Add support for dumping request and response in Go generated clients (#4566)

* Add support for dumping request and response in Go generated clients

The following change adds a new configuration setting, which
controls whether clients want to dump the HTTP request and response.

Useful when debugging API calls and clients.

* samples: Update Go samples with XML

* Use log.Logger when dumping HTTP request and response in Go client

Author: dnaeon

modules/openapi-generator/src/main/resources/go/client.mustache

@@ -9,8 +9,10 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"log"
 	"mime/multipart"
 	"net/http"
+	"net/http/httputil"
 	"net/url"
 	"os"
 	"path/filepath"
@@ -161,7 +163,25 @@ func parameterToJson(obj interface{}) (string, error) {
 
 // callAPI do the request.
 func (c *APIClient) callAPI(request *http.Request) (*http.Response, error) {
-	return c.cfg.HTTPClient.Do(request)
+	if c.cfg.Debug {
+	        dump, err := httputil.DumpRequestOut(request, true)
+		if err != nil {
+		        return nil, err
+		}
+		log.Printf("\n%s\n", string(dump))
+	}
+
+	resp, err := c.cfg.HTTPClient.Do(request)
+
+	if c.cfg.Debug {
+		dump, err := httputil.DumpResponse(resp, true)
+		if err != nil {
+			return resp, err
+		}
+		log.Printf("\n%s\n", string(dump))
+	}
+
+	return resp, err
 }
 
 // ChangeBasePath changes base path to allow switching to mocks

modules/openapi-generator/src/main/resources/go/configuration.mustache

@@ -48,6 +48,7 @@ type Configuration struct {
 	Scheme        string            `json:"scheme,omitempty"`
 	DefaultHeader map[string]string `json:"defaultHeader,omitempty"`
 	UserAgent     string            `json:"userAgent,omitempty"`
+	Debug         bool              `json:"debug,omitempty"`
 	HTTPClient    *http.Client
 }
 
@@ -57,6 +58,7 @@ func NewConfiguration() *Configuration {
 		BasePath:      "{{{basePath}}}",
 		DefaultHeader: make(map[string]string),
 		UserAgent:     "{{#httpUserAgent}}{{{.}}}{{/httpUserAgent}}{{^httpUserAgent}}OpenAPI-Generator/{{{packageVersion}}}/go{{/httpUserAgent}}",
+		Debug:         false,
 	}
 	return cfg
 }

samples/client/petstore/go/go-petstore-withXml/client.go

@@ -17,8 +17,10 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"log"
 	"mime/multipart"
 	"net/http"
+	"net/http/httputil"
 	"net/url"
 	"os"
 	"path/filepath"
@@ -172,7 +174,25 @@ func parameterToJson(obj interface{}) (string, error) {
 
 // callAPI do the request.
 func (c *APIClient) callAPI(request *http.Request) (*http.Response, error) {
-	return c.cfg.HTTPClient.Do(request)
+	if c.cfg.Debug {
+	        dump, err := httputil.DumpRequestOut(request, true)
+		if err != nil {
+		        return nil, err
+		}
+		log.Printf("\n%s\n", string(dump))
+	}
+
+	resp, err := c.cfg.HTTPClient.Do(request)
+
+	if c.cfg.Debug {
+		dump, err := httputil.DumpResponse(resp, true)
+		if err != nil {
+			return resp, err
+		}
+		log.Printf("\n%s\n", string(dump))
+	}
+
+	return resp, err
 }
 
 // ChangeBasePath changes base path to allow switching to mocks

samples/client/petstore/go/go-petstore-withXml/configuration.go

@@ -56,6 +56,7 @@ type Configuration struct {
 	Scheme        string            `json:"scheme,omitempty"`
 	DefaultHeader map[string]string `json:"defaultHeader,omitempty"`
 	UserAgent     string            `json:"userAgent,omitempty"`
+	Debug         bool              `json:"debug,omitempty"`
 	HTTPClient    *http.Client
 }
 
@@ -65,6 +66,7 @@ func NewConfiguration() *Configuration {
 		BasePath:      "http://petstore.swagger.io:80/v2",
 		DefaultHeader: make(map[string]string),
 		UserAgent:     "OpenAPI-Generator/1.0.0/go",
+		Debug:         false,
 	}
 	return cfg
 }