Merge pull request #1 from weisdd/feature/post

Added support for POST requests, updated metricsql

CHANGELOG.md

@@ -1,5 +1,10 @@
 # CHANGELOG
 
+## 0.3.0
+
+* Added support for POST requests;
+* Updated metricsql from `v0.10.1` to `v0.14.0`.
+
 ## 0.2.3
 
 * Added `/federate` to a list of requests that should be rewritten.

cmd/lfgw/helpers.go

@@ -3,10 +3,7 @@ package main
 import (
 	"fmt"
 	"net/http"
-	"net/url"
 	"strings"
-
-	"github.com/VictoriaMetrics/metricsql"
 )
 
 // serverError sends a generic 500 Internal Server Error response to the user.
@@ -26,38 +23,6 @@ func (app *application) clientErrorMessage(w http.ResponseWriter, status int, er
 	fmt.Fprintf(w, "%s", err)
 }
 
-// TODO: refactor/move somewhere else
-// prepareRawQueryParams rewwrites GET "query" and "match" parameters to filter out metrics.
-func (app *application) prepareRawQueryParams(r *http.Request, lf metricsql.LabelFilter) (string, error) {
-	rawQueryParams := &url.Values{}
-
-	err := r.ParseForm()
-	if err != nil {
-		return "", err
-	}
-
-	// TODO: refactor code
-	for k, vv := range r.Form {
-		switch k {
-		case "query", "match[]":
-			for _, v := range vv {
-				{
-					newVal, err := app.modifyMetricExpr(v, lf)
-					if err != nil {
-						return "", err
-					}
-					rawQueryParams.Add(k, newVal)
-				}
-			}
-		default:
-			for _, v := range vv {
-				rawQueryParams.Add(k, v)
-			}
-		}
-	}
-	return rawQueryParams.Encode(), nil
-}
-
 // getRawAccessToken returns a raw access token
 func (app *application) getRawAccessToken(r *http.Request) (string, error) {
 	headers := []string{"X-Forwarded-Access-Token", "X-Auth-Request-Access-Token", "Authorization"}

cmd/lfgw/lf.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"net/url"
 
 	"github.com/VictoriaMetrics/metricsql"
 )
@@ -76,3 +77,29 @@ func (app *application) modifyMetricExpr(query string, newFilter metricsql.Label
 
 	return string(expr.AppendString(nil)), nil
 }
+
+// prepareQueryParams rewrites GET/POST "query" and "match" parameters to filter out metrics.
+func (app *application) prepareQueryParams(params *url.Values, lf metricsql.LabelFilter) (string, error) {
+	newParams := &url.Values{}
+
+	for k, vv := range *params {
+		switch k {
+		case "query", "match[]":
+			for _, v := range vv {
+				{
+					newVal, err := app.modifyMetricExpr(v, lf)
+					if err != nil {
+						return "", err
+					}
+					newParams.Add(k, newVal)
+				}
+			}
+		default:
+			for _, v := range vv {
+				newParams.Add(k, v)
+			}
+		}
+	}
+
+	return newParams.Encode(), nil
+}

cmd/lfgw/middleware.go

@@ -3,6 +3,7 @@ package main
 import (
 	"context"
 	"fmt"
+	"io"
 	"net/http"
 	"strings"
 
@@ -20,11 +21,11 @@ func (app *application) healthzMiddleware(next http.Handler) http.Handler {
 	})
 }
 
-// prohibitedMethods forbids all the methods aside from "GET".
+// prohibitedMethods forbids all the methods aside from "GET" and "POST".
 func (app *application) prohibitedMethodsMiddleware(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		if r.Method != http.MethodGet {
-			w.Header().Set("Allow", http.MethodGet)
+		if r.Method != http.MethodGet && r.Method != http.MethodPost {
+			w.Header().Set("Allow", fmt.Sprintf("%s, %s", http.MethodGet, http.MethodPost))
 			app.clientError(w, http.StatusMethodNotAllowed)
 			return
 		}
@@ -133,14 +134,36 @@ func (app *application) rewriteRequestMiddleware(next http.Handler) http.Handler
 			return
 		}
 
