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Lidarr/src/NzbDrone.Core/HealthCheck/HealthCheckService.cs

163 lines
5.7 KiB

using System;
using System.Collections.Generic;
using System.Linq;
using NLog;
using NzbDrone.Common.Cache;
using NzbDrone.Common.Extensions;
using NzbDrone.Common.Messaging;
using NzbDrone.Common.Reflection;
using NzbDrone.Core.Lifecycle;
using NzbDrone.Core.Messaging.Commands;
using NzbDrone.Core.Messaging.Events;
namespace NzbDrone.Core.HealthCheck
{
public interface IHealthCheckService
{
List<HealthCheck> Results();
}
public class HealthCheckService : IHealthCheckService,
IExecute<CheckHealthCommand>,
IHandleAsync<ApplicationStartedEvent>,
IHandleAsync<IEvent>
{
private readonly IProvideHealthCheck[] _healthChecks;
private readonly IProvideHealthCheck[] _startupHealthChecks;
private readonly IProvideHealthCheck[] _scheduledHealthChecks;
private readonly Dictionary<Type, EventDrivenHealthCheck[]> _eventDrivenHealthChecks;
private readonly IEventAggregator _eventAggregator;
private readonly ICacheManager _cacheManager;
private readonly Logger _logger;
private readonly ICached<HealthCheck> _healthCheckResults;
public HealthCheckService(IEnumerable<IProvideHealthCheck> healthChecks,
IEventAggregator eventAggregator,
ICacheManager cacheManager,
Logger logger)
{
_healthChecks = healthChecks.ToArray();
_eventAggregator = eventAggregator;
_cacheManager = cacheManager;
_logger = logger;
_healthCheckResults = _cacheManager.GetCache<HealthCheck>(GetType());
_startupHealthChecks = _healthChecks.Where(v => v.CheckOnStartup).ToArray();
_scheduledHealthChecks = _healthChecks.Where(v => v.CheckOnSchedule).ToArray();
_eventDrivenHealthChecks = GetEventDrivenHealthChecks();
}
public List<HealthCheck> Results()
{
return _healthCheckResults.Values.ToList();
}
private Dictionary<Type, EventDrivenHealthCheck[]> GetEventDrivenHealthChecks()
{
return _healthChecks
.SelectMany(h => h.GetType().GetAttributes<CheckOnAttribute>().Select(a => Tuple.Create(a.EventType, new EventDrivenHealthCheck(h, a.Condition))))
.GroupBy(t => t.Item1, t => t.Item2)
.ToDictionary(g => g.Key, g => g.ToArray());
}
private void PerformHealthCheck(IProvideHealthCheck[] healthChecks, IEvent message = null)
{
var results = new List<HealthCheck>();
foreach (var healthCheck in healthChecks)
{
if (healthCheck is IProvideHealthCheckWithMessage && message != null)
{
results.Add(((IProvideHealthCheckWithMessage)healthCheck).Check(message));
}
else
{
results.Add(healthCheck.Check());
}
}
foreach (var result in results)
{
if (result.Type == HealthCheckResult.Ok)
{
_healthCheckResults.Remove(result.Source.Name);
}
else
{
if (_healthCheckResults.Find(result.Source.Name) == null)
{
_eventAggregator.PublishEvent(new HealthCheckFailedEvent(result));
}
_healthCheckResults.Set(result.Source.Name, result);
}
}
_eventAggregator.PublishEvent(new HealthCheckCompleteEvent());
}
public void Execute(CheckHealthCommand message)
{
if (message.Trigger == CommandTrigger.Manual)
{
PerformHealthCheck(_healthChecks);
}
else
{
PerformHealthCheck(_scheduledHealthChecks);
}
}
public void HandleAsync(ApplicationStartedEvent message)
{
PerformHealthCheck(_startupHealthChecks);
}
public void HandleAsync(IEvent message)
{
if (message is HealthCheckCompleteEvent)
{
return;
}
EventDrivenHealthCheck[] checks;
if (!_eventDrivenHealthChecks.TryGetValue(message.GetType(), out checks))
{
return;
}
var filteredChecks = new List<IProvideHealthCheck>();
var healthCheckResults = _healthCheckResults.Values.ToList();
foreach (var eventDrivenHealthCheck in checks)
{
if (eventDrivenHealthCheck.Condition == CheckOnCondition.Always)
{
filteredChecks.Add(eventDrivenHealthCheck.HealthCheck);
continue;
}
var healthCheckType = eventDrivenHealthCheck.HealthCheck.GetType();
if (eventDrivenHealthCheck.Condition == CheckOnCondition.FailedOnly &&
healthCheckResults.Any(r => r.Source == healthCheckType))
{
filteredChecks.Add(eventDrivenHealthCheck.HealthCheck);
continue;
}
if (eventDrivenHealthCheck.Condition == CheckOnCondition.SuccessfulOnly &&
healthCheckResults.None(r => r.Source == healthCheckType))
{
filteredChecks.Add(eventDrivenHealthCheck.HealthCheck);
}
}
// TODO: Add debounce
PerformHealthCheck(filteredChecks.ToArray(), message);
}
}
}