├── .assets └── icon.png ├── .github └── workflows │ ├── go-cross.yml │ └── main.yml ├── .gitignore ├── .golangci.yml ├── .traefik.yml ├── LICENSE ├── Makefile ├── demo.go ├── demo_test.go ├── go.mod └── readme.md /.assets/icon.png: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/traefik/plugindemo/8a77aea29f9038903ab44059e2aa42a37ff52752/.assets/icon.png -------------------------------------------------------------------------------- /.github/workflows/go-cross.yml: -------------------------------------------------------------------------------- 1 | name: Go Matrix 2 | on: [push, pull_request] 3 | 4 | jobs: 5 | 6 | cross: 7 | name: Go 8 | runs-on: ${{ matrix.os }} 9 | env: 10 | CGO_ENABLED: 0 11 | 12 | strategy: 13 | matrix: 14 | go-version: [ 1.19, 1.x ] 15 | os: [ubuntu-latest, macos-latest, windows-latest] 16 | 17 | steps: 18 | # https://github.com/marketplace/actions/setup-go-environment 19 | - name: Set up Go ${{ matrix.go-version }} 20 | uses: actions/setup-go@v2 21 | with: 22 | go-version: ${{ matrix.go-version }} 23 | 24 | # https://github.com/marketplace/actions/checkout 25 | - name: Checkout code 26 | uses: actions/checkout@v2 27 | 28 | # https://github.com/marketplace/actions/cache 29 | - name: Cache Go modules 30 | uses: actions/cache@v3 31 | with: 32 | # In order: 33 | # * Module download cache 34 | # * Build cache (Linux) 35 | # * Build cache (Mac) 36 | # * Build cache (Windows) 37 | path: | 38 | ~/go/pkg/mod 39 | ~/.cache/go-build 40 | ~/Library/Caches/go-build 41 | %LocalAppData%\go-build 42 | key: ${{ runner.os }}-${{ matrix.go-version }}-go-${{ hashFiles('**/go.sum') }} 43 | restore-keys: | 44 | ${{ runner.os }}-${{ matrix.go-version }}-go- 45 | 46 | - name: Test 47 | run: go test -v -cover ./... 48 | -------------------------------------------------------------------------------- /.github/workflows/main.yml: -------------------------------------------------------------------------------- 1 | name: Main 2 | 3 | on: 4 | push: 5 | branches: 6 | - master 7 | pull_request: 8 | 9 | jobs: 10 | 11 | main: 12 | name: Main Process 13 | runs-on: ubuntu-latest 14 | env: 15 | GO_VERSION: 1.19 16 | GOLANGCI_LINT_VERSION: v1.50.0 17 | YAEGI_VERSION: v0.14.2 18 | CGO_ENABLED: 0 19 | defaults: 20 | run: 21 | working-directory: ${{ github.workspace }}/go/src/github.com/${{ github.repository }} 22 | 23 | steps: 24 | 25 | # https://github.com/marketplace/actions/setup-go-environment 26 | - name: Set up Go ${{ env.GO_VERSION }} 27 | uses: actions/setup-go@v2 28 | with: 29 | go-version: ${{ env.GO_VERSION }} 30 | 31 | # https://github.com/marketplace/actions/checkout 32 | - name: Check out code 33 | uses: actions/checkout@v2 34 | with: 35 | path: go/src/github.com/${{ github.repository }} 36 | fetch-depth: 0 37 | 38 | # https://github.com/marketplace/actions/cache 39 | - name: Cache Go modules 40 | uses: actions/cache@v3 41 | with: 42 | path: ${{ github.workspace }}/go/pkg/mod 43 | key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }} 44 | restore-keys: | 45 | ${{ runner.os }}-go- 46 | 47 | # https://golangci-lint.run/usage/install#other-ci 48 | - name: Install golangci-lint ${{ env.GOLANGCI_LINT_VERSION }} 49 | run: curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(go env GOPATH)/bin ${GOLANGCI_LINT_VERSION} 50 | 51 | - name: Install Yaegi ${{ env.YAEGI_VERSION }} 52 | run: curl -sfL https://raw.githubusercontent.com/traefik/yaegi/master/install.sh | bash -s -- -b $(go env GOPATH)/bin ${YAEGI_VERSION} 53 | 54 | - name: Setup GOPATH 55 | run: go env -w GOPATH=${{ github.workspace }}/go 56 | 57 | - name: Check and get