From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <tarantool-patches-bounces@dev.tarantool.org>
Received: from [87.239.111.99] (localhost [127.0.0.1])
	by dev.tarantool.org (Postfix) with ESMTP id BC2576B944;
	Tue, 13 Apr 2021 18:40:55 +0300 (MSK)
DKIM-Filter: OpenDKIM Filter v2.11.0 dev.tarantool.org BC2576B944
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=tarantool.org; s=dev;
	t=1618328455; bh=z8ZzfwzoibN3edO4jtzbdTKE3WftbhBM2eJ9aXbS64c=;
	h=To:References:Date:In-Reply-To:Subject:List-Id:List-Unsubscribe:
	 List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:
	 From;
	b=Vpx2vjJH9MvRvANladw4O7RL2WcjIwYtTZ1yMiV9UnNG53ULa+Dy0LyqxlHuQkH29
	 eBDkNAX0NhWE3cJ7JsJOZpbXpBYb5B0ryEQEUr5HJQ0NwcFuwYnD5l/XV9s+alEREC
	 Mr4L0WCs5UelK0KsL5kaScmeprm0vl74efKia6gk=
Received: from smtp50.i.mail.ru (smtp50.i.mail.ru [94.100.177.110])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (No client certificate requested)
 by dev.tarantool.org (Postfix) with ESMTPS id 123926BD2D
 for <tarantool-patches@dev.tarantool.org>;
 Tue, 13 Apr 2021 18:40:53 +0300 (MSK)
DKIM-Filter: OpenDKIM Filter v2.11.0 dev.tarantool.org 123926BD2D
Received: by smtp50.i.mail.ru with esmtpa (envelope-from
 <lvasiliev@tarantool.org>)
 id 1lWL9o-0000Uo-9t; Tue, 13 Apr 2021 18:40:52 +0300
To: Roman Khabibov <roman.habibov@tarantool.org>,
 tarantool-patches@dev.tarantool.org
References: <20210413124559.47410-1-roman.habibov@tarantool.org>
 <20210413124559.47410-3-roman.habibov@tarantool.org>
Message-ID: <28e3e145-d86b-bf21-8a40-73da577bfbff@tarantool.org>
Date: Tue, 13 Apr 2021 18:39:19 +0300
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.6.0
MIME-Version: 1.0
In-Reply-To: <20210413124559.47410-3-roman.habibov@tarantool.org>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
X-7564579A: 646B95376F6C166E
X-77F55803: 4F1203BC0FB41BD92FFCB8E6708E7480257C85EA0BB7A95D0F00AE41BB9A5343182A05F538085040C4CFB936B373BD1E24689DF605BBEBDD9EF76B0356F1766EFB5A0B6A008B5A42
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
X-C1DE0DAB: 0D63561A33F958A50413DF0B6CAB391CFECD081630875D8E303BC9AA8F90FAB3D59269BC5F550898D99A6476B3ADF6B47008B74DF8BB9EF7333BD3B22AA88B938A852937E12ACA7502E6951B79FF9A3F410CA545F18667F91A7EA1CDA0B5A7A0
X-C8649E89: 4E36BF7865823D7055A7F0CF078B5EC49A30900B95165D3454CC76E5F54B410CD8E67D3CF367C172C8D24766199229A929ECBCBCC2B18A3581630F1656010DE11D7E09C32AA3244C6B0D1FD4EB0674F99348F072E0E96AD2BBA718C7E6A9E042729B2BEF169E0186
X-D57D3AED: 3ZO7eAau8CL7WIMRKs4sN3D3tLDjz0dLbV79QFUyzQ2Ujvy7cMT6pYYqY16iZVKkSc3dCLJ7zSJH7+u4VD18S7Vl4ZUrpaVfd2+vE6kuoey4m4VkSEu530nj6fImhcD4MUrOEAnl0W826KZ9Q+tr5ycPtXkTV4k65bRjmOUUP8cvGozZ33TWg5HZplvhhXbhDGzqmQDTd6OAevLeAnq3Ra9uf7zvY2zzsIhlcp/Y7m53TZgf2aB4JOg4gkr2biojnA7/qPBUIXEzvN9/6AiW9A==
X-Mailru-Sender: 48EFD2E18A91C559803250E574CC3D2949C45390F5EEA53D24689DF605BBEBDD4AF810104A35EE5ED35D514C7DAC97282D063C67CFD4E84987597EC79699C0E6F21BD4036121A32F7402F9BA4338D657ED14614B50AE0675
X-Mras: Ok
Subject: Re: [Tarantool-patches] [PATCH v2 2/2] box: set cfg via environment
 variables
X-BeenThere: tarantool-patches@dev.tarantool.org
X-Mailman-Version: 2.1.34
Precedence: list
List-Id: Tarantool development patches <tarantool-patches.dev.tarantool.org>
List-Unsubscribe: <https://lists.tarantool.org/mailman/options/tarantool-patches>, 
 <mailto:tarantool-patches-request@dev.tarantool.org?subject=unsubscribe>
List-Archive: <https://lists.tarantool.org/pipermail/tarantool-patches/>
List-Post: <mailto:tarantool-patches@dev.tarantool.org>
List-Help: <mailto:tarantool-patches-request@dev.tarantool.org?subject=help>
List-Subscribe: <https://lists.tarantool.org/mailman/listinfo/tarantool-patches>, 
 <mailto:tarantool-patches-request@dev.tarantool.org?subject=subscribe>
From: Leonid Vasiliev via Tarantool-patches
 <tarantool-patches@dev.tarantool.org>
Reply-To: Leonid Vasiliev <lvasiliev@tarantool.org>
Errors-To: tarantool-patches-bounces@dev.tarantool.org
Sender: "Tarantool-patches" <tarantool-patches-bounces@dev.tarantool.org>

