This commit converts all the uses of wgkey to the new key interfaces.
It now has specific machine, node and discovery keys and we now should
use them correctly.
Please note the new logic which strips a key prefix (in utils.go) that
is now standard inside tailscale.
In theory we could put it in the database, but to preserve backwards
compatibility and not spend a lot of resources on accounting for both,
we just strip them.
This commit adds a sentral cache to keep track of clients whom has
requested an expiry time, but were we need to keep hold of it until the
second request comes in.
This commit moves the routes lookup functions to be subcommands of
Machine, making them a lot simpler and more specific/composable.
It also moves the register command from cli.go into machine, so we can
clear out the extra file.
Finally a toProto function has been added to convert between the machine
database model and the proto/rpc model.
This tries to make the same functions emit and consume the same type of
data all over the application.
If a function transform data, it should emit new data, not a pointer.
This commit adds some Prometheus metrics to /metrics in headscale.
It will add the standard go metrics, some automatic gin metrics and some
initial headscale specific ones.
Some of them has been added to aid debugging #97 (loop bug)
In the future, we can use the metrics to get rid of the sleep in the
integration tests by checking that our expected number of nodes has been
registered:
```
headscale_machine_registrations_total
```
This commit moves toNode to the bottom of the file, and adds a helper
function for lists of Machines to be converted.
It also adds string helpers for Machines and lists of machines.
Lastly it splits getPeers into getDirectPeers, which exist in the same
namespace, and getShared, which is nodes shared with the namespace.
getPeers is kept as a function putting together the two lists for
convenience.
