add a default user-agent header

cmd/goss/goss.go

@@ -18,7 +18,6 @@ import (
 	"github.com/urfave/cli"
 )
 
-var version string
 
 // converts a cli context into a goss Config
 func newRuntimeConfigFromCLI(c *cli.Context) *util.Config {
@@ -69,7 +68,7 @@ func timeoutFlag(value time.Duration) cli.DurationFlag {
 func main() {
 	app := cli.NewApp()
 	app.EnableBashCompletion = true
-	app.Version = version
+	app.Version = util.Version
 	app.Name = "goss"
 	app.Usage = "Quick and Easy server validation"
 	app.Flags = []cli.Flag{

integration-tests/goss/goss-shared.yaml

@@ -205,6 +205,11 @@ http:
       - "Foo: bar"
     headers: ["Content-Type: application/json"]
     body: ['"Foo": "bar"']
+  http://httpbin/headers:
+    status: 200
+    timeout: 60000
+    headers: ["Content-Type: application/json"]
+    body: ['"User-Agent": "goss']
   http://httpbin/headers?host:
     status: 200
     timeout: 60000

release-build.sh

@@ -22,7 +22,7 @@ fi
 output="${output_dir}/${output_fname}"
 
 GOOS="${os}" GOARCH="${arch}" CGO_ENABLED=0 go build \
-  -ldflags "-X main.version=${version_stamp} -s -w" \
+  -ldflags "-X github.com/goss-org/goss/util.Version=${version_stamp} -s -w" \
   -o "${output}" \
   github.com/goss-org/goss/cmd/goss
 

system/http.go

@@ -16,6 +16,9 @@ import (
 	"github.com/goss-org/goss/util"
 )
 
+const USER_AGENT_HEADER_PREFIX = "user-agent:"
+const DEFAULT_USER_AGENT_PREFIX = "goss/"
+
 type HTTP interface {
 	HTTP() string
 	Status() (int, error)
@@ -47,6 +50,11 @@ type DefHTTP struct {
 
 func NewDefHTTP(_ context.Context, httpStr string, system *System, config util.Config) HTTP {
 	headers := http.Header{}
+
+	if !hasUserAgentHeader(config.RequestHeader) {
+		config.RequestHeader = append(config.RequestHeader, fmt.Sprintf("%s %s%s", USER_AGENT_HEADER_PREFIX, DEFAULT_USER_AGENT_PREFIX, util.Version))
+	}
+
 	for _, r := range config.RequestHeader {
 		str := strings.SplitN(r, ": ", 2)
 		headers.Add(str[0], str[1])
@@ -209,3 +217,12 @@ func (u *DefHTTP) Body() (io.Reader, error) {
 
 	return u.resp.Body, nil
 }
+
+func hasUserAgentHeader(headers []string) bool {
+	for _, header := range headers {
+		if strings.HasPrefix(strings.ToLower(header), USER_AGENT_HEADER_PREFIX) {
+			return true
+		}
+	}
+	return false
+}

util/build.go

@@ -0,0 +1,3 @@
+package util
+
+var Version string