Checkin will connect to pilot and retrieve initial configuration data needed to start envoy.

GetHostPort separates out the host and port portions of an address.

RunProxy will run sidecar with a v2 config generated from template according with the config.

StoreHostPort encodes the host and port as key/value pair strings in the provided map.

WriteBootstrap generates an envoy config based on config and epoch, and returns the filename.

Generate the envoy v2 bootstrap configuration, using template.

EpochFileTemplate is a template for the root config JSON.

TODO: use MeshConfig.StatNameLength instead.

IstioCertDir is the location of istio certificates.

PilotSAN is the DNS name included in the pilot certificate.

CheckinData has data provided by Pilot needed to start and prepare envoy.