The authentication errors were not sent as the connection was closed
immediately. The reason for this was the fact that if a client request
uploaded data with bad credentials, MaxScale would not send a response if
the connection was kept open. Closing the socket solved the hang but
caused confusing errors on the client side.
The libmicrohttpd library appears to require full processing of any data
uploaded by a client request before a request can be sent. With this
change, the clients receive proper authentication errors in all cases.
The actual list of headers is not known when the request is first
generated. This prevents the headers from being generated in admin.cc
which handles things on a lower level.
The moving of the header generation is done with the OPTIONS method in
mind. This header needs to be generated inside the RootResource class
which manages the navigation of the resources.
The data was not processed correctly and instead an error was sent to the
client as soon as the request arrived.
Created a class that somewhat abstracts the internals of the client
request processing.
The HTTP side of the REST API is better handled with an actual
library. The libmicrohttpd library provides a convenient way of handling
the HTTP traffic between the clients and MaxScale.
The class now generates default headers. The ETag and Last-Modified tags
do not represent any actual modification time or resource hash.
The basic functionality of the HTTP responses is tested by the core test
suite. More advanced testing of the whole REST API is still required.
Removed the static `create` functions as only the JSON parsing version
could generated errors and even then the errors were unlikely. By
replacing the static creator function with a normal constructor, the
HttpResponse class can now also be created on the stack making its use
easier.
The admin requests are now processed in blocking mode. The timing out of
connecttions is handled by a specific timeout thread that checks the state
of each admin request.
The simplification will help with the JSON parsing with PUT/POST
commands. If non-blocking IO is used, the network reading code and JSON
parsing needs a lot more work to handle partial reads.
If the administrative interface requires higher performance and
concurrency, a multi-threaded solution could be created.
When MaxScale is started, a separate thread for the administrative
interface is started. This allows the worker threads to handle client
requests while the administrative thread handles the lower priority
administrative requests.
The administrative interface responds to all request with a 200 OK HTTP
response. This allows the administrative interface itself to be tested.
