Adding flask db monitors so HAProxy can ping dbs without relying on django and other dbs.

fabfile.py

@@ -790,6 +790,14 @@ def downgrade_pil():
         sudo('supervisorctl reload')
         # kill()
 
+def setup_db_monitor():
+    pull()
+    with cd(env.NEWSBLUR_PATH):
+        sudo('pip install -r flask/requirements.txt')
+        put('flask/supervisor_db_montior.conf', '/etc/supervisor/conf.d/db_monitor.conf', use_sudo=True)
+        sudo('supervisorctl reread')
+        sudo('supervisorctl update')
+        
 # ==============
 # = Setup - DB =
 # ==============

flask/db_monitor.py

@@ -0,0 +1,129 @@
+from flask import Flask, abort
+import flask_settings as settings
+import psycopg2
+import MySQLdb
+import pymongo
+import redis
+import pyes
+app = Flask(__name__)
+
+@app.route("/db_check/postgres")
+def db_check_postgres():
+    connect_params = "dbname='%s' user='%s' password='%s' host='%s' port='%s'" % (
+        settings.DATABASES['default']['NAME'],
+        settings.DATABASES['default']['USER'],
+        settings.DATABASES['default']['PASSWORD'],
+        settings.DATABASES['default']['HOST'],
+        settings.DATABASES['default']['PORT'],
+    )
+    try:
+        conn = psycopg2.connect(connect_params)
+    except:
+        print " ---> Postgres can't connect to the database: %s" % connect_params
+        abort(502)
+
+    cur = conn.cursor()
+    cur.execute("""SELECT id FROM feeds ORDER BY feeds.id DESC LIMIT 1""")
+    rows = cur.fetchall()
+    for row in rows:
+        return unicode(row[0])
+    
+    abort(404)
+
+@app.route("/db_check/mysql")
+def db_check_mysql():
+    connect_params = "dbname='%s' user='%s' password='%s' host='%s' port='%s'" % (
+        settings.DATABASES['default']['NAME'],
+        settings.DATABASES['default']['USER'],
+        settings.DATABASES['default']['PASSWORD'],
+        settings.DATABASES['default']['HOST'],
+        settings.DATABASES['default']['PORT'],
+    )
+    try:
+
+        conn = MySQLdb.connect(host=settings.DATABASES['default']['HOST'],
+                               port=settings.DATABASES['default']['PORT'],
+                               user=settings.DATABASES['default']['USER'],
+                               passwd=settings.DATABASES['default']['PASSWORD'],
+                               db=settings.DATABASES['default']['NAME'])
+    except:
+        print " ---> Mysql can't connect to the database: %s" % connect_params
+        abort(502)
+
+    cur = conn.cursor()
+    cur.execute("""SELECT id FROM feeds ORDER BY feeds.id DESC LIMIT 1""")
+    rows = cur.fetchall()
+    for row in rows:
+        return unicode(row[0])
+    
+    abort(404)
+
+@app.route("/db_check/mongo")
+def db_check_mongo():
+    try:
+        client = pymongo.MongoClient('mongodb://%s' % settings.MONGO_DB['host'])
+        db = client.newsblur
+    except:
+        abort(502)
+    
+    return unicode(db.stories.count())
+
+@app.route("/db_check/redis")
+def db_check_redis():
+    try:
+        r = redis.Redis(settings.REDIS['host'], db=0)
+    except:
+        abort(502)
+    
+    randkey = r.randomkey()
+    if randkey:
+        return unicode(randkey)
+    else:
+        abort(404)
+
+@app.route("/db_check/redis_story")
+def db_check_redis_story():
+    try:
+        r = redis.Redis(settings.REDIS_STORY['host'], db=1)
+    except:
+        abort(502)
+    
+    randkey = r.randomkey()
+    if randkey:
+        return unicode(randkey)
+    else:
+        abort(404)
+
+@app.route("/db_check/redis_sessions")
+def db_check_redis_sessions():
+    try:
+        r = redis.Redis(settings.REDIS_SESSIONS['host'], db=5)
+    except:
+        abort(502)
+    
+    randkey = r.randomkey()
+    if randkey:
+        return unicode(randkey)
+    else:
+        abort(404)
+
+@app.route("/db_check/elasticsearch")
+def db_check_elasticsearch():
+    try:
+        conn = pyes.ES(settings.ELASTICSEARCH_FEED_HOSTS)
+    except:
+        abort(502)
+    
+    if conn.indices.exists_index('feeds-index'):
+        return unicode("Index exists, but didn't try search")
+        # query = pyes.query.TermQuery("title", "daring fireball")
+        # results = conn.search(query=query, size=1, doc_types=['feeds-type'], sort="num_subscribers:desc")
+        # for result in results:
+        #     return unicode(result)
+        # else:
+        #     abort(404)
+    else:
+        abort(404)    
+
+if __name__ == "__main__":
+    app.run(debug=True)

flask/flask_settings.py

@@ -0,0 +1 @@
+../local_settings.py

flask/requirements.txt

@@ -0,0 +1,5 @@
+flask==0.10.1
+pymongo==2.6
+psycopg=2.5.4
+redis=2.8.0
+pyes=0.90.1

flask/supervisor_db_monitor.conf

@@ -0,0 +1,8 @@
+[program:db_monitor]
+command=python flask/db_monitor.py
+directory=/srv/newsblur
+user=sclay
+autostart=true
+autorestart=true
+priority=991
+stopsignal=HUP