dependencies 58 | run: | 59 | go mod tidy 60 | git diff --exit-code go.mod 61 | # git diff --exit-code go.sum 62 | go mod download 63 | go mod vendor 64 | # git diff --exit-code ./vendor/ 65 | 66 | - name: Lint and Tests 67 | run: make 68 | 69 | - name: Run tests with Yaegi 70 | run: make yaegi_test 71 | env: 72 | GOPATH: ${{ github.workspace }}/go 73 | -------------------------------------------------------------------------------- /.gitignore: -------------------------------------------------------------------------------- 1 | .idea/ 2 | .DS_Store 3 | -------------------------------------------------------------------------------- /.golangci.yml: -------------------------------------------------------------------------------- 1 | run: 2 | timeout: 3m 3 | skip-files: [] 4 | skip-dirs: [] 5 | 6 | linters-settings: 7 | govet: 8 | enable-all: true 9 | disable: 10 | - fieldalignment 11 | golint: 12 | min-confidence: 0 13 | gocyclo: 14 | min-complexity: 12 15 | goconst: 16 | min-len: 5 17 | min-occurrences: 4 18 | misspell: 19 | locale: US 20 | funlen: 21 | lines: -1 22 | statements: 50 23 | godox: 24 | keywords: 25 | - FIXME 26 | gofumpt: 27 | extra-rules: true 28 | 29 | linters: 30 | enable-all: true 31 | disable: 32 | - deadcode # deprecated 33 | - exhaustivestruct # deprecated 34 | - golint # deprecated 35 | - ifshort # deprecated 36 | - interfacer # deprecated 37 | - maligned # deprecated 38 | - nosnakecase # deprecated 39 | - scopelint # deprecated 40 | - scopelint # deprecated 41 | - structcheck # deprecated 42 | - varcheck # deprecated 43 | - sqlclosecheck # not relevant (SQL) 44 | - rowserrcheck # not relevant (SQL) 45 | - execinquery # not relevant (SQL) 46 | - cyclop # duplicate of gocyclo 47 | - bodyclose # Too many false positives: https://github.com/timakin/bodyclose/issues/30 48 | - dupl 49 | - testpackage 50 | - tparallel 51 | - paralleltest 52 | - nlreturn 53 | - wsl 54 | - exhaustive 55 | - exhaustruct 56 | - goerr113 57 | - wrapcheck 58 | - ifshort 59 | - noctx 60 | - lll 61 | - gomnd 62 | - forbidigo 63 | - varnamelen 64 | 65 | issues: 66 | exclude-use-default: false 67 | max-per-linter: 0 68 | max-same-issues: 0 69 | exclude: [] 70 | exclude-rules: 71 | - path: (.+)_test.go 72 | linters: 73 | - goconst 74 | - funlen 75 | - godot 76 | -------------------------------------------------------------------------------- /.traefik.yml: -------------------------------------------------------------------------------- 1 | displayName: Demo Plugin 2 | type: middleware 3 | iconPath: .assets/icon.png 4 | 5 | import: github.com/traefik/plugindemo 6 | 7 | summary: '[Demo] Add Request Header' 8 | 9 | testData: 10 | Headers: 11 | X-Demo: test 12 | X-URL: '{{URL}}' 13 | -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | Apache License 2 | Version 2.0, January 2004 3 | http://www.apache.org/licenses/ 4 | 5 | TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 6 | 7 | 1. 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The text should be enclosed in the appropriate 184 | comment syntax for the file format. We also recommend that a 185 | file or class name and description of purpose be included on the 186 | same "printed page" as the copyright notice for easier 187 | identification within third-party archives. 188 | 189 | Copyright 2020 Containous SAS 190 | Copyright 2020 Traefik Labs 191 | 192 | Licensed under the Apache License, Version 2.0 (the "License"); 193 | you may not use this file except in compliance with the License. 