test: call router for router operations

Before this patch, most tests used an assumption that main server is
a router. Yet these are two different concepts.

`main_server` entity was introduced in Cartridge test helpers Cluster
as some server you may refer to for maintenance work, like clusterwide
configuration update. Any cluster server is fine to do such operation:
router or not. Since most cluster configurations start with router
definition, it is often a first server in a list and is chosen to be
main_server as well. But no one guarantees that main_server provides
router API (both for vshard and crud).

test/helper.lua

@@ -133,7 +133,7 @@ function helpers.insert_objects(g, space_name, objects)
     local inserted_objects = {}
 
     for _, obj in ipairs(objects) do
-        local result, err = g.cluster.main_server.net_box:call('crud.insert_object', {space_name, obj})
+        local result, err = g.router:call('crud.insert_object', {space_name, obj})
 
         t.assert_equals(err, nil)
 
@@ -354,7 +354,7 @@ function helpers.assert_ge(actual, expected, message)
 end
 
 function helpers.get_other_storage_bucket_id(cluster, bucket_id)
-    return cluster.main_server.net_box:eval([[
+    return cluster:server('router'):eval([[
         local vshard = require('vshard')
 
         local bucket_id = ...
@@ -392,7 +392,7 @@ end
 helpers.tarantool_version_at_least = crud_utils.tarantool_version_at_least
 
 function helpers.update_sharding_key_cache(cluster, space_name)
-    return cluster.main_server.net_box:eval([[
+    return cluster:server('router'):eval([[
         local sharding_key = require('crud.common.sharding_key')
 
         local space_name = ...
@@ -401,7 +401,7 @@ function helpers.update_sharding_key_cache(cluster, space_name)
 end
 
 function helpers.get_sharding_key_cache(cluster)
-    return cluster.main_server.net_box:eval([[
+    return cluster:server('router'):eval([[
         local vshard = require('vshard')
         local sharding_metadata_cache = require('crud.common.sharding.router_metadata_cache')
 
@@ -416,7 +416,7 @@ end
 -- object through net.box that's why we get a sign of record
 -- existence of cache but not the cache itself
 function helpers.update_sharding_func_cache(cluster, space_name)
-    return cluster.main_server.net_box:eval([[
+    return cluster:server('router'):eval([[
         local sharding_func = require('crud.common.sharding_func')
 
         local space_name = ...
@@ -433,7 +433,7 @@ end
 -- object through net.box that's why we get size of cache
 -- but not the cache itself
 function helpers.get_sharding_func_cache_size(cluster)
-    return cluster.main_server.net_box:eval([[
+    return cluster:server('router'):eval([[
         local vshard = require('vshard')
         local sharding_metadata_cache = require('crud.common.sharding.router_metadata_cache')
 
@@ -734,6 +734,9 @@ function helpers.start_cluster(g, cartridge_cfg, vshard_cfg)
         vtest.cluster_new(g, g.cfg)
         g.cfg.engine = nil
     end
+
+    g.router = g.cluster:server('router')
+    assert(g.router ~= nil, 'router found')
 end
 
 function helpers.stop_cluster(cluster, backend)
@@ -744,14 +747,6 @@ function helpers.stop_cluster(cluster, backend)
     end
 end
 
-function helpers.get_router(cluster, backend)
-    if backend == helpers.backend.CARTRIDGE then
-        return cluster:server('router')
-    elseif backend == helpers.backend.VSHARD then
-        return cluster.main_server
-    end
-end
-
 function helpers.parse_module_version(str)
     -- https://github.com/tarantool/luatest/blob/f37b353b77be50a1f1ce87c1ff2edf0c1b96d5d1/luatest/utils.lua#L166-L173
     local splitstr = str:split('.')

test/integration/borders_test.lua

@@ -26,7 +26,7 @@ end)
 
 pgroup.test_non_existent_space = function(g)
     -- min
-    local result, err = g.cluster.main_server.net_box:call('crud.min', {
+    local result, err = g.router:call('crud.min', {
         'non_existent_space',
         nil,
         {mode = 'write'},
@@ -36,7 +36,7 @@ pgroup.test_non_existent_space = function(g)
     t.assert_str_contains(err.err, "Space \"non_existent_space\" doesn't exist")
 