Hi! Thank you for the patch.

On 4/13/21 3:45 PM, Roman Khabibov via Tarantool-patches wrote:
> Add ability to set box.cfg options via env variables. These
> variables should have name "TT_<OPTION>". When Tarantool instance
> is started under tarantoolctl utility env variables options have
> more priority than instance file's cfg.
> 
> Closes #5602
> 
> @TarantoolBot document
> Title: Set box.cfg options via env variables
> 
> Now, it is possible to set box.cfg options via environment
> variables. The name of variable should correspond the following
> pattern: "TT_<NAME>", where <NAME> is an option name. For example:
> "TT_LISTEN", "TT_READAHEAD".
> If it is complex value, for example, "replication" can be set by a
> table, the corresponding environment variable value has the syntax
> of lua array (without keys):
> 
> `export TT_REPLICATION="{'uri1', 'uri2'}"`
> ---
>   changelogs/unreleased/environment-cfg.md      |   5 +
>   src/box/lua/load_cfg.lua                      | 114 ++++++++++++++++++
>   test/app-tap/tarantoolctl.test.lua            |  33 ++++-
>   .../gh-5602-environment-vars-cfg.result       |  41 +++++++
>   .../gh-5602-environment-vars-cfg.test.lua     |  57 +++++++++
>   test/box-tap/gh-5602-test-cases-script.lua    |  69 +++++++++++
>   6 files changed, 318 insertions(+), 1 deletion(-)
>   create mode 100755 changelogs/unreleased/environment-cfg.md
>   create mode 100644 test/box-tap/gh-5602-environment-vars-cfg.result
>   create mode 100755 test/box-tap/gh-5602-environment-vars-cfg.test.lua
>   create mode 100755 test/box-tap/gh-5602-test-cases-script.lua
> 
> diff --git a/changelogs/unreleased/environment-cfg.md b/changelogs/unreleased/environment-cfg.md
> new file mode 100755
> index 000000000..894c40bf6
> --- /dev/null
> +++ b/changelogs/unreleased/environment-cfg.md
> @@ -0,0 +1,5 @@
> +## feature/core
> +
> +* Now, it is possibly to set box.cfg options with environment variables.
> +The priority of sources of configuration options is the following (from low
> +to high): default, tarantoolctl, environment, box.cfg{}. (gh-5602).
> diff --git a/src/box/lua/load_cfg.lua b/src/box/lua/load_cfg.lua
> index f90ba8a9a..df6a52e94 100644
> --- a/src/box/lua/load_cfg.lua
> +++ b/src/box/lua/load_cfg.lua
> @@ -525,6 +525,26 @@ local function prepare_cfg(cfg, default_cfg, template_cfg,
>       return new_cfg
>   end
>   
> +---
> +-- Transfer options from env_cfg to cfg.
> +--

