Add support for files (#11)

README.md

@@ -74,5 +74,7 @@ endpoints:
   defaultResponseContent: "Sample service"  
   # Default response content-type, if not provided "text/plain; charset=utf-8"
   defaultResponseContentType: text/plain; charset=utf-8
+  # Path to the file that is returned by default, if provided then defaultResponseContent is ignored
+  defaultResponseFile: "mockice/index.html"
 
 ```

pkg/endpoint/endpoint.go

@@ -1,7 +1,11 @@
 package endpoint
 
 import (
+	"io"
+	"io/ioutil"
 	"net/http"
+	"os"
+	"strings"
 
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
@@ -14,6 +18,7 @@ type Config struct {
 	DefaultResponseCode        *int     `yaml:"defaultResponseCode"`
 	DefaultResponseContent     string   `yaml:"defaultResponseContent"`
 	DefaultResponseContentType *string  `yaml:"defaultResponseContentType"`
+	DefaultResponseFile        *string  `yaml:"defaultResponseFile"`
 }
 
 // DefaultConfig generates default configuration with /hello endpoint
@@ -51,17 +56,28 @@ func (e *Endpoint) Handle(writer http.ResponseWriter, request *http.Request) {
 		return
 	}
 
-	if e.config.DefaultResponseContentType != nil {
-		writer.Header().Set("Content-Type", *e.config.DefaultResponseContentType)
+	writer.Header().Set("Content-Type", e.defaultContentType())
+
+	var reader io.ReadCloser
+	if e.config.DefaultResponseFile != nil {
+		file, err := e.fileReader(writer)
+		if err != nil {
+			http.Error(writer, err.Error(), http.StatusInternalServerError)
+			e.log.Error(err)
+			return
+		}
+
+		reader = file
 	} else {
-		writer.Header().Set("Content-Type", "text/plain; charset=utf-8")
+		reader = ioutil.NopCloser(strings.NewReader(e.config.DefaultResponseContent))
 	}
+	defer reader.Close()
 
 	if e.config.DefaultResponseCode != nil {
 		writer.WriteHeader(*e.config.DefaultResponseCode)
 	}
 
-	_, err := writer.Write([]byte(e.config.DefaultResponseContent))
+	_, err := io.Copy(writer, reader)
 	if err != nil {
 		err = errors.Wrapf(err, "while writing response")
 		http.Error(writer, err.Error(), http.StatusInternalServerError)
@@ -70,6 +86,22 @@ func (e *Endpoint) Handle(writer http.ResponseWriter, request *http.Request) {
 	}
 }
 
+func (e *Endpoint) defaultContentType() string {
+	if e.config.DefaultResponseContentType != nil {
+		return *e.config.DefaultResponseContentType
+	}
+	return "text/plain; charset=utf-8"
+}
+
+func (e *Endpoint) fileReader(writer io.Writer) (io.ReadCloser, error) {
+	file, err := os.Open(*e.config.DefaultResponseFile)
+	if err != nil {
+		return nil, errors.Wrapf(err, "while opening file %s", *e.config.DefaultResponseFile)
+	}
+
+	return file, nil
+}
+
 // Name returns name of the endpoint
 func (e *Endpoint) Name() string {
 	return e.config.Name

pkg/endpoint/endpoint_test.go

@@ -3,6 +3,7 @@ package endpoint_test
 import (
 	"bytes"
 	"fmt"
+	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
 	"strings"
@@ -105,6 +106,37 @@ func TestEndpoint_Handle(t *testing.T) {
 				DefaultResponseCode:    intPointer(http.StatusNotModified),
 			},
 		},
+		"With file": {
+			method:               http.MethodGet,
+			expectedResponseCode: http.StatusOK,
+			config: endpoint.Config{
+				Name:                       "simple",
+				DefaultResponseCode:        intPointer(http.StatusOK),
+				DefaultResponseContentType: stringPointer("text/markdown; charset=utf-8"),
+				DefaultResponseFile:        stringPointer("testdata/test.md"),
+			},
+		},
+		"With file and content": {
+			method:               http.MethodGet,
+			expectedResponseCode: http.StatusOK,
+			config: endpoint.Config{
+				Name:                       "simple",
+				DefaultResponseContent:     "test",
+				DefaultResponseCode:        intPointer(http.StatusOK),
+				DefaultResponseContentType: stringPointer("text/markdown; charset=utf-8"),
+				DefaultResponseFile:        stringPointer("testdata/test.md"),
+			},
+		},
+		"With not existing file": {
+			method:               http.MethodGet,
+			expectedResponseCode: http.StatusInternalServerError,
+			config: endpoint.Config{
+				Name:                       "simple",
+				DefaultResponseCode:        intPointer(http.StatusOK),
+				DefaultResponseContentType: stringPointer("text/markdown; charset=utf-8"),
+				DefaultResponseFile:        stringPointer("testdata/test.md.fail"),
+			},
+		},
 	} {
 		t.Run(testName, func(t *testing.T) {
 			// Given
@@ -133,11 +165,26 @@ func TestEndpoint_Handle(t *testing.T) {
 
 			buff := new(bytes.Buffer)
 			buff.ReadFrom(recorder.Result().Body)
-			g.Expect(buff.String()).To(Equal(testCase.config.DefaultResponseContent))
+			if testCase.config.DefaultResponseFile == nil {
+				g.Expect(buff.String()).To(Equal(testCase.config.DefaultResponseContent))
+			} else {
+				content, err := readFile(*testCase.config.DefaultResponseFile)
+				g.Expect(err).To(Succeed())
+				g.Expect(buff.String()).To(Equal(content))
+			}
 		})
 	}
 }
 
+func readFile(path string) (string, error) {
+	content, err := ioutil.ReadFile(path)
+	if err != nil {
+		return "", err
+	}
+
+	return string(content), nil
+}
+
 func stringPointer(value string) *string {
 	return &value
 }

pkg/endpoint/testdata/test.md

@@ -0,0 +1,3 @@
+# Header
+
+Text