Gangway (Prow API)

Architecture

See the design doc.

Gangway uses gRPC to serve several endpoints. These can be seen in the gangway.proto file, which describes the gRPC endpoints. The proto describes the interface at a high level, and is converted into low-level Golang types into gangway.pb.go and gangway_grpc.pb.go. These low-level Golang types are then used in the gangway.go file to implement the high-level intent of the proto file.

As Gangway only understands gRPC natively, if you want to use a REST client against it you must deploy Gangway. For example, on GKE you can use Cloud Endpoints and deploy Gangway behind a reverse proxy called “ESPv2”. This ESPv2 container will forward HTTP requests made to it to the equivalent gRPC endpoint in Gangway and back again.

Configuration setup

Server-side configuration

Gangway has its own security check to see whether the client is allowed to, for example, trigger the job that it wants to trigger (we don’t want to let any random client trigger any Prow Job that Prow knows about). In the central Prow config under the gangway section, prospective Gangway users can list themselves in there. For an example, see the section filled out for Gangway’s own integration tests and search for allowed_jobs_filters.

Client-side configuration

The table below lists the supported endpoints.

See gangway.proto and the Gangway Google client.

Tutorial

See the example.