Launch fairings are now fallible and take the place of attach fairings,
but they are only run, as the name implies, at launch time.
This is is a fundamental shift from eager execution of set-up routines,
including the now defunct attach fairings, to lazy execution,
precipitated by the transition to `async`. The previous functionality,
while simple, caused grave issues:
1. A instance of 'Rocket' with async attach fairings requires an async
runtime to be constructed.
2. The instance is accessible in non-async contexts.
3. The async attach fairings have no runtime in which to be run.
Here's an example:
```rust
let rocket = rocket::ignite()
.attach(AttachFairing::from(|rocket| async {
Ok(rocket.manage(load_from_network::<T>().await))
}));
let state = rocket.state::<T>();
```
This had no real meaning previously yet was accepted by running the
attach fairing future in an isolated runtime. In isolation, this causes
no issue, but when attach fairing futures share reactor state with other
futures in Rocket, panics ensue.
The new Rocket application lifecycle is this:
* Build - A Rocket instance is constructed. No fairings are run.
* Ignition - All launch fairings are run.
* Liftoff - If all launch fairings succeeded, the server is started.
New 'liftoff' fairings are run in this third phase.
Prior to this commit, it was not possible to test Rocket crates in
production mode without setting a global secret key or bypassing secret
key checking - the testing script did the latter. The consequence is
that it became impossible to test secret key related failures because
the tests passed regardless.
This commit undoes this. As a consequence, all tests are now aware of
the difference between debug and release configurations, the latter of
which validates 'secret_key' by default. New 'Client::debug()' and
'Client::debug_with()' simplify creating an instance of 'Client' with
configuration in debug mode to avoid undesired test failures.
The summary of changes in this commit are:
* Config 'secret_key' success and failure are now tested.
* 'secret_key' validation was moved to pre-launch from 'Config:from()'.
* 'Config::from()' only extracts the config.
* Added 'Config::try_from()' for non-panicking extraction.
* 'Config' now knows the profile it was extracted from.
* The 'Config' provider sets a profile of 'Config.profile'.
* 'Rocket', 'Client', 'Fairings', implement 'Debug'.
* 'fairing::Info' implements 'Copy', 'Clone'.
* 'Fairings' keeps track of, logs attach fairings.
* 'Rocket::reconfigure()' was added to allow modifying a config.
Internally, the testing script was refactored to properly test the
codebase with the new changes. In particular, it no longer sets a rustc
'cfg' to avoid secret-key checking.
Resolves#1543.
Fixes#1564.
This is largely an internal change. Prior to this commit, the 'Manifest'
type, now replaced with the 'Cargo' type, robbed responsibility from the
core 'Rocket' type. This new construction restores the previous
responsibility and makes it clear that 'Cargo' is _only_ for freezing,
and representing the stability of, Rocket's internal state.
The directory structure has changed to better isolate crates serving
core and contrib. The new directory structure is:
contrib/
lib/ - the contrib library
core/
lib/ - the core Rocket library
codegen/ - the "compile extension" codegen library
codegen_next/ - the new proc-macro library
examples/ - unchanged
scripts/ - unchanged
site/ - unchanged
This commit also removes the following files:
appveyor.yml - AppVeyor (Rust on Windows) is far too spotty for use
rustfmt.toml - rustfmt is, unfortunately, not mature enough for use
Finally, all example Cargo crates were marked with 'publish = false'.