Provide a way to update to the new agent build config format (#3181)

datadog_checks_dev/datadog_checks/dev/tooling/commands/env/start.py

@@ -81,10 +81,11 @@ def start(ctx, check, env, agent, dev, base):
     agent_ver = ctx.obj.get('agent{}'.format(agent), agent)
     if isinstance(agent_ver, string_types):
         agent_build = agent_ver
-        echo_warning(
-            'Agent fields missing from ddev config, please update to the latest config, '
-            'falling back to latest docker image...'
-        )
+        if agent_ver != agent:
+            echo_warning(
+                'Agent fields missing from ddev config, please update to the latest config via '
+                '`ddev config update`, falling back to latest docker image...'
+            )
     else:
         agent_build = agent_ver.get(env_type, env_type)
 

datadog_checks_dev/datadog_checks/dev/tooling/config.py

@@ -95,6 +95,19 @@ def restore_config():
 def update_config():
     config = copy_default_config()
     config.update(load_config())
+
+    # Support legacy config where agent5 and agent6 were strings
+    if isinstance(config['agent6'], string_types):
+        config['agent6'] = OrderedDict((
+            ('docker', config['agent6']),
+            ('local', 'latest'),
+        ))
+    if isinstance(config['agent5'], string_types):
+        config['agent5'] = OrderedDict((
+            ('docker', config['agent5']),
+            ('local', 'latest'),
+        ))
+
     save_config(config)
     return config