Enable benchHandler on "/bench/" in addition of "/bench"

Adding the trailing slash allows to trigger the bench handler for
performance measurements in situations where a trailing slash
character '/' is added to the request.

For example, in traefik addPrefix middleware, if you specify a
"/bench" prefix, a request on "http://localhost" will be transformed
from "GET /" to "GET /bench/" with no way to remove the trailing
'/' (at least without adding another rewrite rule, which would
modify measurements).

.github/workflows/go-cross.yml

@@ -0,0 +1,45 @@
+name: Go Matrix
+on: [push, pull_request]
+
+jobs:
+
+  cross:
+    name: Go
+    runs-on: ${{ matrix.os }}
+    env:
+      CGO_ENABLED: 0
+
+    strategy:
+      matrix:
+        go-version: [ 1.14, 1.15, 1.x ]
+        os: [ubuntu-latest, macos-latest, windows-latest]
+
+    steps:
+      # https://github.com/marketplace/actions/setup-go-environment
+      - name: Set up Go ${{ matrix.go-version }}
+        uses: actions/setup-go@v2
+        with:
+          go-version: ${{ matrix.go-version }}
+
+      # https://github.com/marketplace/actions/checkout
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      # https://github.com/marketplace/actions/cache
+      - name: Cache Go modules
+        uses: actions/cache@v2
+        with:
+          path: |
+            ~/go/pkg/mod              # Module download cache
+            ~/.cache/go-build         # Build cache (Linux)
+            ~/Library/Caches/go-build # Build cache (Mac)
+            '%LocalAppData%\go-build' # Build cache (Windows)
+          key: ${{ runner.os }}-${{ matrix.go-version }}-go-${{ hashFiles('**/go.sum') }}
+          restore-keys: |
+            ${{ runner.os }}-${{ matrix.go-version }}-go-
+
+      - name: Test
+        run: go test -v -cover ./...
+
+      - name: Build
+        run: go build -v -ldflags "-s -w" -trimpath

.github/workflows/main.yml

@@ -0,0 +1,81 @@
+name: Main
+
+on:
+  push:
+    branches:
+      - master
+    tags:
+      - v*
+  pull_request:
+
+jobs:
+
+  main:
+    name: Main Process
+    runs-on: ubuntu-latest
+    env:
+      GO_VERSION: 1.15
+      GOLANGCI_LINT_VERSION: v1.33.0
+      SEIHON_VERSION: v0.5.1
+      CGO_ENABLED: 0
+
+    steps:
+
+      # https://github.com/marketplace/actions/setup-go-environment
+      - name: Set up Go ${{ env.GO_VERSION }}
+        uses: actions/setup-go@v2
+        with:
+          go-version: ${{ env.GO_VERSION }}
+
+      # https://github.com/marketplace/actions/checkout
+      - name: Check out code
+        uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+
+      # https://github.com/marketplace/actions/cache
+      - name: Cache Go modules
+        uses: actions/cache@v2
+        with:
+          path: ~/go/pkg/mod
+          key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
+          restore-keys: |
+            ${{ runner.os }}-go-
+
+      - name: Check and get dependencies
+        run: |
+          go mod tidy
+          git diff --exit-code go.mod
+          git diff --exit-code go.sum
+          go mod download
+
+      # https://golangci-lint.run/usage/install#other-ci
+      - name: Install golangci-lint ${{ env.GOLANGCI_LINT_VERSION }}
+        run: |
+          curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(go env GOPATH)/bin ${GOLANGCI_LINT_VERSION}
+          golangci-lint --version
+
+      - name: Make
+        run: make
+
+      - name: Make Image
+        run: make image
+
+      # Install Docker image multi-arch builder
+      - name: Install seihon ${{ env.SEIHON_VERSION }}
+        if: startsWith(github.ref, 'refs/tags/v')
+        run: |
+          curl -sSfL https://raw.githubusercontent.com/ldez/seihon/master/godownloader.sh | sh -s -- -b $(go env GOPATH)/bin ${SEIHON_VERSION}
+          seihon --version
+
+      - name: Docker Login
+        if: startsWith(github.ref, 'refs/tags/v')
+        env:
+          DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
+          DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
+        run: |
+          echo "${DOCKER_PASSWORD}" | docker login --username "${DOCKER_USERNAME}" --password-stdin
+
+      - name: Deploy Docker Images (seihon)
+        if: startsWith(github.ref, 'refs/tags/v')
+        run: make publish-images

