Use custom ngrok config so we can specify api url.

We use a config file so we can set ngrok's API port (web_addr). We use
the API to get the public URL and if there's already ngrok running, it
will just choose a random API port and we won't be able to get the right
url.

bootstrap/bootstrap.go

@@ -18,7 +18,7 @@ package bootstrap
 import (
 	"context"
 	"fmt"
-	"net"
+	"io/ioutil"
 	"os"
 	"os/exec"
 	"os/signal"
@@ -129,16 +129,30 @@ Follow these instructions to create a token (we don't store any tokens):
 	// Create ngrok tunnel.
 	colorstring.Println("[white]=> creating secure tunnel")
 	s.Start()
-	// Check if there is already an ngrok running by seeing if there's already
-	// something bound to its API port.
-	conn, err := net.Dial("tcp", ngrokAPIURL)
-	// We expect an error.
-	if err == nil {
-		conn.Close() // nolint: errcheck
-		return errors.New("unable to start ngrok because there is already something bound to its API port: " + ngrokAPIURL)
+
+	// We use a config file so we can set ngrok's API port (web_addr). We use
+	// the API to get the public URL and if there's already ngrok running, it
+	// will just choose a random API port and we won't be able to get the right
+	// url.
+	ngrokConfig := fmt.Sprintf(`
+web_addr: %s
+tunnels:
+  atlantis:
+    addr: %d
+    bind_tls: true
+    proto: http
+`, ngrokAPIURL, atlantisPort)
+
+	ngrokConfigFile, err := ioutil.TempFile("", "")
+	if err != nil {
+		return errors.Wrap(err, "creating ngrok config file")
+	}
+	err = ioutil.WriteFile(ngrokConfigFile.Name(), []byte(ngrokConfig), 0600)
+	if err != nil {
+		return errors.Wrap(err, "writing ngrok config file")
 	}
 
-	ngrokCmd, err := executeCmd("/tmp/ngrok", []string{"http", "4141"})
+	ngrokCmd, err := executeCmd("/tmp/ngrok", []string{"start", "atlantis", "--config", ngrokConfigFile.Name()})
 	if err != nil {
 		return errors.Wrapf(err, "creating ngrok tunnel")
 	}

bootstrap/utils.go

@@ -24,13 +24,15 @@ import (
 	"path/filepath"
 	"syscall"
 
+	"github.com/pkg/errors"
 	"golang.org/x/crypto/ssh/terminal"
 )
 
-var hashicorpReleasesURL = "https://releases.hashicorp.com"
-var terraformVersion = "0.10.8"
-var ngrokDownloadURL = "https://bin.equinox.io/c/4VmDzA7iaHb"
-var ngrokAPIURL = "localhost:4040"
+const hashicorpReleasesURL = "https://releases.hashicorp.com"
+const terraformVersion = "0.10.8"
+const ngrokDownloadURL = "https://bin.equinox.io/c/4VmDzA7iaHb"
+const ngrokAPIURL = "localhost:41414" // We hope this isn't used.
+const atlantisPort = 4141
 
 func readPassword() (string, error) {
 	password, err := terminal.ReadPassword(syscall.Stdin)
@@ -90,35 +92,38 @@ func unzip(archive, target string) error {
 }
 
 func getTunnelAddr() (string, error) {
-	response, err := http.Get(fmt.Sprintf("http://%s/api/tunnels", ngrokAPIURL))
+	tunAPI := fmt.Sprintf("http://%s/api/tunnels", ngrokAPIURL)
+	response, err := http.Get(tunAPI)
 	if err != nil {
 		return "", err
 	}
 	defer response.Body.Close() // nolint: errcheck
 
-	type tunnel struct {
-		Name      string `json:"name"`
-		URI       string `json:"uri"`
-		PublicURL string `json:"public_url"`
-		Proto     string `json:"http"`
-	}
-
 	type tunnels struct {
-		Tunnels []tunnel
+		Tunnels []struct {
+			PublicURL string `json:"public_url"`
+			Proto     string `json:"proto"`
+			Config    struct {
+				Addr string `json:"addr"`
+			} `json:"config"`
+		} `json:"tunnels"`
 	}
 
 	var t tunnels
 
-	err = json.NewDecoder(response.Body).Decode(&t)
-	if err != nil {
-		return "", err
+	if err = json.NewDecoder(response.Body).Decode(&t); err != nil {
+		return "", errors.Wrapf(err, "parsing ngrok api at %s", tunAPI)
 	}
 
-	if len(t.Tunnels) != 2 {
-		return "", fmt.Errorf("didn't find tunnels that were expected to be created")
+	// Find the tunnel we just created.
+	expAtlantisURL := fmt.Sprintf("localhost:%d", atlantisPort)
+	for _, tun := range t.Tunnels {
+		if tun.Proto == "https" && tun.Config.Addr == expAtlantisURL {
+			return tun.PublicURL, nil
+		}
 	}
 
-	return t.Tunnels[1].PublicURL, nil
+	return "", fmt.Errorf("did not find ngrok tunnel with proto 'https' and config.addr '%s' in list of tunnels at %s", expAtlantisURL, tunAPI)
 }
 
 // nolint: unparam