Fix API Key authentication

google-api-go-client deprecated setting the api key directly in
the transport and switched to using generic client options. Since
we are passing in our own HTTP client, we need to instantiate a
Google transport with the API key option in order for it to
authenticate correctly.

collector/collector.go

@@ -65,9 +65,14 @@ func newCollector(config Config) (coll prometheus.Collector, err error) {
 		options = append(options, option.WithCredentialsFile(config.CredentialsFile))
 	}
 
+	svc, err := newPagespeedScrapeService(config.ScrapeTimeout, options...)
+	if err != nil {
+		return nil, err
+	}
+
 	return collector{
 		requests:      config.ScrapeRequests,
-		scrapeService: newPagespeedScrapeService(config.ScrapeTimeout, options...),
+		scrapeService: svc,
 		parallel:      config.Parallel,
 	}, nil
 }

collector/scrape.go

@@ -12,6 +12,7 @@ import (
 	"golang.org/x/oauth2"
 	"google.golang.org/api/option"
 	"google.golang.org/api/pagespeedonline/v5"
+	googlehttp "google.golang.org/api/transport/http"
 )
 
 var _ scrapeService = &pagespeedScrapeService{}
@@ -22,9 +23,14 @@ type scrapeService interface {
 
 // newPagespeedScrapeService creates a new HTTP client service for pagespeed.
 // If the client timeout is set to 0 there will be no timeout
-func newPagespeedScrapeService(clientTimeout time.Duration, options ...option.ClientOption) scrapeService {
+func newPagespeedScrapeService(clientTimeout time.Duration, options ...option.ClientOption) (scrapeService, error) {
+	transport, err := googlehttp.NewTransport(context.Background(), http.DefaultTransport, options...)
+	if err != nil {
+		return nil, err
+	}
+
 	client := &http.Client{
-		Transport: http.DefaultTransport,
+		Transport: transport,
 	}
 
 	if clientTimeout != 0 {
@@ -34,7 +40,7 @@ func newPagespeedScrapeService(clientTimeout time.Duration, options ...option.Cl
 	return &pagespeedScrapeService{
 		scrapeClient: client,
 		options:      options,
-	}
+	}, nil
 }
 
 type pagespeedScrapeService struct {

go.mod

@@ -4,13 +4,10 @@ go 1.12
 
 require (
 	github.com/gammazero/workerpool v0.0.0-20190521015540-3b91a70bc0a1
-	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
-	github.com/modern-go/reflect2 v1.0.1 // indirect
 	github.com/pkg/errors v0.8.1
 	github.com/prometheus/client_golang v1.5.1
-	github.com/prometheus/tsdb v0.7.1 // indirect
 	github.com/sirupsen/logrus v1.4.2
 	github.com/stretchr/testify v1.7.0
-	golang.org/x/oauth2 v0.0.0-20220411215720-9780585627b5
-	google.golang.org/api v0.81.0
+	golang.org/x/oauth2 v0.0.0-20220524215830-622c5d57e401
+	google.golang.org/api v0.82.0
 )