diff --git a/changelogs/unreleased/gh-9842-rpc-for-roles.md b/changelogs/unreleased/gh-9842-rpc-for-roles.md
index e5539f7b64ce0f82f099c23e37ad197c0cdedf64..4f26e4b25cc822f2ab7c607a9264734fd48f35d4 100644
--- a/changelogs/unreleased/gh-9842-rpc-for-roles.md
+++ b/changelogs/unreleased/gh-9842-rpc-for-roles.md
@@ -4,3 +4,5 @@
`connect()` function of this module (gh-9842).
* Introduced the `filter()` function in the `experimental.connpool`
module (gh-9842).
+* Introduced the `call()` function in the `experimental.connpool`
+ module (gh-9842).
diff --git a/src/box/lua/experimental/connpool.lua b/src/box/lua/experimental/connpool.lua
index 17907c52c234e8d85b37285d567efe1bd40d2a4c..fdc6c759163d7ad51f209a90dd574db76a704001 100644
--- a/src/box/lua/experimental/connpool.lua
+++ b/src/box/lua/experimental/connpool.lua
@@ -112,7 +112,80 @@ local function filter(opts)
return candidates
end
+local function get_connection(all_candidates, prefer_local)
+ local candidates = table.copy(all_candidates)
+ if prefer_local ~= false then
+ local candidate_idx = nil
+ for n, candidate in ipairs(candidates) do
+ if candidate == box.info.name then
+ candidate_idx = n
+ local conn = connect(box.info.name, {wait_connected = false})
+ if conn:wait_connected() then
+ return conn
+ end
+ break
+ end
+ end
+ if candidate_idx ~= nil then
+ table.remove(candidates, candidate_idx)
+ end
+ end
+
+ while #candidates > 0 do
+ local n = math.random(#candidates)
+ local instance_name = table.remove(candidates, n)
+ local conn = connect(instance_name, {wait_connected = false})
+ if conn:wait_connected() then
+ return conn
+ end
+ end
+ return nil
+end
+
+local function call(func_name, args, opts)
+ checks('string', '?table', {
+ labels = '?table',
+ roles = '?table',
+ prefer_local = '?boolean',
+ -- The following options passed directly to net.box.call().
+ timeout = '?',
+ buffer = '?',
+ on_push = '?function',
+ on_push_ctx = '?',
+ is_async = '?boolean',
+ })
+ opts = opts or {}
+
+ local candidates_opts = {
+ labels = opts.labels,
+ roles = opts.roles,
+ }
+ local candidates = filter(candidates_opts)
+ if next(candidates) == nil then
+ local msg = "Couldn't execute function %s: no candidates are " ..
+ "available with these conditions"
+ error(msg:format(func_name), 0)
+ end
+
+ local conn = get_connection(candidates, opts.prefer_local)
+ if conn == nil then
+ local msg = "Couldn't execute function %s: connection to " ..
+ "candidates failed"
+ error(msg:format(func_name), 0)
+ end
+
+ local net_box_call_opts = {
+ timeout = opts.timeout,
+ buffer = opts.buffer,
+ on_push = opts.on_push,
+ on_push_ctx = opts.on_push_ctx,
+ is_async = opts.is_async,
+ }
+ return conn:call(func_name, args, net_box_call_opts)
+end
+
return {
connect = connect,
filter = filter,
+ call = call,
}
diff --git a/test/config-luatest/rpc_test.lua b/test/config-luatest/rpc_test.lua
index d38d5d9caaf542393bb716fb4268ca0cbb432ecf..40bed364b9e1c12d11ccbf4af9df625b25e13974 100644
--- a/test/config-luatest/rpc_test.lua
+++ b/test/config-luatest/rpc_test.lua
@@ -204,3 +204,122 @@ g.test_filter = function(g)
g.server_3:exec(check)
g.server_4:exec(check)
end
+
+g.test_call = function(g)
+ local dir = treegen.prepare_directory(g, {}, {})
+ local config = [[
+ credentials:
+ users:
+ guest:
+ roles: [super]
+
+ iproto:
+ listen:
+ - uri: 'unix/:./{{ instance_name }}.iproto'
+
+ groups:
+ group-001:
+ replicasets:
+ replicaset-001:
+ instances:
+ instance-001:
+ roles: [one]
+ database:
+ mode: rw
+ labels:
+ l1: 'first'
+ l2: 'second'
+ instance-002: {}
+ replicaset-002:
+ instances:
+ instance-003:
+ roles: [one]
+ database:
+ mode: rw
+ labels:
+ l2: 'second'
+ instance-004:
+ roles: [one]
+ labels:
+ l1: 'first'
+ l3: 'second'
+ ]]
+ treegen.write_script(dir, 'config.yaml', config)
+
+ local role = string.dump(function()
+ local function f1()
+ return box.info.name
+ end
+
+ local function f2(a, b, c)
+ return a + b * c
+ end
+
+ rawset(_G, 'f1', f1)
+ rawset(_G, 'f2', f2)
+
+ return {
+ stop = function() end,
+ apply = function() end,
+ validate = function() end,
+ }
+ end)
+ treegen.write_script(dir, 'one.lua', role)
+
+ local opts = {
+ env = {LUA_PATH = os.environ()['LUA_PATH']},
+ config_file = 'config.yaml',
+ chdir = dir,
+ }
+ g.server_1 = server:new(fun.chain(opts, {alias = 'instance-001'}):tomap())
+ g.server_2 = server:new(fun.chain(opts, {alias = 'instance-002'}):tomap())
+ g.server_3 = server:new(fun.chain(opts, {alias = 'instance-003'}):tomap())
+ g.server_4 = server:new(fun.chain(opts, {alias = 'instance-004'}):tomap())
+
+ g.server_1:start({wait_until_ready = false})
+ g.server_2:start({wait_until_ready = false})
+ g.server_3:start({wait_until_ready = false})
+ g.server_4:start({wait_until_ready = false})
+
+ g.server_1:wait_until_ready()
+ g.server_2:wait_until_ready()
+ g.server_3:wait_until_ready()
+ g.server_4:wait_until_ready()
+
+ -- Make sure module pool is working.
+ local function check()
+ local connpool = require('experimental.connpool')
+ local opts = {
+ labels = {l1 = 'first'},
+ roles = {'one'},
+ }
+ local candidates = connpool.filter(opts)
+
+ local is_candidate = false
+ for _, candidate_name in ipairs(candidates) do
+ is_candidate = is_candidate or candidate_name == box.info.name
+ end
+
+ t.assert(not is_candidate or box.info.name == 'instance-001' or
+ box.info.name == 'instance-004')
+
+ if is_candidate then
+ t.assert(opts.prefer_local == nil)
+ t.assert_equals(connpool.call('f1', nil, opts), box.info.name)
+ opts.prefer_local = true
+ t.assert_equals(connpool.call('f1', nil, opts), box.info.name)
+ else
+ t.assert(opts.prefer_local == nil)
+ t.assert_items_include(candidates, {connpool.call('f1', nil, opts)})
+ opts.prefer_local = true
+ t.assert_items_include(candidates, {connpool.call('f1', nil, opts)})
+ end
+
+ t.assert_equals(connpool.call('f2', {1,2,3}, {roles = {'one'}}), 7)
+ end
+
+ g.server_1:exec(check)
+ g.server_2:exec(check)
+ g.server_3:exec(check)
+ g.server_4:exec(check)
+end