feat: Replace default Go user-agent with oauth2-proxy and version (#2570)

* feat: Replace default Go user-agent with oauth2-proxy and version

* Add to CHANGELOG

* Make userAgentTransport configurable and composable

* Use correct naming convention for DefaultHTTPClient

* Move version to own package and use named arguments

* Update version path in Makefile

* Fix import path in Makefile

* Change importpath in dist.sh

* Minor style issues

pkg/providers/oidc/provider_verifier.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 
 	"github.com/coreos/go-oidc/v3/oidc"
+	"github.com/oauth2-proxy/oauth2-proxy/v7/pkg/requests"
 	k8serrors "k8s.io/apimachinery/pkg/util/errors"
 )
 
@@ -130,6 +131,7 @@ func getVerifierBuilder(ctx context.Context, opts ProviderVerifierOptions) (veri
 
 // newVerifierBuilder returns a function to create a IDToken verifier from an OIDC config.
 func newVerifierBuilder(ctx context.Context, issuerURL, jwksURL string, supportedSigningAlgs []string) verifierBuilder {
+	ctx = oidc.ClientContext(ctx, requests.DefaultHTTPClient)
 	keySet := oidc.NewRemoteKeySet(ctx, jwksURL)
 	return func(oidcConfig *oidc.Config) *oidc.IDTokenVerifier {
 		if len(supportedSigningAlgs) > 0 {

pkg/requests/builder.go

@@ -58,7 +58,7 @@ func (r *builder) WithMethod(method string) Builder {
 
 // WithHeaders replaces the request header map with the given header map.
 func (r *builder) WithHeaders(header http.Header) Builder {
-	r.header = header
+	r.header = header.Clone()
 	return r
 }
 
@@ -99,7 +99,7 @@ func (r *builder) do() Result {
 	}
 	req.Header = r.header
 
-	resp, err := http.DefaultClient.Do(req)
+	resp, err := DefaultHTTPClient.Do(req)
 	if err != nil {
 		r.result = &result{err: fmt.Errorf("error performing request: %v", err)}
 		return r.result

pkg/requests/builder_test.go

@@ -8,6 +8,8 @@ import (
 	"fmt"
 	"net/http"
 
+	"github.com/oauth2-proxy/oauth2-proxy/v7/pkg/version"
+
 	"github.com/bitly/go-simplejson"
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
@@ -19,7 +21,7 @@ var _ = Describe("Builder suite", func() {
 
 	baseHeaders := http.Header{
 		"Accept-Encoding": []string{"gzip"},
-		"User-Agent":      []string{"Go-http-client/1.1"},
+		"User-Agent":      []string{"oauth2-proxy/" + version.VERSION},
 	}
 
 	BeforeEach(func() {

pkg/requests/http.go

@@ -0,0 +1,29 @@
+package requests
+
+import (
+	"net/http"
+
+	"github.com/oauth2-proxy/oauth2-proxy/v7/pkg/version"
+)
+
+type userAgentTransport struct {
+	next      http.RoundTripper
+	userAgent string
+}
+
+func (t *userAgentTransport) RoundTrip(req *http.Request) (*http.Response, error) {
+	r := req.Clone(req.Context())
+	setDefaultUserAgent(r.Header, t.userAgent)
+	return t.next.RoundTrip(r)
+}
+
+var DefaultHTTPClient = &http.Client{Transport: &userAgentTransport{
+	next:      http.DefaultTransport,
+	userAgent: "oauth2-proxy/" + version.VERSION,
+}}
+
+func setDefaultUserAgent(header http.Header, userAgent string) {
+	if header != nil && len(header.Values("User-Agent")) == 0 {
+		header.Set("User-Agent", userAgent)
+	}
+}

pkg/version/version.go

@@ -0,0 +1,4 @@
+package version
+
+// VERSION contains version information
+var VERSION = "undefined"