feat: create initial proxy logic (#1)

* feat: create initial proxy logic

Signed-off-by: Smuu <[email protected]>

* feat: add logging

Signed-off-by: Smuu <[email protected]>

* feat: add support for handling grpc

Signed-off-by: Smuu <[email protected]>

* bugfix: handle grpc headers

Signed-off-by: Smuu <[email protected]>

* feat: remove support for grpc

Signed-off-by: Smuu <[email protected]>

* feat: add support for subdomains

Signed-off-by: Smuu <[email protected]>

* feat: dont use subdomain

Signed-off-by: Smuu <[email protected]>

* bugfix: forewarding

Signed-off-by: Smuu <[email protected]>

* feat: fix replacing not working due to compression

Signed-off-by: Smuu <[email protected]>

* feat: handle websocket connections sperately

Signed-off-by: Smuu <[email protected]>

* feat: allow all origing

Signed-off-by: Smuu <[email protected]>

* debugging

Signed-off-by: Smuu <[email protected]>

* debugging

Signed-off-by: Smuu <[email protected]>

* feat: decompression with other protocols

Signed-off-by: Smuu <[email protected]>

* feat: contiunue with original even if decompression failed

Signed-off-by: Smuu <[email protected]>

* testing

Signed-off-by: Smuu <[email protected]>

---------

Signed-off-by: Smuu <[email protected]>

.github/workflows/docker-build-publish.yaml

@@ -0,0 +1,25 @@
+name: Docker Build & Publish
+
+# Trigger on all push events, new semantic version tags, and all PRs
+on:
+  push:
+    branches:
+      - "main"
+      - "v[0-9].[0-9].x"
+      - "v[0-9].[0-9][0-9].x"
+      - "v[0-9].x"
+    tags:
+      - "v[0-9]+.[0-9]+.[0-9]+"
+      - "v[0-9]+.[0-9]+.[0-9]+-alpha.[0-9]+"
+      - "v[0-9]+.[0-9]+.[0-9]+-beta.[0-9]+"
+      - "v[0-9]+.[0-9]+.[0-9]+-rc[0-9]+"
+  pull_request:
+
+jobs:
+  docker-security-build:
+    permissions:
+      contents: write
+      packages: write
+    uses: celestiaorg/.github/.github/workflows/[email protected] # yamllint disable-line rule:line-length
+    with:
+      dockerfile: Dockerfile

Dockerfile

@@ -0,0 +1,27 @@
+# Use the official Golang image to create a build artifact.
+FROM golang:1.21.1 AS builder
+
+# Set the working directory inside the container.
+WORKDIR /app
+
+# Copy go mod and sum files
+#COPY go.mod go.sum ./
+COPY go.mod ./
+
+# Download all dependencies.
+RUN go mod download
+
+# Copy the source code into the container.
+COPY . .
+
+# Build the Go app
+RUN CGO_ENABLED=0 GOOS=linux go build -o main .
+
+# Use a lightweight image for the final image.
+FROM alpine:3
+
+# Copy the binary.
+COPY --from=builder /app/main /app/main
+
+# Run the binary.
+CMD ["/app/main"]

README.md

@@ -1 +1,5 @@
-# autoscale-proxy
+# autoscale-proxy
+
+## ToDo
+
+- use internal services instead of domain names

go.mod

@@ -0,0 +1,8 @@
+module github.com/celestiaorg/autoscale-proxy
+
+go 1.21.1
+
+require (
+	github.com/andybalholm/brotli v1.0.6
+	github.com/gorilla/websocket v1.5.0
+)

go.sum

@@ -0,0 +1,4 @@
+github.com/andybalholm/brotli v1.0.6 h1:Yf9fFpf49Zrxb9NlQaluyE92/+X7UVHlhMNJN2sxfOI=
+github.com/andybalholm/brotli v1.0.6/go.mod h1:fO7iG3H7G2nSZ7m0zPUDn85XEX2GTukHGRSepvi9Eig=
+github.com/gorilla/websocket v1.5.0 h1:PPwGk2jz7EePpoHN/+ClbZu8SPxiqlu12wZP/3sWmnc=
+github.com/gorilla/websocket v1.5.0/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=

