Add output of client certificate

Co-authored-by: Fernandez Ludovic <ldez@users.noreply.github.com>

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,72 @@
+name: Bug Report
+description: Create a report to help us improve.
+body:
+  - type: checkboxes
+    id: terms
+    attributes:
+      label: Welcome!
+      description: |
+        The issue tracker is for reporting bugs and feature requests only.
+
+        All new/updated issues are triaged regularly by the maintainers.
+        All issues closed by a bot are subsequently double-checked by the maintainers.
+
+        DO NOT FILE ISSUES FOR GENERAL SUPPORT QUESTIONS.
+
+      options:
+        - label: Yes, I've searched similar issues on [GitHub](https://github.com/traefik/whoami/issues) and didn't find any.
+          required: true
+
+  - type: textarea
+    attributes:
+      label: What did you do?
+      description: |
+        How to write a good bug report?
+
+        - Respect the issue template as much as possible.
+        - The title should be short and descriptive.
+        - Explain the conditions which led you to report this issue: the context.
+        - The context should lead to something, an idea or a problem that you’re facing.
+        - Remain clear and concise.
+        - Format your messages to help the reader focus on what matters and understand the structure of your message, use [Markdown syntax](https://help.github.com/articles/github-flavored-markdown)
+      placeholder: What did you do?
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: What were you expecting?
+      placeholder: What were you expecting?
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: What version are you using?
+      description: |
+        `latest` is not considered as a valid version.
+      placeholder: Paste your output here.
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: What is your environment & configuration?
+      description: arguments, toml, provider, platform, ...
+      placeholder: Add information here.
+      value: |
+        ```yaml
+        # (paste your configuration here)
+        ```
+
+        Add more configuration information here.
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: If applicable, please paste the log output in DEBUG level
+      description: "`--log.level=DEBUG` switch."
+      placeholder: Paste your output here.
+    validations:
+      required: false

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,5 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Traefik Community Support
+    url: https://community.traefik.io/
+    about: If you have a question, or are looking for advice, please post on our Discuss forum! The community loves to chime in to help. Happy Coding!

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -0,0 +1,30 @@
+name: Feature Request
+description: Suggest an idea for this project.
+body:
+  - type: checkboxes
+    id: terms
+    attributes:
+      label: Welcome!
+      description: |
+        The issue tracker is for reporting bugs and feature requests only.
+
+        DO NOT FILE ISSUES FOR GENERAL SUPPORT QUESTIONS.
+      options:
+        - label: Yes, I've searched similar issues on [GitHub](https://github.com/traefik/whoami/issues) and didn't find any.
+          required: true
+
+  - type: textarea
+    attributes:
+      label: What did you expect to see?
+      description: |
+        How to write a good issue?
+
+        - Respect the issue template as much as possible.
+        - The title should be short and descriptive.
+        - Explain the conditions which led you to report this issue: the context.
+        - The context should lead to something, an idea or a problem that you’re facing.
+        - Remain clear and concise.
+        - Format your messages to help the reader focus on what matters and understand the structure of your message, use [Markdown syntax](https://help.github.com/articles/github-flavored-markdown)
+      placeholder: What did you expect to see?
+    validations:
+      required: true

.github/workflows/ci.yml

@@ -0,0 +1,49 @@
+name: Main
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+
+jobs:
+
+  main:
+    name: Main Process
+    runs-on: ubuntu-latest
+    env:
+      GO_VERSION: stable
+      GOLANGCI_LINT_VERSION: v1.63.4
+      CGO_ENABLED: 0
+
+    steps:
+
+      # https://github.com/marketplace/actions/checkout
+      - name: Check out code
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      # https://github.com/marketplace/actions/setup-go-environment
+      - name: Set up Go ${{ env.GO_VERSION }}
+        uses: actions/setup-go@v5
+        with:
+          go-version: ${{ env.GO_VERSION }}
+
+      - name: Check and get dependencies
+        run: |
+          go mod tidy
+          git diff --exit-code go.mod
+          git diff --exit-code go.sum
+
+      # 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