     -- max
-    local result, err = g.cluster.main_server.net_box:call('crud.max', {
+    local result, err = g.router:call('crud.max', {
         'non_existent_space',
         nil,
         {mode = 'write'},
@@ -48,7 +48,7 @@ end
 
 pgroup.test_non_existent_index = function(g)
     -- min
-    local result, err = g.cluster.main_server.net_box:call('crud.min', {
+    local result, err = g.router:call('crud.min', {
         'customers',
         'non_existent_index',
         {mode = 'write'},
@@ -57,7 +57,7 @@ pgroup.test_non_existent_index = function(g)
     t.assert_equals(result, nil)
     t.assert_str_contains(err.err, "Index \"non_existent_index\" of space \"customers\" doesn't exist")
 
-    local result, err = g.cluster.main_server.net_box:call('crud.min', {
+    local result, err = g.router:call('crud.min', {
         'customers',
         13,
         {mode = 'write'},
@@ -67,7 +67,7 @@ pgroup.test_non_existent_index = function(g)
     t.assert_str_contains(err.err, "Index \"13\" of space \"customers\" doesn't exist")
 
     -- max
-    local result, err = g.cluster.main_server.net_box:call('crud.max', {
+    local result, err = g.router:call('crud.max', {
         'customers',
         'non_existent_index',
         {mode = 'write'},
@@ -76,7 +76,7 @@ pgroup.test_non_existent_index = function(g)
     t.assert_equals(result, nil)
     t.assert_str_contains(err.err, "Index \"non_existent_index\" of space \"customers\" doesn't exist")
 
-    local result, err = g.cluster.main_server.net_box:call('crud.max', {
+    local result, err = g.router:call('crud.max', {
         'customers',
         13,
         {mode = 'write'},
@@ -88,7 +88,7 @@ end
 
 pgroup.test_empty_space = function(g)
     -- min
-    local result, err = g.cluster.main_server.net_box:call('crud.min', {
+    local result, err = g.router:call('crud.min', {
         'customers',
         nil,
         {mode = 'write'},
@@ -98,7 +98,7 @@ pgroup.test_empty_space = function(g)
     t.assert_equals(#result.rows, 0)
 
     -- min by age index with fields
-    local result, err = g.cluster.main_server.net_box:call('crud.min', {
+    local result, err = g.router:call('crud.min', {
         'customers',
         'age_index',
         {fields = {'name'}, mode = 'write'},
@@ -108,7 +108,7 @@ pgroup.test_empty_space = function(g)
     t.assert_equals(#result.rows, 0)
 
     -- max
-    local result, err = g.cluster.main_server.net_box:call('crud.max', {
+    local result, err = g.router:call('crud.max', {
         'customers',
         nil,
         {mode = 'write'},
@@ -118,7 +118,7 @@ pgroup.test_empty_space = function(g)
     t.assert_equals(#result.rows, 0)
 
     -- max by age index with fields
-    local result, err = g.cluster.main_server.net_box:call('crud.max', {
+    local result, err = g.router:call('crud.max', {
         'customers',
         'age_index',
         {fields = {'name'}, mode = 'write'},
@@ -148,71 +148,71 @@ pgroup.test_min = function(g)
     table.sort(customers, function(obj1, obj2) return obj1.id < obj2.id end)
 
     -- by primary
-    local result, err = g.cluster.main_server.net_box:call('crud.min', {
+    local result, err = g.router:call('crud.min', {
         'customers', nil, {mode = 'write'},
     })
     t.assert_equals(err, nil)
     local objects = crud.unflatten_rows(result.rows, result.metadata)
     t.assert_equals(objects, helpers.get_objects_by_idxs(customers, {1}))
 
     -- by primary, index ID is specified
-    local result, err = g.cluster.main_server.net_box:call('crud.min', {
+    local result, err = g.router:call('crud.min', {
         'customers', 0, {mode = 'write'},
     })
     t.assert_equals(err, nil)
     local objects = crud.unflatten_rows(result.rows, result.metadata)
     t.assert_equals(objects, helpers.get_objects_by_idxs(customers, {1}))
 
