78 lines
2.3 KiB
Go
78 lines
2.3 KiB
Go
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package middlewares
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import (
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"net/http"
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"strconv"
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"strings"
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"github.com/containous/traefik/log"
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"github.com/containous/traefik/types"
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"github.com/vulcand/oxy/forward"
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"github.com/vulcand/oxy/utils"
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)
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//ErrorPagesHandler is a middleware that provides the custom error pages
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type ErrorPagesHandler struct {
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HTTPCodeRanges [][2]int
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BackendURL string
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errorPageForwarder *forward.Forwarder
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}
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//NewErrorPagesHandler initializes the utils.ErrorHandler for the custom error pages
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func NewErrorPagesHandler(errorPage types.ErrorPage, backendURL string) (*ErrorPagesHandler, error) {
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fwd, err := forward.New()
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if err != nil {
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return nil, err
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}
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//Break out the http status code ranges into a low int and high int
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//for ease of use at runtime
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var blocks [][2]int
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for _, block := range errorPage.Status {
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codes := strings.Split(block, "-")
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//if only a single HTTP code was configured, assume the best and create the correct configuration on the user's behalf
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if len(codes) == 1 {
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codes = append(codes, codes[0])
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}
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lowCode, err := strconv.Atoi(codes[0])
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if err != nil {
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return nil, err
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}
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highCode, err := strconv.Atoi(codes[1])
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if err != nil {
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return nil, err
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}
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blocks = append(blocks, [2]int{lowCode, highCode})
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}
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return &ErrorPagesHandler{
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HTTPCodeRanges: blocks,
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BackendURL: backendURL + errorPage.Query,
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errorPageForwarder: fwd},
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nil
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}
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func (ep *ErrorPagesHandler) ServeHTTP(w http.ResponseWriter, req *http.Request, next http.HandlerFunc) {
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recorder := newRetryResponseRecorder()
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recorder.responseWriter = w
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next.ServeHTTP(recorder, req)
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w.WriteHeader(recorder.Code)
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//check the recorder code against the configured http status code ranges
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for _, block := range ep.HTTPCodeRanges {
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if recorder.Code >= block[0] && recorder.Code <= block[1] {
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log.Errorf("Caught HTTP Status Code %d, returning error page", recorder.Code)
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finalURL := strings.Replace(ep.BackendURL, "{status}", strconv.Itoa(recorder.Code), -1)
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if newReq, err := http.NewRequest(http.MethodGet, finalURL, nil); err != nil {
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w.Write([]byte(http.StatusText(recorder.Code)))
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} else {
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ep.errorPageForwarder.ServeHTTP(w, newReq)
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}
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return
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}
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}
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//did not catch a configured status code so proceed with the request
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utils.CopyHeaders(w.Header(), recorder.Header())
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w.Write(recorder.Body.Bytes())
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}
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