1) Just `--- Transfer options from env_cfg to cfg.`

> +local function apply_env_cfg(cfg, env_cfg)
> +    if env_cfg == nil then
> +        return
> +    end
> +
> +    for k, v in pairs(env_cfg) do
> +        -- If Tarantool started with tarantoolctl then we have to
> +        -- ignore configuration from tarantoolctl, because they
> +        -- has priority lower than environment variables.
> +        if cfg[k] == nil or os.getenv('TARANTOOLCTL') == 'true' then
> +            cfg[k] = v

2) I thought, and it;s strange that we use knowledge about the control
tool inside the core code. Maybe do the additional env processing in 
tarantoolctl?

> +        elseif type(v) == 'table' then

3) What is this case?

> +            apply_env_cfg(cfg[k], v)
> +        end
> +    end
> +end
> +
>   local function apply_default_cfg(cfg, default_cfg, module_cfg)
>       for k,v in pairs(default_cfg) do
>           if cfg[k] == nil then
> @@ -647,6 +667,98 @@ local function on_initial_config()
>       end
>   end
>   
> +---
> +-- Erase quotes at the begin and the end of string.
> +--

4) Just `---Erase quotes at the begin and the end of string.`

> +local function dequote(str)
> +    if string.sub(str, 1, 1) == '\'' and string.sub(str, -1) == '\'' or
> +       string.sub(str, 1, 1) == '"' and string.sub(str, -1) == '"' then
> +        return string.sub(str, 2, -2)
> +    end
> +    return str
> +end
> +
> +---
> +-- Convert raw option value becoming from the corresponding

5) `---Convert raw option value becoming from the corresponding`

> +-- environment variable represented as string to string, number or
> +-- boolean (depending on option).
> +--

6) No extra blank line is needed(`--`).

> +local function process_option_value(option, raw_value)

7) Add `env` to the function name.
For example:`process_env_option_value`

> +    local param_type = template_cfg[option]
> +
> +    -- May be peculiar to "feedback*" parameters.
> +    if param_type == nil then
> +        return nil
> +    end
> +
> +    local value = nil
> +    local err_msg_fmt = 'Environment variable TT_%s has ' ..
> +        'incorrect value for option \'%s\': should be %s'
> +
> +    -- "log_level" option should be a number.

8) This comment is deprecated.

> +    if param_type == 'number' then
> +        value = tonumber(raw_value)
> +        if value == nil then
> +            error(err_msg_fmt:format(string.upper(option), option,
> +                    "convertible to number"))

9) Use one `tab` and single quotes.

> +        end
> +    -- "log_nonblock" option should be boolean.

10) This comment is deprecated.

> +    elseif param_type == 'boolean' then
> +        if raw_value == 'true' then
> +            value = true
> +        elseif raw_value == 'false' then
> +            value = false
> +        else
> +            error(err_msg_fmt:format(string.upper(option), option,
> +                    "'true' or 'false'"))

11) Use one `tab` and single quotes.
12) Why are "TRUE" and "FALSE" is invalid?

> +        end
> +    elseif param_type == 'string, number' then
> +        -- Firstly, try to convert to number.
> +        value = tonumber(raw_value)
> +        if value == nil then
> +            value = raw_value
> +        end
> +    elseif param_type == 'string, number, table' then

13) Move this case to a separate function. It's very hard to read now.