main.go

@@ -0,0 +1,236 @@
+package main
+
+import (
+	"bytes"
+	"compress/flate"
+	"compress/gzip"
+	"io"
+	"log"
+	"net/http"
+	"os"
+	"strings"
+
+	"github.com/andybalholm/brotli"
+	"github.com/gorilla/websocket"
+)
+
+var (
+	debugLog *log.Logger
+	infoLog  *log.Logger
+	errorLog *log.Logger
+)
+
+func init() {
+	debugLog = log.New(os.Stdout, "DEBUG: ", log.Ldate|log.Ltime|log.Lshortfile)
+	infoLog = log.New(os.Stdout, "INFO: ", log.Ldate|log.Ltime|log.Lshortfile)
+	errorLog = log.New(os.Stderr, "ERROR: ", log.Ldate|log.Ltime|log.Lshortfile)
+}
+
+func replaceDomainInResponse(originalSubdomain, replaceSubdomain, originalDomain string, buffer *bytes.Buffer) {
+	body := buffer.String()
+	fullReplace := replaceSubdomain + "." + "lunaroasis.net" // We know that statescale and snapscale are under this domain
+	fullOriginal := originalSubdomain + "." + originalDomain // Original domain can vary
+	replacedBody := strings.ReplaceAll(body, fullReplace, fullOriginal)
+	buffer.Reset()
+	buffer.WriteString(replacedBody)
+}
+
+func proxyRequest(fullSubdomain, path string, buffer *bytes.Buffer, r *http.Request) (int, map[string]string, error) {
+	client := &http.Client{}
+	target := "https://" + fullSubdomain + ".lunaroasis.net" + path
+	newReq, err := http.NewRequest(r.Method, target, r.Body)
+	if err != nil {
+		errorLog.Printf("Failed to create request: %v", err)
+		return 0, nil, err
+	}
+	newReq.Header = r.Header
+
+	resp, err := client.Do(newReq)
+	if err != nil {
+		errorLog.Printf("Failed to send request: %v", err)
+		return 0, nil, err
+	}
+	defer resp.Body.Close()
+
+	headers := make(map[string]string)
+	for key, values := range resp.Header {
+		for _, value := range values {
+			headers[key] = value
+		}
+	}
+
+	encoding := resp.Header.Get("Content-Encoding")
+	var reader io.Reader
+	switch encoding {
+	case "br":
+		// Decompress Brotli data
+		reader = brotli.NewReader(resp.Body)
+	case "gzip":
+		// Decompress Gzip data
+		reader, err = gzip.NewReader(resp.Body)
+		if err != nil {
+			errorLog.Printf("Failed to create gzip reader: %v", err)
+			return 0, nil, err
+		}
+	case "deflate":
+		// Decompress Deflate data
+		reader = flate.NewReader(resp.Body)
+	default:
+		reader = resp.Body
+	}
+	io.Copy(buffer, reader)
+
+	return resp.StatusCode, headers, nil
+}
+
+func handleHttpRequest(w http.ResponseWriter, r *http.Request) {
+	infoLog.Printf("Received request from %s", r.Host)
+
+	hostParts := strings.Split(r.Host, ".")
+	if len(hostParts) < 3 {
+		errorLog.Printf("Invalid domain: %s", r.Host)
+		http.Error(w, "Invalid domain", http.StatusBadRequest)
+		return
+	}
+
+	subdomain := hostParts[0] // Extract original domain
+	originalDomain := strings.Join(hostParts[1:], ".")
+
+	// Check for WebSocket upgrade headers
+	if strings.ToLower(r.Header.Get("Upgrade")) == "websocket" {
+		// Handle WebSocket requests by proxying to snapscale
+		proxyWebSocketRequest(subdomain, w, r)
+		return
+	}
+
+	buffer := new(bytes.Buffer)
+	backupBuffer := new(bytes.Buffer)
+
+	debugLog.Printf("Proxying request to %s", subdomain+"-statescale")
+	statusCode, headers, err := proxyRequest(subdomain+"-statescale", r.RequestURI, buffer, r)
+	debugLog.Printf("Received status code %d", statusCode)
+	if err != nil || statusCode >= 400 {
+		debugLog.Printf("Proxying request to %s", subdomain+"-snapscale")
+		backupStatusCode, backupHeaders, _ := proxyRequest(subdomain+"-snapscale", r.RequestURI, backupBuffer, r)
+		debugLog.Printf("Received status code %d", backupStatusCode)