.gitignore

@@ -1 +1,3 @@
-/whoamI
+.idea
+vendor/
+/whoami

.golangci.toml

@@ -0,0 +1,49 @@
+[run]
+  deadline = "2m"
+  skip-files = []
+
+[linters-settings]
+
+  [linters-settings.govet]
+    check-shadowing = true
+
+  [linters-settings.gocyclo]
+    min-complexity = 12.0
+
+  [linters-settings.maligned]
+    suggest-new = true
+
+  [linters-settings.goconst]
+    min-len = 3.0
+    min-occurrences = 3.0
+
+  [linters-settings.misspell]
+    locale = "US"
+
+[linters]
+  enable-all = true
+  disable = [
+    "maligned",
+    "lll",
+    "gosec",
+    "dupl",
+    "prealloc",
+    "gochecknoglobals",
+    "gochecknoinits",
+    "gomnd",
+    "wsl",
+    "nlreturn",
+    "testpackage",
+    "paralleltest",
+    "tparallel",
+    "goerr113",
+    "wrapcheck",
+    "exhaustive",
+    "exhaustivestruct",
+  ]
+
+[issues]
+  exclude-use-default = false
+  max-per-linter = 0
+  max-same-issues = 0
+  exclude = []

Dockerfile

@@ -1,5 +1,26 @@
+FROM golang:1-alpine as builder
+
+RUN apk --no-cache --no-progress add git ca-certificates tzdata make \
+    && update-ca-certificates \
+    && rm -rf /var/cache/apk/*
+
+WORKDIR /go/whoami
+
+# Download go modules
+COPY go.mod .
+COPY go.sum .
+RUN GO111MODULE=on GOPROXY=https://proxy.golang.org go mod download
+
+COPY . .
+
+RUN make build
+
 # Create a minimal container to run a Golang static binary
 FROM scratch
-COPY whoamI /
-ENTRYPOINT ["/whoamI"]
+
+COPY --from=builder /usr/share/zoneinfo /usr/share/zoneinfo
+COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
+COPY --from=builder /go/whoami/whoami .
+
+ENTRYPOINT ["/whoami"]
 EXPOSE 80

LICENSE

@@ -0,0 +1,202 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [2015-2018] [Containous]
+   Copyright [2020] [Traefik Labs]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

Makefile

@@ -0,0 +1,22 @@
+.PHONY: default build image check publish-images
+
+TAG_NAME := $(shell git tag -l --contains HEAD)
+
+IMAGE_NAME := traefik/whoami
+
+default: check test build
+
+build:
+	CGO_ENABLED=0 go build -a --trimpath --installsuffix cgo --ldflags="-s" -o whoami
+
+test:
+	go test -v -cover ./...
+
+check:
+	golangci-lint run
+
+image:
+	docker build -t $(IMAGE_NAME) .
+
+publish-images:
+	seihon publish -v "$(TAG_NAME)" -v "latest" --image-name $(IMAGE_NAME) --dry-run=false

README.md

@@ -1,11 +1,38 @@
-# whoamI
+# whoami
+
+[![Docker Pulls](https://img.shields.io/docker/pulls/traefik/whoami.svg)](https://hub.docker.com/r/traefik/whoami/)
+[![Build Status](https://github.com/traefik/whoami/workflows/Main/badge.svg?branch=master)](https://github.com/traefik/whoami/actions)
 
