From 0defb3cec50cf801932403e03024027ab41fa938 Mon Sep 17 00:00:00 2001
From: Will McCutchen <will@mccutch.org>
Date: Tue, 5 Jul 2022 09:20:59 -0400
Subject: [PATCH] Add /hostname endpoint (#81)
This adds a new /hostname endpoint as originally proposed in #66. In
this implementation, it exposes a dummy hostname by default, and only
exposes the real hostname (via `os.Hostname()`) if the
`-use-real-hostname` flag is given on the command line.
---
Makefile | 2 +-
README.md | 45 +++++++++++++++++++++++---------------
cmd/go-httpbin/main.go | 34 ++++++++++++++++++++++-------
httpbin/handlers.go | 8 +++++++
httpbin/handlers_test.go | 46 +++++++++++++++++++++++++++++++++++++++
httpbin/httpbin.go | 17 +++++++++++++++
httpbin/static/index.html | 1 +
7 files changed, 126 insertions(+), 27 deletions(-)
diff --git a/Makefile b/Makefile
index e5e0d13..b577d44 100644
--- a/Makefile
+++ b/Makefile
@@ -16,7 +16,7 @@ TOOL_BIN_DIR ?= $(shell go env GOPATH)/bin
TOOL_GOLINT := $(TOOL_BIN_DIR)/golint
TOOL_STATICCHECK := $(TOOL_BIN_DIR)/staticcheck
-GO_SOURCES = $(wildcard **/*.go)
+GO_SOURCES = $(shell find . -name *.go)
# =============================================================================
diff --git a/README.md b/README.md
index c954209..0b05863 100644
--- a/README.md
+++ b/README.md
@@ -6,29 +6,34 @@ A reasonably complete and well-tested golang port of [Kenneth Reitz][kr]'s
[](https://pkg.go.dev/github.com/mccutchen/go-httpbin/v2)
[](https://github.com/mccutchen/go-httpbin/actions/workflows/test.yaml)
[](https://codecov.io/gh/mccutchen/go-httpbin)
+[](https://hub.docker.com/r/mccutchen/go-httpbin/)
## Usage
-Run as a standalone binary, configured by command line flags or environment
-variables:
-```
-$ go-httpbin --help
-Usage of go-httpbin:
- -host string
- Host to listen on (default "0.0.0.0")
- -https-cert-file string
- HTTPS Server certificate file
- -https-key-file string
- HTTPS Server private key file
- -max-body-size int
- Maximum size of request or response, in bytes (default 1048576)
- -max-duration duration
- Maximum duration a response may take (default 10s)
- -port int
- Port to listen on (default 8080)
-```
+### Configuration
+
+go-httpbin can be configured via either command line arguments or environment
+variables (or a combination of the two):
+
+| Argument| Env var | Documentation | Default |
+| - | - | - | - |
+| `-host` | `HOST` | Host to listen on | "0.0.0.0" |
+| `-https-cert-file` | `HTTPS_CERT_FILE` | HTTPS Server certificate file | |
+| `-https-key-file` | `HTTPS_KEY_FILE` | HTTPS Server private key file | |
+| `-max-body-size` | `MAX_BODY_SIZE` | Maximum size of request or response, in bytes | 1048576 |
+| `-max-duration` | `MAX_DURATION` | Maximum duration a response may take | 10s |
+| `-port` | `PORT` | Port to listen on | 8080 |
+| `-use-real-hostname` | `USE_REAL_HOSTNAME` | Expose real hostname as reported by os.Hostname() in the /hostname endpoint | false |
+
+**Note:** Command line arguments take precedence over environment variables.
+
+
+### Standalone binary
+
+Follow the [Installation](#installation) instructions to install go-httpbin as
+a standalone binary. (This currently requires a working Go runtime.)