-		rawQueryParams, err := app.prepareRawQueryParams(r, lf)
+		err := r.ParseForm()
 		if err != nil {
 			app.errorLog.Printf("%s", err)
 			app.clientError(w, http.StatusBadRequest)
 			return
 		}
 
-		r.URL.RawQuery = rawQueryParams
+		// Adjust GET params
+		getParams := r.URL.Query()
+		newGetParams, err := app.prepareQueryParams(&getParams, lf)
+		if err != nil {
+			app.errorLog.Printf("%s", err)
+			app.clientError(w, http.StatusBadRequest)
+			return
+		}
+		r.URL.RawQuery = newGetParams
+
+		// Adjust POST params
+		// Partially inspired by https://github.com/bitsbeats/prometheus-acls/blob/master/internal/labeler/middleware.go
+		if r.Method == http.MethodPost {
+			newPostParams, err := app.prepareQueryParams(&r.PostForm, lf)
+			if err != nil {
+				app.errorLog.Printf("%s", err)
+				app.clientError(w, http.StatusBadRequest)
+				return
+			}
+			newBody := strings.NewReader(newPostParams)
+			r.ContentLength = newBody.Size()
+			r.Body = io.NopCloser(newBody)
+		}
 
 		next.ServeHTTP(w, r)
 	})

go.mod

@@ -3,8 +3,8 @@ module gitlab.rshbdev.ru/rshbintech/integrations/ckpr/infra/images/lfgw
 go 1.16
 
 require (
-	github.com/VictoriaMetrics/metrics v1.14.0 // indirect
-	github.com/VictoriaMetrics/metricsql v0.10.1
+	github.com/VictoriaMetrics/metrics v1.17.2 // indirect
+	github.com/VictoriaMetrics/metricsql v0.14.0
 	github.com/caarlos0/env/v6 v6.5.0
 	github.com/coreos/go-oidc/v3 v3.0.0
 	github.com/golang/protobuf v1.4.3 // indirect

go.sum

@@ -36,8 +36,12 @@ github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym
 github.com/VictoriaMetrics/metrics v1.12.2/go.mod h1:Z1tSfPfngDn12bTfZSCqArT3OPY3u88J12hSoOhuiRE=
 github.com/VictoriaMetrics/metrics v1.14.0 h1:yvyEVo7cPN2Hv+Hrm1zPTA1f/squmEZTq6xtPH/8F64=
 github.com/VictoriaMetrics/metrics v1.14.0/go.mod h1:Z1tSfPfngDn12bTfZSCqArT3OPY3u88J12hSoOhuiRE=
+github.com/VictoriaMetrics/metrics v1.17.2 h1:9zPJ7DPfxdJWshOGLPLpAtPL0ZZ9AeUyQC3fIqG6Lvo=
+github.com/VictoriaMetrics/metrics v1.17.2/go.mod h1:Z1tSfPfngDn12bTfZSCqArT3OPY3u88J12hSoOhuiRE=
 github.com/VictoriaMetrics/metricsql v0.10.1 h1:wLl/YbMmBGFPyLKMfqNLC333iygibosSM5iSvlH2B4A=
 github.com/VictoriaMetrics/metricsql v0.10.1/go.mod h1:ylO7YITho/Iw6P71oEaGyHbO94bGoGtzWfLGqFhMIg8=
+github.com/VictoriaMetrics/metricsql v0.14.0 h1:XGbpZJVskUPJFo2C7vG6ATxXBwkBFPe7EWZXB2HZt2U=
+github.com/VictoriaMetrics/metricsql v0.14.0/go.mod h1:ylO7YITho/Iw6P71oEaGyHbO94bGoGtzWfLGqFhMIg8=
 github.com/caarlos0/env/v6 v6.5.0 h1:f4C7ZQwm0nRFo8vETCQviLUOtOlOwsOhgc/QXp0zrTM=
 github.com/caarlos0/env/v6 v6.5.0/go.mod h1:5ZqhjfyF261xGkANuSuMQ1FeA9ikA3wzDY64wSd9k8k=
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=