bugfix: Initialize metrics with empty tags (#2847)

* Initialize metrics with empty tags

* Better name for Project tags

* No need for dedicated set scope tags on metrics

server/events/command/project_context.go

@@ -98,20 +98,23 @@ type ProjectContext struct {
 	ExecutionOrderGroup int
 }
 
-// SetScopeTags adds ProjectContext tags to a new returned scope.
-func (p ProjectContext) SetScopeTags(scope tally.Scope) tally.Scope {
+// SetProjectScopeTags adds ProjectContext tags to a new returned scope.
+func (p ProjectContext) SetProjectScopeTags(scope tally.Scope) tally.Scope {
 	v := ""
 	if p.TerraformVersion != nil {
 		v = p.TerraformVersion.String()
 	}
-	return scope.Tagged(map[string]string{
-		"base_repo":         p.BaseRepo.FullName,
-		"pr_number":         strconv.Itoa(p.Pull.Num),
-		"project":           p.ProjectName,
-		"project_path":      p.RepoRelDir,
-		"terraform_version": v,
-		"workspace":         p.Workspace,
-	})
+
+	tags := ProjectScopeTags{
+		BaseRepo:         p.BaseRepo.FullName,
+		PrNumber:         strconv.Itoa(p.Pull.Num),
+		Project:          p.ProjectName,
+		ProjectPath:      p.RepoRelDir,
+		TerraformVersion: v,
+		Workspace:        p.Workspace,
+	}
+
+	return scope.Tagged(tags.Loadtags())
 }
 
 // GetShowResultFileName returns the filename (not the path) to store the tf show result

server/events/command/scope_tags.go

@@ -0,0 +1,38 @@
+package command
+
+import (
+	"reflect"
+	"regexp"
+	"strings"
+)
+
+type ProjectScopeTags struct {
+	BaseRepo         string
+	PrNumber         string
+	Project          string
+	ProjectPath      string
+	TerraformVersion string
+	Workspace        string
+}
+
+func (s ProjectScopeTags) Loadtags() map[string]string {
+	tags := make(map[string]string)
+
+	v := reflect.ValueOf(s)
+	t := v.Type()
+
+	for i := 0; i < v.NumField(); i++ {
+		tags[toSnakeCase(t.Field(i).Name)] = v.Field(i).String()
+	}
+
+	return tags
+}
+
+func toSnakeCase(str string) string {
+	var matchFirstCap = regexp.MustCompile("(.)([A-Z][a-z]+)")
+	var matchAllCap = regexp.MustCompile("([a-z0-9])([A-Z])")
+
+	snake := matchFirstCap.ReplaceAllString(str, "${1}_${2}")
+	snake = matchAllCap.ReplaceAllString(snake, "${1}_${2}")
+	return strings.ToLower(snake)
+}

server/events/instrumented_project_command_runner.go

@@ -19,7 +19,8 @@ type InstrumentedProjectCommandRunner struct {
 }
 
 func NewInstrumentedProjectCommandRunner(scope tally.Scope, projectCommandRunner ProjectCommandRunner) *InstrumentedProjectCommandRunner {
-	scope = scope.SubScope("project")
+	projectTags := command.ProjectScopeTags{}
+	scope = scope.Tagged(projectTags.Loadtags())
 
 	for _, m := range []string{metrics.ExecutionSuccessMetric, metrics.ExecutionErrorMetric, metrics.ExecutionFailureMetric} {
 		metrics.InitCounter(scope, m)
@@ -49,7 +50,7 @@ func (p *InstrumentedProjectCommandRunner) ApprovePolicies(ctx command.ProjectCo
 
 func RunAndEmitStats(commandName string, ctx command.ProjectContext, execute func(ctx command.ProjectContext) command.ProjectResult, scope tally.Scope) command.ProjectResult {
 	// ensures we are differentiating between project level command and overall command
-	scope = ctx.SetScopeTags(scope)
+	scope = ctx.SetProjectScopeTags(scope)
 	logger := ctx.Log
 
 	executionTime := scope.Timer(metrics.ExecutionTimeMetric).Start()

server/events/project_command_context_builder.go

@@ -78,7 +78,7 @@ func (cb *CommandScopedStatsProjectCommandContextBuilder) BuildProjectContext(
 		// specifically use the command name in the context instead of the arg
 		// since we can return multiple commands worth of contexts for a given command name arg
 		// to effectively pipeline them.
-		cmd.Scope = cmd.SetScopeTags(cmd.Scope)
+		cmd.Scope = cmd.SetProjectScopeTags(cmd.Scope)
 		projectCmds = append(projectCmds, cmd)
 	}