Add template build time stats (#4557)

- Expose time in Template pages
- Show progress bar when building a workspace

coderd/database/queries.sql.go

@@ -2597,6 +2597,42 @@ func (q *sqlQuerier) InsertDeploymentID(ctx context.Context, value string) error
 	return err
 }
 
+const getTemplateAverageBuildTime = `-- name: GetTemplateAverageBuildTime :one
+WITH build_times AS (
+SELECT
+	EXTRACT(EPOCH FROM (pj.completed_at - pj.started_at))::FLOAT AS exec_time_sec
+FROM
+	workspace_builds
+JOIN template_versions ON
+	workspace_builds.template_version_id = template_versions.id
+JOIN provisioner_jobs pj ON
+	workspace_builds.job_id = pj.id
+WHERE
+	template_versions.template_id = $1 AND
+		(workspace_builds.transition = 'start') AND
+		(pj.completed_at IS NOT NULL) AND (pj.started_at IS NOT NULL) AND
+		(pj.started_at > $2) AND
+		(pj.canceled_at IS NULL) AND
+		((pj.error IS NULL) OR (pj.error = ''))
+ORDER BY
+	workspace_builds.created_at DESC
+)
+SELECT coalesce((PERCENTILE_DISC(0.5) WITHIN GROUP(ORDER BY exec_time_sec)), -1)::FLOAT
+FROM build_times
+`
+
+type GetTemplateAverageBuildTimeParams struct {
+	TemplateID uuid.NullUUID `db:"template_id" json:"template_id"`
+	StartTime  sql.NullTime  `db:"start_time" json:"start_time"`
+}
+
+func (q *sqlQuerier) GetTemplateAverageBuildTime(ctx context.Context, arg GetTemplateAverageBuildTimeParams) (float64, error) {
+	row := q.db.QueryRowContext(ctx, getTemplateAverageBuildTime, arg.TemplateID, arg.StartTime)
+	var column_1 float64
+	err := row.Scan(&column_1)
+	return column_1, err
+}
+
 const getTemplateByID = `-- name: GetTemplateByID :one
 SELECT
 	id, created_at, updated_at, organization_id, deleted, name, provisioner, active_version_id, description, max_ttl, min_autostart_interval, created_by, icon, user_acl, group_acl