Add tnt_cartridge_config_applied metric

Author: p0rtale

CHANGELOG.md

@@ -5,6 +5,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Added
+- `tnt_cartridge_config_applied` metric
 
 ## [1.3.1] - 2025-02-24
 

doc/monitoring/api_reference.rst

@@ -564,6 +564,7 @@ Metrics functions
     *   ``luajit``
     *   ``cartridge_issues``
     *   ``cartridge_failover``
+    *   ``cartridge_config``
     *   ``clock``
     *   ``event_loop``
     *   ``config``

doc/monitoring/metrics_reference.rst

@@ -414,6 +414,9 @@ Cartridge
         *   -   ``tnt_cartridge_failover_trigger_total``
             -   Count of failover triggers in cluster.
 
+        *   -   ``tnt_cartridge_config_applied``
+            -   Whether the Cartridge configuration was successfully applied (1 if applied, 0 otherwise).
+
 ..  _metrics-reference-luajit:
 
 LuaJIT metrics

metrics/cartridge/config.lua

@@ -0,0 +1,32 @@
+local utils = require('metrics.utils')
+local collectors_list = {}
+local vars = nil
+
+local function update()
+    if vars == nil then
+        local is_cartridge = pcall(require, 'cartridge')
+        if not is_cartridge then
+            return
+        end
+
+        vars = require('cartridge.vars').new('cartridge.twophase')
+    end
+
+    local config_applied = vars.config_applied
+    if config_applied ~= nil then
+        collectors_list.config_applied =
+            utils.set_gauge(
+                'cartridge_config_applied',
+                'Whether the Cartridge configuration was successfully applied',
+                config_applied and 1 or 0,
+                nil,
+                nil,
+                {default = true}
+            )
+    end
+end
+
+return {
+    update = update,
+    list = collectors_list,
+}

metrics/tarantool.lua

@@ -22,6 +22,7 @@ local default_metrics = {
     luajit              = require('metrics.tarantool.luajit'),
     cartridge_issues    = require('metrics.cartridge.issues'),
     cartridge_failover  = require('metrics.cartridge.failover'),
+    cartridge_config    = require('metrics.cartridge.config'),
     clock               = require('metrics.tarantool.clock'),
     event_loop          = require('metrics.tarantool.event_loop'),
     config              = require('metrics.tarantool.config'),

test/integration/cartridge_metrics_test.lua

@@ -144,3 +144,34 @@ g.test_failover = function()
     g.cluster.main_server:start()
     g.cluster:wait_until_healthy()
 end
+
+g.test_config_applied_metric = function()
+    local main_server = g.cluster:server('main')
+
+    t.helpers.retrying({}, function()
+        local resp = main_server:http_request('get', '/metrics')
+        local config_metric = utils.find_metric('tnt_cartridge_config_applied', resp.json)
+
+        t.assert_is_not(config_metric, nil, 'Cartridge config applied metric presents in /metrics response')
+        t.assert_equals(config_metric[1].value, 1, 'Config should be applied')
+    end)
+
+    local patch = require('cartridge').config_patch_clusterwide
+    local ok, err = patch({
+        ['conflict'] = {},
+        ['conflict.yml'] = "text",
+    })
+    t.assert_equals(ok, nil)
+    t.assert_covers(err, {
+        class_name = 'PatchConfigError',
+        err = 'Ambiguous sections "conflict" and "conflict.yml"',
+    })
+
+    t.helpers.retrying({}, function()
+        local resp = main_server:http_request('get', '/metrics')
+        local config_metric = utils.find_metric('tnt_cartridge_config_applied', resp.json)
+
+        t.assert_is_not(config_metric, nil, 'Cartridge config applied metric presents in /metrics response')
+        t.assert_equals(config_metric[1].value, 0, 'Config should not be applied')
+    end)
+end