make http client configurable

app.go

@@ -7,6 +7,7 @@ import (
 	"time"
 	log "github.com/sirupsen/logrus"
 	"github.com/kelseyhightower/envconfig"
+	"net"
 )
 
 func main() {
@@ -19,12 +20,20 @@ func main() {
 	log.Info("Listening on", config.Port)
 
 	httpClient := &http.Client{
-			// TODO: make these options configurable
-			Transport: &http.Transport{
-				MaxIdleConnsPerHost: 100,
-			},
-			Timeout: time.Millisecond * 1500,
-		}
+		Transport: &http.Transport{
+			MaxIdleConnsPerHost: config.HTTPClientMaxIdleConnsPerHost,
+			DialContext: (&net.Dialer{
+				Timeout:   time.Duration(config.HTTPClientDialerTimeoutMS) * time.Millisecond,
+				KeepAlive: time.Duration(config.HTTPClientDialerKeepAliveMS) * time.Millisecond,
+			}).DialContext,
+			MaxIdleConns:          config.HTTPClientMaxIdleConns,
+			IdleConnTimeout:       time.Duration(config.HTTPClientIdleConnTimeoutMS) * time.Millisecond,
+			TLSHandshakeTimeout:   time.Duration(config.HTTPClientTLSHandshakeTimeoutMS) * time.Millisecond,
+			ExpectContinueTimeout: time.Duration(config.HTTPClientExpectContinueTimeoutMS) * time.Millisecond,
+
+		},
+		Timeout: time.Duration(config.HTTPClientTimeoutMS) * time.Millisecond,
+	}
 
 	service := &Service{config.ServiceBaseURL, httpClient}
 	handler := &Handler{*service}

config.go

@@ -1,9 +1,17 @@
 package main
 
 type AppConfig struct {
-	Port           int    `default:"8000"`
-	ServiceBaseURL string `envconfig:"SERVICE_BASE_URL" required:"true"`
-	Env            string `envconfig:"ENV_NAME" required:"true"`
+	Port                          int    `default:"8000"`
+	ServiceBaseURL                string `envconfig:"SERVICE_BASE_URL" required:"true"`
+	Env                           string `envconfig:"ENV_NAME" required:"true"`
+	HTTPClientMaxIdleConnsPerHost int `envconfig:"HTTP_CLIENT_MAX_IDLE_CONNS_PER_HOST" required:"true"`
+	HTTPClientMaxIdleConns int `envconfig:"HTTP_CLIENT_MAX_IDLE_CONNS" required:"true"`
+	HTTPClientDialerTimeoutMS int `envconfig:"HTTP_CLIENT_DIALER_TIMEOUT_MS" required:"true"`
+	HTTPClientDialerKeepAliveMS int `envconfig:"HTTP_CLIENT_DIALER_KEEPALIVE_MS" required:"true"`
+	HTTPClientIdleConnTimeoutMS int `envconfig:"HTTP_CLIENT_IDLE_CONN_TIMEOUT_MS" required:"true"`
+	HTTPClientTLSHandshakeTimeoutMS int `envconfig:"HTTP_CLIENT_TLS_HANDSHAKE_TIMEOUT_MS" required:"true"`
+	HTTPClientExpectContinueTimeoutMS int `envconfig:"HTTP_CLIENT_EXPECT_CONTINUE_TIMEOUT_MS" required:"true"`
+	HTTPClientTimeoutMS int `envconfig:"HTTP_CLIENT_TIMEOUT_MS" required:"true"`
 }
 
 func (c *AppConfig) IsLocal() bool {

docker-compose.yml

@@ -7,6 +7,15 @@ services:
       - SERVICE_BASE_URL=http://fake-service:9090/service
       - ENV_NAME=local
       - LOG_LEVEL=debug
+      - HTTP_CLIENT_MAX_IDLE_CONNS_PER_HOST=1
+      - HTTP_CLIENT_MAX_IDLE_CONNS=1
+      - HTTP_CLIENT_DIALER_TIMEOUT_MS=30000
+      - HTTP_CLIENT_DIALER_KEEPALIVE_MS=30000
+      - HTTP_CLIENT_IDLE_CONN_TIMEOUT_MS=90000
+      - HTTP_CLIENT_TLS_HANDSHAKE_TIMEOUT_MS=10000
+      - HTTP_CLIENT_EXPECT_CONTINUE_TIMEOUT_MS=1000
+      - HTTP_CLIENT_TIMEOUT_MS=1500
+
     links:
       - fake-service
     ports:

locust/locustfile.py

@@ -6,9 +6,6 @@ def api(l):
 class UserBehavior(TaskSet):
     tasks = {api: 5}
 
-    def on_start(self):
-        login(self)
-
 class WebsiteUser(HttpLocust):
     task_set = UserBehavior
     min_wait = 5

scripts/docker-build-app-image.sh

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+sudo docker build -t http-client-test .

scripts/docker-run.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+
+set -e
+set -u
+
+sudo docker run -p '8000:8000' \
+    -e 'ENV_NAME=test' \
+    -e 'SERVICE_BASE_URL=http://ec2-54-197-30-116.compute-1.amazonaws.com:8001/service' \
+    -e 'LOG_LEVEL=warn' \
+    -e 'HTTP_CLIENT_MAX_IDLE_CONNS_PER_HOST=100' \
+    -e 'HTTP_CLIENT_MAX_IDLE_CONNS=100' \
+    -e 'HTTP_CLIENT_DIALER_TIMEOUT_MS=30000' \
+    -e 'HTTP_CLIENT_DIALER_KEEPALIVE_MS=30000' \
+    -e 'HTTP_CLIENT_IDLE_CONN_TIMEOUT_MS=90000' \
+    -e 'HTTP_CLIENT_TLS_HANDSHAKE_TIMEOUT_MS=10000' \
+    -e 'HTTP_CLIENT_EXPECT_CONTINUE_TIMEOUT_MS=1000' \
+    -e 'HTTP_CLIENT_TIMEOUT_MS=1500' \
+    http-client-test