https

.gitignore

@@ -19,3 +19,5 @@
 
 # Builds
 /build
+/cert.pem
+/key.pem

README.md

@@ -1,57 +1,23 @@
-# go-template
+# builder-tools
 
-[![Goreport status](https://goreportcard.com/badge/github.com/flashbots/go-template)](https://goreportcard.com/report/github.com/flashbots/go-template)
-[![Test status](https://github.com/flashbots/go-template/workflows/Checks/badge.svg?branch=main)](https://github.com/flashbots/go-template/actions?query=workflow%3A%22Checks%22)
+WIP Toolbox
 
-Toolbox and building blocks for new Go projects, to get started quickly and right-footed!
+- [Create ECDSA keypair](cmd/ecdsa-gen/main.go)
+- [Create TLS certificate + key (PEM format)](cmd/tls-gen/main.go)
+- [Server using custom TLS certificate](cmd/https-server/main.go)
+- [Client allowing only server using the custom TLS certificate](cmd/https-client/main.go)
 
-* [`Makefile`](https://github.com/flashbots/go-template/blob/main/Makefile) with `lint`, `test`, `build`, `fmt` and more
-* Linting with `gofmt`, `gofumpt`, `go vet`, `staticcheck` and `golangci-lint`
-* Logging setup using the [slog logger](https://pkg.go.dev/golang.org/x/exp/slog) (with debug and json logging options)
-* [GitHub Workflows](.github/workflows/) for linting and testing, as well as releasing and publishing Docker images
-* Entry files for [CLI](/cmd/cli/main.go) and [HTTP server](/cmd/httpserver/main.go)
-* Webserver with
-  * Graceful shutdown, implementing `livez`, `readyz` and draining API handlers
-  * Prometheus metrics
-  * Using https://pkg.go.dev/github.com/go-chi/chi/v5 for routing
-  * [Urfave](https://cli.urfave.org/) for cli args
-* https://github.com/uber-go/nilaway
-* See also:
-  * Public project setup: https://github.com/flashbots/flashbots-repository-template
-  * Repository for common Go utilities: https://github.com/flashbots/go-utils
-
-Pick and choose whatever is useful to you! Don't feel the need to use everything, or even to follow this structure.
-
----
-
-## Getting started
-
-**Build CLI**
-
-```bash
-make build-cli
-```
-
-**Build HTTP server**
 
 ```bash
-make build-httpserver
-```
+# create the TLS cert
+$ go run cmd/tls-gen/main.go --host foo.com,0.0.0.0,127.0.0.1
 
-**Install dev dependencies**
+# run the server (serving the created TLS cert)
+$ go run cmd/https-server/main.go
 
-```bash
-go install mvdan.cc/[email protected]
-go install honnef.co/go/tools/cmd/[email protected]
-go install github.com/golangci/golangci-lint/cmd/[email protected]
-go install go.uber.org/nilaway/cmd/[email protected]
-go install github.com/daixiang0/[email protected]
-```
+# check with curl
+$ curl --insecure https://localhost:8080
 
-**Lint, test, format**
-
-```bash
-make lint
-make test
-make fmt
-```
+# run the client (allowing only server with that specific TLS cert)
+$ go run cmd/https-client/main.go
+```

cmd/https-client/main.go

@@ -0,0 +1,81 @@
+package main
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"errors"
+	"io"
+	"log"
+	"net/http"
+	"os"
+
+	"github.com/flashbots/go-template/common"
+	"github.com/urfave/cli/v2" // imports as package "cli"
+)
+
+var flags []cli.Flag = []cli.Flag{
+	&cli.StringFlag{
+		Name:  "server-addr",
+		Value: "https://0.0.0.0:8080",
+		Usage: "address to serve certificate on",
+	},
+}
+
+func main() {
+	app := &cli.App{
+		Name:   "https-client",
+		Usage:  "Client to allow only specific self-signed server cert",
+		Flags:  flags,
+		Action: runCli,
+	}
+
+	if err := app.Run(os.Args); err != nil {
+		log.Fatal(err)
+	}
+}
+
+func runCli(cCtx *cli.Context) error {
+	log := common.SetupLogger(&common.LoggingOpts{})
+
+	serverAddr := cCtx.String("server-addr")
+
+	certFile := "cert.pem"
+
+	certData, err := os.ReadFile(certFile)
+	if err != nil {
+		log.Error("could not read cert data", "err", err)
+		return err
+	}
+
+	roots := x509.NewCertPool()
+	ok := roots.AppendCertsFromPEM(certData)
+	if !ok {
+		log.Error("invalid certificate received", "cert", string(certData))
+		return errors.New("invalid certificate")
+	}
+
+	client := &http.Client{
+		Transport: &http.Transport{
+			TLSClientConfig: &tls.Config{
+				RootCAs: roots,
+			},
+		},
+	}
+
+	resp, err := client.Get(serverAddr)
+	if err != nil {
+		log.Error("http request error", "err", err)
+		return err
+	}
+	defer resp.Body.Close()
+
+	respBody, err := io.ReadAll(resp.Body)
+	if err != nil {
+		log.Error("could not read proxied service body", "err", err)
+		return err
+	}
+
+	log.Info("Received", "resp", string(respBody))
+
+	return nil
+}

cmd/https-server/main.go

@@ -0,0 +1,66 @@
+package main
+
+import (
+	"crypto/tls"
+	"io"
+	"log"
+	"net/http"
+	"os"
+	"time"
+
+	"github.com/flashbots/go-template/common"
+	"github.com/urfave/cli/v2" // imports as package "cli"
+)
+
+var flags []cli.Flag = []cli.Flag{
+	&cli.StringFlag{
+		Name:  "listen-addr",
+		Value: "0.0.0.0:8080",
+		Usage: "address to serve certificate on",
+	},
+}
+
+func main() {
+	app := &cli.App{
+		Name:   "https-server",
+		Usage:  "Server with custom cert",
+		Flags:  flags,
+		Action: runCli,
+	}
+
+	if err := app.Run(os.Args); err != nil {
+		log.Fatal(err)
+	}
+}
+
+func runCli(cCtx *cli.Context) error {
+	listenAddr := cCtx.String("listen-addr")
+	certFile := "cert.pem"
+	keyFile := "key.pem"
+
+	log := common.SetupLogger(&common.LoggingOpts{})
+
+	mux := http.NewServeMux()
+	mux.HandleFunc("/", getRoot)
+
+	srv := &http.Server{
+		Addr:              listenAddr,
+		Handler:           mux,
+		ReadHeaderTimeout: time.Second,
+		TLSConfig: &tls.Config{
+			MinVersion:               tls.VersionTLS13,
+			PreferServerCipherSuites: true,
+		},
+	}
+
+	log.Info("Starting HTTPS server", "addr", listenAddr)
+	if err := srv.ListenAndServeTLS(certFile, keyFile); err != nil {
+		log.Error("proxy exited", "err", err)
+		return err
+	}
+	return nil
+}
+
+func getRoot(w http.ResponseWriter, r *http.Request) {
+	_, _ = io.WriteString(w, "checkcheck\n")
+}