feat: add limiter service written in go

.gitignore

@@ -68,3 +68,6 @@ typings/
 # IDEs
 .vscode
 .history
+
+# macOS
+.DS_Store

api/garden.yml

@@ -1,14 +1,14 @@
 ---
 kind: Build
 type: container
-name: api-build
+name: api
 description: The backend build for the voting UI
 
 ---
 kind: Deploy
 type: container
 name: api
-build: api-build
+build: api
 description: The backend deploy for the voting UI
 spec:
   args: [python, app.py]
@@ -25,7 +25,7 @@ spec:
   ingresses:
     - path: /
       port: http
-      hostname: api.${variables.base-hostname}
+      hostname: api-${variables.base-hostname}
   healthCheck:
     httpGet:
       path: /health
@@ -38,6 +38,6 @@ kind: Test
 type: container
 name: unit
 description: Unit test for backend API
-build: api-build
+build: api
 spec:
-  args: ["echo", "ok"]
+  args: ["echo", "ok"]

limiter/Dockerfile

@@ -0,0 +1,7 @@
+FROM golang:alpine as prod
+RUN mkdir /app
+ADD ./src /app/
+WORKDIR /app
+RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o main .
+CMD ["/app/main"]
+EXPOSE 8080

limiter/Dockerfile.syncmode

@@ -0,0 +1,8 @@
+FROM cosmtrek/air:latest as sync
+
+# We do not copy anything on purpose in sync mode.
+# Code will be copied using mutagen as part of Garden's code synchronization feature.
+RUN mkdir /app
+WORKDIR /app
+
+EXPOSE 8080

limiter/garden.yml

@@ -0,0 +1,54 @@
+# Production container to be used without sync mode.
+kind: Build
+type: container
+name: limiter-prod
+include:
+  - src
+  - Dockerfile
+exclude:
+  - src/tmp/*
+spec:
+  dockerfile: "Dockerfile"
+
+---
+
+# The sync container only provides the tools necessary for building the library
+# when using it during inner loop development together with Garden's sync mode.
+kind: Build
+type: container
+name: limiter-sync
+include:
+  - Dockerfile.syncmode
+spec:
+  dockerfile: "Dockerfile.syncmode"
+
+---
+
+kind: Deploy
+type: container
+name: limiter
+build:
+  $if: ${this.mode=='sync'}
+  $then: limiter-sync
+  $else: limiter-prod
+include: []
+dependencies:
+  - deploy.api
+spec:
+  sync:
+    command: [air]
+    paths:
+      - target: /app
+        source: ./src
+        mode: one-way-replica
+        exclude: ["tmp/*/**"]
+  ports:
+    - name: http
+      containerPort: 8080
+      servicePort: 80
+  ingresses:
+    - path: /
+      port: http
+      hostname: limiter-${var.base-hostname}
+  env:
+    PROXY_URL: http://api

limiter/src/.air.toml

@@ -0,0 +1,44 @@
+root = "."
+testdata_dir = "testdata"
+tmp_dir = "tmp"
+
+[build]
+  args_bin = []
+  bin = "./tmp/main"
+  cmd = "go build -o ./tmp/main ."
+  delay = 0
+  exclude_dir = ["assets", "tmp", "vendor", "testdata"]
+  exclude_file = []
+  exclude_regex = ["_test.go"]
+  exclude_unchanged = false
+  follow_symlink = false
+  full_bin = ""
+  include_dir = []
+  include_ext = ["go", "tpl", "tmpl", "html"]
+  include_file = []
+  kill_delay = "0s"
+  log = "build-errors.log"
+  poll = false
+  poll_interval = 0
+  rerun = false
+  rerun_delay = 500
+  send_interrupt = false
+  stop_on_error = false
+
+[color]
+  app = ""
+  build = "yellow"
+  main = "magenta"
+  runner = "green"
+  watcher = "cyan"
+
+[log]
+  main_only = false
+  time = false
+
+[misc]
+  clean_on_exit = false
+
+[screen]
+  clear_on_rebuild = false
+  keep_scroll = true

limiter/src/.gitignore

@@ -0,0 +1 @@
+tmp

limiter/src/go.mod

@@ -0,0 +1,12 @@
+module example.garden.io/m
+
+go 1.20
+
+require github.com/didip/tollbooth/v7 v7.0.1
+
+require (
+	github.com/didip/tollbooth v4.0.2+incompatible // indirect
+	github.com/go-pkgz/expirable-cache v0.1.0 // indirect
+	github.com/patrickmn/go-cache v2.1.0+incompatible // indirect
+	golang.org/x/time v0.3.0 // indirect
+)

