public HealthCheckBuilder Add <TCheck>(IHealthCheckSettings settings) where TCheck : class, IHealthCheck
{
if (settings == null)
{
throw new ArgumentNullException(nameof(settings));
}
if (string.IsNullOrEmpty(settings.Name))
{
throw new ArgumentException($"Property {nameof(settings.Name)} cannot be null or empty.", nameof(settings));
}
Services.TryAddTransient <TCheck>();
Settings.Add(typeof(TCheck), settings);
return(this);
}
public async override Task CheckHealthAsync(HealthCheckContext context, IHealthCheckSettings settings)
{
DbConnection connection = _dbContext.Database.GetDbConnection();
try
{
await connection.OpenAsync();
if (connection.State == ConnectionState.Open)
{
context.Succeed();
}
else
{
context.Fail();
}
}
finally
{
connection.Close();
}
}
public HealthCheckContext(IHealthCheckSettings settings)
{
Settings = settings;
Stopwatch = new Stopwatch();
}
private async Task <HealthCheckResult> CheckHealthAsync(HealthCheckPolicy policy, IHealthCheckSettings settings)
{
var checkCache = _resultCache[settings.Name];
var utcNow = _clock.UtcNow;
HealthCheckResult result = null;
if (!checkCache.ShouldCheck(utcNow))
{
result = checkCache.Result;
}
else
{
using (CancellationTokenSource cts = new CancellationTokenSource(settings.Timeout))
{
IHealthCheck check = checkCache.Check;
var healthContext = new HealthCheckContext(settings);
healthContext.CancellationToken = cts.Token;
try
{
await check.CheckHealthAsync(healthContext);
result = new HealthCheckResult
{
Name = settings.Name,
Elapsed = healthContext.ElapsedMilliseconds,
Message = healthContext.Message,
Status = healthContext.HasSucceeded ? HealthStatus.Healthy : healthContext.HasWarned ? HealthStatus.Warning : HealthStatus.Unhealthy,
Issued = utcNow.ToUnixTimeSeconds(),
NextTry = utcNow.AddSeconds(settings.Frequency),
Critical = settings.Critical,
Properties = healthContext.Properties?.ToDictionary(kvp => kvp.Key, kvp => JToken.FromObject(kvp.Value))
};
checkCache.Result = result;
}
catch (Exception e)
{
result = new HealthCheckResult
{
Name = settings.Name,
Elapsed = healthContext.ElapsedMilliseconds,
Message = "An error occured. See logs for more details.",
Status = HealthStatus.Unhealthy,
Issued = utcNow.ToUnixTimeSeconds(),
NextTry = utcNow.AddSeconds(settings.Frequency),
Critical = settings.Critical,
Exception = e
};
checkCache.Result = result;
}
}
}
return(result);
}