Kiper

Open policy agent built for 3scale.

Not much to see here yet. Just getting started.

Instructions

• Compile:

go build

• Start the OPA server with the rules in example.rego:

./kiper opa run --server --set=plugins.envoy_ext_authz_grpc.addr=:9191 --set=plugins.envoy_ext_authz_grpc.query=data.envoy.authz.allow --set=decision_logs.console=true --ignore=.* example.rego

• Start Envoy with the given config file that authorizes using the server above:

envoy -c envoy_config.yaml

• The example.rego policy defines a limit of 5 requests per second for the "/abc" path, but each user identified by the "user_id" header can only make 3 requests per second. To test this, you'll need to start a server in 8080 or choose another one, but remember to change it in envoy_config.yaml as well. For testing purposes you can use: python -m http.server 8080. Now make requests to Envoy:
  • curl -v http://localhost:8000/abc -H "user_id:a". Authorized: total (1/5), user_a (1/3), user_b (0/3).
  • curl -v http://localhost:8000/abc -H "user_id:a". Authorized: total (2/5), user_a (2/3), user_b (0/3).
  • curl -v http://localhost:8000/abc -H "user_id:a". Authorized: total (3/5), user_a (3/3), user_b (0/3).
  • curl -v http://localhost:8000/abc -H "user_id:a". Limited: total (3/5), user_a (4/3), user_b (0/3).
  • curl -v http://localhost:8000/abc -H "user_id:b". Authorized: total (4/5), user_a (3/3), user_b (1/3).
  • curl -v http://localhost:8000/abc -H "user_id:b". Authorized: total (5/5), user_a (3/3), user_b (2/3).
  • curl -v http://localhost:8000/abc -H "user_id:b": Limited: total (6/5), user_a (3/3), user_b (3/3).

Use Redis as the storage for the limits

By default, the limits are stored in memory. You can use Redis if you need to share the limits between several instances or need to persist them. Simply set the REDIS_URL env. It accepts a URL with this format: redis://host:port/db (db is optional).