.github/workflows/go-cross.yml

@@ -0,0 +1,36 @@
+name: Go Matrix
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+
+jobs:
+
+  cross:
+    name: Go
+    runs-on: ${{ matrix.os }}
+    env:
+      CGO_ENABLED: 0
+
+    strategy:
+      matrix:
+        go-version: [ stable, oldstable ]
+        os: [ubuntu-latest, macos-latest, windows-latest]
+
+    steps:
+      # https://github.com/marketplace/actions/checkout
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      # https://github.com/marketplace/actions/setup-go-environment
+      - name: Set up Go ${{ matrix.go-version }}
+        uses: actions/setup-go@v5
+        with:
+          go-version: ${{ matrix.go-version }}
+
+      - name: Test
+        run: go test -v -cover ./...
+
+      - name: Build
+        run: go build -v -ldflags "-s -w" -trimpath

.github/workflows/release.yml

@@ -0,0 +1,55 @@
+name: "Release a tag"
+on:
+  push:
+    tags:
+      - v*
+
+jobs:
+  release:
+    name: Release Process
+    runs-on: ubuntu-latest
+    env:
+      GO_VERSION: stable
+      CGO_ENABLED: 0
+
+    steps:
+
+      # https://github.com/marketplace/actions/checkout
+      - name: Check out code
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      # https://github.com/marketplace/actions/setup-go-environment
+      - name: Set up Go ${{ env.GO_VERSION }}
+        uses: actions/setup-go@v5
+        with:
+          go-version: ${{ env.GO_VERSION }}
+
+      - name: dockerhub-login
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
+
+      - name: ghcr-login
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: traefiker
+          password: ${{ secrets.GHCR_TOKEN }}
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      # https://goreleaser.com/ci/actions/
+      - name: Run GoReleaser
+        uses: goreleaser/goreleaser-action@v5
+        with:
+          version: latest
+          args: release --clean
+        env:
+          GITHUB_TOKEN: ${{ secrets.GH_TOKEN_REPO }}

.gitignore

@@ -1,3 +1,4 @@
 .idea
 vendor/
 /whoami
+dist/

.golangci.yml

@@ -0,0 +1,84 @@
+run:
+  timeout: 2m
+
+linters-settings:
+  govet:
+    enable-all: true
+    disable:
+      - fieldalignment
+  gocyclo:
+    min-complexity: 16
+  goconst:
+    min-len: 3
+    min-occurrences: 3
+  misspell:
+    locale: US
+  funlen:
+    lines: -1
+    statements: 40
+  gofumpt:
+    extra-rules: true
+  depguard:
+    rules:
+      main:
+        deny:
+          - pkg: "github.com/instana/testify"
+            desc: not allowed
+          - pkg: "github.com/pkg/errors"
+            desc: Should be replaced by standard lib errors package
+  godox:
+    keywords:
+      - FIXME
+  gocritic:
+    enabled-tags:
+      - diagnostic
+      - style
+      - performance
+    disabled-checks:
+      - sloppyReassign
+      - rangeValCopy
+      - octalLiteral
+      - paramTypeCombine # already handle by gofumpt.extra-rules
+    settings:
+      hugeParam:
+        sizeThreshold: 100
+  forbidigo:
+    forbid:
+      - '^print(ln)?$'
+      - '^panic$'
+      - '^spew\.Print(f|ln)?$'
+      - '^spew\.Dump$'
+
+linters:
+  enable-all: true
+  disable:
+    - rowserrcheck # not relevant (SQL)
+    - sqlclosecheck # not relevant (SQL)
+    - cyclop # duplicate of gocyclo
+    - dupl
+    - exhaustive
+    - exhaustruct
+    - exportloopref
+    - forbidigo
+    - gochecknoglobals
+    - gochecknoinits
+    - err113
+    - mnd
+    - gosec
+    - lll
+    - nilnil
+    - nlreturn
+    - paralleltest
+    - prealloc
+    - testpackage
+    - tparallel
+    - varnamelen
+    - wrapcheck
+    - wsl
+
+issues:
+  exclude-use-default: false
+  max-issues-per-linter: 0
+  max-same-issues: 0
+  exclude:
+    - 'package-comments: should have a package comment'

