Config Bootstrapper¶

Status	Implemented
Revision	2026-10-27, skywire f37a464a4
Code	`pkg/deployment/conf`, `pkg/services/confbs`, `deployment`

Abstract¶

The Config Bootstrapper serves the deployment's service configuration. It returns the list of deployment services with their dmsg addresses, the dmsg servers to bootstrap from, and the key lists that visors trust. It publishes the same document as a signed CXO feed.

Overview¶

A visor that has no configuration for the deployment asks the bootstrapper for the services and the dmsg servers it needs to reach them. A running visor subscribes to the CXO feed and so follows changes to the document without a new release. The document served is deployment.Services, which is also embedded in the binary as deployment.Prod.

Addressing¶

The bootstrapper is served over dmsg HTTP at dmsg://<conf-pk>:80. The dmsg port is the service setting dmsg_port, dmsg.DefaultDmsgHTTPPort when 0. The CXO feed is served on dmsg port 78 (skyenv.DmsgConfCXOPort).

Data Formats¶

Services document¶

deployment.Services, the body of GET / and the content of the CXO leaf. Every field is optional in the encoding.

JSON key	Type	Meaning
`dmsg_discovery`, `transport_discovery`, `address_resolver`, `route_finder`, `service_discovery`	string	service addresses
`dmsg_discovery_dmsg`, `transport_discovery_dmsg`, `address_resolver_dmsg`, `route_finder_dmsg`, `service_discovery_dmsg`	string	`dmsg://<pk>:80` addresses of the services
`reward_system`, `reward_system_dmsg`	string	reward system address
`conf_dmsg`	string	address of the bootstrapper
`route_setup_nodes`	[]string	public keys of route setup nodes
`transport_setup`	[]string	public keys of transport setup nodes
`survey_whitelist`	[]string	public keys allowed to read surveys
`stun_servers`	[]string	STUN servers
`dns_server`, `geoip`	string	DNS and geoip addresses
`dmsg_servers`	[]object	`deployment.DmsgServerEntry`: `static` (server key), `server.address`, optional `server.address_ws`
`wss_domain_suffix`, `wss_domain_aliases`, `browse_origin_suffix`, `wasm_module_source`		settings for browser visors

dmsghttp document¶

httputil.DMSGHTTPConf, the body of GET /dmsghttp.

JSON key	Type	Meaning
`dmsg_servers`	[]object	`static` and `server.address` of each server (`httputil.DMSGServersConf`)
`dmsg_discovery`	string	`dmsg://` address of dmsg discovery
`transport_discovery`	string	`dmsg://` address of Transport Discovery
`address_resolver`	string	`dmsg://` address of the Address Resolver
`route_finder`	string	`dmsg://` address of the Route Finder
`service_discovery`	string	`dmsg://` address of Service Discovery

Overrides file¶

The service setting config_path names a JSON file of type api.Config. A missing file, or an empty path, leaves the embedded defaults in place.

JSON key	Type	Replaces
`stun_servers`	[]string	`Services.StunServers`
`route_setup_nodes`	[]string	`Services.RouteSetupNodes`
`survey_whitelist`	[]string	`Services.SurveyWhitelist`
`transport_setup`	[]string	`Services.TransportSetupPKs`

A field absent from the file keeps its default.

Interfaces¶

HTTP API¶

None of the routes requires authentication.

Method and path	Response
`GET /`	200 with the `deployment.Services` document
`GET /dmsghttp`	200 with the `httputil.DMSGHTTPConf` document
`GET /health`	200 with `service_name` `config-bootstrapper`, `build_info`, `started_at`, `dmsg_address`

CXO Feeds¶

The publisher (api.ServicesCXOPublisher) serves one feed on dmsg port 78, signed by the bootstrapper's key. The leaf services/current (deployment.ServicesCXOPath) holds the gzipped JSON of the Services document that GET / returns. The publisher compares the document with the last one it published every minute (servicesPublishInterval) and publishes only when it changed. The feed is open to any subscriber, and its sequence prevents an older document from replacing a newer one.

Behaviour¶

The served document starts as deployment.Prod, with the overrides applied. The dmsg_servers list is refreshed from dmsg discovery at start and then every 5 minutes (dmsgServersRefreshInterval), by reading /dmsg-discovery/all_servers. If the answer is empty or the request fails, the previous list is kept.

GET /dmsghttp builds its document from the *_dmsg addresses of the services document and from the current server list. The result is cached for 5 minutes.

Security Considerations¶

The document is public. Visors that use it trust the dmsg identity of the bootstrapper and, for the CXO feed, the signature of its key. The document carries the keys that visors trust for route setup, transport setup and surveys, so these are changed at the bootstrapper.

References¶

Skywire Visor
Service Discovery