backend_factory.go

package main

import (
	"context"
	"net/http"

	cb "github.com/devopsfaith/krakend-circuitbreaker/gobreaker/proxy"
	"github.com/devopsfaith/krakend-martian"
	metrics "github.com/devopsfaith/krakend-metrics/gin"
	"github.com/devopsfaith/krakend-oauth2-clientcredentials"
	juju "github.com/devopsfaith/krakend-ratelimit/juju/proxy"
	"github.com/devopsfaith/krakend/config"
	"github.com/devopsfaith/krakend/logging"
	"github.com/devopsfaith/krakend/proxy"
)

// NewBackendFactory creates a BackendFactory by stacking all the available middlewares:
// - oauth2 client credentials
// - martian
// - rate-limit
// - circuit breaker
// - metrics collector
func NewBackendFactory(logger logging.Logger, metricCollector *metrics.Metrics) proxy.BackendFactory {
	requestExecutorFactory := func(cfg *config.Backend) proxy.HTTPRequestExecutor {
		clientFactory := oauth2client.NewHTTPClient(cfg)
		return func(ctx context.Context, req *http.Request) (*http.Response, error) {
			return clientFactory(ctx).Do(req.WithContext(ctx))
		}
	}
	backendFactory := martian.NewConfiguredBackendFactory(logger, requestExecutorFactory)
	backendFactory = juju.BackendFactory(backendFactory)
	backendFactory = cb.BackendFactory(backendFactory)
	backendFactory = metricCollector.BackendFactory("backend", backendFactory)
	return backendFactory
}