commit 61c5dcbfcb856a7f3efbd6eff81460d7eec0d9ea
author Andrew Davies <awdavies@google.com> Mon Oct 26 20:09:46 2020 +0000
committer CQ Bot <commit-bot@chromium.org> Mon Oct 26 20:09:46 2020 +0000
tree ac22efc128d5ff3781791090ba20b2303d4b7e47
parent ce0e2d63d0e162730495683a4a4a5c8bd63b16f8

[ffx] Add default config rules for client commands.

This change does a few things:
-- Makes `-t` set `target.default` in the runtime config.
-- Makes a macro that allows for config fallback of any arbitraty struct
   field that is an `Option<String>` and `Option<f64>`
   (more types will be added as needed).
-- Changes get-ssh-address command to use `target.default` rather than
   accepting a parameter.
-- Uses backup of timeout to a config value.
-- Removes use of `inner_lock` on TargetCollection to make deadlocks
less likely to occur from misuse (as there is now no way to access the
inner locking mechanisms).
-- Removes timeouts inside the daemon, allowing for target queries to
run an arbitrary amount of time if necessary (as long as the client
stays up).

Example usage of macro:

```rust
 #[derive(FfxConfigBacked, Default)]
 struct Foo {
   #[ffx_config_default(key = "timeout", default = "1.0")]
   field_one: Option<f64>,

   #[ffx_config_default("nodename")]
   field_two: Option<String>
 }
```

These will generate according functions for looking up the respective
values from the FFX config.

This is used in the two plugins, one for getting the default target, the
other for setting a timeout for getting the ssh address of a target.

Bug: 59622

Change-Id: I5a98842512990a33761e1abc6c9838d64ea46550
Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/436334
Reviewed-by: Matthew Boetger <boetger@google.com>
Commit-Queue: Andrew Davies <awdavies@google.com>
API-Review: James Tucker <raggi@google.com>
Testability-Review: James Tucker <raggi@google.com>