 Tiny Go webserver that prints os information and HTTP request to output
 
-```sh
-$ docker run -d -P --name iamfoo emilevauge/whoami
+## Usage
+
+### Paths
+
+- `/data?size=n[&unit=u]`: creates a response with a size `n`. The unit of measure, if specified, accepts the following values: `KB`, `MB`, `GB`, `TB` (optional, default: bytes).
+- `/echo`: webSocket echo.
+- `/bench`: always return the same response (`1`).
+- `/[?wait=d]`: returns the whoami information (request and network information). The optional `wait` query parameter can be provided to tell the server to wait before sending the response. The duration is expected in Go's [`time.Duration`](https://golang.org/pkg/time/#ParseDuration) format (e.g. `/?wait=100ms` to wait 100 milliseconds).
+- `/api`: returns the whoami information as JSON.
+- `/health`: heath check
+    - `GET`, `HEAD`, ...: returns a response with the status code defined by the `POST`
+    - `POST`: changes the status code of the `GET` (`HEAD`, ...) response.
+
+### Flags
+
+- `cert`: give me a certificate.
+- `key`: give me a key.
+- `port`: give me a port number. (default: 80)
+- `name`: give me a name. (it can be also defined with `WHOAMI_NAME` environment variable)
+
+## Examples
+
+```console
+$ docker run -d -P --name iamfoo traefik/whoami
+
 $ docker inspect --format '{{ .NetworkSettings.Ports }}'  iamfoo
 map[80/tcp:[{0.0.0.0 32769}]]
+
 $ curl "http://0.0.0.0:32769"
 Hostname :  6e0030e67d6a
 IP :  127.0.0.1
@@ -17,3 +44,27 @@ Host: 0.0.0.0:32769
 User-Agent: curl/7.35.0
 Accept: */*
 ```
+
+```console
+# updates health check status
+$ curl -X POST -d '500' http://localhost:80/health
+
+# calls the health check
+$ curl -v http://localhost:80/health
+*   Trying ::1:80...
+* TCP_NODELAY set
+* Connected to localhost (::1) port 80 (#0)
+> GET /health HTTP/1.1
+> Host: localhost:80
+> User-Agent: curl/7.65.3
+> Accept: */*
+> 
+* Mark bundle as not supporting multiuse
+< HTTP/1.1 500 Internal Server Error
+< Date: Mon, 16 Sep 2019 22:52:40 GMT
+< Content-Length: 0
+```
+
+```console
+docker run -d -P -v ./certs:/certs --name iamfoo traefik/whoami --cert /certs/cert.cer --key /certs/key.key
+```

app.go

@@ -1,25 +1,45 @@
 package main
 
 import (
+	"bytes"
 	"encoding/json"
 	"flag"
 	"fmt"
-	"sync"
-
-	"github.com/gorilla/websocket"
-	// "github.com/pkg/profile"
+	"io"
 	"log"
 	"net"
 	"net/http"
 	"net/url"
 	"os"
+	"strconv"
+	"strings"
+	"sync"
 	"time"
+
+	"github.com/gorilla/websocket"
 )
 
-var port string
+// Units.
+const (
+	_        = iota
+	KB int64 = 1 << (10 * iota)
+	MB
+	GB
+	TB
+)
+
+var (
+	cert string
+	key  string
+	port string
+	name string
+)
 
 func init() {
+	flag.StringVar(&cert, "cert", "", "give me a certificate")
+	flag.StringVar(&key, "key", "", "give me a key")
 	flag.StringVar(&port, "port", "80", "give me a port number")
+	flag.StringVar(&name, "name", os.Getenv("WHOAMI_NAME"), "give me a name")
 }
 
 var upgrader = websocket.Upgrader{
@@ -28,17 +48,51 @@ var upgrader = websocket.Upgrader{
 }
 
 func main() {
-	// defer profile.Start().Stop()
 	flag.Parse()
+
+	http.HandleFunc("/data", dataHandler)
 	http.HandleFunc("/echo", echoHandler)
 	http.HandleFunc("/bench", benchHandler)
-	http.HandleFunc("/", whoamI)
-	http.HandleFunc("/api", api)
+	http.HandleFunc("/bench/", benchHandler)
+	http.HandleFunc("/", whoamiHandler)
+	http.HandleFunc("/api", apiHandler)
 	http.HandleFunc("/health", healthHandler)
+
 	fmt.Println("Starting up on port " + port)
