A self link to the resource itself provides a convenient way for the
client to request a resource, modify it and call the self link to update
it. This removes some of the burden on the client to keep track of the
resource links by placing these in the resource itself.
The parameter names for monitors and servers now use a set of constant
names. This removes some of the errors caused by spelling mistakes when
the same parameter name is repeated in multiple places.
The service, filter and listener parameters should also be converted to
constants. This allows for a consistent user experience.
The relationships from servers to services and monitors and filters to
services were not implemented. Now each server lists the services and
monitors that use it and each filter lists the services that use the
filter.
This enables the creation of a server and linking of that server to
services and monitors in one atomic operation.
The JSON API (http://jsonapi.org/) specifies a way to express relations in
a somewhat generic way. By moving towards a more generic schema for the
resources, it will be easier to handle the modification of the relations
between these resources.
When a resource has a relation to another resource, it should be expressed
as a working link to the resource. By passing the hostname of the server
to the functions, we are able to generate working relation links.
If a resource can be accessed from more than one place, it should be a
link. The previous change that duplicated the content for nested resources
wasn't a very clean solution. With links, the content is easier to browse
using a normal browser.
The modules that implement a diagnostics entry point now return a JSON
type object. This removes the need to format data inside the modules.
The module implementations of these are not yet complete which means that
MaxScale will fail to compile.
As a service is a collection of other resources, it makes sense to expand
those resources that were previously expressed as relative paths. This way
the API can be readily consumed without altering the pathnames to
links. The downside to this is the increased bandwidth consumption and
possible excess data.
Monitors can now be printed in JSON format. The REST API resource
`/monitors` accepts GET requests and returns a JSON representation of the
monitors as a response.
This number (defaults to 1) sets how many times mon_connect_to_db
will try to connect to a backend before returning an error. Every
connection attempt may take backend_connect_timeout seconds to
complete.
Also refactored code a bit. Renamed mon_connect_to_db to
mon_ping_or_connect_to_db, since it does not connect if the connection
is already alive.
