Factored throttling client out of aggregator.

cmd/csaf_aggregator/client.go

@@ -9,56 +9,16 @@
 package main
 
 import (
-	"context"
 	"errors"
 	"io"
 	"net/http"
-	"net/url"
 
-	"golang.org/x/time/rate"
+	"github.com/csaf-poc/csaf_distribution/util"
 )
 
-type client interface {
-	Do(req *http.Request) (*http.Response, error)
-	Get(url string) (*http.Response, error)
-	Head(url string) (*http.Response, error)
-	Post(url, contentType string, body io.Reader) (*http.Response, error)
-	PostForm(url string, data url.Values) (*http.Response, error)
-}
-
-type limitingClient struct {
-	client
-	limiter *rate.Limiter
-}
-
-func (lc *limitingClient) Do(req *http.Request) (*http.Response, error) {
-	lc.limiter.Wait(context.Background())
-	return lc.client.Do(req)
-}
-
-func (lc *limitingClient) Get(url string) (*http.Response, error) {
-	lc.limiter.Wait(context.Background())
-	return lc.client.Get(url)
-}
-
-func (lc *limitingClient) Head(url string) (*http.Response, error) {
-	lc.limiter.Wait(context.Background())
-	return lc.client.Head(url)
-}
-
-func (lc *limitingClient) Post(url, contentType string, body io.Reader) (*http.Response, error) {
-	lc.limiter.Wait(context.Background())
-	return lc.client.Post(url, contentType, body)
-}
-
-func (lc *limitingClient) PostForm(url string, data url.Values) (*http.Response, error) {
-	lc.limiter.Wait(context.Background())
-	return lc.client.PostForm(url, data)
-}
-
 var errNotFound = errors.New("not found")
 
-func downloadJSON(c client, url string, found func(io.Reader) error) error {
+func downloadJSON(c util.Client, url string, found func(io.Reader) error) error {
 	res, err := c.Get(url)
 	if err != nil || res.StatusCode != http.StatusOK ||
 		res.Header.Get("Content-Type") != "application/json" {

cmd/csaf_aggregator/config.go

@@ -21,6 +21,7 @@ import (
 	"github.com/BurntSushi/toml"
 	"github.com/ProtonMail/gopenpgp/v2/crypto"
 	"github.com/csaf-poc/csaf_distribution/csaf"
+	"github.com/csaf-poc/csaf_distribution/util"
 	"golang.org/x/time/rate"
 )
 
@@ -105,7 +106,7 @@ func (c *config) cryptoKey() (*crypto.Key, error) {
 	return c.key, c.keyErr
 }
 
-func (c *config) httpClient(p *provider) client {
+func (c *config) httpClient(p *provider) util.Client {
 
 	client := http.Client{}
 	if p.Insecure != nil && *p.Insecure || c.Insecure != nil && *c.Insecure {
@@ -126,9 +127,9 @@ func (c *config) httpClient(p *provider) client {
 	if p.Rate != nil {
 		r = *p.Rate
 	}
-	return &limitingClient{
-		client:  &client,
-		limiter: rate.NewLimiter(rate.Limit(r), 1),
+	return &util.LimitingClient{
+		Client:  &client,
+		Limiter: rate.NewLimiter(rate.Limit(r), 1),
 	}
 }
 

cmd/csaf_aggregator/processor.go

@@ -39,7 +39,7 @@ type worker struct {
 	cfg      *config
 	signRing *crypto.KeyRing
 
-	client           client               // client per provider
+	client           util.Client          // client per provider
 	provider         *provider            // current provider
 	metadataProvider interface{}          // current metadata provider
 	loc              string               // URL of current provider-metadata.json

util/client.go

@@ -0,0 +1,63 @@
+// This file is Free Software under the MIT License
+// without warranty, see README.md and LICENSES/MIT.txt for details.
+//
+// SPDX-License-Identifier: MIT
+//
+// SPDX-FileCopyrightText: 2022 German Federal Office for Information Security (BSI) <https://www.bsi.bund.de>
+// Software-Engineering: 2022 Intevation GmbH <https://intevation.de>
+
+package util
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/url"
+
+	"golang.org/x/time/rate"
+)
+
+// Client is an interface to abstract http.Client.
+type Client interface {
+	Do(req *http.Request) (*http.Response, error)
+	Get(url string) (*http.Response, error)
+	Head(url string) (*http.Response, error)
+	Post(url, contentType string, body io.Reader) (*http.Response, error)
+	PostForm(url string, data url.Values) (*http.Response, error)
+}
+
+// LimitingClient is a Client implementing rate throttling.
+type LimitingClient struct {
+	Client
+	Limiter *rate.Limiter
+}
+
+// Do implements the respective method of the Client interface.
+func (lc *LimitingClient) Do(req *http.Request) (*http.Response, error) {
+	lc.Limiter.Wait(context.Background())
+	return lc.Client.Do(req)
+}
+
+// Get implements the respective method of the Client interface.
+func (lc *LimitingClient) Get(url string) (*http.Response, error) {
+	lc.Limiter.Wait(context.Background())
+	return lc.Client.Get(url)
+}
+
+// Head implements the respective method of the Client interface.
+func (lc *LimitingClient) Head(url string) (*http.Response, error) {
+	lc.Limiter.Wait(context.Background())
+	return lc.Client.Head(url)
+}
+
+// Post implements the respective method of the Client interface.
+func (lc *LimitingClient) Post(url, contentType string, body io.Reader) (*http.Response, error) {
+	lc.Limiter.Wait(context.Background())
+	return lc.Client.Post(url, contentType, body)
+}
+
+// PostForm implements the respective method of the Client interface.
+func (lc *LimitingClient) PostForm(url string, data url.Values) (*http.Response, error) {
+	lc.Limiter.Wait(context.Background())
+	return lc.Client.PostForm(url, data)
+}