Implement the related handler methods of the transparent operations based on proxy

support index file
support object downloading
support health checking
support related manipulating operations except getting chart version

src/chartserver/base_handler.go

@@ -2,15 +2,16 @@ package chartserver
 
 import (
 	"net/http"
-	"net/http/httputil"
 )
 
 //BaseHandler defines the handlers related with the chart server itself.
 type BaseHandler struct {
 	//Proxy used to to transfer the traffic of requests
 	//It's mainly used to talk to the backend chart server
-	trafficProxy *httputil.ReverseProxy
+	trafficProxy *ProxyEngine
 }
 
 //GetHealthStatus will return the health status of the backend chart repository server
-func (bh *BaseHandler) GetHealthStatus(w http.ResponseWriter, req *http.Request) {}
+func (bh *BaseHandler) GetHealthStatus(w http.ResponseWriter, req *http.Request) {
+	bh.trafficProxy.ServeHTTP(w, req)
+}

src/chartserver/controller.go

@@ -2,7 +2,6 @@ package chartserver
 
 import (
 	"errors"
-	"net/http/httputil"
 	"net/url"
 )
 
@@ -29,8 +28,8 @@ func NewController(backendServer *url.URL) (*Controller, error) {
 		return nil, errors.New("failed to create chartserver.Controller: backend sever address is required")
 	}
 
-	//Currently, no customization requirements needed, so let's use the simple proxy here now
-	proxy := httputil.NewSingleHostReverseProxy(backendServer)
+	//Use customized reverse proxy
+	proxy := NewProxyEngine(backendServer)
 
 	//Initialize chart operator for use
 	operator := &ChartOperator{}

src/chartserver/manipulation_handler.go

@@ -2,7 +2,6 @@ package chartserver
 
 import (
 	"net/http"
-	"net/http/httputil"
 )
 
 //ManipulationHandler includes all the handler methods for the purpose of manipulating the
@@ -10,28 +9,41 @@ import (
 type ManipulationHandler struct {
 	//Proxy used to to transfer the traffic of requests
 	//It's mainly used to talk to the backend chart server
-	trafficProxy *httputil.ReverseProxy
+	trafficProxy *ProxyEngine
 
 	//Parse and process the chart version to provide required info data
 	chartOperator *ChartOperator
 }
 
 //ListCharts lists all the charts under the specified namespace
-func (mh *ManipulationHandler) ListCharts(w http.ResponseWriter, req *http.Request) {}
+func (mh *ManipulationHandler) ListCharts(w http.ResponseWriter, req *http.Request) {
+	mh.trafficProxy.ServeHTTP(w, req)
+}
 
 //GetChart returns all the chart versions under the specified chart
-func (mh *ManipulationHandler) GetChart(w http.ResponseWriter, req *http.Request) {}
+func (mh *ManipulationHandler) GetChart(w http.ResponseWriter, req *http.Request) {
+	mh.trafficProxy.ServeHTTP(w, req)
+}
 
 //GetChartVersion get the specified version for one chart
 //This handler should return the details of the chart version,
 //maybe including metadata,dependencies and values etc.
-func (mh *ManipulationHandler) GetChartVersion(w http.ResponseWriter, req *http.Request) {}
+func (mh *ManipulationHandler) GetChartVersion(w http.ResponseWriter, req *http.Request) {
+	w.WriteHeader(http.StatusNotImplemented)
+	w.Write([]byte("not implemented"))
+}
 
 //UploadChartVersion will save the new version of the chart to the backend storage
-func (mh *ManipulationHandler) UploadChartVersion(w http.ResponseWriter, req *http.Request) {}
+func (mh *ManipulationHandler) UploadChartVersion(w http.ResponseWriter, req *http.Request) {
+	mh.trafficProxy.ServeHTTP(w, req)
+}
 
 //UploadProvenanceFile will save the provenance file of the chart to the backend storage
-func (mh *ManipulationHandler) UploadProvenanceFile(w http.ResponseWriter, req *http.Request) {}
+func (mh *ManipulationHandler) UploadProvenanceFile(w http.ResponseWriter, req *http.Request) {
+	mh.trafficProxy.ServeHTTP(w, req)
+}
 
 //DeleteChartVersion will delete the specified version of the chart
-func (mh *ManipulationHandler) DeleteChartVersion(w http.ResponseWriter, req *http.Request) {}
+func (mh *ManipulationHandler) DeleteChartVersion(w http.ResponseWriter, req *http.Request) {
+	mh.trafficProxy.ServeHTTP(w, req)
+}

src/chartserver/repo_handler.go

@@ -2,7 +2,6 @@ package chartserver
 
 import (
 	"net/http"
-	"net/http/httputil"
 )
 
