Setup an Otoroshi cluster

Route plugins: Additional Headers In

In this tutorial, you create an cluster of Otoroshi.

Summary

  1. Deploy an Otoroshi cluster with one leader and 2 workers
  2. Add a load balancer in front of the workers
  3. Validate the installation by adding a header on the requests

Let’s start by downloading the latest jar of Otoroshi.

curl -L -o otoroshi.jar 'https://github.com/MAIF/otoroshi/releases/download/v16.17.0/otoroshi.jar'

Then create an instance of Otoroshi and indicates with the otoroshi.cluster.mode environment variable that it will be the leader.

java -Dhttp.port=8091 -Dhttps.port=9091 -Dotoroshi.cluster.mode=leader -jar otoroshi.jar

Let’s create two Otoroshi workers, exposed on :8082/:8092 and :8083/:8093 ports, and setting the leader URL in the otoroshi.cluster.leader.urls environment variable.

The first worker will listen on the :8082/:8092 ports

java \
  -Dotoroshi.cluster.worker.name=worker-1 \
  -Dhttp.port=8092 \
  -Dhttps.port=9092 \
  -Dotoroshi.cluster.mode=worker \
  -Dotoroshi.cluster.leader.urls.0='http://127.0.0.1:8091' -jar otoroshi.jar

The second worker will listen on the :8083/:8093 ports

java \
  -Dotoroshi.cluster.worker.name=worker-2 \
  -Dhttp.port=8093 \
  -Dhttps.port=9093 \
  -Dotoroshi.cluster.mode=worker \
  -Dotoroshi.cluster.leader.urls.0='http://127.0.0.1:8091' -jar otoroshi.jar

Once launched, you can navigate to the cluster view. The cluster is now configured, you can see the 3 instances and some health informations on each instance.

To complete our installation, we want to spread the incoming requests accross otoroshi worker instances.

In this tutorial, we will use haproxy has a TCP loadbalancer. If you don’t have haproxy installed, you can use docker to run an haproxy instance as explained below.

But first, we need an haproxy configuration file named haproxy.cfg with the following content :

frontend front_nodes_http
    bind *:8080
    mode tcp
    default_backend back_http_nodes
    timeout client          1m

backend back_http_nodes
    mode tcp
    balance roundrobin
    server node1 host.docker.internal:8092 # (1)
    server node2 host.docker.internal:8093 # (1)
    timeout connect        10s
    timeout server          1m

and run haproxy with this config file

no docker
haproxy -c -f ./haproxy.cfg
docker (on linux)
docker run -p 8080:8080 -v $(pwd)/haproxy.cfg:/usr/local/etc/haproxy/haproxy.cfg:ro --add-host=host.docker.internal:host-gateway haproxy
docker (on macos)
docker run -p 8080:8080 -v $(pwd)/haproxy.cfg:/usr/local/etc/haproxy/haproxy.cfg:ro haproxy
docker (on windows)
docker run -p 8080:8080 -v $(pwd)/haproxy.cfg:/usr/local/etc/haproxy/haproxy.cfg:ro haproxy

The last step is to create a route, add a rule to add, in the headers, a specific value to identify the worker used.

Create this route, exposed on http://api.oto.tools:xxxx, which will forward all requests to the mirror https://mirror.otoroshi.io.

curl -X POST 'http://otoroshi-api.oto.tools:8091/api/routes' \
-H "Content-type: application/json" \
-u admin-api-apikey-id:admin-api-apikey-secret \
-d @- <<'EOF'
{
  "name": "myapi",
  "frontend": {
    "domains": ["api.oto.tools"]
  },
  "backend": {
    "targets": [
      {
        "hostname": "mirror.otoroshi.io",
        "port": 443,
        "tls": true
      }
    ]
  },
  "plugins": [
    {
        "enabled": true,
        "plugin": "cp:otoroshi.next.plugins.AdditionalHeadersIn",
        "config": {
            "headers": {
                "worker-name": "${config.otoroshi.cluster.worker.name}"
            }
        }
    }
  ]
}
EOF

Once created, call two times the service. If all is working, the header received by the backend service will have worker-1 and worker-2 as value.

curl 'http://api.oto.tools:8080'
## Response headers
{
    ...
    "worker-name": "worker-2"
    ...
}

This should output worker-1, then worker-2, etc. Well done, your loadbalancing is working and your cluster is set up correctly.