> +        if string.sub(raw_value, 1, 1) == '{' and
> +           string.sub(raw_value, -1) == '}' then
> +            value = string.sub(raw_value, 2, -2)
> +            value = require('csv').load(value)[1]
> +            for i, item in pairs(value) do

14) Add a comment that now it can only be a string or a number (bool and
table are not supported).

> +                item = dequote(item)
> +                value[i] = tonumber(item)
> +                if value[i] == nil then
> +                    value[i] = item
> +                end
> +            end
> +        else
> +            value = tonumber(raw_value)
> +            if value == nil then
> +                value = raw_value
> +            end
> +        end
> +    else
> +        value = raw_value
> +    end
> +
> +    return value
> +end
> +
> +---
> +-- Pull and process configuration values from environment.
> +--

15) Just `--- Pull and process configuration values from environment.`

> +local function collect_env_cfg()
> +    local env_cfg = {}
> +    for option, _ in pairs(template_cfg) do
> +        local env_var_name = 'TT_' .. string.upper(option)
> +        local raw_value = os.getenv(env_var_name)
> +        if raw_value ~= nil then
> +            env_cfg[option] = process_option_value(option, raw_value)
> +        end
> +    end
> +
> +    return env_cfg
> +end
> +
>   -- Whether box is loaded.
>   --
>   -- `false` when box is not configured or when the initialization
> @@ -669,6 +781,8 @@ local function load_cfg(cfg)
>       cfg = upgrade_cfg(cfg, translate_cfg)
>       cfg = prepare_cfg(cfg, default_cfg, template_cfg,
>                         module_cfg, modify_cfg)
> +    local env_cfg = collect_env_cfg()
> +    apply_env_cfg(cfg, env_cfg)
>       apply_default_cfg(cfg, default_cfg, module_cfg);
>       -- Save new box.cfg
>       box.cfg = cfg
> diff --git a/test/app-tap/tarantoolctl.test.lua b/test/app-tap/tarantoolctl.test.lua
> index 3c3023d34..060316714 100755
> --- a/test/app-tap/tarantoolctl.test.lua
> +++ b/test/app-tap/tarantoolctl.test.lua
> @@ -160,7 +160,7 @@ local function merge(...)
>   end
>   
>   local test = tap.test('tarantoolctl')
> -test:plan(8)
> +test:plan(9)
>   
>   -- basic start/stop test
>   -- must be stopped afterwards
> @@ -632,4 +632,35 @@ test:test('filter_xlog', function(test)
>       end
>   end)
>   
> +-- gh-5602: Check that environment cfg variables are more
> +-- prioritized than tarantoolctl cfg.
> +do
> +    local dir = fio.tempdir()
> +    local code = [[ box.cfg ]]
> +    create_script(dir, 'show_cfg.lua', code)
> +    local code = [[ box.cfg{checkpoint_interval=3302, readahead=10001} ]]
> +    create_script(dir, 'cfg_script.lua', code)
> +
> +    local status, err = pcall(function()
> +        test:test("check answers in case of call", function(test_i)
> +            test_i:plan(4)
> +            os.setenv('TT_CHECKPOINT_INTERVAL', '3301')
> +            os.setenv('TT_READAHEAD', '10000')
> +            check_ok(test_i, dir, 'start', 'cfg_script', 0)
> +            tctl_wait_start(dir, 'cfg_script')
> +            check_ok(test_i, dir, 'eval',  'cfg_script show_cfg.lua', 0,
> +                     '---\n- 3301\n- 10000\n...', nil)
> +            check_ok(test_i, dir, 'stop', 'cfg_script', 0)
> +        end)
> +    end)
> +
> +    cleanup_instance(dir, 'cfg_script')
> +    recursive_rmdir(dir)
> +
> +    if status == false then
> +        print(("Error: %s"):format(err))
> +        os.exit()
> +    end
> +end
> +
>   os.exit(test:check() == true and 0 or -1)
> diff --git a/test/box-tap/gh-5602-environment-vars-cfg.result b/test/box-tap/gh-5602-environment-vars-cfg.result
> new file mode 100644
> index 000000000..c90dd301b
> --- /dev/null
> +++ b/test/box-tap/gh-5602-environment-vars-cfg.result
> @@ -0,0 +1,41 @@
> +TAP version 13
> +1..5
> +ok - box.cfg is successful
> +ok - listen
> +ok - readahead
> +ok - strip_core
> +ok - log_format is not set
> +TAP version 13
> +1..7
> +ok - box.cfg is successful
> +ok - listen
> +ok - replication is table
> +ok - replication URI 1
> +ok - replication URI 2
> +ok - replication_connect_timeout
> +ok - replication_synchro_quorum
> +TAP version 13
> +1..3
> +ok - box.cfg is successful
> +ok - box.cfg{} background value is prioritized
> +ok - box.cfg{} vinyl_timeout value is prioritized
> +TAP version 13
> +1..2
> +ok - box.cfg is not successful
> +ok - bad sql_cache_size value
> +TAP version 13
> +1..2
> +ok - box.cfg is not successful
> +ok - bad strip_core value
> +TAP version 13
> +1..2
> +ok - box.cfg is not successful
> +ok - bad replication value
> +TAP version 13
> +1..6
> +ok - set 1
> +ok - set 2
> +ok - set 3
> +ok - set 4
> +ok - set 5
> +ok - set 6
> diff --git a/test/box-tap/gh-5602-environment-vars-cfg.test.lua b/test/box-tap/gh-5602-environment-vars-cfg.test.lua
> new file mode 100755
> index 000000000..3d19fdc90
> --- /dev/null
> +++ b/test/box-tap/gh-5602-environment-vars-cfg.test.lua
> @@ -0,0 +1,57 @@
> +#!/usr/bin/env tarantool
> +
> +local os = require('os')
> +local fio = require('fio')
> +local tap = require('tap')
> +
> +local test = tap.test('gh-5602')
> +
> +-- gh-5602: Check that environment cfg variables working.
> +local TARANTOOL_PATH = arg[-1]
> +local script_name = 'gh-5602-test-cases-script.lua'
> +local path_to_script = fio.pathjoin(
> +        os.getenv('PWD'),
> +        'box-tap',
> +        script_name)
> +
> +---
> +-- Generate shell command where set is sequence of environment

