api: migrate to httpd role server

[themilchenko]

Since the httpd role was released this role need to support this feature.

After the patch metrics-export-role supports an httpd role. It is possible to determine a list of servers that role will reuse in the following configuration.

Closes #15

[oleg-jukovec]

The tests are red.

[oleg-jukovec]

Please, fix the comments below. We could also to improve the code and to use router:delete instead of the call:

metrics-export-role/roles/metrics-export.lua

Lines 27 to 38 in a5b80a0

	local function delete_route(httpd, name)
	local route = assert(httpd.iroutes[name])
	httpd.iroutes[name] = nil
	table.remove(httpd.routes, route)
	-- Update httpd.iroutes numeration.
	for n, r in ipairs(httpd.routes) do
	if r.name then
	httpd.iroutes[r.name] = n
	end
	end
	end

[themilchenko]

Please, fix the comments below. We could also to improve the code and to use router:delete instead of the call:

metrics-export-role/roles/metrics-export.lua

Lines 27 to 38 in a5b80a0

	local function delete_route(httpd, name)
	local route = assert(httpd.iroutes[name])
	httpd.iroutes[name] = nil
	table.remove(httpd.routes, route)
	-- Update httpd.iroutes numeration.
	for n, r in ipairs(httpd.routes) do
	if r.name then
	httpd.iroutes[r.name] = n
	end
	end
	end

Replaced on router:delete instead of the call.

[oleg-jukovec]

Thank you for the patch!

[DifferentialOrange]

Should be ready to merge.