     -- by primary with fields
-    local result, err = g.cluster.main_server.net_box:call('crud.min', {
+    local result, err = g.router:call('crud.min', {
         'customers', nil, {fields = {'name', 'last_name'}, mode = 'write'},
     })
     t.assert_equals(err, nil)
     local objects = crud.unflatten_rows(result.rows, result.metadata)
     t.assert_equals(objects, {{name = "Elizabeth", last_name = "Jackson"}})
 
     -- by age index
-    local result, err = g.cluster.main_server.net_box:call('crud.min', {
+    local result, err = g.router:call('crud.min', {
         'customers', 'age_index', {mode = 'write'},
     })
     t.assert_equals(err, nil)
     local objects = crud.unflatten_rows(result.rows, result.metadata)
     t.assert_equals(objects, helpers.get_objects_by_idxs(customers, {4}))
 
     -- by age index, index ID is specified
-    local result, err = g.cluster.main_server.net_box:call('crud.min', {
+    local result, err = g.router:call('crud.min', {
         'customers', 2, {mode = 'write'},
     })
     t.assert_equals(err, nil)
     local objects = crud.unflatten_rows(result.rows, result.metadata)
     t.assert_equals(objects, helpers.get_objects_by_idxs(customers, {4}))
 
     -- by age index with fields
-    local result, err = g.cluster.main_server.net_box:call('crud.min', {
+    local result, err = g.router:call('crud.min', {
         'customers', 'age_index', {fields = {'name', 'last_name'}, mode = 'write'},
     })
     t.assert_equals(err, nil)
     local objects = crud.unflatten_rows(result.rows, result.metadata)
     t.assert_equals(objects, {{name = "William", last_name = "White"}})
 
     -- by composite index full_name
-    local result, err = g.cluster.main_server.net_box:call('crud.min', {
+    local result, err = g.router:call('crud.min', {
         'customers', 'full_name', {mode = 'write'},
     })
     t.assert_equals(err, nil)
     local objects = crud.unflatten_rows(result.rows, result.metadata)
     t.assert_equals(objects, helpers.get_objects_by_idxs(customers, {3}))
 
     -- by composite index full_name, index ID is specified
-    local result, err = g.cluster.main_server.net_box:call('crud.min', {
+    local result, err = g.router:call('crud.min', {
         'customers', 5, {mode = 'write'},
     })
     t.assert_equals(err, nil)
     local objects = crud.unflatten_rows(result.rows, result.metadata)
     t.assert_equals(objects, helpers.get_objects_by_idxs(customers, {3}))
 
     -- by composite index full_name with fields
-    local result, err = g.cluster.main_server.net_box:call('crud.min', {
+    local result, err = g.router:call('crud.min', {
         'customers', 'full_name', {fields = {'name', 'last_name'}, mode = 'write'},
     })
     t.assert_equals(err, nil)
@@ -240,71 +240,71 @@ pgroup.test_max = function(g)
     table.sort(customers, function(obj1, obj2) return obj1.id < obj2.id end)
 
     -- by primary
-    local result, err = g.cluster.main_server.net_box:call('crud.max', {
+    local result, err = g.router:call('crud.max', {
         'customers', nil, {mode = 'write'},
     })
     t.assert_equals(err, nil)
     local objects = crud.unflatten_rows(result.rows, result.metadata)
     t.assert_equals(objects, helpers.get_objects_by_idxs(customers, {4}))
 
     -- by primary, index ID is specified
-    local result, err = g.cluster.main_server.net_box:call('crud.max', {
+    local result, err = g.router:call('crud.max', {
         'customers', 0, {mode = 'write'},
     })
     t.assert_equals(err, nil)
     local objects = crud.unflatten_rows(result.rows, result.metadata)
     t.assert_equals(objects, helpers.get_objects_by_idxs(customers, {4}))
 
     -- by primary with fields
-    local result, err = g.cluster.main_server.net_box:call('crud.max', {
+    local result, err = g.router:call('crud.max', {
         'customers', nil, {fields = {'name', 'last_name'}, mode = 'write'}
     })
     t.assert_equals(err, nil)
     local objects = crud.unflatten_rows(result.rows, result.metadata)
     t.assert_equals(objects, {{name = "William", last_name = "White"}})
 
