This lets the 'childhurd' service start in the background, letting
shepherd perform other tasks in the meantime, including serving
clients (such as the 'herd' command).
* gnu/build/secret-service.scm (with-modules): New macro.
(wait-for-readable-fd): Add cooperative implementation when Fibers is in
use.
(secret-service-send-secrets): Define 'sleep' so that it cooperates when
Fibers is in use.
* gnu/services/virtualization.scm (secret-service-activation): Remove.
(secret-service-shepherd-services): New procedure.
(secret-service-type)[extensions]: Remove ACTIVATION-SERVICE-TYPE
extension. Add SHEPHERD-ROOT-SERVICE-TYPE and
USER-PROCESSES-SERVICE-TYPE extensions.
* gnu/build/secret-service.scm (delete-file*): New procedure.
(secret-service-receive-secrets): Use it.
This allows the client running on the host to know when it's actually
connect to the server running in the guest. Failing that, the client
would connect right away to QEMU and send secrets even though the server
is not running yet in the guest, which is unreliable.
* gnu/build/secret-service.scm (secret-service-send-secrets): Add
#:handshake-timeout. Read from SOCK an initial message from the
server. Return #f on error.
(secret-service-receive-secrets): Send 'secret-service-server' message
to the client. Close SOCK upon timeout.
* gnu/services/virtualization.scm (hurd-vm-shepherd-service): 'start'
method returns #f when 'secret-service-send-secrets' returns #f.
* gnu/build/secret-service.scm (secret-service-receive-secrets)
[wait-for-client]: Call 'select' with a 60s timeout before 'accept'.
Return #f upon timeout.
[read-secrets]: Return FILES on success.
Adjust caller of 'wait-for-client' to handle #f.
This adds a "secret-service" that can be added to a Childhurd VM to receive
out-of-band secrets (keys) sent from the host.
Co-authored-by: Ludovic Courtès <ludo@gnu.org>
* gnu/services/virtualization.scm (secret-service-activation): New procedure.
(secret-service-type): New variable.
* gnu/build/secret-service.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add it.