+
+	if len(cert) > 0 && len(key) > 0 {
+		log.Fatal(http.ListenAndServeTLS(":"+port, cert, key, nil))
+	}
 	log.Fatal(http.ListenAndServe(":"+port, nil))
 }
 
+func benchHandler(w http.ResponseWriter, _ *http.Request) {
+	w.Header().Set("Connection", "keep-alive")
+	w.Header().Set("Content-Type", "text/plain")
+	_, _ = fmt.Fprint(w, "1")
+}
+
+func echoHandler(w http.ResponseWriter, r *http.Request) {
+	conn, err := upgrader.Upgrade(w, r, nil)
+	if err != nil {
+		log.Println(err)
+		return
+	}
+
+	for {
+		messageType, p, err := conn.ReadMessage()
+		if err != nil {
+			return
+		}
+
+		printBinary(p)
+		err = conn.WriteMessage(messageType, p)
+		if err != nil {
+			return
+		}
+	}
+}
+
 func printBinary(s []byte) {
 	fmt.Printf("Received b:")
 	for n := 0; n < len(s); n++ {
@@ -46,42 +100,67 @@ func printBinary(s []byte) {
 	}
 	fmt.Printf("\n")
 }
-func benchHandler(w http.ResponseWriter, r *http.Request) {
-	w.Header().Set("Connection", "keep-alive")
-	w.Header().Set("Content-Type", "text/plain")
-	fmt.Fprint(w, "1")
-}
-func echoHandler(w http.ResponseWriter, r *http.Request) {
-	conn, err := upgrader.Upgrade(w, r, nil)
+
+func dataHandler(w http.ResponseWriter, r *http.Request) {
+	u, _ := url.Parse(r.URL.String())
+	queryParams := u.Query()
+
+	size, err := strconv.ParseInt(queryParams.Get("size"), 10, 64)
 	if err != nil {
-		log.Println(err)
+		size = 1
+	}
+	if size < 0 {
+		size = 0
+	}
+
+	unit := queryParams.Get("unit")
+	switch strings.ToLower(unit) {
+	case "kb":
+		size *= KB
+	case "mb":
+		size *= MB
+	case "gb":
+		size *= GB
+	case "tb":
+		size *= TB
+	}
+
+	attachment, err := strconv.ParseBool(queryParams.Get("attachment"))
+	if err != nil {
+		attachment = false
+	}
+
+	content := fillContent(size)
+
+	if attachment {
+		w.Header().Set("Content-Disposition", "Attachment")
+		http.ServeContent(w, r, "data.txt", time.Now(), content)
 		return
 	}
-	for {
-		messageType, p, err := conn.ReadMessage()
-		if err != nil {
-			return
-		}
-		printBinary(p)
-		err = conn.WriteMessage(messageType, p)
-		if err != nil {
-			return
-		}
+
+	if _, err := io.Copy(w, content); err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
 	}
 }
 
-func whoamI(w http.ResponseWriter, req *http.Request) {
+func whoamiHandler(w http.ResponseWriter, req *http.Request) {
 	u, _ := url.Parse(req.URL.String())
-	queryParams := u.Query()
-	wait := queryParams.Get("wait")
+	wait := u.Query().Get("wait")
 	if len(wait) > 0 {
 		duration, err := time.ParseDuration(wait)
 		if err == nil {
 			time.Sleep(duration)
 		}
 	}
+
+	if name != "" {
+		_, _ = fmt.Fprintln(w, "Name:", name)
+	}
+
 	hostname, _ := os.Hostname()
-	fmt.Fprintln(w, "Hostname:", hostname)
+	_, _ = fmt.Fprintln(w, "Hostname:", hostname)
+
 	ifaces, _ := net.Interfaces()
 	for _, i := range ifaces {
 		addrs, _ := i.Addrs()
@@ -94,22 +173,36 @@ func whoamI(w http.ResponseWriter, req *http.Request) {
 			case *net.IPAddr:
 				ip = v.IP
 			}
-			fmt.Fprintln(w, "IP:", ip)
+			_, _ = fmt.Fprintln(w, "IP:", ip)
 		}
 	}
-	req.Write(w)
+
+	_, _ = fmt.Fprintln(w, "RemoteAddr:", req.RemoteAddr)
+	if err := req.Write(w); err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
 }
 
-func api(w http.ResponseWriter, req *http.Request) {
+func apiHandler(w http.ResponseWriter, req *http.Request) {
 	hostname, _ := os.Hostname()
+
 	data := struct {
 		Hostname string      `json:"hostname,omitempty"`
 		IP       []string    `json:"ip,omitempty"`