.goreleaser.yml

@@ -0,0 +1,142 @@
+project_name: whoami
+
+builds:
+  - binary: whoami
+    goos:
+      - windows
+      - darwin
+      - linux
+    goarch:
+      - amd64
+      - arm
+      - arm64
+    goarm:
+      - '7'
+
+changelog:
+  sort: asc
+  filters:
+    exclude:
+      - '^docs:'
+      - '^doc:'
+      - '^chore:'
+      - '^chore(deps):'
+      - '^test:'
+      - '^tests:'
+
+archives:
+  - id: whoami
+    name_template: '{{ .ProjectName }}_v{{ .Version }}_{{ .Os }}_{{ .Arch }}{{ if .Arm}}v{{ .Arm }}{{ end }}'
+    format: tar.gz
+    format_overrides:
+      - goos: windows
+        format: zip
+    files:
+      - LICENSE
+
+docker_manifests:
+  - name_template: 'traefik/whoami:{{ .Tag }}'
+    image_templates:
+      - 'traefik/whoami:{{ .Tag }}-amd64'
+      - 'traefik/whoami:{{ .Tag }}-arm64'
+      - 'traefik/whoami:{{ .Tag }}-armv7'
+  - name_template: 'traefik/whoami:latest'
+    image_templates:
+      - 'traefik/whoami:{{ .Tag }}-amd64'
+      - 'traefik/whoami:{{ .Tag }}-arm64'
+      - 'traefik/whoami:{{ .Tag }}-armv7'
+  - name_template: 'traefik/whoami:v{{ .Major }}.{{ .Minor }}'
+    image_templates:
+      - 'traefik/whoami:v{{ .Major }}.{{ .Minor }}-amd64'
+      - 'traefik/whoami:v{{ .Major }}.{{ .Minor }}-arm64'
+      - 'traefik/whoami:v{{ .Major }}.{{ .Minor }}-armv7'
+
+  - name_template: 'ghcr.io/traefik/whoami:{{ .Tag }}'
+    image_templates:
+      - 'ghcr.io/traefik/whoami:{{ .Tag }}-amd64'
+      - 'ghcr.io/traefik/whoami:{{ .Tag }}-arm64'
+      - 'ghcr.io/traefik/whoami:{{ .Tag }}-armv7'
+  - name_template: 'ghcr.io/traefik/whoami:latest'
+    image_templates:
+      - 'ghcr.io/traefik/whoami:{{ .Tag }}-amd64'
+      - 'ghcr.io/traefik/whoami:{{ .Tag }}-arm64'
+      - 'ghcr.io/traefik/whoami:{{ .Tag }}-armv7'
+  - name_template: 'ghcr.io/traefik/whoami:v{{ .Major }}.{{ .Minor }}'
+    image_templates:
+      - 'ghcr.io/traefik/whoami:v{{ .Major }}.{{ .Minor }}-amd64'
+      - 'ghcr.io/traefik/whoami:v{{ .Major }}.{{ .Minor }}-arm64'
+      - 'ghcr.io/traefik/whoami:v{{ .Major }}.{{ .Minor }}-armv7'
+
+dockers:
+  - use: buildx
+    goos: linux
+    goarch: amd64
+    dockerfile: buildx.Dockerfile
+    image_templates:
+      - 'traefik/whoami:latest-amd64'
+      - 'traefik/whoami:{{ .Tag }}-amd64'
+      - 'traefik/whoami:v{{ .Major }}.{{ .Minor }}-amd64'
+      - 'ghcr.io/traefik/whoami:latest-amd64'
+      - 'ghcr.io/traefik/whoami:{{ .Tag }}-amd64'
+      - 'ghcr.io/traefik/whoami:v{{ .Major }}.{{ .Minor }}-amd64'
+    build_flag_templates:
+      - '--pull'
+      # https://github.com/opencontainers/image-spec/blob/main/annotations.md#pre-defined-annotation-keys
+      - '--label=org.opencontainers.image.title={{.ProjectName}}'
+      - '--label=org.opencontainers.image.description=Tiny Go webserver that prints OS information and HTTP request to output'
