We used to launch a thread for API server inside the wallet crate, now we do it inside api crate, so the cmd tool launches API and exit. This fix makes sure that command will wait for API thread.
* Middleware and handler (mw implements the same trait) could be attached to multiple nodes inside the router
* Middleware could be attached to the router (syntactic sugar, it is attached to the root node) as well as to any node
* Handler's call method receives an iterator of handlers and responsible for calling the next handler if needed
* Support TLS in ApiServer
This is ground work to support TLS in Grin APIs (like wallet ot node). Particular API implemention needs to decide if TLS is used or not and pass certificate data etc.
* P12 format support
* New method to start TLS server
* Transparent TLS support in API client (depends on URL scheme http/https)
* Refactoring
* Initial support for graceful shutdown (commentred out int this PR, unstable for now)
* API server tests (TLS server test is disabled by default, hyper client rejects self-signed certificates, so extra step is needed to install local CA (I used mkcert)
* Add a cert file to make test complile
* block_sums and full kernel sum verification
* rustfmt
* add docs/comments
* docs
* rustfmt
* comment on fact total_kernel_sum is redundant now
* make sure we setup block_sums correctly on a fork
* rustfmt
* replace those asserts with errors
* rustfmt
* Make it simpler to implement middleware
* Switch from the current thread runtime to the default one. It enables us to inject TLS support later one and potentially more scalable, unfortunately it involves some additonal cloning of the router, because we can't rely on thread local vars anymore
* Introduce `call` entrypoint for Handler, so it's possible to handle any HTTP method in one place, handy for middleware
* Implement example of middleware
* Move Proof and Difficulty types to pow module. Difficulty scaling calculation.
* Diffculty scaling and size shift for 2nd PoW
* Backport e7eb26ee
* Test compilation fixes
* Scaling only need to go one way, as @tromp pointed out
Address ##1525 in particular and improve error messages in general.
Instead of `Request Error: Error { inner:` a client would get:
`Generic error: Invalid request body: missing field `method` at line 1 column 162`