     -- by age index
-    local result, err = g.cluster.main_server.net_box:call('crud.max', {
+    local result, err = g.router:call('crud.max', {
         'customers', 'age_index', {mode = 'write'},
     })
     t.assert_equals(err, nil)
     local objects = crud.unflatten_rows(result.rows, result.metadata)
     t.assert_equals(objects, helpers.get_objects_by_idxs(customers, {2}))
 
     -- by age index, index ID is specified
-    local result, err = g.cluster.main_server.net_box:call('crud.max', {
+    local result, err = g.router:call('crud.max', {
         'customers', 2, {mode = 'write'},
     })
     t.assert_equals(err, nil)
     local objects = crud.unflatten_rows(result.rows, result.metadata)
     t.assert_equals(objects, helpers.get_objects_by_idxs(customers, {2}))
 
     -- by age index with fields
-    local result, err = g.cluster.main_server.net_box:call('crud.max', {
+    local result, err = g.router:call('crud.max', {
         'customers', 'age_index', {fields = {'name', 'last_name'}, mode = 'write'},
     })
     t.assert_equals(err, nil)
     local objects = crud.unflatten_rows(result.rows, result.metadata)
     t.assert_equals(objects, {{name = "Mary", last_name = "Brown"}})
 
     -- by composite index full_name
-    local result, err = g.cluster.main_server.net_box:call('crud.max', {
+    local result, err = g.router:call('crud.max', {
         'customers', 'full_name', {mode = 'write'},
     })
     t.assert_equals(err, nil)
     local objects = crud.unflatten_rows(result.rows, result.metadata)
     t.assert_equals(objects, helpers.get_objects_by_idxs(customers, {4}))
 
     -- by composite index full_name, index ID is specified
-    local result, err = g.cluster.main_server.net_box:call('crud.max', {
+    local result, err = g.router:call('crud.max', {
         'customers', 5, {mode = 'write'},
     })
     t.assert_equals(err, nil)
     local objects = crud.unflatten_rows(result.rows, result.metadata)
     t.assert_equals(objects, helpers.get_objects_by_idxs(customers, {4}))
 
     -- by composite index full_name with fields
-    local result, err = g.cluster.main_server.net_box:call('crud.max', {
+    local result, err = g.router:call('crud.max', {
         'customers', 'full_name', {fields = {'name', 'last_name'}, mode = 'write'},
     })
     t.assert_equals(err, nil)
@@ -334,15 +334,15 @@ pgroup.test_equal_secondary_keys = function(g)
     table.sort(customers, function(obj1, obj2) return obj1.id < obj2.id end)
 
     -- min
-    local result, err = g.cluster.main_server.net_box:call('crud.min', {
+    local result, err = g.router:call('crud.min', {
         'customers', 'age_index', {mode = 'write'},
     })
     t.assert_equals(err, nil)
     local objects = crud.unflatten_rows(result.rows, result.metadata)
     t.assert_equals(objects, helpers.get_objects_by_idxs(customers, {1}))
 
     -- max
-    local result, err = g.cluster.main_server.net_box:call('crud.max', {
+    local result, err = g.router:call('crud.max', {
         'customers', 'age_index', {mode = 'write'},
     })
     t.assert_equals(err, nil)
@@ -369,7 +369,7 @@ pgroup.test_opts_not_damaged = function(g)
 
     -- min
     local min_opts = {timeout = 1, fields = {'name', 'age'}, mode = 'write'}
-    local new_min_opts, err = g.cluster.main_server:eval([[
+    local new_min_opts, err = g.router:eval([[
         local crud = require('crud')
 
         local min_opts = ...
@@ -384,7 +384,7 @@ pgroup.test_opts_not_damaged = function(g)
 
     -- max
     local max_opts = {timeout = 1, fields = {'name', 'age'}, mode = 'write'}
-    local new_max_opts, err = g.cluster.main_server:eval([[
+    local new_max_opts, err = g.router:eval([[
         local crud = require('crud')
 
         local max_opts = ...