Mercurial > gemma
view controllers/externalwfs.go @ 379:0a9aaf21f69f
feat: usermanagement
Togglable userdetails card
author | Thomas Junk <thomas.junk@intevation.de> |
---|---|
date | Fri, 10 Aug 2018 14:49:29 +0200 |
parents | 15369b41be74 |
children | ac23905e64b1 |
line wrap: on
line source
package controllers import ( "compress/flate" "compress/gzip" "encoding/xml" "io" "io/ioutil" "log" "net/http" "net/url" "strings" "time" "github.com/gorilla/mux" "golang.org/x/net/html/charset" "gemma.intevation.de/gemma/config" ) // roundTripFunc is a helper type to make externalWFSDirector a http.RoundTripper. type roundTripFunc func(*http.Request) (*http.Response, error) func (rtf roundTripFunc) RoundTrip(req *http.Request) (*http.Response, error) { return rtf(req) } func externalWFSDirector(req *http.Request) { abort := func(format string, args ...interface{}) { log.Printf(format, args...) panic(http.ErrAbortHandler) } external := config.ExternalWFSs() if external == nil || len(external) == 0 { abort("No external WFS proxy config found\n") } vars := mux.Vars(req) wfs := vars["wfs"] rest := vars["rest"] log.Printf("rest: %s\n", rest) alias, found := external[wfs] if !found { abort("No config found for %s\n", wfs) } data, ok := alias.(map[string]interface{}) if !ok { abort("error: badly configured external WFS %s\n", wfs) } urlS, found := data["url"] if !found { abort("error: missing url for external WFS %s\n", wfs) } prefix, ok := urlS.(string) if !ok { abort("error: badly configured url for external WFS %s\n", wfs) } https := useHTTPS(req) log.Printf("%v\n", prefix) nURL := prefix + "/" + rest + "?" + req.URL.RawQuery log.Printf("%v\n", nURL) u, err := url.Parse(nURL) if err != nil { abort("Invalid url: %v\n", err) } req.URL = u req.Header.Set("X-Gemma-From", prefix) to := https + "://" + req.Host + "/api/externalwfs/" + wfs req.Header.Set("X-Gemma-To", to) req.Host = u.Host //log.Printf("headers: %v\n", req.Header) } func externalWFSTransport(req *http.Request) (*http.Response, error) { from := req.Header.Get("X-Gemma-From") to := req.Header.Get("X-Gemma-To") req.Header.Del("X-Gemma-From") req.Header.Del("X-Gemma-To") // To prevent some caching effects. req.Header.Del("If-None-Match") resp, err := http.DefaultTransport.RoundTrip(req) if err != nil { return nil, err } resp.Header.Set("X-Gemma-From", from) resp.Header.Set("X-Gemma-To", to) return resp, err } type nopCloser struct { io.Writer } func (nopCloser) Close() error { return nil } func encoding(h http.Header) ( func(io.Reader) (io.ReadCloser, error), func(io.Writer) (io.WriteCloser, error), ) { switch enc := h.Get("Content-Encoding"); { case strings.Contains(enc, "gzip"): log.Println("gzip compression") return func(r io.Reader) (io.ReadCloser, error) { return gzip.NewReader(r) }, func(w io.Writer) (io.WriteCloser, error) { return gzip.NewWriter(w), nil } case strings.Contains(enc, "deflate"): log.Println("Deflate compression") return func(r io.Reader) (io.ReadCloser, error) { return flate.NewReader(r), nil }, func(w io.Writer) (io.WriteCloser, error) { return flate.NewWriter(w, flate.DefaultCompression) } default: log.Println("No content compression") return func(r io.Reader) (io.ReadCloser, error) { if r2, ok := r.(io.ReadCloser); ok { return r2, nil } return ioutil.NopCloser(r), nil }, func(w io.Writer) (io.WriteCloser, error) { if w2, ok := w.