16) `--- Generate shell command where set is sequence of environment`

> +-- variables, then path to tarantool, the first arg is path to
> +-- test script and the second one is number of set.
> +--

17) No extra blank line is needed(`--`).

> +local function shell_command(set, i)
> +    return ('%s %s %s %d'):format(
> +        set,
> +        TARANTOOL_PATH,
> +        path_to_script,
> +        i)
> +end
> +
> +local set_1 = ('%s %s %s %s'):format('TT_LISTEN=3301', 'TT_READAHEAD=10000',
> +    'TT_STRIP_CORE=false', 'TT_LOG_FORMAT=json')
> +local set_2 = ('%s %s %s %s'):format('TT_LISTEN=3301',
> +    'TT_REPLICATION=\"{\'0.0.0.0:12345\', \'1.1.1.1:12345\'}\"',
> +    'TT_REPLICATION_CONNECT_TIMEOUT=0.01',
> +    'TT_REPLICATION_SYNCHRO_QUORUM=\'4 + 1\'')
> +local set_3 = 'TT_BACKGROUND=true TT_VINYL_TIMEOUT=60.1'
> +local set_4 = 'TT_SQL_CACHE_SIZE=a'
> +local set_5 = 'TT_STRIP_CORE=a'
> +local set_6 = 'TT_REPLICATION=\"{0.0.0.0:12345\', \'1.1.1.1:12345\'}\"'
> +
> +local sets = {}
> +sets[1] = set_1
> +sets[2] = set_2
> +sets[3] = set_3
> +sets[4] = set_4
> +sets[5] = set_5
> +sets[6] = set_6
> +
> +test:plan(#sets)
> +for i, set in ipairs(sets) do
> +    local tmpdir = fio.tempdir()
> +    local new_path = fio.pathjoin(tmpdir, script_name)
> +    fio.copyfile(path_to_script, new_path)
> +    test:is(os.execute(shell_command(set, i)), 0, 'set '..i)
> +end
> +
> +os.exit(test:check() and 0 or 1)
> diff --git a/test/box-tap/gh-5602-test-cases-script.lua b/test/box-tap/gh-5602-test-cases-script.lua