Examples:
@@ -43,6 +48,8 @@ $ openssl req -new -x509 -sha256 -key server.key -out server.crt -days 3650
$ go-httpbin -host 127.0.0.1 -port 8081 -https-cert-file ./server.crt -https-key-file ./server.key
```
+### Docker
+
Docker images are published to [Docker Hub][docker-hub]:
```bash
@@ -53,6 +60,8 @@ $ docker run -P mccutchen/go-httpbin
$ docker run -e HTTPS_CERT_FILE='/tmp/server.crt' -e HTTPS_KEY_FILE='/tmp/server.key' -p 8080:8080 -v /tmp:/tmp mccutchen/go-httpbin
```
+### Unit testing helper library
+
The `github.com/mccutchen/go-httpbin/httpbin/v2` package can also be used as a
library for testing an application's interactions with an upstream HTTP
service, like so:
diff --git a/cmd/go-httpbin/main.go b/cmd/go-httpbin/main.go
index 0743a11..b9196f4 100644
--- a/cmd/go-httpbin/main.go
+++ b/cmd/go-httpbin/main.go
@@ -22,12 +22,13 @@ const (
)
var (
- host string
- port int
- maxBodySize int64
- maxDuration time.Duration
- httpsCertFile string
- httpsKeyFile string
+ host string
+ port int
+ maxBodySize int64
+ maxDuration time.Duration
+ httpsCertFile string
+ httpsKeyFile string
+ useRealHostname bool
)
func main() {
@@ -37,6 +38,7 @@ func main() {
flag.StringVar(&httpsKeyFile, "https-key-file", "", "HTTPS Server private key file")
flag.Int64Var(&maxBodySize, "max-body-size", httpbin.DefaultMaxBodySize, "Maximum size of request or response, in bytes")
flag.DurationVar(&maxDuration, "max-duration", httpbin.DefaultMaxDuration, "Maximum duration a response may take")
+ flag.BoolVar(&useRealHostname, "use-real-hostname", false, "Expose value of os.Hostname() in the /hostname endpoint instead of dummy value")
flag.Parse()
// Command line flags take precedence over environment vars, so we only
@@ -88,6 +90,13 @@ func main() {
}
}
+ // useRealHostname will be true if either the `-use-real-hostname`
+ // arg is given on the command line or if the USE_REAL_HOSTNAME env var
+ // is one of "1" or "true".
+ if useRealHostnameEnv := os.Getenv("USE_REAL_HOSTNAME"); useRealHostnameEnv == "1" || useRealHostnameEnv == "true" {
+ useRealHostname = true
+ }
+
logger := log.New(os.Stderr, "", 0)
// A hacky log helper function to ensure that shutdown messages are
@@ -101,11 +110,20 @@ func main() {
logger.Printf(logFmt, time.Now().Format(dateFmt), fmt.Sprintf(msg, args...))
}
- h := httpbin.New(
+ opts := []httpbin.OptionFunc{
httpbin.WithMaxBodySize(maxBodySize),
httpbin.WithMaxDuration(maxDuration),
httpbin.WithObserver(httpbin.StdLogObserver(logger)),
- )
+ }
+ if useRealHostname {
+ hostname, err := os.Hostname()
+ if err != nil {
+ fmt.Fprintf(os.Stderr, "Error: use-real-hostname=true but hostname lookup failed: %s\n", err)
+ os.Exit(1)
+ }
+ opts = append(opts, httpbin.WithHostname(hostname))
+ }
+ h := httpbin.New(opts...)
listenAddr := net.JoinHostPort(host, strconv.Itoa(port))
diff --git a/httpbin/handlers.go b/httpbin/handlers.go
index 3ff4ccf..ebb2c33 100644
--- a/httpbin/handlers.go
+++ b/httpbin/handlers.go
@@ -1004,3 +1004,11 @@ func (h *HTTPBin) Bearer(w http.ResponseWriter, r *http.Request) {
})
writeJSON(w, body, http.StatusOK)
}
+
+// Hostname - returns the hostname.
