except praw.errors.NotFound :
+            log.info(f"Subreddit {sub_reddits} is invalid or doesn''t exist.")
+            submission_content = "Sorry couldn't fetch; something went wrong, please do send a report to @sathyabhat"
+    return submission_content
+
+
+def clean_up_subreddits(sub_reddits):
+    log.debug('Got subreddits to clean: {0}'.format(sub_reddits))
+    return sub_reddits.strip().replace(" ", "").replace(',', '+')

source-code/chapter-4/exercise-3/newsbot/requirements.txt

@@ -0,0 +1,2 @@
+praw==3.6.0
+requests==2.20.0

source-code/chapter-4/exercise-3/docker-subreddit-fetcher/telegram.py → source-code/chapter-4/exercise-3/newsbot/telegram.py

@@ -10,9 +10,9 @@
 
 
 def get_updates(last_updated):
-    log.debug('Checking for requests, last updated passed is: {}'.format(last_updated))
+    log.debug('Checking for requests, last updated passed is: {last_updated}')
     sleep(UPDATE_PERIOD)
-    response = requests.get(API_BASE + BOT_KEY + '/getUpdates', params={'offset': last_updated+1})
+    response = requests.get(f"{API_BASE}/getUpdates", params={'offset': last_updated+1})
     json_response = FALSE_RESPONSE
     if response.status_code != 200:
         # wait for a bit, try again
@@ -23,46 +23,49 @@ def get_updates(last_updated):
     except ValueError:
         sleep(UPDATE_PERIOD*20)
         get_updates(last_updated)
-    log.info('received response: {}'.format(json_response))
+    log.info(f"received response: {json_response}")
     return json_response
 
 
 def post_message(chat_id, text):
-    log.info('posting {} to {}'.format(text, chat_id))
+    log.debug(f"posting {text} to {chat_id}")
     payload = {'chat_id': chat_id, 'text': text}
-    requests.post(API_BASE + BOT_KEY + '/sendMessage', data=payload)
+    requests.post(f"{API_BASE}/sendMessage", data=payload)
 
 
 def handle_incoming_messages(last_updated):
     r = get_updates(last_updated)
     split_chat_text = []
     if r['ok']:
         for req in r['result']:
-            chat_sender_id = req['message']['chat']['id']
+            if 'message' in req:
+                chat_sender_id = req['message']['chat']['id']
+            else:
+                chat_sender_id = req['edited_message']['chat']['id']
             try:
                 chat_text = req['message']['text']
                 split_chat_text = chat_text.split()
             except KeyError:
                 chat_text = ''
                 split_chat_text.append(chat_text)
                 log.debug('Looks like no chat text was detected... moving on')
-            try:
+
+            if 'message' in req:
                 person_id = req['message']['from']['id']
-            except KeyError:
-                pass
+            else:
+                person_id = req['edited_message']['from']['id']
 
-            log.info('Chat text received: {0}'.format(chat_text))
+            log.info(f"Chat text received: {chat_text}")
             r = re.search('(source+)(.*)', chat_text)
 
             if (r is not None and r.group(1) == 'source'):
                 if r.group(2):
                     sources_dict[person_id] = r.group(2)
-                    log.debug('Sources set for {0} to {1}'.format(sources_dict[person_id], r.group(2)))
-                    post_message(person_id, 'Sources set as {0}!'.format(r.group(2)))
+                    post_message(person_id, f"Sources set as {r.group(2)}!")
                 else:
                     post_message(person_id, 'We need a comma separated list of subreddits! No subreddit, no news :-(')
             if chat_text == '/stop':
-                log.debug('Added {0} to skip list'.format(chat_sender_id))
+                log.debug(f"Added {chat_sender_id} to skip list")
                 skip_list.append(chat_sender_id)
                 post_message(chat_sender_id, "Ok, we won't send you any more messages.")
 
@@ -89,5 +92,5 @@ def handle_incoming_messages(last_updated):
                 f.write(str(last_updated))
                 States.last_updated = last_updated
                 log.debug(
-                    'Updated last_updated to {0}'.format(last_updated))
+                    f'Updated last_updated to {last_updated}')
             f.close()