instrumentation: add telemetry around failures (#207)

This will start collecting errors. We can continue tweaking this, but
this will get us to the basics at least.

== In scope:
- Reporting the Go version
- Reporting the OS type
- Reproting the architecture (e.g. amd64)

== Out of scope:
- Discerning the different error types we have. For now, any errors will
  get sent.

.github/workflows/goreleaser.yml

@@ -19,6 +19,13 @@ jobs:
         with:
           go-version: 1.16
 
+      - name: Prepare instrumentation
+        run: |
+          echo -n "$SENTRY_DSN" >> $GITHUB_WORKSPACE/internal/instrumentation/sentry_dsn
+        shell: bash
+        env:
+          SENTRY_DSN : ${{secrets.SENTRY_DSN}}
+
       - name: Run GoReleaser
         uses: goreleaser/[email protected]
         with:

go.mod

@@ -9,6 +9,7 @@ require (
 	github.com/briandowns/spinner v1.12.0
 	github.com/charmbracelet/glamour v0.2.0
 	github.com/fatih/color v1.10.0 // indirect
+	github.com/getsentry/sentry-go v0.10.0
 	github.com/golang/mock v1.5.0
 	github.com/golang/snappy v0.0.3 // indirect
 	github.com/google/go-cmp v0.5.5

internal/cli/root.go

@@ -2,10 +2,12 @@ package cli
 
 import (
 	"context"
+	"fmt"
 	"os"
 
 	"github.com/auth0/auth0-cli/internal/buildinfo"
 	"github.com/auth0/auth0-cli/internal/display"
+	"github.com/auth0/auth0-cli/internal/instrumentation"
 	"github.com/spf13/cobra"
 )
 
@@ -93,9 +95,18 @@ func Execute() {
 	// rootCmd.AddCommand(actionsCmd(cli))
 	// rootCmd.AddCommand(triggersCmd(cli))
 
+	defer func() {
+		if v := recover(); v != nil {
+			err := fmt.Errorf("panic: %v", v)
+			instrumentation.ReportException(err)
+		}
+	}()
+
 	if err := rootCmd.ExecuteContext(context.TODO()); err != nil {
 		cli.renderer.Heading("error")
 		cli.renderer.Errorf(err.Error())
+
+		instrumentation.ReportException(err)
 		os.Exit(1)
 	}
 }

internal/instrumentation/instrumentation.go

@@ -0,0 +1,29 @@
+package instrumentation
+
+import (
+	_ "embed"
+	"time"
+
+	"github.com/getsentry/sentry-go"
+)
+
+//go:embed sentrydsn.txt
+var sentryDSN string
+
+// ReportException is designed to be called once as the CLI exits. We're
+// purposefully initializing a client all the time given this context.
+func ReportException(err error) {
+	if sentryDSN == "" {
+		return
+	}
+
+	if err := sentry.Init(sentry.ClientOptions{Dsn: sentryDSN}); err != nil {
+		return
+	}
+
+	// Flush buffered events before the program terminates.
+	sentry.CaptureException(err)
+
+	// Allow up to 2s to flush, otherwise quit.
+	sentry.Flush(2 * time.Second)
+}