limiter/src/go.sum

@@ -0,0 +1,16 @@
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/didip/tollbooth v4.0.2+incompatible h1:fVSa33JzSz0hoh2NxpwZtksAzAgd7zjmGO20HCZtF4M=
+github.com/didip/tollbooth v4.0.2+incompatible/go.mod h1:A9b0665CE6l1KmzpDws2++elm/CsuWBMa5Jv4WY0PEY=
+github.com/didip/tollbooth/v7 v7.0.1 h1:TkT4sBKoQoHQFPf7blQ54iHrZiTDnr8TceU+MulVAog=
+github.com/didip/tollbooth/v7 v7.0.1/go.mod h1:VZhDSGl5bDSPj4wPsih3PFa4Uh9Ghv8hgacaTm5PRT4=
+github.com/go-pkgz/expirable-cache v0.1.0 h1:3bw0m8vlTK8qlwz5KXuygNBTkiKRTPrAGXU0Ej2AC1g=
+github.com/go-pkgz/expirable-cache v0.1.0/go.mod h1:GTrEl0X+q0mPNqN6dtcQXksACnzCBQ5k/k1SwXJsZKs=
+github.com/patrickmn/go-cache v2.1.0+incompatible h1:HRMgzkcYKYpi3C8ajMPV8OFXaaRUnok+kx1WdO15EQc=
+github.com/patrickmn/go-cache v2.1.0+incompatible/go.mod h1:3Qf8kWWT7OJRJbdiICTKqZju1ZixQ/KpMGzzAfe6+WQ=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+golang.org/x/time v0.3.0 h1:rg5rLMjNzMS1RkNLzCG38eapWhnYLFYXDXj2gOlr8j4=
+golang.org/x/time v0.3.0/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

limiter/src/main.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"log"
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+	"os"
+
+	"github.com/didip/tollbooth"
+)
+
+func main() {
+	remote, err := url.Parse(os.Getenv("PROXY_URL"))
+	if err != nil {
+		panic(err)
+	}
+
+	// Rate limiter: Allow one vote per second.
+	// Suggestion: Try reducing this to 0.1 to allow one vote every 10 seconds.
+	// When using garden deploy --sync, the code change will be automatically synchronized
+	// See also https://docs.garden.io/guides/code-synchronization
+	limiter := tollbooth.NewLimiter(1, nil)
+	limiter.SetMessage("Please slow down.")
+	limiter.SetOnLimitReached(func(w http.ResponseWriter, r *http.Request) {
+		log.Printf("%s: Limiting: Too many requests", r.URL)
+	})
+
+	// Reverse proxy
+	handler := func(p *httputil.ReverseProxy) func(http.ResponseWriter, *http.Request) {
+		log.Println("Hello world!")
+
+		return func(w http.ResponseWriter, r *http.Request) {
+			log.Printf("%s: OK: Forwarding", r.URL)
+			r.Host = remote.Host
+			p.ServeHTTP(w, r)
+		}
+	}
+
+	proxy := httputil.NewSingleHostReverseProxy(remote)
+	http.Handle("/", tollbooth.LimitFuncHandler(limiter, handler(proxy)))
+	err = http.ListenAndServe(":8080", nil)
+	if err != nil {
+		panic(err)
+	}
+}

result/garden.yml

@@ -20,7 +20,7 @@ spec:
   ingresses:
     - path: /
       port: ui
-      hostname: result.${var.base-hostname}
+      hostname: result-${var.base-hostname}
   ports:
     - name: ui
       protocol: TCP

vote/garden.yml

@@ -27,12 +27,12 @@ spec:
   ingresses:
     - path: /
       port: http
-      hostname: vote.${var.base-hostname}
+      hostname: vote-${var.base-hostname}
   env:
-    HOSTNAME: vote.${var.base-hostname}
+    HOSTNAME: vote-${var.base-hostname}
     VUE_APP_USERNAME: ${local.username}
 dependencies:
-  - deploy.api
+  - deploy.limiter
   - deploy.result
 
 ---
@@ -55,7 +55,7 @@ type: container
 name: e2e-runner
 dependencies: [deploy.vote]
 spec:
-  image: ${actions.deploy.vote.outputs.deployedImageId}
+  image: ${actions.build.vote.outputs.deploymentImageId}
 
 ---
 kind: Test

vote/vue.config.js

@@ -5,7 +5,7 @@ module.exports = {
     progress: false,
     proxy: {
       '^/api': {
-        target: 'http://api',
+        target: `http://limiter`, // limiter is a rate limiting reverse proxy for the api
         changeOrigin: true,
         secure: false,
         logLevel: 'debug',