Local Development Server Options

The local development server (dev_appserver.py) is part of the App Engine components of the gcloud CLI. This topic provides advanced information about the dev_appserver.py usage. See Using the Local Development Server for more information about local testing.

Set up the local development server tool

A sample dev_appserver.py command might look as follows:

python2 DEVAPPSERVER_ROOT/google_appengine/dev_appserver.py OPTION yaml_path FILES

Replace the following:

  • DEVAPPSERVER_ROOT with the path to the root directory where you extract the archived version of devapp_server.py. For more information about downloading and using the archived version of dev_appserver.py, see Using the local development server.
  • OPTION with a flag supported by the local development server.
  • FILES specifies one or more app.yaml files, one per service, for the positional argument yaml_path.

For a complete list of options, run the following:

DEVAPPSERVER_ROOT/google_appengine/dev_appserver.py -h

Common options

The most common options are as follows:

--admin_host=ADMIN_HOST
Host name to which the local development server's administration console should bind (default: localhost).
--admin_port=ADMIN_PORT
Port to which the local development server's administration console should bind (default: 8000).
--enable_sendmail=yes|no
Uses the local computer's Sendmail installation for sending email messages.
--enable_task_running=yes|no
Enables the development server to run push tasks. The default is yes. If you specify no, the server will not run push tasks.
--help
Prints a helpful message then quits.
--host=...
The host address to use for the server. You may need to set this to be able to access the development server from another computer on your network. An address of 0.0.0.0 allows both localhost access and IP or hostname access. Default is localhost.
--log_level=...
The lowest logging level at which logging messages will be written to the console; messages of the specified logging level or higher will be output. Possible values are debug, info, warning, error, and critical.
--port=...
The port number to use for the server. Default is 8080. If multiple servers are launched such as for services, they will be assigned subsequent ports, such as 8081, 8082.
--logs_path=...
By default, the logs for the local development server are stored in memory only. Specify this option when you run the local development server to store the logs into a file, which makes the logs available across server restarts. You must specify the directory path and name to a SQLite database file. A SQLite database file is created with the specified name if the file does not already exist. For example: --logs_path=/home/logs/boglogs.db
--require_indexes=yes|no
Disables automatic generation of entries in the index.yaml file. Instead, when the application makes a query that requires that its index be defined in the file and the index definition is not found, an exception will be raised, similar to what would happen when running on App Engine. The default value is no.
--runtime_python_path=...
The path to your Python 3 binary. To run a Python 3 app on the dev_appserver, specify this flag.
--smtp_host=...
The hostname of the SMTP server to use for sending email messages.
--smtp_port=...
The port number of the SMTP server to use for sending email messages.
--smtp_user=...
The username to use with the SMTP server for sending email messages.
--smtp_password=...
The password to use with the SMTP server for sending email messages.
--storage_path=...
Path at which all local files, such as the Datastore, Blobstore, Cloud Storage files and logs, will be stored, unless overridden by --datastore_path, --blobstore_path, or --logs_path.
--support_datastore_emulator=yes|no
Use the Cloud Datastore Emulator (beta) for local datastore emulation.
--datastore_emulator_port=...
The port number to use for Cloud Datastore Emulator (beta).
--env_var=...
User defined environment variable for the local runtime process. Each env_var is in the format of key=value, and you can define multiple environment variables. In addition to env_variables in the app.yaml, this flag allows setting extra environment variables for local processes. For example:--env_var KEY_1=val1 --env_var KEY_2=val2