+      - '--label=org.opencontainers.image.source={{.GitURL}}'
+      - '--label=org.opencontainers.image.url={{.GitURL}}'
+      - '--label=org.opencontainers.image.documentation={{.GitURL}}'
+      - '--label=org.opencontainers.image.created={{.Date}}'
+      - '--label=org.opencontainers.image.revision={{.FullCommit}}'
+      - '--label=org.opencontainers.image.version={{.Version}}'
+      - '--platform=linux/amd64'
+
+  - use: buildx
+    goos: linux
+    goarch: arm64
+    dockerfile: buildx.Dockerfile
+    image_templates:
+      - 'traefik/whoami:latest-arm64'
+      - 'traefik/whoami:{{ .Tag }}-arm64'
+      - 'traefik/whoami:v{{ .Major }}.{{ .Minor }}-arm64'
+      - 'ghcr.io/traefik/whoami:latest-arm64'
+      - 'ghcr.io/traefik/whoami:{{ .Tag }}-arm64'
+      - 'ghcr.io/traefik/whoami:v{{ .Major }}.{{ .Minor }}-arm64'
+    build_flag_templates:
+      - '--pull'
+      # https://github.com/opencontainers/image-spec/blob/main/annotations.md#pre-defined-annotation-keys
+      - '--label=org.opencontainers.image.title={{.ProjectName}}'
+      - '--label=org.opencontainers.image.description=Tiny Go webserver that prints OS information and HTTP request to output'
+      - '--label=org.opencontainers.image.source={{.GitURL}}'
+      - '--label=org.opencontainers.image.url={{.GitURL}}'
+      - '--label=org.opencontainers.image.documentation={{.GitURL}}'
+      - '--label=org.opencontainers.image.created={{.Date}}'
+      - '--label=org.opencontainers.image.revision={{.FullCommit}}'
+      - '--label=org.opencontainers.image.version={{.Version}}'
+      - '--platform=linux/arm64'
+
+  - use: buildx
+    goos: linux
+    goarch: arm
+    goarm: '7'
+    dockerfile: buildx.Dockerfile
+    image_templates:
+      - 'traefik/whoami:latest-armv7'
+      - 'traefik/whoami:{{ .Tag }}-armv7'
+      - 'traefik/whoami:v{{ .Major }}.{{ .Minor }}-armv7'
+      - 'ghcr.io/traefik/whoami:latest-armv7'
+      - 'ghcr.io/traefik/whoami:{{ .Tag }}-armv7'
+      - 'ghcr.io/traefik/whoami:v{{ .Major }}.{{ .Minor }}-armv7'
+    build_flag_templates:
+      - '--pull'
+      # https://github.com/opencontainers/image-spec/blob/main/annotations.md#pre-defined-annotation-keys
+      - '--label=org.opencontainers.image.title={{.ProjectName}}'
+      - '--label=org.opencontainers.image.description=Tiny Go webserver that prints OS information and HTTP request to output'
+      - '--label=org.opencontainers.image.source={{.GitURL}}'
+      - '--label=org.opencontainers.image.url={{.GitURL}}'
+      - '--label=org.opencontainers.image.documentation={{.GitURL}}'
+      - '--label=org.opencontainers.image.created={{.Date}}'
+      - '--label=org.opencontainers.image.revision={{.FullCommit}}'
+      - '--label=org.opencontainers.image.version={{.Version}}'
+      - '--platform=linux/arm/v7'