194 | You may obtain a copy of the License at 195 | 196 | http://www.apache.org/licenses/LICENSE-2.0 197 | 198 | Unless required by applicable law or agreed to in writing, software 199 | distributed under the License is distributed on an "AS IS" BASIS, 200 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 201 | See the License for the specific language governing permissions and 202 | limitations under the License. 203 | -------------------------------------------------------------------------------- /Makefile: -------------------------------------------------------------------------------- 1 | .PHONY: lint test vendor clean 2 | 3 | export GO111MODULE=on 4 | 5 | default: lint test 6 | 7 | lint: 8 | golangci-lint run 9 | 10 | test: 11 | go test -v -cover ./... 12 | 13 | yaegi_test: 14 | yaegi test -v . 15 | 16 | vendor: 17 | go mod vendor 18 | 19 | clean: 20 | rm -rf ./vendor -------------------------------------------------------------------------------- /demo.go: -------------------------------------------------------------------------------- 1 | // Package plugindemo a demo plugin. 2 | package plugindemo 3 | 4 | import ( 5 | "bytes" 6 | "context" 7 | "fmt" 8 | "net/http" 9 | "text/template" 10 | ) 11 | 12 | // Config the plugin configuration. 13 | type Config struct { 14 | Headers map[string]string `json:"headers,omitempty"` 15 | } 16 | 17 | // CreateConfig creates the default plugin configuration. 18 | func CreateConfig() *Config { 19 | return &Config{ 20 | Headers: make(map[string]string), 21 | } 22 | } 23 | 24 | // Demo a Demo plugin. 25 | type Demo struct { 26 | next http.Handler 27 | headers map[string]string 28 | name string 29 | template *template.Template 30 | } 31 | 32 | // New created a new Demo plugin. 33 | func New(ctx context.Context, next http.Handler, config *Config, name string) (http.Handler, error) { 34 | if len(config.Headers) == 0 { 35 | return nil, fmt.Errorf("headers cannot be empty") 36 | } 37 | 38 | return &Demo{ 39 | headers: config.Headers, 40 | next: next, 41 | name: name, 42 | template: template.New("demo").Delims("[[", "]]"), 43 | }, nil 44 | } 45 | 46 | func (a *Demo) ServeHTTP(rw http.ResponseWriter, req *http.Request) { 47 | for key, value := range a.headers { 48 | tmpl, err := a.template.Parse(value) 49 | if err != nil { 50 | http.Error(rw, err.Error(), http.StatusInternalServerError) 51 | return 52 | } 53 | 54 | writer := &bytes.Buffer{} 55 | 56 | err = tmpl.Execute(writer, req) 57 | if err != nil { 58 | http.Error(rw, err.Error(), http.StatusInternalServerError) 59 | return 60 | } 61 | 62 | req.Header.Set(key, writer.String()) 63 | } 64 | 65 | a.next.ServeHTTP(rw, req) 66 | } 67 | -------------------------------------------------------------------------------- /demo_test.go: -------------------------------------------------------------------------------- 1 | package plugindemo_test 2 | 3 | import ( 4 | "context" 5 | "net/http" 6 | "net/http/httptest" 7 | "testing" 8 | 9 | "github.com/traefik/plugindemo" 10 | ) 11 | 12 | func TestDemo(t *testing.T) { 13 | cfg := plugindemo.CreateConfig() 14 | cfg.Headers["X-Host"] = "[[.Host]]" 15 | cfg.Headers["X-Method"] = "[[.Method]]" 16 | cfg.Headers["X-URL"] = "[[.URL]]" 17 | cfg.Headers["X-URL"] = "[[.URL]]" 18 | cfg.Headers["X-Demo"] = "test" 19 | 20 | ctx := context.Background() 21 | next := http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {}) 22 | 23 | handler, err := plugindemo.New(ctx, next, cfg, "demo-plugin") 24 | if err != nil { 25 | t.Fatal(err) 26 | } 27 | 28 | recorder := httptest.NewRecorder() 29 | 30 | req, err := http.NewRequestWithContext(ctx, http.MethodGet, "http://localhost", nil) 31 | if err != nil { 32 | t.Fatal(err) 33 | } 34 | 35 | handler.ServeHTTP(recorder, req) 36 | 37 | assertHeader(t, req, "X-Host", "localhost") 38 | assertHeader(t, req, "X-URL", "http://localhost") 39 | assertHeader(t, req, "X-Method", "GET") 40 | assertHeader(t, req, "X-Demo", "test") 41 | } 42 | 43 | func assertHeader(t *testing.T, req *http.Request, key, expected string) { 44 | t.Helper() 45 | 46 | if req.Header.Get(key) != expected { 47 | t.Errorf("invalid header value: %s", req.Header.Get(key)) 48 | } 49 | } 50 | -------------------------------------------------------------------------------- /go.mod: -------------------------------------------------------------------------------- 1 | module github.com/traefik/plugindemo 2 | 3 | go 1.19 4 | -------------------------------------------------------------------------------- /readme.md: -------------------------------------------------------------------------------- 1 | This repository includes an example plugin, `demo`, for you to use as a reference for developing your own plugins. 2 | 3 | [![Build Status](https://github.com/traefik/plugindemo/workflows/Main/badge.svg?branch=master)](https://github.com/traefik/plugindemo/actions) 4 | 5 | The existing plugins can be browsed into the [Plugin Catalog](https://plugins.traefik.io). 6 | 7 | # Developing a Traefik plugin 8 | 9 | [Traefik](https://traefik.io) plugins are developed using the [Go language](https://golang.org). 10 | 11 | A [Traefik](https://traefik.io) middleware plugin is just a [Go package](https://golang.org/ref/spec#Packages) that provides an `http.Handler` to perform specific processing of requests and responses. 12 | 13 | Rather than being pre-compiled and linked, however, plugins are executed on the fly by [Yaegi](https://github.com/traefik/yaegi), an embedded Go interpreter. 14 | 15 | ## Usage 16 | 17 | For a plugin to be active for a given Traefik instance, it must be declared in the static configuration. 18 | 19 | Plugins are parsed and loaded exclusively during startup, which allows Traefik to check the integrity of the code and catch errors early on. 20 | If an error occurs during loading, the plugin is disabled. 21 | 22 | For security reasons, it is not possible to start a new plugin or modify an existing one while Traefik is running. 23 | 24 | Once loaded, middleware plugins behave exactly like statically compiled middlewares. 25 | Their instantiation and behavior are driven by the dynamic configuration. 26 | 27 | Plugin dependencies must be [vendored](https://golang.org/ref/mod#vendoring) for each plugin. 28 | Vendored packages should be included in the plugin's GitHub repository. ([Go modules](https://blog.golang.org/using-go-modules) are not supported.) 29 | 30 | ### Configuration 31 | 32 | For each plugin, the Traefik static configuration must define the module name (as is usual for Go packages). 33 | 34 | The following declaration (given here in YAML) defines a plugin: 35 | 36 | ```yaml 37 | # Static configuration 38 | 39 | experimental: 40 | plugins: 41 | example: 42 | moduleName: github.com/traefik/plugindemo 43 | version: v0.2.1 44 | ``` 45 | 46 | Here is an example of a file provider dynamic configuration (given here in YAML), where the interesting part is the `http.middlewares` section: 47 | 48 | ```yaml 49 | # Dynamic configuration 50 | 51 | http: 52 | routers: 53 | my-router: 54 | rule: host(`demo.localhost`) 55 | service: service-foo 56 | entryPoints: 57 | - web 58 | middlewares: 59 | - my-plugin 60 | 61 | services: 62 | service-foo: 63 | loadBalancer: 64 | servers: 65 | - url: http://127.0.0.1:5000 66 | 67 | middlewares: 68 | my-plugin: 69 | plugin: 70 | example: 71 | headers: 72 | Foo: Bar 73 | ``` 74 | 75 | ### Local Mode 76 | 77 | Traefik also offers a developer mode that can be used for temporary testing of plugins not hosted on GitHub. 