Updates for new
x509API and for OCaml 4.06 (#143).
Add some diagrams to the tutorial (#134).
Add FAQ: how can I import a sturdy ref that I need to start my vat? (#137)
Add build dependency on conf-capnproto (#146). Projects using the schema compiler themselves should also now add this dependency instead of relying on
capnpto pull it in.
Remove generics from persistent.capnp (#141) so that it compiles on systems with older capnproto compilers (e.g. Ubuntu 14.04).
Fmt.failwith, which requires fmt.0.8.4 (#139).
Uri.with_userinfo, which is only in
uri>= 1.6.0 (#138).
Move test-lwt to unix module (#133).
This release adds a new
capnp-rpc-mirage package, which provides support for
using the library within a MirageOS unikernel.
See https://github.com/mirage/capnp-rpc#how-can-i-use-this-with-mirage for details.
There are a few minor API changes:
Capnp_rpc_unix.Vat_config.derived_id ?name configis now
Capnp_rpc_unix.Vat_config.derived_id config name.
If you weren't passing a
~nameargument before, use
"main"to get the same ID.
Socket_addressmodule is now called
There is an explicit network parameter in
This is needed to support Mirage, where the network isn't a global.
Fix race when reconnecting.
We notified the user that the capability had broken while
the old connection was still shutting down.
If they immediately tried to reconnect, we tried to reuse the old connection.
Now, we wait for it to be removed.
Fix handling of leaks in switchable.
If we detected the ref-count was invalid, we tried to resolve to an error,
but resolving now checks that the ref-count is valid first so this failed.
Documentation and examples:
Fixed ref-counting bug in calculator example.
Also, changed the service ID to match what the C++ client expects.
With these changes, the C++ client's tests pass when used with the OCaml service.
Also test answering questions with errors or with a promise from another question.
Use a better way to get the client certificate from a TLS connection
(suggested by @hannesm).
capnp://URI handling to
This allows it to be shared with the Mirage code.
Capnp_rpc_lwt.VAT_NETWORKwith simpler signature than
The address sub-module of
S.NETWORKis now available separately as
0.2 Persistence, encryption and access control
This release brings support for RPC Level 2.
The API for implementing services and clients is mostly unchanged,
but the APIs for setting up networking are very different.
If you read the tutorial with the 0.1 release, you will probably
want to read the new version again from the "Networking" point
The main change is that when connecting to a service you now give a URI of the form:
The client will connect to
address, check the server's public key matches
and then pass the (secret)
service ID to get access to a particular service.
The server will typically display the URI to use on start-up, or write it to a file.
The communications are encrypted using TLS.
If you want to disable TLS, use the form
This should only be needed for interoperability with non-TLS services,
as the system will generate keys and certificates automatically,
making secure use just as easy as the non-secure case.
The other major new feature is support for persistent services.
In version 0.1 you could specify an
offer argument when creating a vat,
telling it a service to provide in response to bootstrap requests.
Now, you pass a
restore argument, which can restore different services
depending on the service ID provided by the client.
Restorer.Table module provides a table-based lookup restorer,
to which services can be added dynamically.
If you have a lot of services and don't want to add them all at startup,
you can use
Restorer.Table.of_loader and provide your own function for loading services.
The tutorial has been extended and a FAQ added.
The recommended layout of protocol files has changed.
Clientsub-module is gone, and
The examples now have
.mlifiles and there is a new
store.mlexample demonstrating persistence.
The examples have been updated to the new layout convention.
Main API changes:
Capnp_rpc_lwt.Capabilitymodule adds some useful functions:
brokencreates a broken capability.
when_brokenallows you to be notified when a capability breaks (e.g. because of a network failure).
wait_until_settledwaits until a promise has resolved, if you don't want to pipeline (e.g. you want to send a large amount of data, so prefer to find out where the service is and avoid any forwarding).
equaltests if two capabilities designate the same service.
Capnp_rpc_lwt.Sturdy_refmodule provides an abstraction for off-line capabilities.
Sturdy_ref.connectcan be used to get a live connection.
If you try to connect to multiple services in the same vat, it will share a single connection automatically.
Sturdy_ref.buildercan be used for passing sturdy refs in messages.
Capnp_rpc_lwt.Restorermodule is used to implement sturdy-refs at the hosting side.
Capnp_rpc_lwt.Persistencemodule provides support for the Cap'n Proto persistence protocol.
Persistence.saveto request a sturdy ref from a service, and
services can use
Persistence.with_sturdy_refto answer such requests automatically.
Capnp_rpc_unix.Vat_configcollects together all vat configuration in one place.
Capnp_rpc_unix.File_storecan store Cap'n Proto structs in a directory.
It can be useful when implementing persistence.
Capnp_rpc_lwt.Authmodule provides support for generating and handling secret keys and fingerprints.
Capnp_rpc_lwt.Tls_wrapperprovides support for doing TLS handshakes, with authentication and encryption.
In the core
capnp-rpc package (which applications do not normally use directly):
cap#when_releasedmethod can be used to find out when a capability is no longer needed.
The restorer uses this to remove dynamically loaded services from its table automatically.
when_brokenhelper adds a callback to call when a promise or far-ref becomes broken.
NETWORK_TYPESis now separate from
Initial release. RPC Level 1 is fully implemented.