Dockerfile

@@ -1,10 +1,26 @@
-FROM golang:1.11 as builder
+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 --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

@@ -186,7 +186,8 @@
       same "printed page" as the copyright notice for easier
       identification within third-party archives.
 
-   Copyright [2015-2018] [Containous]
+   Copyright [2015-2019] [Containous]
+   Copyright [2020-2022] [Traefik Labs]
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.

Makefile

@@ -1,12 +1,17 @@
-.PHONY: default build dependencies image
+.PHONY: default check test build image
 
-default: build
+IMAGE_NAME := traefik/whoami
+
+default: check test build
 
 build:
-	CGO_ENABLED=0 go build -a --installsuffix cgo --ldflags="-s" -o whoami
+	CGO_ENABLED=0 go build -a --trimpath --installsuffix cgo --ldflags="-s" -o whoami
 
-dependencies:
-	go mod download
+test:
+	go test -v -cover ./...
+
+check:
+	golangci-lint run
 
 image:
-	docker build -t containous/whoami .
+	docker build -t $(IMAGE_NAME) .

README.md

@@ -1,13 +1,69 @@
 # whoami
 
-[![Docker Pulls](https://img.shields.io/docker/pulls/containous/whoami.svg)](https://hub.docker.com/r/containous/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
+Tiny Go webserver that prints OS information and HTTP request to output.
+
+## Usage
+
+### Paths
+
+#### `/[?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).
+
+The optional `env` query parameter can be set to `true` to add the environment variables to the response.
+
+#### `/api`
+
+Returns the whoami information (and some extra information) as JSON.
+
+The optional `env` query parameter can be set to `true` to add the environment variables to the response.
+
+#### `/bench`
+
+Always return the same response (`1`).
+
+#### `/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.
+
+#### `/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
+
+| Flag      | Env var              | Description                             |
+|-----------|----------------------|-----------------------------------------|
+| `cert`    |                      | Give me a certificate.                  |
+| `key`     |                      | Give me a key.                          |
+| `cacert`  |                      | Give me a CA chain, enforces mutual TLS |
+| `port`    | `WHOAMI_PORT_NUMBER` | Give me a port number. (default: `80`)  |
+| `name`    | `WHOAMI_NAME`        | Give me a name.                         |
+| `verbose` |                      | Enable verbose logging.                 |
+
+## Examples
 
 ```console
-$ docker run -d -P --name iamfoo containous/whoami
+$ 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
@@ -19,3 +75,39 @@ 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/example.cert --key /certs/example.key
+```
+
+```yml
+version: '3.9'
+
+services:
+  whoami:
+    image: traefik/whoami
+    command:
+       # It tells whoami to start listening on 2001 instead of 80
+       - --port=2001
+       - --name=iamfoo
+```

app.go

@@ -1,7 +1,8 @@
 package main
 
 import (
-	"bytes"
+	"crypto/tls"
+	"crypto/x509"
 	"encoding/json"
 	"flag"
 	"fmt"
@@ -9,7 +10,6 @@ import (
 	"log"
 	"net"
 	"net/http"
-	"net/url"
 	"os"
 	"strconv"
 	"strings"
@@ -19,6 +19,7 @@ import (
 	"github.com/gorilla/websocket"
 )
 
+// Units.
 const (
 	_        = iota
 	KB int64 = 1 << (10 * iota)
@@ -27,43 +28,113 @@ const (
 	TB
 )
 
-var cert string
-var key string
-var port 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")
-}
-
 var upgrader = websocket.Upgrader{
 	ReadBufferSize:  1024,
 	WriteBufferSize: 1024,
+	CheckOrigin: func(_ *http.Request) bool {
+		return true
+	},
+}
+
+var (
+	cert    string
+	key     string
+	ca      string
+	port    string
+	name    string
+	verbose bool
+)
+
+func init() {
+	flag.BoolVar(&verbose, "verbose", false, "Enable verbose logging")
