Work on data source proxying, #6

pkg/api/api_dataproxy.go

@@ -0,0 +1,63 @@
+package api
+
+import (
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+	"strings"
+
+	"github.com/torkelo/grafana-pro/pkg/bus"
+	"github.com/torkelo/grafana-pro/pkg/log"
+	"github.com/torkelo/grafana-pro/pkg/middleware"
+	m "github.com/torkelo/grafana-pro/pkg/models"
+)
+
+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
+}
+
+func NewReverseProxy(target *url.URL, proxyPath string) *httputil.ReverseProxy {
+	targetQuery := target.RawQuery
+
+	director := func(req *http.Request) {
+		req.URL.Scheme = target.Scheme
+		req.URL.Host = target.Host
+		req.URL.Path = singleJoiningSlash(target.Path, proxyPath)
+		if targetQuery == "" || req.URL.RawQuery == "" {
+			req.URL.RawQuery = targetQuery + req.URL.RawQuery
+		} else {
+			req.URL.RawQuery = targetQuery + "&" + req.URL.RawQuery
+		}
+
+		log.Info("Proxy: %v", req.URL.Path)
+	}
+	return &httputil.ReverseProxy{Director: director}
+}
+
+// TODO: need to cache datasources
+func ProxyDataSourceRequest(c *middleware.Context) {
+	name := c.Params(":name")
+
+	query := m.GetDataSourceByNameQuery{
+		Name:      name,
+		AccountId: c.GetAccountId(),
+	}
+
+	err := bus.Dispatch(&query)
+	if err != nil {
+		c.JsonApiErr(500, "Unable to load datasource meta data", err)
+	}
+
+	proxyPath := c.Params("*")
+	url, _ := url.Parse(query.Result.Url)
+	proxy := NewReverseProxy(url, proxyPath)
+	proxy.ServeHTTP(c.RW(), c.Req.Request)
+}