78 | To use a plugin in local mode, the Traefik static configuration must define the module name (as is usual for Go packages) and a path to a [Go workspace](https://golang.org/doc/gopath_code.html#Workspaces), which can be the local GOPATH or any directory. 79 | 80 | The plugins must be placed in `./plugins-local` directory, 81 | which should be in the working directory of the process running the Traefik binary. 82 | The source code of the plugin should be organized as follows: 83 | 84 | ``` 85 | ./plugins-local/ 86 | └── src 87 | └── github.com 88 | └── traefik 89 | └── plugindemo 90 | ├── demo.go 91 | ├── demo_test.go 92 | ├── go.mod 93 | ├── LICENSE 94 | ├── Makefile 95 | └── readme.md 96 | ``` 97 | 98 | ```yaml 99 | # Static configuration 100 | 101 | experimental: 102 | localPlugins: 103 | example: 104 | moduleName: github.com/traefik/plugindemo 105 | ``` 106 | 107 | (In the above example, the `plugindemo` plugin will be loaded from the path `./plugins-local/src/github.com/traefik/plugindemo`.) 108 | 109 | ```yaml 110 | # Dynamic configuration 111 | 112 | http: 113 | routers: 114 | my-router: 115 | rule: host(`demo.localhost`) 116 | service: service-foo 117 | entryPoints: 118 | - web 119 | middlewares: 120 | - my-plugin 121 | 122 | services: 123 | service-foo: 124 | loadBalancer: 125 | servers: 126 | - url: http://127.0.0.1:5000 127 | 128 | middlewares: 129 | my-plugin: 130 | plugin: 131 | example: 132 | headers: 133 | Foo: Bar 134 | ``` 135 | 136 | ## Defining a Plugin 137 | 138 | A plugin package must define the following exported Go objects: 139 | 140 | - A type `type Config struct { ... }`. The struct fields are arbitrary. 141 | - A function `func CreateConfig() *Config`. 142 | - A function `func New(ctx context.Context, next http.Handler, config *Config, name string) (http.Handler, error)`. 143 | 144 | ```go 145 | // Package example a example plugin. 146 | package example 147 | 148 | import ( 149 | "context" 150 | "net/http" 151 | ) 152 | 153 | // Config the plugin configuration. 154 | type Config struct { 155 | // ... 156 | } 157 | 158 | // CreateConfig creates the default plugin configuration. 159 | func CreateConfig() *Config { 160 | return &Config{ 161 | // ... 162 | } 163 | } 164 | 165 | // Example a plugin. 166 | type Example struct { 167 | next http.Handler 168 | name string 169 | // ... 170 | } 171 | 172 | // New created a new plugin. 173 | func New(ctx context.Context, next http.Handler, config *Config, name string) (http.Handler, error) { 174 | // ... 175 | return &Example{ 176 | // ... 177 | }, nil 178 | } 179 | 180 | func (e *Example) ServeHTTP(rw http.ResponseWriter, req *http.Request) { 181 | // ... 182 | e.next.ServeHTTP(rw, req) 183 | } 184 | ``` 185 | 186 | ## Logs 187 | 188 | Currently, the only way to send logs to Traefik is to use `os.Stdout.WriteString("...")` or `os.Stderr.WriteString("...")`. 189 | 190 | In the future, we will try to provide something better and based on levels. 191 | 192 | ## Plugins Catalog 193 | 194 | Traefik plugins are stored and hosted as public GitHub repositories. 195 | 196 | Every 30 minutes, the Plugins Catalog online service polls Github to find plugins and add them to its catalog. 197 | 198 | ### Prerequisites 199 | 200 | To be recognized by Plugins Catalog, your repository must meet the following criteria: 201 | 202 | - The `traefik-plugin` topic must be set. 203 | - The `.traefik.yml` manifest must exist, and be filled with valid contents. 