+	flag.StringVar(&cert, "cert", "", "give me a certificate")
+	flag.StringVar(&key, "key", "", "give me a key")
+	flag.StringVar(&ca, "cacert", "", "give me a CA chain, enforces mutual TLS")
+	flag.StringVar(&port, "port", getEnv("WHOAMI_PORT_NUMBER", "80"), "give me a port number")
+	flag.StringVar(&name, "name", os.Getenv("WHOAMI_NAME"), "give me a name")
+}
+
+// Data whoami information.
+type 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"`
+	RemoteAddr string            `json:"remoteAddr,omitempty"`
+	Environ    map[string]string `json:"environ,omitempty"`
 }
 
 func main() {
 	flag.Parse()
 
-	http.HandleFunc("/data", dataHandler)
-	http.HandleFunc("/echo", echoHandler)
-	http.HandleFunc("/bench", benchHandler)
-	http.HandleFunc("/", whoamiHandler)
-	http.HandleFunc("/api", apiHandler)
-	http.HandleFunc("/health", healthHandler)
+	mux := http.NewServeMux()
+	mux.Handle("/data", handle(dataHandler, verbose))
+	mux.Handle("/echo", handle(echoHandler, verbose))
+	mux.Handle("/bench", handle(benchHandler, verbose))
+	mux.Handle("/api", handle(apiHandler, verbose))
+	mux.Handle("/health", handle(healthHandler, verbose))
+	mux.Handle("/", handle(whoamiHandler, verbose))
 
-	fmt.Println("Starting up on port " + port)
+	if cert == "" || key == "" {
+		log.Printf("Starting up on port %s", port)
 
-	if len(cert) > 0 && len(key) > 0 {
-		log.Fatal(http.ListenAndServeTLS(":"+port, cert, key, nil))
+		log.Fatal(http.ListenAndServe(":"+port, mux))
 	}
-	log.Fatal(http.ListenAndServe(":"+port, nil))
+
+	server := &http.Server{
+		Addr:      ":" + port,
+		TLSConfig: &tls.Config{ClientAuth: tls.RequestClientCert},
+		Handler:   mux,
+	}
+
+	if ca != "" {
+		server.TLSConfig = setupMutualTLS(ca)
+	}
+
+	log.Printf("Starting up with TLS on port %s", port)
+
+	log.Fatal(server.ListenAndServeTLS(cert, key))
+}
+
+func setupMutualTLS(ca string) *tls.Config {
+	clientCACert, err := os.ReadFile(ca)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	clientCertPool := x509.NewCertPool()
+	clientCertPool.AppendCertsFromPEM(clientCACert)
+
+	tlsConfig := &tls.Config{
+		ClientAuth:               tls.RequireAndVerifyClientCert,
+		ClientCAs:                clientCertPool,
+		PreferServerCipherSuites: true,
+		MinVersion:               tls.VersionTLS12,
+	}
+
+	return tlsConfig
+}
+
+func handle(next http.HandlerFunc, verbose bool) http.Handler {
+	if !verbose {
+		return next
+	}
+
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		next(w, r)
+
+		// <remote_IP_address> - [<timestamp>] "<request_method> <request_path> <request_protocol>" -
+		log.Printf("%s - - [%s] \"%s %s %s\" - -", r.RemoteAddr, time.Now().Format("02/Jan/2006:15:04:05 -0700"), r.Method, r.URL.Path, r.Proto)
+	})
 }
 
 func benchHandler(w http.ResponseWriter, _ *http.Request) {
 	w.Header().Set("Connection", "keep-alive")
 	w.Header().Set("Content-Type", "text/plain")
-	fmt.Fprint(w, "1")
+	_, _ = fmt.Fprint(w, "1")
 }
 
 func echoHandler(w http.ResponseWriter, r *http.Request) {
@@ -89,15 +160,14 @@ func echoHandler(w http.ResponseWriter, r *http.Request) {
 
 func printBinary(s []byte) {
 	fmt.Printf("Received b:")
-	for n := 0; n < len(s); n++ {
+	for n := range s {
 		fmt.Printf("%d,", s[n])
 	}
 	fmt.Printf("\n")
 }
 
 func dataHandler(w http.ResponseWriter, r *http.Request) {
-	u, _ := url.Parse(r.URL.String())
-	queryParams := u.Query()
+	queryParams := r.URL.Query()
 
 	size, err := strconv.ParseInt(queryParams.Get("size"), 10, 64)
 	if err != nil {
@@ -110,13 +180,13 @@ func dataHandler(w http.ResponseWriter, r *http.Request) {
 	unit := queryParams.Get("unit")
 	switch strings.ToLower(unit) {
 	case "kb":
-		size = size * KB
+		size *= KB
 	case "mb":
-		size = size * MB
+		size *= MB
 	case "gb":
-		size = size * GB
+		size *= GB
 	case "tb":
-		size = size * TB
+		size *= TB
 	}
 
