From f3bf33da27cb70a8cc14053eaaeb5a64b8c94c61 Mon Sep 17 00:00:00 2001
From: shreyas-goenka <88374338+shreyas-goenka@users.noreply.github.com>
Date: Fri, 1 Nov 2024 19:38:09 +0530
Subject: [PATCH] Add `cmd-exec-id` to user agent (#1808)

## Changes

This PR adds the `cmd-exec-id` field to the user agent. This allows us
to correlate multiple HTTP requests made from the CLI.

### Why Not Use HTTP traceparent?
We considered using the traceparent header in HTTP as an alternative,
but it's not a good fit for our use case. Here's why:
1. Purpose of traceparent: It's designed to trace a single HTTP request
across a distributed system as it moves through subsystems and proxies.
2. Our requirement: We need to trace multiple HTTP requests made during
a single command execution in the CLI.

For more details about how traceparent itself works and how it's used in
the Go SDK, see
https://github.com/databricks/databricks-sdk-go/pull/914.

## Tests
Unit test
---
 cmd/root/root.go                            |  1 +
 cmd/root/user_agent_command_exec_id.go      | 14 +++++++++++
 cmd/root/user_agent_command_exec_id_test.go | 26 +++++++++++++++++++++
 cmd/root/user_agent_command_test.go         |  9 ++++++-
 4 files changed, 49 insertions(+), 1 deletion(-)
 create mode 100644 cmd/root/user_agent_command_exec_id.go
 create mode 100644 cmd/root/user_agent_command_exec_id_test.go

diff --git a/cmd/root/root.go b/cmd/root/root.go
index eda873d1..7059586f 100644
--- a/cmd/root/root.go
+++ b/cmd/root/root.go
@@ -75,6 +75,7 @@ func New(ctx context.Context) *cobra.Command {
 
 		// Configure our user agent with the command that's about to be executed.
 		ctx = withCommandInUserAgent(ctx, cmd)
+		ctx = withCommandExecIdInUserAgent(ctx)
 		ctx = withUpstreamInUserAgent(ctx)
 		cmd.SetContext(ctx)
 		return nil
diff --git a/cmd/root/user_agent_command_exec_id.go b/cmd/root/user_agent_command_exec_id.go
new file mode 100644
index 00000000..3bf32b70
--- /dev/null
+++ b/cmd/root/user_agent_command_exec_id.go
@@ -0,0 +1,14 @@
+package root
+
+import (
+	"context"
+
+	"github.com/databricks/databricks-sdk-go/useragent"
+	"github.com/google/uuid"
+)
+
+func withCommandExecIdInUserAgent(ctx context.Context) context.Context {
+	// A UUID that will allow us to correlate multiple API requests made by
+	// the same CLI invocation.
+	return useragent.InContext(ctx, "cmd-exec-id", uuid.New().String())
+}
diff --git a/cmd/root/user_agent_command_exec_id_test.go b/cmd/root/user_agent_command_exec_id_test.go
new file mode 100644
index 00000000..5c436510
--- /dev/null
+++ b/cmd/root/user_agent_command_exec_id_test.go
@@ -0,0 +1,26 @@
+package root
+
+import (
+	"context"
+	"regexp"
+	"testing"
+
+	"github.com/databricks/databricks-sdk-go/useragent"
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestWithCommandExecIdInUserAgent(t *testing.T) {
+	ctx := withCommandExecIdInUserAgent(context.Background())
+
+	// Check that the command exec ID is in the user agent string.
+	ua := useragent.FromContext(ctx)
+	re := regexp.MustCompile(`cmd-exec-id/([a-f0-9-]+)`)
+	matches := re.FindAllStringSubmatch(ua, -1)
+
+	// Assert that we have exactly one match and that it's a valid UUID.
+	require.Len(t, matches, 1)
+	_, err := uuid.Parse(matches[0][1])
+	assert.NoError(t, err)
+}
diff --git a/cmd/root/user_agent_command_test.go b/cmd/root/user_agent_command_test.go
index 9620bb5b..a3f5bbcb 100644
--- a/cmd/root/user_agent_command_test.go
+++ b/cmd/root/user_agent_command_test.go
@@ -1,13 +1,15 @@
 package root
 
 import (
+	"context"
 	"testing"
 
+	"github.com/databricks/databricks-sdk-go/useragent"
 	"github.com/spf13/cobra"
 	"github.com/stretchr/testify/assert"
 )
 
-func TestCommandString(t *testing.T) {
+func TestWithCommandInUserAgent(t *testing.T) {
 	root := &cobra.Command{
 		Use: "root",
 	}
@@ -26,4 +28,9 @@ func TestCommandString(t *testing.T) {
 	assert.Equal(t, "root", commandString(root))
 	assert.Equal(t, "hello", commandString(hello))
 	assert.Equal(t, "hello_world", commandString(world))
+
+	ctx := withCommandInUserAgent(context.Background(), world)
+
+	ua := useragent.FromContext(ctx)
+	assert.Contains(t, ua, "cmd/hello_world")
 }