From c0f884f049aafa7100c4c0b7670289340bfafd56 Mon Sep 17 00:00:00 2001
From: Anders Pitman <tapitman11@gmail.com>
Date: Fri, 8 Jan 2021 14:18:51 -0700
Subject: [PATCH] Improve argument parsing and error messages

---
 client.go               | 17 ++++++++++++++---
 cmd/boringproxy/main.go | 30 +++++++++++++++++++++++-------
 2 files changed, 37 insertions(+), 10 deletions(-)

diff --git a/client.go b/client.go
index c1a8471..0601021 100644
--- a/client.go
+++ b/client.go
@@ -11,6 +11,7 @@ import (
 	"log"
 	"net"
 	"net/http"
+	"os"
 	"strings"
 	"sync"
 	"time"
@@ -105,19 +106,29 @@ func (c *Client) RunPuppetClient() {
 	url := fmt.Sprintf("https://%s/api/users/%s/clients/%s", c.server, c.user, c.clientName)
 	clientReq, err := http.NewRequest("PUT", url, nil)
 	if err != nil {
-		log.Fatal("Failed to PUT client")
+		fmt.Fprintf(os.Stderr, "Failed to create request for URL %s", url)
+		os.Exit(1)
 	}
 	if len(c.token) > 0 {
 		clientReq.Header.Add("Authorization", "bearer "+c.token)
 	}
 	resp, err := c.httpClient.Do(clientReq)
 	if err != nil {
-		log.Fatal("Failed to PUT client")
+		fmt.Fprintf(os.Stderr, "Failed to create client. Ensure the server is running. URL: %s", url)
+		os.Exit(1)
 	}
 	defer resp.Body.Close()
 
 	if resp.StatusCode != 200 {
-		log.Fatal("Failed to PUT client")
+		body, err := ioutil.ReadAll(resp.Body)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Failed to create client. HTTP Status code: %d. Failed to read body", resp.StatusCode)
+			os.Exit(1)
+		}
+
+		msg := string(body)
+		fmt.Fprintf(os.Stderr, "Failed to create client. Are the user (%s) and token correct? HTTP Status code: %d. Message: %s", c.user, resp.StatusCode, msg)
+		os.Exit(1)
 	}
 
 	for {
diff --git a/cmd/boringproxy/main.go b/cmd/boringproxy/main.go
index 5746857..1119726 100644
--- a/cmd/boringproxy/main.go
+++ b/cmd/boringproxy/main.go
@@ -17,6 +17,11 @@ Commands:
 Use "%[1]s command -h" for a list of flags for the command.
 `
 
+func fail(msg string) {
+	fmt.Fprintln(os.Stderr, msg)
+	os.Exit(1)
+}
+
 func main() {
 	if len(os.Args) < 2 {
 		fmt.Fprintln(os.Stderr, os.Args[0]+": Need a command")
@@ -32,7 +37,7 @@ func main() {
 	case "server":
 		boringproxy.Listen()
 	case "client":
-                flagSet := flag.NewFlagSet(os.Args[0], flag.ExitOnError)
+		flagSet := flag.NewFlagSet(os.Args[0], flag.ExitOnError)
 		server := flagSet.String("server", "", "boringproxy server")
 		token := flagSet.String("token", "", "Access token")
 		name := flagSet.String("client-name", "", "Client name")
@@ -41,10 +46,22 @@ func main() {
 		acmeEmail := flagSet.String("acme-email", "", "Email for ACME (ie Let's Encrypt)")
 		dnsServer := flagSet.String("dns-server", "", "Custom DNS server")
 
-                err := flagSet.Parse(os.Args[2:])
-                if err != nil {
-                        fmt.Fprintf(os.Stderr, "%s: parsing flags: %s\n", os.Args[0], err)
-                }
+		err := flagSet.Parse(os.Args[2:])
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "%s: parsing flags: %s\n", os.Args[0], err)
+		}
+
+		if *server == "" {
+			fail("-server is required")
+		}
+
+		if *token == "" {
+			fail("-token is required")
+		}
+
+		if *name == "" {
+			fail("-client-name is required")
+		}
 
 		config := &boringproxy.ClientConfig{
 			ServerAddr: *server,
@@ -59,7 +76,6 @@ func main() {
 		client := boringproxy.NewClient(config)
 		client.RunPuppetClient()
 	default:
-		fmt.Fprintln(os.Stderr, os.Args[0]+": Invalid command "+command)
-		os.Exit(1)
+		fail(os.Args[0] + ": Invalid command " + command)
 	}
 }