 	attachment, err := strconv.ParseBool(queryParams.Get("attachment"))
@@ -124,10 +194,10 @@ func dataHandler(w http.ResponseWriter, r *http.Request) {
 		attachment = false
 	}
 
-	content := fillContent(size)
+	content := &contentReader{size: size}
 
 	if attachment {
-		w.Header().Add("Content-Disposition", "Attachment")
+		w.Header().Set("Content-Disposition", "Attachment")
 		http.ServeContent(w, r, "data.txt", time.Now(), content)
 		return
 	}
@@ -138,76 +208,75 @@ func dataHandler(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
-func whoamiHandler(w http.ResponseWriter, req *http.Request) {
-	u, _ := url.Parse(req.URL.String())
-	wait := u.Query().Get("wait")
-	if len(wait) > 0 {
+func whoamiHandler(w http.ResponseWriter, r *http.Request) {
+	queryParams := r.URL.Query()
+
+	wait := queryParams.Get("wait")
+	if wait != "" {
 		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()
-		// handle err
-		for _, addr := range addrs {
-			var ip net.IP
-			switch v := addr.(type) {
-			case *net.IPNet:
-				ip = v.IP
-			case *net.IPAddr:
-				ip = v.IP
+	for _, ip := range getIPs() {
+		_, _ = fmt.Fprintln(w, "IP:", ip)
 	}
-			fmt.Fprintln(w, "IP:", ip)
+
+	_, _ = fmt.Fprintln(w, "RemoteAddr:", r.RemoteAddr)
+
+	if r.TLS != nil {
+		for i, cert := range r.TLS.PeerCertificates {
+			_, _ = fmt.Fprintf(w, "Certificate[%d] Subject: %v\n", i, cert.Subject)
 		}
 	}
 
-	if err := req.Write(w); err != nil {
+	if err := r.Write(w); err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
+
+	if ok, _ := strconv.ParseBool(queryParams.Get("env")); ok {
+		for _, env := range os.Environ() {
+			_, _ = fmt.Fprintln(w, env)
+		}
+	}
 }
 
-func apiHandler(w http.ResponseWriter, req *http.Request) {
+func apiHandler(w http.ResponseWriter, r *http.Request) {
+	queryParams := r.URL.Query()
+
 	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"`
-	}{
+	environ := make(map[string]string)
+
+	if ok, _ := strconv.ParseBool(queryParams.Get("env")); ok {
+		for _, env := range os.Environ() {
+			before, after, _ := strings.Cut(env, "=")
+			environ[before] = after
+		}
+	}
+
+	data := Data{
 		Hostname:   hostname,
-		IP:       []string{},
-		Headers:  req.Header,
-		URL:      req.URL.RequestURI(),
-		Host:     req.Host,
-		Method:   req.Method,
-	}
-
-	ifaces, _ := net.Interfaces()
-	for _, i := range ifaces {
-		addrs, _ := i.Addrs()
-		// handle err
-		for _, addr := range addrs {
-			var ip net.IP
-			switch v := addr.(type) {
-			case *net.IPNet:
-				ip = v.IP
-			case *net.IPAddr:
-				ip = v.IP
-			}
-			data.IP = append(data.IP, ip.String())
-		}
+		IP:         getIPs(),
+		Headers:    r.Header,
+		URL:        r.URL.RequestURI(),
+		Host:       r.Host,
+		Method:     r.Method,
+		Name:       name,
+		RemoteAddr: r.RemoteAddr,
+		Environ:    environ,
 	}
 
+	w.Header().Set("Content-Type", "application/json")
 	if err := json.NewEncoder(w).Encode(data); err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
@@ -218,8 +287,10 @@ type healthState struct {
 	StatusCode int
 }
 
-var currentHealthState = healthState{http.StatusOK}
-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 {
@@ -242,18 +313,34 @@ func healthHandler(w http.ResponseWriter, req *http.Request) {
 	}
 }
 
-func fillContent(length int64) io.ReadSeeker {
-	charset := "-ABCDEFGHIJKLMNOPQRSTUVWXYZ"
-	b := make([]byte, length, length)
-
-	for i := range b {
-		b[i] = charset[i%len(charset)]
+func getEnv(key, fallback string) string {
+	value := os.Getenv(key)
+	if value == "" {
+		return fallback
+	}
+	return value
 }
 
-	if length > 0 {
-		b[0] = '|'
-		b[length-1] = '|'
+func getIPs() []string {
+	var ips []string
+
+	ifaces, _ := net.Interfaces()
+	for _, i := range ifaces {
+		addrs, _ := i.Addrs()
+		// handle err
+		for _, addr := range addrs {
+			var ip net.IP
+			switch v := addr.(type) {
+			case *net.IPNet:
