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cloudflare · Nov 18, 2024 · db9d140 · db9d140
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diff --git a/Dockerfile b/Dockerfile
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+FROM golang:1.23 AS build
+
+WORKDIR /usr/src/app
+
+COPY go.mod ./
+RUN go mod download && go mod verify
+
+COPY main.go index.html .
+RUN CGO_ENABLED=0 go build -v -o /usr/local/bin/app ./...
+
+FROM debian:bookworm-slim
+COPY --from=build /usr/local/bin/app /usr/local/bin/
+
+CMD ["/usr/local/bin/app", "-addr", "0.0.0.0"]
diff --git a/LICENSE b/LICENSE
@@ -0,0 +1,13 @@
+Copyright (c) 2024 Cloudflare, Inc.
+
+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.
diff --git a/README.md b/README.md
@@ -0,0 +1,12 @@
+# Cloudflare Container Example
+
+This repo contains a simple example application which can be run in Cloudflare's
+container runtime.
+
+The example app serves a single HTML page with an incrementing visit counter and a
+toggleable health status. The health status can be modified by sending a POST
+request to `/health` with the `status` query parameter set to either `healthy`
+or `unhealthy`. The health status can be queried by sending a GET request to
+`/health`: if the application is healthy it will return an empty response with
+a 200 status code; otherwise, it will send an empty response with a 503 status
+code.
diff --git a/go.mod b/go.mod
@@ -0,0 +1,3 @@
+module github.com/cloudflare/hello-world-container-image
+
+go 1.23.2
diff --git a/index.html b/index.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<head>
+  <meta charset="utf-8"/>
+  <title>Cloudflare Container Example</title>
+</head>
+<body>
+  <h1>Cloudflare Container Example</h1>
+  <p>
+    This page is rendered and served by an application running on Cloudflare's container platform.
+    It has been visited <strong>{{ .Visits }}</strong> time(s).
+  </p>
+
+  <form method="POST" action="/health?h={{ if .Healthy }}false{{ else }}true{{ end }}">
+    <p>
+      Health status:
+      {{ if .Healthy }}
+      <span style="color:green;">HEALTHY</span>
+      {{ else }}
+      <span style="color:red;">UNHEALTHY</span>
+      {{ end }}
+    </p>
+    <button type="submit">Toggle health status</button>
+  </form>
+</body>
diff --git a/main.go b/main.go
@@ -0,0 +1,84 @@
+package main
+
+import (
+	_ "embed"
+	"flag"
+	"fmt"
+	"html/template"
+	"log"
+	"net/http"
+)
+
+//go:embed index.html
+var content string
+var templates = template.Must(template.New("index.html").Parse(content))
+
+type State struct {
+	Visits  int
+	Healthy bool
+}
+
+func index(s *State) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if err := templates.Execute(w, s); err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+		}
+
+		s.Visits += 1
+	}
+}
+
+func health(s *State) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		switch r.Method {
+		case http.MethodGet:
+			if s.Healthy {
+				w.WriteHeader(http.StatusOK)
+			} else {
+				w.WriteHeader(http.StatusServiceUnavailable)
+			}
+		case http.MethodPost:
+			if err := r.ParseForm(); err != nil {
+				http.Error(w, err.Error(), http.StatusInternalServerError)
+				return
+			}
+
+			params := r.URL.Query()
+			h, ok := params["h"]
+			if !ok {
+				w.WriteHeader(http.StatusNotModified)
+				return
+			}
+
+			if len(h) != 1 || (h[0] != "true" && h[0] != "false") {
+				w.WriteHeader(http.StatusBadRequest)
+				return
+			}
+
+			healthy := h[0] == "true"
+			if healthy == s.Healthy {
+				w.WriteHeader(http.StatusNotModified)
+				return
+			}
+
+			s.Healthy = healthy
+			http.Redirect(w, r, "/", http.StatusSeeOther)
+		default:
+			w.WriteHeader(http.StatusMethodNotAllowed)
+		}
+	}
+}
+
+func main() {
+	addr := flag.String("addr", "127.0.0.1", "address to listen on")
+	port := flag.Int("port", 8000, "TCP port to listen on")
+
+	flag.Parse()
+
+	s := State{Healthy: true}
+	http.HandleFunc("/", index(&s))
+	http.HandleFunc("/health", health(&s))
+
+	log.Printf("Listening on %s:%d...", *addr, *port)
+	log.Fatal(http.ListenAndServe(fmt.Sprintf("%s:%d", *addr, *port), nil))
+}
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		module github.com/cloudflare/hello-world-container-image

		go 1.23.2