Optional lambda deploy with zappa, and a little refactoring

.gitignore

@@ -1,4 +1,5 @@
 ve
+venv
 settings.py
 __pycache__
 *.pyc

README.md

@@ -1,13 +1,21 @@
-This Python 3.x script tries to connect to databases and sends a Slack alert with error text if it fails.
+This Python 3.6 script tries to connect to databases and sends a Slack alert with error text if it fails. Note: Python3.6 is compatible with AWS Lambda deployment. If you're not deploying to AWS Lambda, any other verson of Python3 will do.
 
 ## Setup
 
-* Create a Python 3.x virtualenv: `virtualenv -p /path/to/python3 venv`
+* Create a Python 3.6 virtualenv: `virtualenv -p /path/to/python3.6 venv`
 * Activate the virtualenv: `source venv/bin/activate`
-* Install requirements: `pip install -r requirements.txt`
-* Create a settings file and fill it out: `cp settings.py.example settings.py`
+* Create a settings file and fill it out: `cp settings.py.example settings.py`.
+* If you want to deploy the script to lambda, set `lambda_deploy = True` and `pip install -r requirements-lambda.txt`
+* Else, leave `lambda_deploy = False` and `pip install -r requirements-nolambda.txt`
 * Run script with `python check_dbs.py`
 
+## Deploy to AWS Lambda with zappa
+
+* in settings.py, set `lambda_deploy = True`
+* copy zappa_settings.json.example to zappa_settings.json and fill it out
+* set up your AWS creds that allow you to create s3 buckets, and add your target s3 bucket to zappa_settings.json
+* `zappa deploy production` or whatever the name of your stage is
+
 ## TODO:
 
 * Add support for email and SMS alerts.

check_dbs.py

@@ -1,4 +1,4 @@
-from connect import connect_psql, connect_mysql, post_to_slack
+from connect import connect_psql, connect_mysql
 import settings
 
 def main():

connect.py

@@ -1,24 +1,42 @@
-import psycopg2
 import sys
 import settings
 import pymysql.cursors
 import requests
 import json
+if settings.lambda_deploy:
+    import pg8000
+else:
+    import psycopg2
 
+def slack_alert(name, slack_webhook_url = settings.slack_webhook_url):
+    message = "db-status {} connection error: {}".format(name,sys.exc_info())
+    text = json.dumps({ 'text' : message })
+    print(text)
+    if settings.slack_alerts:
+        r = requests.post(slack_webhook_url, data = text)
 
 def connect_psql(psql):
-    try:
-        con = psycopg2.connect(dbname = psql['db'],
-                                host = psql['host'], 
-                                port = psql['port'], 
-                                user = psql['user'], 
-                                password = psql['pwd'])
-        con.close()
-    except:
-        message = "{} connection error: {}".format(psql['name'],sys.exc_info())
-        if settings.slack_alerts:
-            post_to_slack(message)
-
+    if settings.lambda_deploy:
+        try:
+            con = pg8000.connect(database = psql['db'],
+                                    host = psql['host'], 
+                                    port = psql['port'], 
+                                    user = psql['user'], 
+                                    password = psql['pwd'])
+            con.close()
+        except:
+            slack_alert(psql['name'])
+
+    else:
+        try:
+            con = psycopg2.connect(dbname = psql['db'],
+                                    host = psql['host'], 
+                                    port = psql['port'], 
+                                    user = psql['user'], 
+                                    password = psql['pwd'])
+            con.close()
+        except:
+            slack_alert(psql['name'])
 
 def connect_mysql(mysql):
     try:
@@ -30,12 +48,4 @@ def connect_mysql(mysql):
                               cursorclass=pymysql.cursors.DictCursor)
         con.close()
     except:
-        message = "{} connection error: {}".format(mysql['name'],sys.exc_info())
-        if settings.slack_alerts:
-            post_to_slack(message)
-
-
-def post_to_slack(message, slack_webhook_url=settings.slack_webhook_url):
-    text = json.dumps({ 'text' : message })
-    print(text)
-    r = requests.post(slack_webhook_url, data = text)
+        slack_alert(mysql['name'])

requirements-lambda.txt

@@ -0,0 +1,3 @@
+-r requirements.txt
+zappa==0.44.3
+pg8000==1.11.0

requirements-nolambda.txt

@@ -0,0 +1,2 @@
+-r requirements.txt
+psycopg2==2.7.1

requirements.txt

@@ -1,2 +1 @@
-psycopg2==2.7.1
 PyMySQL==0.7.11

settings.py.example

@@ -19,5 +19,6 @@ databases = {
     }
 }
 
-slack_alerts = False
+lambda_deploy = False
+slack_alerts = True
 slack_webhook_url = 'set this up at https://yourslackteam.slack.com/apps/search?q=webhooks'

zappa_settings.json.example

@@ -0,0 +1,15 @@
+{
+    "production": {
+        "app_function": "check_dbs.main",
+        "aws_region": "us-west-1",
+        "profile_name": "default",
+        "project_name": "db-status",
+        "runtime": "python3.6",
+        "s3_bucket": "",
+        "keep_warm": false,
+        "events": [{
+                   "function": "check_dbs.main", // The function to execute
+                   "expression": "rate(15 minutes)" // When to execute it (in cron or rate format)
+               }],
+    }
+}