Bootstrap configuration

To use the xDS API, it’s necessary to supply a bootstrap configuration file. This provides static server configuration and configures Envoy to access dynamic configuration if needed. This is supplied on the command-line via the -c flag, i.e.:

./envoy -c <path to config>.{json,yaml,pb,pb_text}

where the extension reflects the underlying config representation.

The Bootstrap message is the root of the configuration. A key concept in the Bootstrap message is the distinction between static and dynamic resources. Resources such as a Listener or Cluster may be supplied either statically in static_resources or have an xDS service such as LDS or CDS configured in dynamic_resources.