diff --git a/cmd/gopherproxy/main.go b/cmd/gopherproxy/main.go index 9a7d1f9..84bde30 100644 --- a/cmd/gopherproxy/main.go +++ b/cmd/gopherproxy/main.go @@ -8,12 +8,16 @@ import ( ) var ( - bind = flag.String("bind", "0.0.0.0:8000", "[int]:port to bind to") - uri = flag.String("uri", "floodgap.com", ":[port] to proxy to") + // TODO: Allow config file and environment vars + // (opt -> env -> config -> default) + bind = flag.String("bind", "0.0.0.0:8000", "[int]:port to bind to") + robotsfile = flag.String("robots-file", "robots.txt", "robots.txt file") + uri = flag.String("uri", "floodgap.com", ":[port] to proxy to") ) func main() { flag.Parse() - log.Fatal(gopherproxy.ListenAndServe(*bind, *uri)) + // Use a config struct + log.Fatal(gopherproxy.ListenAndServe(*bind, *robotsfile, *uri)) } diff --git a/gopherproxy.go b/gopherproxy.go index dd416b2..42f67cf 100644 --- a/gopherproxy.go +++ b/gopherproxy.go @@ -10,6 +10,8 @@ import ( "net/url" "strings" + "github.com/temoto/robotstxt" + "github.com/prologic/go-gopher" ) @@ -74,12 +76,21 @@ func renderDirectory(w http.ResponseWriter, tpl *template.Template, hostport str }{title, out}) } -// Handler returns a Handler that proxies requests +// GopherHandler returns a Handler that proxies requests // to the specified Gopher server as denoated by the first argument // to the request path and renders the content using the provided template. -func Handler(tpl *template.Template, uri string) http.HandlerFunc { +// The optional robots parameters points to a robotstxt.RobotsData struct +// to test user agents against a configurable robotst.txt file. +func GopherHandler(tpl *template.Template, robotsdata *robotstxt.RobotsData, uri string) http.HandlerFunc { return func(w http.ResponseWriter, req *http.Request) { - parts := strings.Split(strings.TrimPrefix(req.URL.Path, "/"), "/") + agent := req.UserAgent() + path := strings.TrimPrefix(req.URL.Path, "/") + + if robotsdata != nil && !robotsdata.TestAgent(path, agent) { + log.Printf("UserAgent %s ignored robots.txt", agent) + } + + parts := strings.Split(path, "/") hostport := parts[0] if len(hostport) == 0 { @@ -89,13 +100,11 @@ func Handler(tpl *template.Template, uri string) http.HandlerFunc { var qs string - path := strings.Join(parts[1:], "/") - if req.URL.RawQuery != "" { qs = fmt.Sprintf("?%s", url.QueryEscape(req.URL.RawQuery)) } - uri, err := url.QueryUnescape(path) + uri, err := url.QueryUnescape(strings.Join(parts[1:], "/")) if err != nil { io.WriteString(w, fmt.Sprintf("Error:
%s
", err)) return @@ -126,13 +135,44 @@ func Handler(tpl *template.Template, uri string) http.HandlerFunc { } } +// RobotsTxtHandler returns the contents of the robots.txt file +// if configured and valid. +func RobotsTxtHandler(robotstxtdata []byte) http.HandlerFunc { + return func(w http.ResponseWriter, req *http.Request) { + if robotstxtdata == nil { + http.Error(w, "Not Found", http.StatusNotFound) + return + } + + w.Header().Set("Content-Type", "text/plain") + w.Write(robotstxtdata) + } +} + // ListenAndServe creates a listening HTTP server bound to // the interface specified by bind and sets up a Gopher to HTTP // proxy proxying requests as requested and by default will prozy // to a Gopher server address specified by uri if no servers is -// specified by the request. -func ListenAndServe(bind, uri string) error { - var tpl *template.Template +// specified by the request. The robots argument is a pointer to +// a robotstxt.RobotsData struct for testing user agents against +// a configurable robots.txt file. +func ListenAndServe(bind, robotsfile, uri string) error { + var ( + tpl *template.Template + robotsdata *robotstxt.RobotsData + ) + + robotstxtdata, err := ioutil.ReadFile(robotsfile) + if err != nil { + log.Printf("error reading robots.txt: %s", err) + robotstxtdata = nil + } else { + robotsdata, err = robotstxt.FromBytes(robotstxtdata) + if err != nil { + log.Printf("error reading robots.txt: %s", err) + robotstxtdata = nil + } + } tpldata, err := ioutil.ReadFile(".template") if err == nil { @@ -144,6 +184,8 @@ func ListenAndServe(bind, uri string) error { log.Fatal(err) } - http.HandleFunc("/", Handler(tpl, uri)) + http.HandleFunc("/", GopherHandler(tpl, robotsdata, uri)) + http.HandleFunc("/robots.txt", RobotsTxtHandler(robotstxtdata)) + return http.ListenAndServe(bind, nil) } diff --git a/robots.txt b/robots.txt new file mode 100644 index 0000000..1f53798 --- /dev/null +++ b/robots.txt @@ -0,0 +1,2 @@ +User-agent: * +Disallow: /