OSV user agent (#390)

Add a user agent to osv-scanner OSV API requests to help see usage and
and help with debugging slow queries.

Closes #388

cmd/osv-scanner/main.go

@@ -6,6 +6,7 @@ import (
 	"io"
 	"os"
 
+	"github.com/google/osv-scanner/pkg/osv"
 	"github.com/google/osv-scanner/pkg/osvscanner"
 	"github.com/google/osv-scanner/pkg/reporter"
 
@@ -27,6 +28,8 @@ func run(args []string, stdout, stderr io.Writer) int {
 		r.PrintText(fmt.Sprintf("osv-scanner version: %s\ncommit: %s\nbuilt at: %s\n", ctx.App.Version, commit, date))
 	}
 
+	osv.RequestUserAgent = "osv-scanner/" + version
+
 	app := &cli.App{
 		Name:      "osv-scanner",
 		Version:   version,

pkg/osv/osv.go

@@ -28,6 +28,8 @@ const (
 	maxConcurrentRequests = 25
 )
 
+var RequestUserAgent = ""
+
 // Package represents a package identifier for OSV.
 type Package struct {
 	PURL      string `json:"purl,omitempty"`
@@ -146,7 +148,16 @@ func MakeRequestWithClient(request BatchedQuery, client *http.Client) (*BatchedR
 		resp, err := makeRetryRequest(func() (*http.Response, error) {
 			// We do not need a specific context
 			//nolint:noctx
-			return client.Post(QueryEndpoint, "application/json", requestBuf)
+			req, err := http.NewRequest(http.MethodPost, QueryEndpoint, requestBuf)
+			if err != nil {
+				return nil, err
+			}
+			req.Header.Set("Content-Type", "application/json")
+			if RequestUserAgent != "" {
+				req.Header.Set("User-Agent", RequestUserAgent)
+			}
+
+			return client.Do(req)
 		})
 		if err != nil {
 			return nil, err
@@ -179,8 +190,17 @@ func Get(id string) (*models.Vulnerability, error) {
 // client.
 func GetWithClient(id string, client *http.Client) (*models.Vulnerability, error) {
 	resp, err := makeRetryRequest(func() (*http.Response, error) {
+		// We do not need a specific context
 		//nolint:noctx
-		return client.Get(GetEndpoint + "/" + id)
+		req, err := http.NewRequest(http.MethodGet, GetEndpoint+"/"+id, nil)
+		if err != nil {
+			return nil, err
+		}
+		if RequestUserAgent != "" {
+			req.Header.Set("User-Agent", RequestUserAgent)
+		}
+
+		return client.Do(req)
 	})
 	if err != nil {
 		return nil, err

pkg/osvscanner/osvscanner.go

@@ -536,6 +536,10 @@ func DoScan(actions ScannerActions, r reporter.Reporter) (models.VulnerabilityRe
 		return models.VulnerabilityResults{}, NoPackagesFoundErr
 	}
 
+	if osv.RequestUserAgent == "" {
+		osv.RequestUserAgent = "osv-scanner-api"
+	}
+
 	resp, err := osv.MakeRequest(query)
 	if err != nil {
 		return models.VulnerabilityResults{}, fmt.Errorf("scan failed %w", err)