Use pkg/browser where possible and remove explicit firefox support

Closes #13 and closes #10

Author: nhooyr

go.mod

@@ -3,6 +3,7 @@ module go.coder.com/sshcode
 go 1.12
 
 require (
+	github.com/pkg/browser v0.0.0-20180916011732-0a3d74bf9ce4
 	go.coder.com/flog v0.0.0-20190129195112-eaed154a0db8
 	golang.org/x/sys v0.0.0-20190418153312-f0ce4c0180be // indirect
 	golang.org/x/xerrors v0.0.0-20190410155217-1f06c39b4373

go.sum

@@ -4,6 +4,8 @@ github.com/mattn/go-colorable v0.0.9 h1:UVL0vNpWh04HeJXV0KLcaT7r06gOH2l4OW6ddYRU
 github.com/mattn/go-colorable v0.0.9/go.mod h1:9vuHe8Xs5qXnSaW/c/ABM9alt+Vo+STaOChaDxuIBZU=
 github.com/mattn/go-isatty v0.0.4 h1:bnP0vzxcAdeI1zdubAl5PjU6zsERjGZb7raWodagDYs=
 github.com/mattn/go-isatty v0.0.4/go.mod h1:M+lRXTBqGeGNdLjl/ufCoiOlB5xdOkqRJdNxMWT7Zi4=
+github.com/pkg/browser v0.0.0-20180916011732-0a3d74bf9ce4 h1:49lOXmGaUpV9Fz3gd7TFZY106KVlPVa5jcYD1gaQf98=
+github.com/pkg/browser v0.0.0-20180916011732-0a3d74bf9ce4/go.mod h1:4OwLy04Bl9Ef3GJJCoec+30X3LQs/0/m4HFRt/2LUSA=
 go.coder.com/flog v0.0.0-20190129195112-eaed154a0db8 h1:PtQ3moPi4EAz3cyQhkUs1IGIXa2QgJpP60yMjOdu0kk=
 go.coder.com/flog v0.0.0-20190129195112-eaed154a0db8/go.mod h1:83JsYgXYv0EOaXjIMnaZ1Fl6ddNB3fJnDZ/8845mUJ8=
 golang.org/x/sys v0.0.0-20190418153312-f0ce4c0180be h1:mI+jhqkn68ybP0ORJqunXn+fq+Eeb4hHKqLQcFICjAc=

main.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"flag"
 	"fmt"
+	"github.com/pkg/browser"
 	"math/rand"
 	"net"
 	"net/http"
@@ -139,29 +140,37 @@ func openBrowser(url string) {
 	var openCmd *exec.Cmd
 	switch {
 	case commandExists("google-chrome"):
-		openCmd = exec.Command("google-chrome", fmtChromeOptions(url)...)
+		openCmd = exec.Command("google-chrome", chromeOptions(url)...)
 	case commandExists("chromium"):
-		openCmd = exec.Command("chromium", fmtChromeOptions(url)...)
+		openCmd = exec.Command("chromium", chromeOptions(url)...)
 	case commandExists("chromium-browser"):
-		openCmd = exec.Command("chromium-browser", fmtChromeOptions(url)...)
-	case commandExists("firefox"):
-		openCmd = exec.Command("firefox", "--url="+url, "-safe-mode")
+		openCmd = exec.Command("chromium-browser", chromeOptions(url)...)
 	case pathExists("/Applications/Google Chrome.app/Contents/MacOS/Google Chrome"):
-		openCmd = exec.Command("/Applications/Google Chrome.app/Contents/MacOS/Google Chrome", fmtChromeOptions(url)...)
+		openCmd = exec.Command("/Applications/Google Chrome.app/Contents/MacOS/Google Chrome", chromeOptions(url)...)
 	default:
-		flog.Info("unable to find a browser to open: sshcode only supports firefox, chrome, and chromium")
+		err := browser.OpenURL(url)
+		if err != nil {
+			flog.Error("failed to open browser: %v", err)
+		}
+		return
 	}
 
+	// We do not use CombinedOutput because if there is no chrome instance, this will block
+	// and become the parent process instead of using an existing chrome instance.
 	err := openCmd.Start()
 	if err != nil {
-		flog.Fatal("failed to open browser: %v", err)
+		flog.Error("failed to open browser: %v", err)
 	}
 }
 
-func fmtChromeOptions(url string) []string {
+func chromeOptions(url string) []string {
 	return []string{"--app=" + url, "--disable-extensions", "--disable-plugins"}
 }
 
+func firefoxOptions(url string) []string  {
+	return []string{"--url="+url, "-safe-mode"}
+}
+
 // Checks if a command exists locally.
 func commandExists(name string) bool {
 	_, err := exec.LookPath(name)