 		Headers  http.Header `json:"headers,omitempty"`
+		URL      string      `json:"url,omitempty"`
+		Host     string      `json:"host,omitempty"`
+		Method   string      `json:"method,omitempty"`
+		Name     string      `json:"name,omitempty"`
 	}{
-		hostname,
-		[]string{},
-		req.Header,
+		Hostname: hostname,
+		IP:       []string{},
+		Headers:  req.Header,
+		URL:      req.URL.RequestURI(),
+		Host:     req.Host,
+		Method:   req.Method,
+		Name:     name,
 	}
 
 	ifaces, _ := net.Interfaces()
@@ -124,35 +217,61 @@ func api(w http.ResponseWriter, req *http.Request) {
 			case *net.IPAddr:
 				ip = v.IP
 			}
-			data.IP = append(data.IP, ip.String())
+			if ip != nil {
+				data.IP = append(data.IP, ip.String())
+			}
 		}
 	}
-	json.NewEncoder(w).Encode(data)
+
+	w.Header().Set("Content-Type", "application/json")
+	if err := json.NewEncoder(w).Encode(data); err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
 }
 
 type healthState struct {
 	StatusCode int
 }
 
-var currentHealthState = healthState{200}
-var mutexHealthState = &sync.RWMutex{}
+var (
+	currentHealthState = healthState{http.StatusOK}
+	mutexHealthState   = &sync.RWMutex{}
+)
 
 func healthHandler(w http.ResponseWriter, req *http.Request) {
 	if req.Method == http.MethodPost {
 		var statusCode int
-		err := json.NewDecoder(req.Body).Decode(&statusCode)
-		if err != nil {
-			w.WriteHeader(http.StatusBadRequest)
-			w.Write([]byte(err.Error()))
-		} else {
-			fmt.Printf("Update health check status code [%d]\n", statusCode)
-			mutexHealthState.Lock()
-			defer mutexHealthState.Unlock()
-			currentHealthState.StatusCode = statusCode
+
+		if err := json.NewDecoder(req.Body).Decode(&statusCode); err != nil {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
 		}
+
+		fmt.Printf("Update health check status code [%d]\n", statusCode)
+
+		mutexHealthState.Lock()
+		defer mutexHealthState.Unlock()
+		currentHealthState.StatusCode = statusCode
 	} else {
 		mutexHealthState.RLock()
 		defer mutexHealthState.RUnlock()
 		w.WriteHeader(currentHealthState.StatusCode)
 	}
 }
+
+func fillContent(length int64) io.ReadSeeker {
+	charset := "-ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+	b := make([]byte, length)
+
+	for i := range b {
+		b[i] = charset[i%len(charset)]
+	}
+
+	if length > 0 {
+		b[0] = '|'
+		b[length-1] = '|'
+	}
+
+	return bytes.NewReader(b)
+}

build.sh

@@ -1,3 +0,0 @@
-#!/bin/sh
-CGO_ENABLED=0 go build -a --installsuffix cgo --ldflags="-s" -o whoamI
-docker build -t emilevauge/whoami .

go.mod

@@ -0,0 +1,5 @@
+module github.com/traefik/whoami
+
+go 1.13
+
+require github.com/gorilla/websocket v1.4.2

go.sum

@@ -0,0 +1,2 @@
+github.com/gorilla/websocket v1.4.2 h1:+/TMaTYc4QFitKJxsQ7Yye35DkWvkdLcvGKqM+x0Ufc=
+github.com/gorilla/websocket v1.4.2/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=

tmpl.Dockerfile

@@ -0,0 +1,25 @@
+FROM golang:1-alpine as builder
+
+RUN apk --no-cache --no-progress add git ca-certificates tzdata make \
+    && update-ca-certificates \
+    && rm -rf /var/cache/apk/*
+
+WORKDIR /go/whoami
+
+# Download go modules
+COPY go.mod .
+COPY go.sum .
+RUN GO111MODULE=on GOPROXY=https://proxy.golang.org go mod download
+
+COPY . .
+
+RUN GOARCH={{ .GoARCH }} GOARM={{ .GoARM }} make build
+
+FROM scratch
+
+COPY --from=builder /usr/share/zoneinfo /usr/share/zoneinfo
+COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
+COPY --from=builder /go/whoami/whoami .
+
+ENTRYPOINT ["/whoami"]
+EXPOSE 80