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

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

Commented in the issue, cited here:

> @opomuc @olegrok I don't know what are you trying to do here. It seems
> you just try to start an instance w/o box.cfg() call inside. I don't
> see a reason to support this case. However more meaningful error
> message from tarantoolctl start in the case would helpful.
>
> Re config module errors: I don't know whether you use it correctly. If
> so, file another issue to this module.
>
> https://github.com/tarantool/tarantool/issues/3953#issuecomment-478439448

I propose to consider this issue as a problem with an error message.

WBR, Alexander Turenko.

On Wed, Mar 27, 2019 at 04:40:14PM +0300, Roman Khabibov wrote:
> box.cfg{} metatables are uninitialized when start() called
> before box.cfg{}. It led to unexpected error.
> 
> Closes #3953
> ---
> Branch: https://github.com/tarantool/tarantool/tree/romanhabibov/gh-3953-tctl
> Issue: https://github.com/tarantool/tarantool/issues/3953
> 
>  extra/dist/tarantoolctl.in         | 7 -------
>  test/app-tap/tarantoolctl.test.lua | 4 +++-
>  2 files changed, 3 insertions(+), 8 deletions(-)
> 
> diff --git a/extra/dist/tarantoolctl.in b/extra/dist/tarantoolctl.in
> index 47fcf895f..91747e3ba 100755
> --- a/extra/dist/tarantoolctl.in
> +++ b/extra/dist/tarantoolctl.in
> @@ -547,13 +547,6 @@ local function start()
>          end
>          os.exit(1)
>      end
> -    local old_call = getmetatable(box.cfg).__call
> -    getmetatable(box.cfg).__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

So if a user lean on that value (s)he now cannot?

> -        end
> -        old_call(old_cfg, cfg)

So if a user set a metatable on box.cfg() with __call method, it will
not more called?

> -    end
>      return 0
>  end
>  
> diff --git a/test/app-tap/tarantoolctl.test.lua b/test/app-tap/tarantoolctl.test.lua
> index db046e03f..1755fcc66 100755
> --- a/test/app-tap/tarantoolctl.test.lua
> +++ b/test/app-tap/tarantoolctl.test.lua
> @@ -165,10 +165,12 @@ do
>      local dir = fio.tempdir()
>      local code = [[ box.cfg{memtx_memory = 104857600} ]]
>      create_script(dir, 'script.lua', code)
> +    create_script(dir, 'init.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', 'init.lua', 0, nil, "Starting instance init...")

So we're 'successfully' started an instance, it executes a script and
then 'tarantoolctl status' and 'tarantoolctl enter' don't show it as
running. It does not look as a right behaviour.

>              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")
> -- 
> 2.20.1 (Apple Git-117)
>