From 60bd9b77d1e556a1256ede304bebc2c243066117 Mon Sep 17 00:00:00 2001
From: Ales Verbic <verbotenj@blinklabs.io>
Date: Sun, 21 Jul 2024 18:49:48 -0400
Subject: [PATCH] feat: add custom timeout configuration for HTTP client

Signed-off-by: Ales Verbic <verbotenj@blinklabs.io>
---
 api/api.go       | 21 ++++++++++++++--
 api/api_test.go  | 64 ++++++++++++++++++++++++++++++++++++++++++++++++
 config/config.go |  5 +++-
 3 files changed, 87 insertions(+), 3 deletions(-)
 create mode 100644 api/api_test.go

diff --git a/api/api.go b/api/api.go
index 37ab599..282740d 100644
--- a/api/api.go
+++ b/api/api.go
@@ -24,7 +24,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/blinklabs-io/cardano-models"
+	models "github.com/blinklabs-io/cardano-models"
 	"github.com/blinklabs-io/gouroboros/ledger"
 	"github.com/fxamacker/cbor/v2"
 	ginzap "github.com/gin-contrib/zap"
@@ -113,6 +113,9 @@ func handleSubmitTx(c *gin.Context) {
 			}
 		}
 	}
+	// Create custom HTTP client
+	client := createHTTPClient(cfg)
+
 	// Send request to each backend
 	for _, backend := range cfg.Backends {
 		go func(backend string) {
@@ -138,7 +141,7 @@ func handleSubmitTx(c *gin.Context) {
 				return
 			}
 			req.Header.Add("Content-Type", "application/cbor")
-			resp, err := http.DefaultClient.Do(req)
+			resp, err := client.Do(req)
 			if err != nil {
 				logger.Errorf(
 					"failed to send request to backend %s: %s",
@@ -175,3 +178,17 @@ func handleSubmitTx(c *gin.Context) {
 	// Return transaction ID
 	c.String(202, tx.Hash())
 }
+
+// createHTTPClient with custom timeout
+func createHTTPClient(cfg *config.Config) *http.Client {
+	return &http.Client{
+		Timeout: time.Duration(cfg.Api.ClientTimeout) * time.Millisecond,
+		Transport: &http.Transport{
+			MaxIdleConns:          100,
+			IdleConnTimeout:       90 * time.Second,
+			DisableCompression:    false,
+			TLSHandshakeTimeout:   10 * time.Second,
+			ExpectContinueTimeout: 1 * time.Second,
+		},
+	}
+}
diff --git a/api/api_test.go b/api/api_test.go
new file mode 100644
index 0000000..06978c5
--- /dev/null
+++ b/api/api_test.go
@@ -0,0 +1,64 @@
+package api
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+
+	"github.com/blinklabs-io/tx-submit-api-mirror/config"
+)
+
+func TestHTTPClientTimeout(t *testing.T) {
+	client := createHTTPClient(&config.Config{
+		Api: config.ApiConfig{
+			ClientTimeout: 100,
+		},
+	})
+
+	// Create a test server that introduces a delay
+	testServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		time.Sleep(200 * time.Millisecond) // Delay longer than client timeout
+		w.WriteHeader(http.StatusOK)
+	}))
+	defer testServer.Close()
+
+	// Make a request to the test server
+	resp, err := client.Get(testServer.URL)
+
+	// Verify that the request timed out
+	if err == nil {
+		t.Errorf("Expected timeout error, but got nil")
+	}
+	if resp != nil {
+		t.Errorf("Expected no response, but got %v", resp)
+	}
+}
+
+func TestHTTPClientTimeoutPass(t *testing.T) {
+	client := createHTTPClient(&config.Config{
+		Api: config.ApiConfig{
+			ClientTimeout: 300,
+		},
+	})
+
+	// Create a test server that introduces a delay
+	testServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		time.Sleep(200 * time.Millisecond) // Delay shorter than client timeout
+		w.WriteHeader(http.StatusOK)
+	}))
+	defer testServer.Close()
+
+	// Make a request to the test server
+	resp, err := client.Get(testServer.URL)
+
+	// Verify that the request did not time out
+	if err != nil {
+		t.Errorf("Expected no error, but got %v", err)
+	}
+	if resp == nil {
+		t.Errorf("Expected response, but got nil")
+	} else if resp.StatusCode != http.StatusOK {
+		t.Errorf("Expected status OK, but got %v", resp.StatusCode)
+	}
+}
diff --git a/config/config.go b/config/config.go
index 6a05caa..4ab2bee 100644
--- a/config/config.go
+++ b/config/config.go
@@ -16,9 +16,10 @@ package config
 
 import (
 	"fmt"
+	"os"
+
 	"github.com/kelseyhightower/envconfig"
 	"gopkg.in/yaml.v2"
-	"os"
 )
 
 type Config struct {
@@ -34,6 +35,7 @@ type LoggingConfig struct {
 type ApiConfig struct {
 	ListenAddress string `yaml:"address" envconfig:"API_LISTEN_ADDRESS"`
 	ListenPort    uint   `yaml:"port"    envconfig:"API_LISTEN_PORT"`
+	ClientTimeout uint   `yaml:"client_timeout"    envconfig:"CLIENT_TIMEOUT"`
 }
 
 // Singleton config instance with default values
@@ -44,6 +46,7 @@ var globalConfig = &Config{
 	Api: ApiConfig{
 		ListenAddress: "",
 		ListenPort:    8090,
+		ClientTimeout: 60000, // [ms]
 	},
 }