(io.WriteCloser); ok { return w2, nil } return nopCloser{w}, nil } } } func externalWFSModifyResponse(resp *http.Response) error { from := resp.Header.Get("X-Gemma-From") to := resp.Header.Get("X-Gemma-To") resp.Header.Del("X-Gemma-From") resp.Header.Del("X-Gemma-To") if !isXML(resp.Header) { return nil } log.Printf("rewrite from %s to %s\n", from, to) pr, pw := io.Pipe() var ( r io.ReadCloser w io.WriteCloser err error ) reader, writer := encoding(resp.Header) if r, err = reader(resp.Body); err != nil { return err } if w, err = writer(pw); err != nil { return err } go func(force io.ReadCloser) { start := time.Now() defer func() { //r.Close() w.Close() pw.Close() force.Close() log.Printf("rewrite took %s\n", time.Since(start)) }() if err := rewrite(w, r, from, to); err != nil { log.Printf("rewrite failed: %v\n", err) return } log.Println("rewrite successful") }(resp.Body) resp.Body = pr return nil } var xmlContentTypes = []string{ "application/xml", "text/xml", "application/gml+xml", } func isXML(h http.Header) bool { for _, t := range h["Content-Type"] { t = strings.ToLower(t) for _, ct := range xmlContentTypes { if strings.Contains(t, ct) { return true } } } return false } func rewrite(w io.Writer, r io.Reader, from, to string) error { decoder := xml.NewDecoder(r) decoder.CharsetReader = charset.NewReaderLabel encoder := xml.NewEncoder(w) replace := func(s string) string { return strings.Replace(s, from, to, -1) } var n nsdef tokens: for { tok, err := decoder.Token() switch { case tok == nil && err == io.EOF: break tokens case err != nil: return err } switch t := tok.(type) { case xml.StartElement: t = t.Copy() isDef := n.isDef(t.Name.Space) n = n.push() for i := range t.Attr { t.Attr[i].Value = replace(t.Attr[i].Value) n.checkDef(&t.Attr[i]) } for i := range t.Attr { n.adjust(&t.Attr[i]) } switch { case isDef: t.Name.Space = "" default: if s := n.lookup(t.Name.Space); s != "" { t.Name.Space = "" t.Name.Local = s + ":" + t.Name.Local } } tok = t case xml.CharData: tok = xml.CharData(replace(string(t))) case xml.EndElement: s := n.lookup(t.Name.Space) n = n.pop() if n.isDef(t.Name.Space) { t.Name.Space = "" } else if s != "" { t.Name.Space = "" t.Name.Local = s + ":" + t.Name.Local } tok = t } if err := encoder.EncodeToken(tok); err != nil { return err } } return encoder.Flush() } type nsframe struct { def string ns map[string]string } type nsdef []nsframe func (n nsdef) setDef(def string) { if l := len(n); l > 0 { n[l-1].def = def } } func (n nsdef) isDef(s string) bool { for i := len(n) - 1; i >= 0; i-- { if x := n[i].def; x != "" { return s == x } } return false } func (n nsdef) define(ns, s string) { if l := len(n); l > 0 { n[l-1].ns[ns] = s } } func (n nsdef) lookup(ns string) string { for i := len(n) - 1; i >= 0; i-- { if s := n[i].ns[ns]; s != "" { return s } } return "" } func (n nsdef) checkDef(at *xml.Attr) { if at.Name.Space == "" && at.Name.Local == "xmlns" { n.setDef(at.Value) } } func (n nsdef) adjust(at *xml.Attr) { switch { case at.Name.Space == "xmlns": n.define(at.Value, at.Name.Local) at.Name.Local = "xmlns:" + at.Name.Local at.Name.Space = "" case at.Name.Space != "": if n.isDef(at.Name.Space) { at.Name.Space = "" } else if s := n.lookup(at.Name.Space); s != "" { at.Name.Local = s + ":" + at.Name.Local at.Name.Space = "" } } } func (n nsdef) push() nsdef { return append(n, nsframe{ns: make(map[string]string)}) } func (n nsdef) pop() nsdef { if l := len(n); l > 0 { n[l-1] = nsframe{} n = n[:l-1] } return n }