From a5197840dfa4fd3925b508614bc4b46bf01e9bef Mon Sep 17 00:00:00 2001
From: Matthew Hooker <mwhooker@gmail.com>
Date: Thu, 2 Nov 2017 23:45:01 -0700
Subject: [PATCH] add config key reporting

---
 packer/telemetry.go      | 39 +++++++++++++++++++++++++++++----------
 packer/telemetry_test.go | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 61 insertions(+), 10 deletions(-)
 create mode 100644 packer/telemetry_test.go

diff --git a/packer/telemetry.go b/packer/telemetry.go
index 60005e606..f413dd34a 100644
--- a/packer/telemetry.go
+++ b/packer/telemetry.go
@@ -91,16 +91,11 @@ func (c *CheckpointTelemetry) AddSpan(name, pluginType string, options interface
 	}
 	log.Printf("[INFO] (telemetry) Starting %s %s", pluginType, name)
 
-	//strOpts := []string{}
-	if m, ok := options.(map[string]interface{}); ok {
-		for k, _ := range m {
-			log.Println("AddSpan options:", k)
-		}
-	}
 	ts := &TelemetrySpan{
 		Name:      name,
-		Type:      pluginType,
+		Options:   flattenConfigKeys(options),
 		StartTime: time.Now().UTC(),
+		Type:      pluginType,
 	}
 	c.spans = append(c.spans, ts)
 	return ts
@@ -123,6 +118,8 @@ func (c *CheckpointTelemetry) Finalize(command string, errCode int, err error) e
 		extra.Error = err.Error()
 	}
 	params.Payload = extra
+	// b, _ := json.MarshalIndent(params, "", "    ")
+	// log.Println(string(b))
 
 	ctx, cancel := context.WithTimeout(context.Background(), 1500*time.Millisecond)
 	defer cancel()
@@ -132,12 +129,12 @@ func (c *CheckpointTelemetry) Finalize(command string, errCode int, err error) e
 }
 
 type TelemetrySpan struct {
-	Name      string    `json:"name"`
-	Type      string    `json:"type"`
-	StartTime time.Time `json:"start_time"`
 	EndTime   time.Time `json:"end_time"`
 	Error     string    `json:"error"`
+	Name      string    `json:"name"`
 	Options   []string  `json:"options"`
+	StartTime time.Time `json:"start_time"`
+	Type      string    `json:"type"`
 }
 
 func (s *TelemetrySpan) End(err error) {
@@ -151,3 +148,25 @@ func (s *TelemetrySpan) End(err error) {
 		log.Printf("[INFO] (telemetry) found error: %s", err.Error())
 	}
 }
+
+func flattenConfigKeys(options interface{}) []string {
+	var flatten func(string, interface{}) []string
+
+	flatten = func(prefix string, options interface{}) (strOpts []string) {
+		if m, ok := options.(map[string]interface{}); ok {
+			for k, v := range m {
+				if prefix != "" {
+					k = prefix + "/" + k
+				}
+				if n, ok := v.(map[string]interface{}); ok {
+					strOpts = append(strOpts, flatten(k, n)...)
+				} else {
+					strOpts = append(strOpts, k)
+				}
+			}
+		}
+		return
+	}
+
+	return flatten("", options)
+}
diff --git a/packer/telemetry_test.go b/packer/telemetry_test.go
new file mode 100644
index 000000000..c4192f61f
--- /dev/null
+++ b/packer/telemetry_test.go
@@ -0,0 +1,32 @@
+package packer
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestFlattenConfigKeys_nil(t *testing.T) {
+	f := flattenConfigKeys(nil)
+	assert.Zero(t, f, "Expected empty list.")
+}
+
+func TestFlattenConfigKeys_nested(t *testing.T) {
+	inp := make(map[string]interface{})
+	inp["A"] = ""
+	inp["B"] = []string{}
+
+	c := make(map[string]interface{})
+	c["X"] = ""
+	d := make(map[string]interface{})
+	d["a"] = ""
+
+	c["Y"] = d
+	inp["C"] = c
+
+	assert.Equal(t,
+		[]string{"A", "B", "C/X", "C/Y/a"},
+		flattenConfigKeys(inp),
+		"Input didn't flatten correctly.",
+	)
+}