204 | 205 | If your repository fails to meet either of these prerequisites, Plugins Catalog will not see it. 206 | 207 | ### Manifest 208 | 209 | A manifest is also mandatory, and it should be named `.traefik.yml` and stored at the root of your project. 210 | 211 | This YAML file provides Plugins Catalog with information about your plugin, such as a description, a full name, and so on. 212 | 213 | Here is an example of a typical `.traefik.yml`file: 214 | 215 | ```yaml 216 | # The name of your plugin as displayed in the Plugins Catalog web UI. 217 | displayName: Name of your plugin 218 | 219 | # For now, `middleware` is the only type available. 220 | type: middleware 221 | 222 | # The import path of your plugin. 223 | import: github.com/username/my-plugin 224 | 225 | # A brief description of what your plugin is doing. 226 | summary: Description of what my plugin is doing 227 | 228 | # Medias associated to the plugin (optional) 229 | iconPath: foo/icon.png 230 | bannerPath: foo/banner.png 231 | 232 | # Configuration data for your plugin. 233 | # This is mandatory, 234 | # and Plugins Catalog will try to execute the plugin with the data you provide as part of its startup validity tests. 235 | testData: 236 | Headers: 237 | Foo: Bar 238 | ``` 239 | 240 | Properties include: 241 | 242 | - `displayName` (required): The name of your plugin as displayed in the Plugins Catalog web UI. 243 | - `type` (required): For now, `middleware` is the only type available. 244 | - `import` (required): The import path of your plugin. 245 | - `summary` (required): A brief description of what your plugin is doing. 246 | - `testData` (required): Configuration data for your plugin. This is mandatory, and Plugins Catalog will try to execute the plugin with the data you provide as part of its startup validity tests. 247 | - `iconPath` (optional): A local path in the repository to the icon of the project. 248 | - `bannerPath` (optional): A local path in the repository to the image that will be used when you will share your plugin page in social medias. 249 | 250 | There should also be a `go.mod` file at the root of your project. Plugins Catalog will use this file to validate the name of the project. 251 | 252 | ### Tags and Dependencies 253 | 254 | Plugins Catalog gets your sources from a Go module proxy, so your plugins need to be versioned with a git tag. 255 | 256 | Last but not least, if your plugin middleware has Go package dependencies, you need to vendor them and add them to your GitHub repository. 257 | 258 | If something goes wrong with the integration of your plugin, Plugins Catalog will create an issue inside your Github repository and will stop trying to add your repo until you close the issue. 259 | 260 | ## Troubleshooting 261 | 262 | If Plugins Catalog fails to recognize your plugin, you will need to make one or more changes to your GitHub repository. 263 | 264 | In order for your plugin to be successfully imported by Plugins Catalog, consult this checklist: 265 | 266 | - The `traefik-plugin` topic must be set on your repository. 267 | - There must be a `.traefik.yml` file at the root of your project describing your plugin, and it must have a valid `testData` property for testing purposes. 268 | - There must be a valid `go.mod` file at the root of your project. 269 | - Your plugin must be versioned with a git tag. 270 | - If you have package dependencies, they must be vendored and added to your GitHub repository. 271 | --------------------------------------------------------------------------------