mongod flags for replica set, more python scaffolding from mysql

Dockerfile

@@ -37,6 +37,7 @@ ENTRYPOINT []
 
 CMD [ \
 	"containerpilot", \
-	"mongod" \
+	"mongod", \
+	"--replSet=joyent" \
 ]
 

bin/manage.py

@@ -1,15 +1,26 @@
 import logging
 import os
+import sys
+import inspect
+import json
+import logging
+import socket
+
+from functools import wraps
 
 import consul as pyconsul
-import manta
+#import manta
 from pymongo import MongoClient
 
 consul = pyconsul.Consul(host=os.environ.get('CONSUL', 'consul'))
-local_mongo = MongoClient()
 
 log = logging.getLogger('manage.py')
 
+# consts for node state
+PRIMARY = 'mongodb-primary'
+SECONDARY = 'mongodb-secondary'
+REPLICA = 'mongodb'
+
 def debug(fn):
     """
     Function/method decorator to trace calls via debug logging.
@@ -46,9 +57,145 @@ def get_environ(key, default):
 
 # ---------------------------------------------------------
 
+class MongoDBNode(object):
+    """ MongoDBNode represents this instance of a MongoDB container. """
+
+    def __init__(self, name='', ip=''):
+        self.hostname = socket.gethostname()
+        self.name = name if name else get_name()
+        self.ip = ip if ip else get_ip()
+        self.state = PRIMARY
+        self.conn = None
+
+    def get_state(self):
+        # TODO check mongo if I am primary
+        return self.state
+
+# ---------------------------------------------------------
+
+class ContainerPilot(object):
+    """
+    ContainerPilot config is where we rewrite ContainerPilot's own config
+    so that we can dynamically alter what service we advertise
+    """
+
+    def __init__(self, node):
+        # TODO: we should make sure we can support JSON-in-env-var
+        # the same as ContainerPilot itself
+        self.node = node
+        self.path = get_environ('CONTAINERPILOT', None).replace('file://', '')
+        with open(self.path, 'r') as f:
+            self.config = json.loads(f.read())
+
+    @debug
+    def update(self):
+        state = self.node.get_state()
+        if state and self.config['services'][0]['name'] != state:
+            self.config['services'][0]['name'] = state
+            self.render()
+            return True
+
+    @debug
+    def render(self):
+        new_config = json.dumps(self.config)
+        with open(self.path, 'w') as f:
+            f.write(new_config)
+
+    def reload(self):
+        """ force ContainerPilot to reload its configuration """
+        log.info('Reloading ContainerPilot configuration.')
+        os.kill(1, signal.SIGHUP)
+
+# ---------------------------------------------------------
+# Top-level functions called by ContainerPilot or forked by this program
+
+@debug
+def pre_start():
+    """
+    MongoDB must be running in order to execute most of our setup behavior
+    so we're just going to make sure the directory structures are in
+    place and then let the first health check handler take it from there
+    """
+    #if not os.path.isdir(os.path.join('/data')):
+    #    last_backup = has_snapshot()
+    #    if last_backup:
+    #        get_snapshot(last_backup)
+    #        restore_from_snapshot(last_backup)
+    #    else:
+    #        if not initialize_db():
+    #            log.info('Skipping database setup.')
+    sys.exit(0)
+
+@debug
+def health():
+    """
+    Run a simple health check. Also acts as a check for whether the
+    ContainerPilot configuration needs to be reloaded (if it's been
+    changed externally).
+    """
+
+    # TODO
+    #  - check for primary or replset in consul
+    #  - no others, try setting self as primary and rs.init()
+    #  - otherwise join the replset
+    #  - just leave it alone if I am already in rs.status()
+    #  - if I am primary in rs.status(), tell consul
+    #  - periodic mongodumps to Manta
+
+    try:
+        node = MongoDBNode()
+        cp = ContainerPilot(node)
+        if cp.update():
+            cp.reload()
+            return
+
+    except Exception as ex:
+        log.exception(ex)
+        sys.exit(1)
+
+@debug
+def on_change():
+    # TODO when is this called?
+    time.sleep(1) # avoid hammering Consul
+
+# ---------------------------------------------------------
+
+
+
+def get_from_consul(key):
+    """
+    Return the Value field for a given Consul key.
+    Handles None results safely but lets all other exceptions
+    just bubble up.
+    """
+    result = consul.kv.get(key)
+    if result[1]:
+        return result[1]['Value']
+    return None
+
+# ---------------------------------------------------------
+# utility functions
+
+def get_ip(iface='eth0'):
+    """
+    Use Linux SIOCGIFADDR ioctl to get the IP for the interface.
+    ref http://code.activestate.com/recipes/439094-get-the-ip-address-associated-with-a-network-inter/
+    """
+    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    return socket.inet_ntoa(fcntl.ioctl(
+        sock.fileno(),
+        0x8915, # SIOCGIFADDR
+        struct.pack('256s', iface[:15])
+    )[20:24])
+
+def get_name():
+    return 'mysql-{}'.format(socket.gethostname())
+
+# ---------------------------------------------------------
+
 if __name__ == '__main__':
 
-    manta_config = Manta()
+#    manta_config = Manta()
 
     if len(sys.argv) > 1:
         try:

docker-compose.yml

@@ -14,7 +14,7 @@ mongodb:
 
 consul:
     image: consul:v0.6.4
-#    command: -bootstrap -ui-dir /ui
+    command: agent -dev -ui -client=0.0.0.0
     restart: always
     mem_limit: 128m
     ports: