[tarantool-patches] Re: [PATCH] tarantoolctl: remove metatable assumptions in start()

[Alexander Turenko <alexander.turenko@tarantool.org>]

LGTM.

Kirill, please, proceed.

https://github.com/tarantool/tarantool/issues/3953
https://github.com/tarantool/tarantool/compare/romanhabibov/gh-3953-tctl

WBR, Alexander Turenko.

On Mon, Apr 15, 2019 at 01:59:31PM +0300, Roman Khabibov wrote:
> 
> 
> > On Apr 15, 2019, at 1:41 AM, Alexander Turenko <alexander.turenko@tarantool.org> wrote:
> > 
> > The code is okay, but I would clarify the commit message a bit.
> > 
> >>>> 
> >>>>  There was assumpted uninitialized metamethods of box.cfg{} if user
> >>>>  did't call it in his instance.
> >>> 
> >>> This sentence raises more questions then give answers. What is
> >>> 'uninitialized metamethods'? Whether 'of box.cfg{}' means result of the
> >>> call or a new value of the 'cfg' field of the 'box' table?
> >>> 
> >>> Also I doubt 'There was assumpted' is valid phrase.
> >> 
> >>   tarantoolctl: raise error when box.cfg isn't called
> >> 
> >>   There was no check whether box.cfg{} was initialized in an
> >>   instance. If so, an error should be raised.
> > 
> > 'box' can be initialized (it is a module), 'box.cfg' can be called, but
> > we usually use parentheses to mark a name as a function, so 'box.cfg()'
> > can be called. Technically 'box.cfg{} was initialized' is not correct.
> > 
> > 'If so' here point to the positive case (when called).
> > 
> > Let me propose wording that will satisfy me:
> > 
> >> Added a check whether box.cfg() is called within an instance file. If
> >> box.cfg() is missed, point a user the reason of a fail explicitly.
> >> 
> >> Before this commit the error was look so:
> >> 
> >> /usr/bin/tarantoolctl:541: attempt to index a nil value
> > 
> > Also don't forget to add 'Fixes #xxxx' clause to the end of the commit
> > message.
> Done.
> 
> commit 7aba9a68b1139738fc3da1bfa39c490f3afdfc5e
> Author: Roman Khabibov <roman.habibov@tarantool.org>
> Date:   Mon Mar 25 20:52:05 2019 +0300
> 
>    tarantoolctl: raise error when box.cfg isn't called
> 
>    Added a check whether box.cfg() is called within an instance
>    file. If box.cfg() is missed, point a user the reason of a
>    fail explicitly.
> 
>    Before this commit the error was look so:
> 
>    /usr/bin/tarantoolctl:541: attempt to index a nil value
> 
>    Closes #3953
> 
> diff --git a/extra/dist/tarantoolctl.in b/extra/dist/tarantoolctl.in
> index 47fcf895f..37ded5333 100755
> --- a/extra/dist/tarantoolctl.in
> +++ b/extra/dist/tarantoolctl.in
> @@ -547,8 +547,13 @@ local function start()
>         end
>         os.exit(1)
>     end
> -    local old_call = getmetatable(box.cfg).__call
> -    getmetatable(box.cfg).__call = function(old_cfg, cfg)
> +    local box_cfg_mt = getmetatable(box.cfg)
> +    if box_cfg_mt == nil then
> +        log.error('box.cfg() is not called in an instance file')
> +        os.exit(1)
> +    end
> +    local old_call = box_cfg_mt.__call
> +    box_cfg_mt.__call = function(old_cfg, cfg)
>         if old_cfg.pid_file ~= nil and cfg ~= nil and cfg.pid_file ~= nil then
>             cfg.pid_file = old_cfg.pid_file
>         end
> diff --git a/test/app-tap/tarantoolctl.test.lua b/test/app-tap/tarantoolctl.test.lua
> index db046e03f..7d7c63371 100755
> --- a/test/app-tap/tarantoolctl.test.lua
> +++ b/test/app-tap/tarantoolctl.test.lua
> @@ -163,12 +163,14 @@ test:plan(7)
> -- must be stopped afterwards
> do
>     local dir = fio.tempdir()
> -    local code = [[ box.cfg{memtx_memory = 104857600} ]]
> -    create_script(dir, 'script.lua', code)
> +    create_script(dir, 'script.lua', [[ box.cfg{memtx_memory = 104857600} ]])
> +    create_script(dir, 'no_box_cfg.lua', [[ print('Hi!') ]])
> 
>     local status, err = pcall(function()
>         test:test("basic test", function(test_i)
> -            test_i:plan(16)
> +            test_i:plan(18)
> +            check_ok(test_i, dir, 'start', 'no_box_cfg', 1, nil, "Starting instance",
> +                     "box.cfg() is not called in an instance file")
>             check_ok(test_i, dir, 'start',  'script', 0, nil, "Starting instance")
>             tctl_wait_start(dir, 'script')
>             check_ok(test_i, dir, 'status', 'script', 0, nil, "is running")