+				ip = v.IP
+			case *net.IPAddr:
+				ip = v.IP
+			}
+			if ip != nil {
+				ips = append(ips, ip.String())
+			}
+		}
 	}
 
-	return bytes.NewReader(b)
+	return ips
 }

buildx.Dockerfile

@@ -0,0 +1,17 @@
+# syntax=docker/dockerfile:1.2
+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/*
+
+# syntax=docker/dockerfile:1.2
+# Create a minimal container to run a Golang static binary
+FROM scratch
+
+COPY --from=builder /usr/share/zoneinfo /usr/share/zoneinfo
+COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
+COPY whoami /
+
+ENTRYPOINT ["/whoami"]
+EXPOSE 80

content.go

@@ -0,0 +1,66 @@
+package main
+
+import (
+	"errors"
+	"io"
+)
+
+const contentCharset = "-ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+
+type contentReader struct {
+	size int64
+	cur  int64
+}
+
+// Read implements the io.Read interface.
+func (r *contentReader) Read(p []byte) (int, error) {
+	length := r.size - 1
+
+	if r.cur >= length {
+		return 0, io.EOF
+	}
+	if len(p) == 0 {
+		return 0, nil
+	}
+
+	var n int
+	if r.cur == 0 {
+		p[n] = '|'
+		r.cur++
+		n++
+	}
+
+	for n < len(p) && r.cur <= length {
+		p[n] = contentCharset[int(r.cur)%len(contentCharset)]
+		r.cur++
+		n++
+	}
+
+	if r.cur >= length {
+		p[n-1] = '|'
+	}
+
+	return n, nil
+}
+
+// Seek implements the io.Seek interface.
+func (r *contentReader) Seek(offset int64, whence int) (int64, error) {
+	switch whence {
+	default:
+		return 0, errors.New("seek: invalid whence")
+	case io.SeekStart:
+		offset += 0
+	case io.SeekCurrent:
+		offset += r.cur
+	case io.SeekEnd:
+		offset += r.size - 1
+	}
+
+	if offset < 0 {
+		return 0, errors.New("seek: invalid offset")
+	}
+
+	r.cur = offset
+
+	return offset, nil
+}

content_test.go

@@ -0,0 +1,80 @@
+package main
+
+import (
+	"io"
+	"testing"
+)
+
+func Test_contentReader_Read(t *testing.T) {
+	tests := []struct {
+		name    string
+		size    int64
+		content string
+	}{
+		{
+			name:    "simple",
+			size:    40,
+			content: "|ABCDEFGHIJKLMNOPQRSTUVWXYZ-ABCDEFGHIJK|",
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			t.Parallel()
+
+			d := &contentReader{size: test.size}
+
+			b, err := io.ReadAll(d)
+			if err != nil {
+				t.Errorf("contentReader.Read() error = %v", err)
+				return
+			}
+
+			if string(b) != test.content {
+				t.Errorf("return content does not match expected value: got %s want %s", b, test.content)
+			}
+		})
+	}
+}
+
+func Test_contentReader_ReadSeek(t *testing.T) {
+	tests := []struct {
+		name       string
+		offset     int64
+		seekWhence int
+		size       int64
+		content    string
+	}{
+		{
+			name:       "simple",
+			offset:     10,
+			seekWhence: io.SeekCurrent,
+			size:       40,
+			content:    "JKLMNOPQRSTUVWXYZ-ABCDEFGHIJK|",
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			t.Parallel()
+
+			d := &contentReader{size: test.size}
+
+			_, err := d.Seek(test.offset, test.seekWhence)
+			if err != nil {
+				t.Errorf("contentReader.Seek() error = %v", err)
+				return
+			}
+
+			b, err := io.ReadAll(d)
+			if err != nil {
+				t.Errorf("contentReader.Read() error = %v", err)
+				return
+			}
+
+			if string(b) != test.content {
+				t.Errorf("return content does not match expected value: got %s want %s", b, test.content)
+			}
+		})
+	}
+}

go.mod

@@ -1,3 +1,5 @@
-module github.com/containous/whoami
+module github.com/traefik/whoami
 
-require github.com/gorilla/websocket v1.2.0
+go 1.23
+
+require github.com/gorilla/websocket v1.5.3

go.sum

@@ -1,2 +1,2 @@
-github.com/gorilla/websocket v1.2.0 h1:VJtLvh6VQym50czpZzx07z/kw9EgAxI3x1ZB8taTMQQ=
-github.com/gorilla/websocket v1.2.0/go.mod h1:E7qHFY5m1UJ88s3WnNqhKjPHQ0heANvMoAMk2YaljkQ=
+github.com/gorilla/websocket v1.5.3 h1:saDtZ6Pbx/0u+bgYQ3q96pZgCzfhKXGPqt7kZ72aNNg=
+github.com/gorilla/websocket v1.5.3/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=