 //RepositoryHandler defines all the handlers to handle the requests related with chart repository
@@ -10,18 +9,24 @@ import (
 type RepositoryHandler struct {
 	//Proxy used to to transfer the traffic of requests
 	//It's mainly used to talk to the backend chart server
-	trafficProxy *httputil.ReverseProxy
+	trafficProxy *ProxyEngine
 }
 
 //GetIndexFileWithNS will read the index.yaml data under the specified namespace
 func (rh *RepositoryHandler) GetIndexFileWithNS(w http.ResponseWriter, req *http.Request) {
+	rh.trafficProxy.ServeHTTP(w, req)
 }
 
 //GetIndexFile will read the index.yaml under all namespaces and merge them as a single one
 //Please be aware that, to support this function, the backend chart repository server should
 //enable multi-tenancies
-func (rh *RepositoryHandler) GetIndexFile(w http.ResponseWriter, req *http.Request) {}
+func (rh *RepositoryHandler) GetIndexFile(w http.ResponseWriter, req *http.Request) {
+	w.WriteHeader(http.StatusNotImplemented)
+	w.Write([]byte("not implemented"))
+}
 
 //DownloadChartObject will download the stored chart object to the client
 //e.g: helm install
-func (rh *RepositoryHandler) DownloadChartObject(w http.ResponseWriter, req *http.Request) {}
+func (rh *RepositoryHandler) DownloadChartObject(w http.ResponseWriter, req *http.Request) {
+	rh.trafficProxy.ServeHTTP(w, req)
+}

src/chartserver/reverse_proxy.go

@@ -0,0 +1,115 @@
+package chartserver
+
+import (
+	"bytes"
+	"encoding/json"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+	"os"
+	"strconv"
+	"strings"
+)
+
+const (
+	userName            = "chart_controller"
+	passwordKey         = "UI_SECRET"
+	agentHarbor         = "HARBOR"
+	authHeader          = "Authorization"
+	contentLengthHeader = "Content-Length"
+)
+
+//ProxyEngine is used to proxy the related traffics
+type ProxyEngine struct {
+	//The backend target server the traffic will be forwarded to
+	//Just in case we'll use it
+	backend *url.URL
+
+	//Use go reverse proxy as engine
+	engine *httputil.ReverseProxy
+}
+
+//NewProxyEngine is constructor of NewProxyEngine
+func NewProxyEngine(target *url.URL) *ProxyEngine {
+	return &ProxyEngine{
+		backend: target,
+		engine: &httputil.ReverseProxy{
+			ErrorLog: log.New(os.Stdout, "", log.Ldate|log.Ltime|log.Lshortfile),
+			Director: func(req *http.Request) {
+				director(target, req)
+			},
+			ModifyResponse: modifyResponse,
+		},
+	}
+}
+
+//ServeHTTP serves the incoming http requests
+func (pe *ProxyEngine) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	pe.engine.ServeHTTP(w, req)
+}
+
+//Overwrite the http requests
+func director(target *url.URL, req *http.Request) {
+	targetQuery := target.RawQuery
+
+	//Overwrite the request URL to the target path
+	req.URL.Scheme = target.Scheme
+	req.URL.Host = target.Host
+	req.URL.Path = singleJoiningSlash(target.Path, req.URL.Path)
+	if targetQuery == "" || req.URL.RawQuery == "" {
+		req.URL.RawQuery = targetQuery + req.URL.RawQuery
+	} else {
+		req.URL.RawQuery = targetQuery + "&" + req.URL.RawQuery
+	}
+	if _, ok := req.Header["User-Agent"]; !ok {
+		req.Header.Set("User-Agent", agentHarbor)
+	}
+
+	//Get the password from the env
+	//Ignore the empty checking, the backend server should return the right status code
+	//with invalid credential
+	password := os.Getenv(passwordKey)
+
+	//Add authentication header
+	req.SetBasicAuth(userName, password)
+}
+
+//Modify the http response
+func modifyResponse(res *http.Response) error {
+	//Detect the 401 code, if it is,
+	//overwrite it to 500.
+	//We also re-write the error content
+	if res.StatusCode == http.StatusUnauthorized {
+		errorObj := make(map[string]string)
+		errorObj["error"] = "operation request from unauthentic source is rejected"
+		content, err := json.Marshal(errorObj)
+		if err != nil {
+			return err
+		}
+
+		size := len(content)
+		body := ioutil.NopCloser(bytes.NewReader(content))
+		res.Body = body
+		res.ContentLength = int64(size)
+		res.Header.Set(contentLengthHeader, strconv.Itoa(size))
+		res.StatusCode = http.StatusInternalServerError
+	}
+
+	return nil
+}
+
+//Join the path
+//Copy from the go reverse proxy
+func singleJoiningSlash(a, b string) string {
+	aslash := strings.HasSuffix(a, "/")
+	bslash := strings.HasPrefix(b, "/")
+	switch {
+	case aslash && bslash:
+		return a + b[1:]
+	case !aslash && !bslash:
+		return a + "/" + b
+	}
+	return a + b
+}