feat(app routes): worked on app routes, added unit test, changed Grafana-Context header to start with X to be standard compliant, got cloud saas queries to work via app route feature and header template

pkg/api/pluginproxy/pluginproxy.go

@@ -0,0 +1,99 @@
+package pluginproxy
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+	"text/template"
+
+	"github.com/grafana/grafana/pkg/bus"
+	"github.com/grafana/grafana/pkg/log"
+	"github.com/grafana/grafana/pkg/middleware"
+	m "github.com/grafana/grafana/pkg/models"
+	"github.com/grafana/grafana/pkg/plugins"
+	"github.com/grafana/grafana/pkg/util"
+)
+
+type templateData struct {
+	JsonData       map[string]interface{}
+	SecureJsonData map[string]string
+}
+
+func getHeaders(route *plugins.AppPluginRoute, orgId int64, appId string) (http.Header, error) {
+	result := http.Header{}
+
+	query := m.GetAppSettingByAppIdQuery{OrgId: orgId, AppId: appId}
+
+	if err := bus.Dispatch(&query); err != nil {
+		return nil, err
+	}
+
+	data := templateData{
+		JsonData:       query.Result.JsonData,
+		SecureJsonData: query.Result.SecureJsonData.Decrypt(),
+	}
+
+	for _, header := range route.Headers {
+		var contentBuf bytes.Buffer
+		t, err := template.New("content").Parse(header.Content)
+		if err != nil {
+			return nil, errors.New(fmt.Sprintf("could not parse header content template for header %s.", header.Name))
+		}
+
+		err = t.Execute(&contentBuf, data)
+		if err != nil {
+			return nil, errors.New(fmt.Sprintf("failed to execute header content template for header %s.", header.Name))
+		}
+
+		log.Trace("Adding header to proxy request. %s: %s", header.Name, contentBuf.String())
+		result.Add(header.Name, contentBuf.String())
+	}
+
+	return result, nil
+}
+
+func NewApiPluginProxy(ctx *middleware.Context, proxyPath string, route *plugins.AppPluginRoute, appId string) *httputil.ReverseProxy {
+	targetUrl, _ := url.Parse(route.Url)
+
+	director := func(req *http.Request) {
+
+		req.URL.Scheme = targetUrl.Scheme
+		req.URL.Host = targetUrl.Host
+		req.Host = targetUrl.Host
+
+		req.URL.Path = util.JoinUrlFragments(targetUrl.Path, proxyPath)
+
+		// clear cookie headers
+		req.Header.Del("Cookie")
+		req.Header.Del("Set-Cookie")
+
+		//Create a HTTP header with the context in it.
+		ctxJson, err := json.Marshal(ctx.SignedInUser)
+		if err != nil {
+			ctx.JsonApiErr(500, "failed to marshal context to json.", err)
+			return
+		}
+
+		req.Header.Add("X-Grafana-Context", string(ctxJson))
+
+		if len(route.Headers) > 0 {
+			headers, err := getHeaders(route, ctx.OrgId, appId)
+			if err != nil {
+				ctx.JsonApiErr(500, "Could not generate plugin route header", err)
+				return
+			}
+
+			for key, value := range headers {
+				log.Info("setting key %v value %v", key, value[0])
+				req.Header.Set(key, value[0])
+			}
+		}
+
+	}
+
+	return &httputil.ReverseProxy{Director: director}
+}