It’s often useful to be able to interact with remote services or resources (e.g. databases) during local development. However, access to those remote services is often rightly restricted to traffic coming from the application itself, rather than from the internet.
In these cases,
convox proxy and
convox resources proxy can help by proxying traffic from your local development machine to your app’s services via your Rack.
Access external resources
When possible, resources are generally configured so they are not accessible from the public internet. You can get proxy access with the
convox resources proxy command, e.g.:
$ convox resources proxy mysql-4624
Under the hood, this creates an encrypted and secure websocket tunnel through your Rack process that talks to your database via a socket on your local machine. In other words,
convox resources proxy allows you to communicate with your Postgres database (for example) as if it were running on your own machine.
In our Flask example repo, we’ve created a
counter service and replaced the
redis service with a redis resource (referred to here as
We can’t connect directly to our redis resource because it’s inside our app’s VPC and only accepts internal requests:
$ redis-cli -h lerabcdefghi.jklm5o.ng.0001.use1.cache.amazonaws.com:6379 Could not connect to Redis at lerabcdefghi.jklm5o.ng.0001.use1.cache.amazonaws.com:6379: Connection timed out
The manual way to interact with the redis resource would be to use
convox exec to get a shell in the
counter container and install
redis-cli there, but this is neither efficient nor recommended.
convox resources proxy makes it much easier. In a terminal, run:
$ convox resources proxy redis-9990 proxying 127.0.0.1:6379 to lerabcdefghi.jklm5o.ng.0001.use1.cache.amazonaws.com:6379
Then, in another terminal on your local machine, run:
$ redis-cli 127.0.0.1:6379>
connect: 6379 appear in the terminal where you ran
convox resources proxy as evidence of your connection.
Now you can indirect with your remote redis resource:
127.0.0.1:6379> ping "hello world" "hello world"
Tip: Alternate ports
To avoid local port conflicts (for example, if you already have Postgres running on 5432), you can specify a different local port with
$ convox resources proxy postgres-6525 --listen 5433
When you run the command above, you should see output like:
proxying 127.0.0.1:5433 to dev-postgres-6525.cbm068zjzjcr.us-east-1.rds.amazonaws.com:5432
and then you should be able to connect to localhost:5433.
Access private services with
convox proxy works much the same way as
convox resources proxy except for internal services (i.e. exposed behind an internal ELB inside a VPC) rather than external resources.
Let’s say we want to proxy from port 8000 on our local machine to port 80 of the
counter service in our example repo:
First get the service endpoint by running
$ convox services SERVICE DOMAIN PORTS web flask-counter-NJS6JDQ-842041791.us-east-1.elb.amazonaws.com 80
Then choose a port on your local machine (
8000 in our case), then run the
convox proxy command in a terminal:
$ convox proxy 8000:flask-counter-NJS6JDQ-842041791.us-east-1.elb.amazonaws.com:80 proxying 127.0.0.1:8000 to flask-counter-NJS6JDQ-842041791.us-east-1.elb.amazonaws.com:80
In another terminal, run
$ curl -s localhost:8000 | grep served <h2>This request was served by 3d511a719fc7.</h2> <h2>3d511a719fc7 served 7 requests so far.</h2> <h2>A grand total of 7 requests were served.</h2>
The page is returned as if it were being served from