How to access mongodb on GCE with GAE - mongodb

Question

I´ve deploy my demo app on GAE and works fine with mLab , but when I try to deploy mongodb on GCE (MongoDB (Google Click to Deploy) )the deploy is success but I don´t know how to get te URI to set on my app running on GAE.
I try with internal and external IP but it seems dont work !
Thanks

Answer 1

GAE Standard deployments are sand-boxed. Therefore you can not connect to GCE instances' internal IPs. You can imagine it as two different devices on two different private networks that are not capable to communicate with one another using their internal IPs. However, they can always communicate if one of the devices (GCE instance in this case) has a public IP, and it's private network (firewall) allowed traffic through the port required by the device.
On the other hand, if the GAE deployment is in flex environment, you should be able to connect to the db using the API through internal IPs.
I have tried and succeeded with this flex environment example for both internal and external IP addresses. Like you, I used Cloud Launcher to deploy Mongodb which created GCE instances with public IPs and network tags mongodb and mongodb-db. Then I created a db, username and a password by connecting to the primary db instance through SSH.
To use the internal IP, I just created/modified keys.json file per the example, as follows:
{
"mongoHost": "internal IP address",
"mongoPort": "27017",
"mongoDatabase": "db",
"mongoUser": "username",
"mongoPass": "password"
}
So I didn't have to worry about the URI as the code in server.js took care of it through passing this string:
mongodb://${user}:${pass}#${host}:${port}
But for your demo app, you may have to check the MongoDB official documentation for the standard connection string format URI.
As for using public IPs, I had to create a network firewall rule that allows tcp ingress on port 27017 with target tags identical to the network tags in order to limit access through the port to the MongoDB instances only. Next, I modified the keys.json file as above by replacing the internal IP with the public one.