[tarantool-patches] Re: [PATCH] tarantoolctl doesn't fail when box.cfg is delayed in init script

[Konstantin Osipov]

* Max Melentiev <dmarc-noreply at freelists.org> [19/08/19 10:40]:
> Before this patch tarantoolctl failed with error if box.cfg
> was not called in init script because it used too patch box.cfg
> once again after init script. I've changed it to patch box.cfg
> second time inside wrapper_cfg.

Please explain better what this patch does, not how you achieved
that.

And while you are at it, explain why we need a secondary patching
of box.cfg at all. What's the point of preserving the pid file?

tarantoolctl: allow to start instances without a box.cfg{}

Before this patch, tarantoolctl would fail if box.cfg{} was not
called in an instance script.

This patch allows to start an instance without box.cfg{} in it. 
Such an instance:
- may only be started under systemd? 
- what can it do? 
- ???

Please add a docboc entry, since it 's a significant behaviour
change. How such an instance is used? 

Otherwise LTGM.


> ---
>  extra/dist/tarantoolctl.in | 21 +++++++++------------
>  1 file changed, 9 insertions(+), 12 deletions(-)
> 
> diff --git a/extra/dist/tarantoolctl.in b/extra/dist/tarantoolctl.in
> index 8adb57533..fd1abf9dc 100755
> --- a/extra/dist/tarantoolctl.in
> +++ b/extra/dist/tarantoolctl.in
> @@ -483,6 +483,15 @@ local function wrapper_cfg(cfg)
>          os.exit(1)
>      end
>  
> +    local box_cfg_mt = getmetatable(box.cfg)
> +    local orig_cfg_call = box_cfg_mt.__call
> +    box_cfg_mt.__call = function(old_cfg, new_cfg)
> +        if old_cfg.pid_file ~= nil and new_cfg ~= nil and new_cfg.pid_file ~= nil then
> +            new_cfg.pid_file = old_cfg.pid_file
> +        end
> +        orig_cfg_call(old_cfg, new_cfg)
> +    end
> +
>      return data
>  end
>  
> @@ -547,18 +556,6 @@ local function start()
>          end
>          os.exit(1)
>      end
> -    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
> -        old_call(old_cfg, cfg)
> -    end
>      return 0
>  end

-- 
Konstantin Osipov, Moscow, Russia