Merge pull request #16 from uselagoon/spinner

feat: show a spinner during ssh connection

.goreleaser.yml

@@ -10,7 +10,8 @@ builds:
   - CGO_ENABLED=0
   goarch:
   - amd64
-  - arm64
+  goos:
+  - linux
 - id: ssh-portal
   dir: cmd/ssh-portal
   binary: ssh-portal
@@ -22,4 +23,5 @@ builds:
   - CGO_ENABLED=0
   goarch:
   - amd64
-  - arm64
+  goos:
+  - linux

internal/k8s/client.go

@@ -17,7 +17,7 @@ import (
 	"k8s.io/client-go/tools/remotecommand"
 )
 
-var (
+const (
 	timeout            = 90 * time.Second
 	projectIDLabel     = "lagoon.sh/projectId"
 	environmentIDLabel = "lagoon.sh/environmentId"
@@ -140,20 +140,29 @@ func (c *Client) ensureScaled(ctx context.Context, deployment, namespace string)
 		c.hasRunningPod(ctx, deployment, namespace))
 }
 
-// Exec joins the given streams to the command or, if command is empty, to a
-// shell running in the given pod.
-func (c *Client) Exec(ctx context.Context, deployment, namespace string,
-	command []string, stdio io.ReadWriter, stderr io.Writer, tty bool) error {
+// getExecutor prepares the environment by ensuring pods are scaled etc. and
+// returns an executor object.
+func (c *Client) getExecutor(ctx context.Context, deployment, namespace string,
+	command []string, stdio io.ReadWriter, stderr io.Writer, tty bool) (remotecommand.Executor, error) {
+	// If there's a tty, then animate a spinner if this function takes too long
+	// to return.
+	// Defer context cancel() after wg.Wait() because we need the context to
+	// cancel first in order to shortcut spinAfter() and avoid a spinner if shell
+	// acquisition is fast enough.
 	ctx, cancel := context.WithTimeout(ctx, timeout)
+	if tty {
+		wg := spinAfter(ctx, stderr, 2*time.Second)
+		defer wg.Wait()
+	}
 	defer cancel()
 	// ensure the deployment has at least one replica
 	if err := c.ensureScaled(ctx, deployment, namespace); err != nil {
-		return fmt.Errorf("couldn't scale deployment: %v", err)
+		return nil, fmt.Errorf("couldn't scale deployment: %v", err)
 	}
 	// get the name of the first pod in the deployment
 	podName, err := c.podName(ctx, deployment, namespace)
 	if err != nil {
-		return fmt.Errorf("couldn't get pod name: %v", err)
+		return nil, fmt.Errorf("couldn't get pod name: %v", err)
 	}
 	// check the command. if there isn't one, give the user a shell.
 	if len(command) == 0 {
@@ -173,9 +182,17 @@ func (c *Client) Exec(ctx context.Context, deployment, namespace string,
 		scheme.ParameterCodec,
 	)
 	// construct the executor
-	exec, err := remotecommand.NewSPDYExecutor(c.config, "POST", req.URL())
+	return remotecommand.NewSPDYExecutor(c.config, "POST", req.URL())
+}
+
+// Exec joins the given streams to the command or, if command is empty, to a
+// shell running in the given pod.
+func (c *Client) Exec(ctx context.Context, deployment, namespace string,
+	command []string, stdio io.ReadWriter, stderr io.Writer, tty bool) error {
+	exec, err := c.getExecutor(ctx, deployment, namespace, command, stdio,
+		stderr, tty)
 	if err != nil {
-		return err
+		return fmt.Errorf("couldn't get executor: %v", err)
 	}
 	// execute the command
 	return exec.Stream(remotecommand.StreamOptions{

internal/k8s/spin.go

@@ -0,0 +1,58 @@
+package k8s
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"sync"
+	"time"
+)
+
+const (
+	framerate = 50 * time.Millisecond
+)
+
+var (
+	charset = []string{`|`, `/`, `-`, `\`}
+)
+
+// spinAfter will wait for the given time period and if the given context is
+// not cancelled will start animating a spinner on w until the given context
+// is cancelled.
+//
+// If the given context is cancelled before the wait duration, nothing is
+// written to w.
+//
+// The returned *sync.WaitGroup should be waited on to ensure the spinner
+// finishes cleaning up the animation.
+func spinAfter(ctx context.Context, w io.Writer, wait time.Duration) *sync.WaitGroup {
+	var wg sync.WaitGroup
+	wt := time.NewTimer(wait)
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		select {
+		case <-ctx.Done():
+		case <-wt.C:
+			spin(ctx, w)
+		}
+	}()
+	return &wg
+}
+
+// spin animates a spinner on w until ctx is cancelled.
+func spin(ctx context.Context, w io.Writer) {
+	for {
+		select {
+		case <-ctx.Done():
+			// https://en.wikipedia.org/wiki/ANSI_escape_code#CSI_(Control_Sequence_Introducer)_sequences
+			fmt.Fprint(w, "\033[2K")
+			return
+		default:
+			for _, char := range charset {
+				fmt.Fprintf(w, "%s getting you a shell\r", char)
+				time.Sleep(framerate)
+			}
+		}
+	}
+}