docs/root/configuration/overview/bootstrap.rst
.. _config_overview_bootstrap:
To use the xDS API, it's necessary to supply a bootstrap configuration file. This
provides static server configuration and configures Envoy to access :ref:dynamic configuration if needed <arch_overview_dynamic_config>. This is supplied on the command-line via
the :option:-c flag, i.e.:
.. code-block:: console
./envoy -c <path to config>.{json,yaml,pb,pb_text}
where the extension reflects the underlying config representation.
The :ref:Bootstrap <envoy_v3_api_msg_config.bootstrap.v3.Bootstrap> message is the root of the
configuration. A key concept in the :ref:Bootstrap <envoy_v3_api_msg_config.bootstrap.v3.Bootstrap>
message is the distinction between static and dynamic resources. Resources such
as a :ref:Listener <envoy_v3_api_msg_config.listener.v3.Listener> or :ref:Cluster <envoy_v3_api_msg_config.cluster.v3.Cluster> may be supplied either statically in
:ref:static_resources <envoy_v3_api_field_config.bootstrap.v3.Bootstrap.static_resources> or have
an xDS service such as :ref:LDS <config_listeners_lds> or :ref:CDS <config_cluster_manager_cds> configured in
:ref:dynamic_resources <envoy_v3_api_field_config.bootstrap.v3.Bootstrap.dynamic_resources>.