During desired nodes updates the system validates that the provided node settings are valid in order to avoid boot looping issues. If one of the node settings depends on a secure setting, the validation fails even when the secure setting is present and correct.
server/src/main/java/org/elasticsearch/node/Node.java
protected ReadinessService newReadinessService(ClusterService clusterService, Environment environment) {
        return new ReadinessService(clusterService, environment);
    }
    /**
     * Get Custom Name Resolvers list based on a Discovery Plugins list
     *
     * @param discoveryPlugins Discovery plugins list
     */
    private List<NetworkService.CustomNameResolver> getCustomNameResolvers(List<DiscoveryPlugin> discoveryPlugins) {
        List<NetworkService.CustomNameResolver> customNameResolvers = new ArrayList<>();
        for (DiscoveryPlugin discoveryPlugin : discoveryPlugins) {
            NetworkService.CustomNameResolver customNameResolver = discoveryPlugin.getCustomNameResolver(settings());
            if (customNameResolver != null) {
                customNameResolvers.add(customNameResolver);
            }
        }
        return customNameResolvers;
    }
    /**
     * Constructs a ClusterInfoService which may be mocked for tests.
     */
    protected ClusterInfoService newClusterInfoService(
        Settings settings,
        ClusterService clusterService,
        ThreadPool threadPool,
        NodeClient client
    ) {
        final InternalClusterInfoService service = new InternalClusterInfoService(settings, clusterService, threadPool, client);
        if (DiscoveryNode.isMasterNode(settings)) {