18) `gh-5602-environment-cfg-test-cases.lua`

> new file mode 100755
> index 000000000..a8b2fc987
> --- /dev/null
> +++ b/test/box-tap/gh-5602-test-cases-script.lua
> @@ -0,0 +1,69 @@
> +local tap = require('tap')
> +
> +local test = tap.test('gh-5602')
> +
> +local status, err = pcall(box.cfg, {background = false, vinyl_timeout = 70.1})
> +
> +-- Check that environment cfg values are set correctly.
> +if arg[1] == '1' then
> +    test:plan(5)
> +    test:ok(status ~= false, 'box.cfg is successful')
> +    test:is(box.cfg['listen'], 3301, 'listen')
> +    test:is(box.cfg['readahead'], 10000, 'readahead')
> +    test:is(box.cfg['strip_core'], false, 'strip_core')
> +    test:is(box.cfg['log_format'], 'json', 'log_format is not set')
> +end
> +if arg[1] == '2' then
> +    test:plan(7)
> +    test:ok(status ~= false, 'box.cfg is successful')
> +    test:is(box.cfg['listen'], 3301, 'listen')
> +    local replication = box.cfg['replication']
> +    test:is(type(replication), 'table', 'replication is table')
> +    test:ok(replication[1] == '0.0.0.0:12345' or
> +            replication[1] == '1.1.1.1:12345', 'replication URI 1')
> +    test:ok(replication[2] == '0.0.0.0:12345' or
> +            replication[2] == '1.1.1.1:12345', 'replication URI 2')
> +    test:is(box.cfg['replication_connect_timeout'], 0.01,
> +            'replication_connect_timeout')
> +    test:is(box.cfg['replication_synchro_quorum'], '4 + 1',
> +            'replication_synchro_quorum')
> +end
> +
> +-- Check that box.cfg{} values are more prioritized than
> +-- environment cfg values.
> +if arg[1] == '3' then
> +    test:plan(3)
> +    test:ok(status ~= false, 'box.cfg is successful')
> +    test:is(box.cfg['background'], false,
> +            'box.cfg{} background value is prioritized')
> +    test:is(box.cfg['vinyl_timeout'], 70.1,
> +            'box.cfg{} vinyl_timeout value is prioritized')
> +end
> +
> +local err_msg_fmt = 'Environment variable TT_%s has '..
> +    'incorrect value for option \'%s\': should be %s'
> +
> +-- Check bad environment cfg values.
> +if arg[1] == '4' then
> +    test:plan(2)
> +    test:ok(status == false, 'box.cfg is not successful')
> +    local index = string.find(err, err_msg_fmt:format('SQL_CACHE_SIZE',
> +        'sql_cache_size', 'convertible to number'))
> +    test:ok(index ~= nil, 'bad sql_cache_size value')
> +end
> +if arg[1] == '5' then
> +    test:plan(2)
> +    test:ok(status == false, 'box.cfg is not successful')
> +    local index = string.find(err, err_msg_fmt:format('STRIP_CORE',
> +        'strip_core', '\'true\' or \'false\''))
> +    test:ok(index ~= nil, 'bad strip_core value')
> +end
> +if arg[1] == '6' then
> +    test:plan(2)
> +    test:ok(status == false, 'box.cfg is not successful')
> +    local index = string.find(tostring(err), 'Incorrect value for option '..
> +        '\'replication\': expected host:service or /unix.socket')
> +    test:ok(index ~= nil, 'bad replication value')
> +end
> +
> +os.exit(test:check() and 0 or 1)
>