Mercurial > gemma
view pkg/controllers/proxy.go @ 935:430d52c2f6ef
client: move layer isolines to be drawn at the top
* Move layer isolones to be drawn last (and thus being "on top")
so that the bottleneck (position) layer will not interfere that much
with the colours. It also allows to set a white background with high
opacity on the bottleneck polygon in order to get highly visible
isolines.
author | Bernhard Reiter <bernhard@intevation.de> |
---|---|
date | Mon, 08 Oct 2018 17:20:42 +0200 |
parents | 82765aa6de53 |
children | a244b18cb916 |
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package controllers import ( "compress/flate" "compress/gzip" "crypto/hmac" "crypto/sha256" "encoding/base64" "encoding/xml" "io" "io/ioutil" "log" "net/http" "net/url" "regexp" "strings" "time" "github.com/gorilla/mux" "golang.org/x/net/html/charset" "gemma.intevation.de/gemma/pkg/config" ) // proxyBlackList is a set of URLs that should not be rewritten by the proxy. var proxyBlackList = map[string]struct{}{ "http://www.w3.org/2001/XMLSchema-instance": struct{}{}, "http://www.w3.org/1999/xlink": struct{}{}, "http://www.w3.org/2001/XMLSchema": struct{}{}, "http://www.w3.org/XML/1998/namespace": struct{}{}, "http://www.opengis.net/wfs/2.0": struct{}{}, "http://www.opengis.net/ows/1.1": struct{}{}, "http://www.opengis.net/gml/3.2": struct{}{}, "http://www.opengis.net/fes/2.0": struct{}{}, "http://schemas.opengis.net/gml": struct{}{}, "http://www.opengis.net/wfs": struct{}{}, } func proxyDirector(lookup func(string) (string, bool)) func(*http.Request) { return func(req *http.Request) { log.Printf("proxyDirector: %s\n", req.RequestURI) abort := func(format string, args ...interface{}) { log.Printf(format, args...) panic(http.ErrAbortHandler) } vars := mux.Vars(req) var s string if entry, found := vars["entry"]; found { if s, found = lookup(entry); !found { abort("Cannot find entry '%s'\n", entry) } } else { expectedMAC, err := base64.URLEncoding.DecodeString(vars["hash"]) if err != nil { abort("Cannot base64 decode hash: %v\n", err) } url, err := base64.URLEncoding.DecodeString(vars["url"]) if err != nil { abort("Cannot base64 decode url: %v\n", err) } mac := hmac.New(sha256.New, config.ProxyKey()) mac.Write(url) messageMAC := mac.Sum(nil) s = string(url) if !hmac.Equal(messageMAC, expectedMAC) { abort("HMAC of URL %s failed.\n", s) } } nURL := s + "?" + 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.Host = u.Host //req.Header.Del("If-None-Match") //log.Printf("headers: %v\n", req.Header) } } 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 proxyModifyResponse(suffix string) func(*http.Response) error { return func(resp *http.Response) error { if !isXML(resp.Header) { return nil } 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(suffix, w, r); 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", "application/vnd.ogc.wms_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 } var replaceRe = regexp.MustCompile(`\b(https?://[^\s\?'"]*)`) func replace(suffix, s string) string { proxyKey := config.ProxyKey() proxyPrefix := config.ProxyPrefix() + suffix return replaceRe.ReplaceAllStringFunc(s, func(s string) string { if _, found := proxyBlackList[s]; found { return s } mac := hmac.New(sha256.New, proxyKey) b := []byte(s) mac.Write(b) expectedMAC := mac.Sum(nil) hash := base64.URLEncoding.EncodeToString(expectedMAC) enc := base64.URLEncoding.EncodeToString(b) return proxyPrefix + hash + "/" + enc }) } func rewrite(suffix string, w io.Writer, r io.Reader) error { decoder := xml.NewDecoder(r) decoder.CharsetReader = charset.NewReaderLabel encoder := xml.NewEncoder(w) 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(suffix, 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(suffix, string(t))) case xml.Directive: tok = xml.Directive(replace(suffix, 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 }