Brings the functionality of ssh-ng:// in sync with the legacy ssh://
implementation. Specifying the remote store uri enables various useful
things. eg.
$ nix copy --to ssh-ng://cache?remote-store=file://mnt/cache --all
(cherry picked from commit 8745c63d3c)
This is already used by Hydra, and is very useful when materializing
a remote builder list from service discovery. This allows the service
discovery tool to only sync one file instead of two.
For instance, this reduced the memory consumption of
$ nix copy --from ssh://localhost --to ~/my-nix /nix/store/1n7x0yv8vq6zi90hfmian84vdhd04bgp-blender-2.79a
from 632 MiB to 16 MiB.
This can be iterated on and currently leaves out settings we know we
want to forward, but it fixes#1713 and fixes#1935 and isn't
fundamentally broken like the status quo. Future changes are suggested
in a comment.
The typical use is to inherit Config and add Setting<T> members:
class MyClass : private Config
{
Setting<int> foo{this, 123, "foo", "the number of foos to use"};
Setting<std::string> bar{this, "blabla", "bar", "the name of the bar"};
MyClass() : Config(readConfigFile("/etc/my-app.conf"))
{
std::cout << foo << "\n"; // will print 123 unless overriden
}
};
Currently, this is used by Store and its subclasses for store
parameters. You now get a warning if you specify a non-existant store
parameter in a store URI.
* Unify SSH code in SSHStore and LegacySSHStore.
* Fix a race starting the SSH master. We now wait synchronously for
the SSH master to finish starting. This prevents the SSH clients
from starting their own connections.
* Don't use a master if max-connections == 1.
* Add a "max-connections" store parameter.
* Add a "compress" store parameter.
