Merge features pull request

features

README.md

@@ -17,7 +17,13 @@ Parameters:
 
 For help type **erised -h**
 
-Upon executing **erised** with no parameters it will listen on port **8080** for incoming http requests. 
+Upon executing **erised** with no parameters it will listen on port **8080** for incoming http requests.
+
+The latest version is available as a Docker image at [edaddario/erised](https://hub.docker.com/r/edaddario/erised)
+
+```sh
+docker run --rm -p 8080:8080 edaddario/erised
+```
 
 HTTP methods (e.g. GET, POST, PATCH, etc.), query strings and body are **ignored**. URL Paths are also ignored, except for:
 
@@ -31,11 +37,12 @@ Response behaviour is controlled via custom headers in the http request:
 
 |Name|Purpose|
 |--|--|
-|X-Erised-Data|Returns the **same** value in the response body|
 |X-Erised-Content-Type|Sets the response _Content-Type_. Valid values are **text** (default) for _text/plain_, **json** for _application/json_, **xml** for _application/xml_ and **gzip** for _application/octet-stream_. When using **gzip**, _Content-Encoding_ is also set to **gzip** and the response body is compressed accordingly.|
+|X-Erised-Data|Returns the **same** value in the response body|
+|X-Erised-Headers|Returns the value(s) in the response header. Values **must** be in a JSON array|
+|X-Erised-Location|Sets the response _Location_ to the new (redirected) URL or path, when 300 ≤ _X-Erised-Status-Code_ < 310|
+|X-Erised-Response-Delay|Number of **milliseconds** to wait before sending response back to client|
 |X-Erised-Status-Code|Sets the HTTP Status Code|
-|X-Erised-Location|Sets the response _Location_ to the new (redirected) URL or path, when 300 ≤ _X-Erised-Status-Code_ < 310
-|X-Erised-Response-Delay|Number of milliseconds to wait before sending response back to client
 
 By design, no validation is performed on _X-Erised-Data_ or _X-Erised-Location_.
 
@@ -77,6 +84,7 @@ NetworkAuthenticationRequired or 511
 Any other value will resolve to 200 (OK)
 
 # Release History
+* v0.2.2 - Add custom headers, add dockerfile
 * v0.2.1 - Add gzip compression, improve erised/headers json handling
 * v0.0.3 - Add erised/headers, erised/ip and erised/info paths. Add delayed responses
 * v0.0.2 - Add HTTP redirection status codes (300's), startup configuration parameters and request's logging
@@ -89,7 +97,6 @@ Of all its deficiencies, the most notable are:
 * There are not tests (yet)
 * Server does not shutdown gracefully. To stop, process must be terminated
 * https protocol is not supported
-* **erised** does not scale well
 
 I may or may not address any of this in a future release. Caveat Emptor
 
@@ -210,6 +217,18 @@ curl -w '\n' -v http://localhost:8080
 * Closing connection 0
 ```
 
+### Simple request returning custom headers only:
+```
+curl -w '\n' -I -H "X-Erised-Headers:{\"My-Header\":\"Hello World\",\"Another-Header\":\"Goodbye World\"}" http://localhost:8080
+```
+```sh
+HTTP/1.1 200 OK
+Another-Header: Goodbye World
+Content-Encoding: identity
+Content-Type: text/plain
+My-Header: Hello World
+Date: Sat, 13 Mar 2021 22:56:09 GMT
+```
 ### Request returning _Hello World_ in the response's body:
 ```
 curl -w '\n' -v -H "X-Erised-Data:Hello World" http://localhost:8080

cmd/erised/.dockerignore

@@ -0,0 +1,16 @@
+# Common
+README.md
+CHANGELOG.md
+docker-compose*.yml
+Dockerfile*
+
+# git
+.git
+.gitattributes
+.gitignore
+
+# JetBrains
+.idea
+
+# Other
+bin/

cmd/erised/Dockerfile

@@ -0,0 +1,12 @@
+FROM golang:alpine
+RUN apk update && \
+    apk upgrade && \
+    rm -rf /var/cache/apk/*
+WORKDIR /go/src/app
+COPY . .
+
+RUN go build -o bin/erised -ldflags "-s -w"
+
+EXPOSE 8080
+
+CMD ["bin/erised"]

cmd/erised/main.go

@@ -9,7 +9,7 @@ import (
 	"time"
 )
 
-const version = "v0.2.1"
+const version = "v0.2.2"
 
 type server struct {
 	mux *http.ServeMux
@@ -42,11 +42,12 @@ func setupFlags(f *flag.FlagSet) {
 		fmt.Println("\nParameters:")
 		flag.PrintDefaults()
 		fmt.Println("\nHTTP Headers:")
-		fmt.Println("X-Erised-Data:\t\t\tReturns the same value in the response body")
 		fmt.Println("X-Erised-Content-Type:\t\tSets the response Content-Type")
-		fmt.Println("X-Erised-Status-Code:\t\tSets the HTTP Status Code")
+		fmt.Println("X-Erised-Data:\t\t\tReturns the same value in the response body")
+		fmt.Println("X-Erised-Headers:\t\tReturns the value(s) in the response header(s). Values must be in a JSON array")
 		fmt.Println("X-Erised-Location:\t\tSets the response Location when 300 ≤ X-Erised-Status-Code < 310")
 		fmt.Println("X-Erised-Response-Delay:\tNumber of milliseconds to wait before sending response back to client")
+		fmt.Println("X-Erised-Status-Code:\t\tSets the HTTP Status Code")
 		fmt.Println()
 	}
 }

cmd/erised/serverRoutes.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"encoding/json"
+	"fmt"
 	"log"
 	"net/http"
 	"strconv"
@@ -26,10 +27,27 @@ func (s *server) handleLanding() http.HandlerFunc {
 
 		res.Header().Set("Content-Type", ct)
 		res.Header().Set("Content-Encoding", ce)
+
 		if rd, err := strconv.Atoi(req.Header.Get("X-Erised-Response-Delay")); err == nil {
 			delay = time.Duration(rd) * time.Millisecond
 		}
+
+		hd := req.Header.Get("X-Erised-Headers")
+
+		if json.Valid([]byte(hd)) {
+			var rs map[string]interface{}
+			_ = json.Unmarshal([]byte(hd), &rs)
+
+			if len(rs) != 0 {
+
+				for k, v := range rs {
+					res.Header().Set(k, fmt.Sprintf("%v", v))
+				}
+			}
+		}
+
 		sc := httpStatusCode(req.Header.Get("X-Erised-Status-Code"))
+
 		if sc >= 300 && sc < 310 {
 			res.Header().Set("Location", req.Header.Get("X-Erised-Location"))
 		}
@@ -50,6 +68,7 @@ func (s *server) handleHeaders() http.HandlerFunc {
 		res.Header().Set("Content-Type", "application/json")
 
 		data := "{"
+
 		for k, v := range req.Header {
 			if k == "X-Erised-Data" {
 				if json.Valid([]byte(v[0])) {
@@ -61,6 +80,7 @@ func (s *server) handleHeaders() http.HandlerFunc {
 				data += "\"" + k + "\":\"" + v[0] + "\","
 			}
 		}
+
 		data += "\"Host\":\"" + req.Host + "\""
 		data += "}"