apigateway

A performant API Gateway based on Openresty and NGINX.

Quick start

docker run --name="apigateway" \
            -p 80:80 \
            -e "MARATHON_HOST=http://<marathon_host>:<port>/" \
            -e "LOG_LEVEL=info" \
            adobeapiplatform/apigateway:latest

This command starts an API Gateway that automatically discovers the services running in Marathon. The discovered services are exposed on individual VHosts as you can see in the config file.

Accessing a Marathon app

For example, if you have an application named hello-world you can access it on its VHost in 2 ways:

1. Edit /etc/hosts and add <docker_host_ip> hello-world.api.localhost then browse to http://hello-world.api.localhost
2. Sending the Host header in a curl command: curl -H "Host:hello-world.api.localhost" http://<docker_host_ip>

The discovery script is provided as an example for a quick-start and it can be replaced with your favourite discovery mechanism. The script updates a configuration file containing all the NGINX upstreams that are used in the config file.

Resolvers

While starting up this container automatically creates the /etc/api-gateway/conf.d/includes/resolvers.conf config file using /etc/resolv.conf as the source. To learn more about the resolver directive in NGINX see the docs.

Running the API Gateway outside of Marathon and Mesos

Besides the discovery part which is dependent on Marathon at the moment, the API Gateway can run on its own as well. The Marathon service discovery is activated with the -e "MARATHON_HOST=http://<marathon_host>:<port>/".

Developer guide

To build the docker image locally use:

 make docker

To SSH into the newly built image use ( note that this is not the running image):

 make docker-ssh

Running and Stopping the Docker image

 make docker-run

The main API Gateway process is exposed to port 80. To test that the Gateway works see its health-check:

 $ curl http://<docker_host_ip>/health-check
   API-Platform is running!

If you're up for a quick performance test, you can play with Apache Benchmark via Docker:

 docker run jordi/ab ab -k -n 200000 -c 500 http://<docker_host_ip>/health-check

To run docker mounting the local api-gateway-config directory into /etc/api-gateway/ issue:

$ make docker-debug

In debug mode the docker container starts a special api-gateway compiled --with-debug providing very detailed debugging information. When started with -e "LOG_LEVEL=info" the output is quite verbose. To learn more about this option visit NGINX docs.

When done stop the image:

make docker-stop

SSH into the running image

make docker-attach

Running the container in Mesos with Marathon

Make an HTTP POST on http://<marathon-host>/v2/apps with the following payload. For optimal performance leave the network on HOST mode. To learn more about the network modes visit the Docker documentation.

{
  "id": "api-gateway",
  "container": {
    "type": "DOCKER",
    "docker": {
      "image": "adobeapiplatform/apigateway:latest",
      "forcePullImage": true,
      "network": "HOST"
    }
  },
  "cpus": 4,
  "mem": 4096.0,
  "env": {
    "MARATHON_HOST": "http://<marathon_host>:<marathon_port>"
  },
  "constraints": [  [ "hostname","UNIQUE" ]  ],
  "ports": [ 80 ],
  "healthChecks": [
    {
      "protocol": "HTTP",
      "portIndex": 0,
      "path": "/health-check",
      "gracePeriodSeconds": 3,
      "intervalSeconds": 10,
      "timeoutSeconds": 10
    }
  ],
  "instances": 1
}

To run the Gateway only on specific nodes marked with slave_public you can add the property bellow to the main JSON object:

"acceptedResourceRoles": [ "slave_public" ]

Auto-discover and register Marathon tasks in the Gateway

To enable auto-discovery in a Mesos with Marathon framework define the following Environment Variables:

MARATHON_URL=http://<marathon-url-1>
MARATHON_TASKS=ws-.* ( NOT USED NOW. TBD IF THERE'S A NEED TO FILTER OUT SOME TASKS )

So the Docker command is now :

docker run --name="apigateway" \
            -p 8080:80 \
            -e "MARATHON_HOST=http://<marathon_host>:<port>/" \
            -e "LOG_LEVEL=info" \
            adobeapiplatform/apigateway:latest