+
+		replaceDomainInResponse(subdomain, subdomain+"-snapscale", originalDomain, backupBuffer)
+
+		for key, value := range backupHeaders {
+			w.Header().Set(key, value)
+		}
+		w.WriteHeader(backupStatusCode)
+		encoding := headers["Content-Encoding"]
+		buffer = compressData(buffer, encoding)
+		io.Copy(w, backupBuffer)
+		return
+	}
+
+	replaceDomainInResponse(subdomain, subdomain+"-statescale", originalDomain, buffer)
+	for key, value := range headers {
+		w.Header().Set(key, value)
+	}
+	w.WriteHeader(statusCode)
+	// If the original response was Brotli-compressed, recompress the data
+	encoding := headers["Content-Encoding"]
+	buffer = compressData(buffer, encoding)
+	io.Copy(w, buffer)
+}
+
+var upgrader = websocket.Upgrader{
+	CheckOrigin: func(r *http.Request) bool {
+		return true // Allow all connections
+	},
+}
+
+func proxyWebSocketRequest(subdomain string, w http.ResponseWriter, r *http.Request) {
+	// Build target URL
+	fullSubdomain := subdomain + "-snapscale"
+	target := "wss://" + fullSubdomain + ".lunaroasis.net" + r.RequestURI
+
+	// Create a new WebSocket connection to the target
+	dialer := websocket.Dialer{}
+	targetConn, resp, err := dialer.Dial(target, nil)
+	if err != nil {
+		errorLog.Printf("Failed to connect to target: %v", err)
+		if resp != nil {
+			errorLog.Printf("Handshake response status: %s", resp.Status)
+			// Log all response headers for debugging
+			for k, v := range resp.Header {
+				errorLog.Printf("%s: %s", k, v)
+			}
+		}
+		http.Error(w, "Internal server error", http.StatusInternalServerError)
+		return
+	}
+	defer targetConn.Close()
+
+	// Upgrade the client connection to a WebSocket connection
+	clientConn, err := upgrader.Upgrade(w, r, nil)
+	if err != nil {
+		errorLog.Printf("Failed to upgrade client connection: %v", err)
+		return // No need to send an error response, Upgrade already did if there was an error
+	}
+	defer clientConn.Close()
+
+	// Start goroutines to copy data between the client and target
+	go func() {
+		for {
+			messageType, message, err := targetConn.ReadMessage()
+			if err != nil {
+				errorLog.Printf("Failed to read from target: %v", err)
+				return
+			}
+			err = clientConn.WriteMessage(messageType, message)
+			if err != nil {
+				errorLog.Printf("Failed to write to client: %v", err)
+				return
+			}
+		}
+	}()
+	go func() {
+		for {
+			messageType, message, err := clientConn.ReadMessage()
+			if err != nil {
+				errorLog.Printf("Failed to read from client: %v", err)
+				return
+			}
+			err = targetConn.WriteMessage(messageType, message)
+			if err != nil {
+				errorLog.Printf("Failed to write to target: %v", err)
+				return
+			}
+		}
+	}()
+
+	// The goroutines will run until one of the connections is closed
+	select {}
+}
+
+func compressData(buffer *bytes.Buffer, encoding string) *bytes.Buffer {
+	var compressedData bytes.Buffer
+	var writer io.WriteCloser
+	switch encoding {
+	case "br":
+		writer = brotli.NewWriterLevel(&compressedData, brotli.DefaultCompression)
+	case "gzip":
+		writer = gzip.NewWriter(&compressedData)
+	case "deflate":
+		writer, _ = flate.NewWriter(&compressedData, flate.DefaultCompression)
+	default:
+		return buffer
+	}
+	io.Copy(writer, buffer)
+	writer.Close()
+	return &compressedData
+}
+
+func handleRequest(w http.ResponseWriter, r *http.Request) {
+	handleHttpRequest(w, r)
+}
+
+func main() {
+	infoLog.Println("Starting server on :8080")
+	http.HandleFunc("/", handleRequest)
+	http.ListenAndServe(":8080", nil)
+}