I'd like to know in detail how to connect google compute engine virtual machine instance and app engine.
I've set up a virtual machine instance on Google compute engine, and my Postgres server is running there, following this tutorial: https://cloud.google.com/community/tutorials/setting-up-postgres
I've deployed my flask app under the same project on Google Cloud Platform, creating an app engine instance.
I searched on how to connect compute engine and app engine together, and it seems it should be possible through a VPC connector: connect Google App Engine and Google Compute Engine
This is what my VPC connector looks like:
Serverless VPC access
Name Network Region IP address range Min. throughput Max. throughput
connector-name default europe-west2 10.8.0.0/28 200 300
On my compute engine, I have my VM instance like so:
Name Zone Internal IP External IP
some-name europe-west2-c 10.154.0.2 (nic0) 34.89.113.193
On my flask app, I'm trying to connect to my remote DB like so:
db = PostgresqlExtDatabase(
"some-name", # databse name
user="postgres",
password="some-password",
host="10.154.0.2", # remote host internal ip
port=5432,
)
db.connect()
This is my app.yaml for the vpc access part, I've followed this reference: https://cloud.google.com/appengine/docs/standard/python/connecting-vpc#configuring
vpc_access_connector:
name: projects/some-name/locations/europe-west2/connectors/connector-name
If I understood correctly, if the VPC connector is present, I should just be able to connect using the internal IP address of my VM instance(this case, 10.154.0.2)?
The problem is, when the app is deployed for production, It is still complaining that it cannot connect:
2020-09-26 12:54:51 default[20200926t134815] Is the server running on host "10.154.0.2" and accepting
2020-09-26 12:54:51 default[20200926t134815] TCP/IP connections on port 5432?
If it's connected internally I assume I don't have to add that internal IP to firewall rules, although I did try that as well. As for firewall rules, I have allowed my local machine's IP address so I can connect to the remote Postgres server via PgAdmin.
I've actually tried External IP(34.89.113.193) as well although that doesn't make sense to me.
I'm a bit of a noob on networks and backend stuff in general, any help would be much appreciated.
UPDATED 1 This is my firewall rules:
Direction
Ingress, Egress
Action on match
Allow
Source filters
IP ranges
92.40.176.9/32
78.146.103.141/32
10.154.0.2
Protocols and ports
tcp:5432
Image for reference: Screenshot for the list of firewall rules
