Add Dockerfile

Author: y-popov

Dockerfile

@@ -0,0 +1,24 @@
+# ---- Build stage ----
+FROM golang:1.24-alpine AS builder
+
+# Install CA certificates (needed for HTTPS requests)
+RUN apk add --no-cache ca-certificates
+
+WORKDIR /app
+
+COPY go.mod .
+RUN go mod download
+
+COPY main.go .
+
+# Build static binary
+RUN CGO_ENABLED=0 GOOS=linux go build -o proxy .
+
+# ---- Runtime stage ----
+FROM scratch
+
+COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
+COPY --from=builder /app/proxy /proxy
+
+# Run proxy
+ENTRYPOINT ["/proxy"]

go.mod

@@ -0,0 +1,3 @@
+module myproxy
+
+go 1.24

main.go

@@ -140,8 +140,13 @@ func callAndLogError(f func() error) {
 }
 
 func main() {
+	port := os.Getenv("PORT")
+	if port == "" {
+		port = "8080"
+	}
+
 	server := &http.Server{
-		Addr:    ":8080", // listen on port 8080
+		Addr:    ":" + port, // listen on port 8080
 		Handler: http.HandlerFunc(HandleProxy),
 	}