+func (h *HTTPBin) Hostname(w http.ResponseWriter, r *http.Request) {
+ body, _ := json.Marshal(hostnameResponse{
+ Hostname: h.hostname,
+ })
+ writeJSON(w, body, http.StatusOK)
+}
diff --git a/httpbin/handlers_test.go b/httpbin/handlers_test.go
index 8c4a31c..b27d76f 100644
--- a/httpbin/handlers_test.go
+++ b/httpbin/handlers_test.go
@@ -2571,3 +2571,49 @@ func TestNotImplemented(t *testing.T) {
})
}
}
+
+func TestHostname(t *testing.T) {
+ t.Parallel()
+
+ loadResponse := func(t *testing.T, bodyBytes []byte) hostnameResponse {
+ var resp hostnameResponse
+ err := json.Unmarshal(bodyBytes, &resp)
+ if err != nil {
+ t.Fatalf("failed to unmarshal body %q from JSON: %s", string(bodyBytes), err)
+ }
+ return resp
+ }
+
+ t.Run("default hostname", func(t *testing.T) {
+ t.Parallel()
+
+ var (
+ handler = New().Handler()
+ r, _ = http.NewRequest("GET", "/hostname", nil)
+ w = httptest.NewRecorder()
+ )
+ handler.ServeHTTP(w, r)
+ assertStatusCode(t, w, http.StatusOK)
+ resp := loadResponse(t, w.Body.Bytes())
+ if resp.Hostname != DefaultHostname {
+ t.Errorf("expected hostname %q, got %q", DefaultHostname, resp.Hostname)
+ }
+ })
+
+ t.Run("real hostname", func(t *testing.T) {
+ t.Parallel()
+
+ var (
+ realHostname = "real-hostname"
+ handler = New(WithHostname(realHostname)).Handler()
+ r, _ = http.NewRequest("GET", "/hostname", nil)
+ w = httptest.NewRecorder()
+ )
+ handler.ServeHTTP(w, r)
+ assertStatusCode(t, w, http.StatusOK)
+ resp := loadResponse(t, w.Body.Bytes())
+ if resp.Hostname != realHostname {
+ t.Errorf("expected hostname %q, got %q", realHostname, resp.Hostname)
+ }
+ })
+}
diff --git a/httpbin/httpbin.go b/httpbin/httpbin.go
index d7336ad..7f5fa9e 100644
--- a/httpbin/httpbin.go
+++ b/httpbin/httpbin.go
@@ -10,6 +10,7 @@ import (
const (
DefaultMaxBodySize int64 = 1024 * 1024
DefaultMaxDuration = 10 * time.Second
+ DefaultHostname = "go-httpbin"
)
const (
@@ -87,6 +88,10 @@ type bearerResponse struct {
Token string `json:"token"`
}
+type hostnameResponse struct {
+ Hostname string `json:"hostname"`
+}
+
// HTTPBin contains the business logic
type HTTPBin struct {
// Max size of an incoming request generated response body, in bytes
@@ -101,6 +106,9 @@ type HTTPBin struct {
// Default parameter values
DefaultParams DefaultParams
+
+ // The hostname to expose via /hostname.
+ hostname string
}
// DefaultParams defines default parameter values
@@ -137,6 +145,7 @@ func (h *HTTPBin) Handler() http.Handler {
mux.HandleFunc("/user-agent", h.UserAgent)
mux.HandleFunc("/headers", h.Headers)
mux.HandleFunc("/response-headers", h.ResponseHeaders)
+ mux.HandleFunc("/hostname", h.Hostname)
mux.HandleFunc("/status/", h.Status)
mux.HandleFunc("/unstable", h.Unstable)
@@ -222,6 +231,7 @@ func New(opts ...OptionFunc) *HTTPBin {
MaxBodySize: DefaultMaxBodySize,
MaxDuration: DefaultMaxDuration,
DefaultParams: DefaultDefaultParams,
+ hostname: DefaultHostname,
}
for _, opt := range opts {
opt(h)
@@ -254,6 +264,13 @@ func WithMaxDuration(d time.Duration) OptionFunc {
}
}
+// WithHostname sets the hostname to return via the /hostname endpoint.
+func WithHostname(s string) OptionFunc {
+ return func(h *HTTPBin) {
+ h.hostname = s
+ }
+}
+
// WithObserver sets the request observer callback
func WithObserver(o Observer) OptionFunc {
return func(h *HTTPBin) {
diff --git a/httpbin/static/index.html b/httpbin/static/index.html
index e9ed07b..a4fa3c0 100644
--- a/httpbin/static/index.html
+++ b/httpbin/static/index.html
@@ -88,6 +88,7 @@
<li><a href="/headers"><code>/headers</code></a> Returns request header dict.</li>
<li><a href="/hidden-basic-auth/user/passwd"><code>/hidden-basic-auth/:user/:passwd</code></a> 404'd BasicAuth.</li>
<li><a href="/html"><code>/html</code></a> Renders an HTML Page.</li>
+<li><a href="/hostname"><code>/hostname</code></a> Returns the name of the host serving the request.</li>
<li><a href="/image"><code>/image</code></a> Returns page containing an image based on sent Accept header.</li>
<li><a href="/image/jpeg"><code>/image/jpeg</code></a> Returns a JPEG image.</li>
<li><a href="/image/png"><code>/image/png</code></a> Returns a PNG image.</li>
--
GitLab