server: fix reset option in grep_log for Tarantool EE

server.grep_log() has 'reset' option, which allows to reset the result,
when instance restart is found. It doesn't work on Tarantool EE, as
it tries to find "Tarantool %d+.%d+.%d+-.*%d+-g.*" pattern, but EE
has "Tarantool Enterprise ...".

Let's use tarantool.package value instead of explicitly specifying,
on which tarantool package restart is done.

Closes #319

luatest/server.lua

@@ -12,6 +12,7 @@ local http_client = require('http.client')
 local json = require('json')
 local log = require('log')
 local net_box = require('net.box')
+local tarantool = require('tarantool')
 local uri = require('uri')
 local _, luacov_runner = pcall(require, 'luacov.runner') -- luacov may not be installed
 
@@ -722,7 +723,8 @@ function Server:grep_log(pattern, bytes_num, opts)
                     line = table.concat(buf)
                     buf = nil
                 end
-                if string.match(line, '> Tarantool %d+.%d+.%d+-.*%d+-g.*$') and reset then
+                local package = tarantool.package or 'Tarantool'
+                if string.match(line, '> ' .. package .. ' %d+.%d+.%d+-.*%d+-g.*$') and reset then
                     found = nil -- server was restarted, reset the result
                 else
                     found = string.match(line, pattern) or found

test/server_test.lua

@@ -15,7 +15,10 @@ local command = fio.pathjoin(root, 'test', 'server_instance.lua')
 local server = Server:new({
     command = command,
     workdir = fio.pathjoin(datadir, 'common'),
-    env = {custom_env = 'test_value'},
+    env = {
+        TARANTOOL_LOG = fio.pathjoin(datadir, 'server_test.log'),
+        custom_env = 'test_value',
+    },
     http_port = 8182,
     net_box_port = 3133,
 })
@@ -476,3 +479,21 @@ end
 g.after_test('test_error_level_is_correct', function()
     g.s:drop()
 end)
+
+g.test_grep_log = function()
+    server:connect_net_box()
+
+    -- Test that grep_log just works.
+    server:exec(function() require('log').info('test grep_log') end)
+    t.assert(server:grep_log('test grep_log'))
+
+    -- By default opts.reset in server:grep_log() is true, so we
+    -- should not find the message after instance restart.
+    server:restart()
+    t.helpers.retrying({}, function() server:http_request('get', '/ping') end)
+    server:connect_net_box()
+    t.assert_not(server:grep_log('test grep_log'))
+
+    server.net_box:close()
+    server.net_box = nil
+end