private async Task SetShutdownTime(EC2InstanceStateChangeEvent cloudWatchEvent, ILambdaContext context)
{
Instance instance = await GetInstanceDetails(cloudWatchEvent.Detail.InstanceId, context);
var tag = instance.Tags.FirstOrDefault(x => x.Key == "StopAfterMinutes");
if (tag == null)
{
context.Logger.LogLine($"Instance {instance.InstanceId} does not have a 'StopAfterMinutes' tag. Ignoring");
return;
}
if (!int.TryParse(tag.Value, out var minutes))
{
context.Logger.LogLine($"Instance {instance.InstanceId} has invalid time for 'StopAfterMinutes' tag. Ignoring");
return;
}
SetInstanceShutdownDto shutdownDto = new SetInstanceShutdownDto {
InstanceId = instance.InstanceId, StopAfterMinutes = minutes
};
string message = Newtonsoft.Json.JsonConvert.SerializeObject(shutdownDto);
var snsTopic = GetSnsTopic();
context.Logger.LogLine($"Publishing SetInstanceShutdown message to topic {snsTopic}. Message: {message}");
PublishRequest request = new PublishRequest(snsTopic, message);
await _snsClient.PublishAsync(request);
context.Logger.LogLine($"Published!");
}
private static void LogEvent(EC2InstanceStateChangeEvent cloudWatchEvent, ILambdaContext context)
{
context.Logger.LogLine($"Source: {cloudWatchEvent.Source}");
context.Logger.LogLine($"Region: {cloudWatchEvent.Region}");
context.Logger.LogLine($"DetailType: {cloudWatchEvent.DetailType}");
context.Logger.LogLine($"InstanceId: {cloudWatchEvent.Detail.InstanceId}");
context.Logger.LogLine($"State: {cloudWatchEvent.Detail.State}");
}
private async Task UpdateRoute53Entry(EC2InstanceStateChangeEvent cloudWatchEvent,
ILambdaContext context)
{
Instance instance = await GetInstanceDetails(cloudWatchEvent.Detail.InstanceId, context);
if (instance != null)
{
HostedZone zone = await GetZone(instance, context);
await UpdateRoute53(zone, instance, context);
}
else
{
context.Logger.LogLine($"**** InstanceId Not Found: {cloudWatchEvent.Detail.InstanceId}");
}
}
/// <summary>
/// Instance is stopping
///
/// Remove the route 53 entry for it.
/// </summary>
/// <param name="cloudWatchEvent"></param>
/// <param name="context"></param>
/// <returns></returns>
private async Task RemoveRoute53Entry(EC2InstanceStateChangeEvent cloudWatchEvent,
ILambdaContext context)
{
Instance instance = await GetInstanceDetails(cloudWatchEvent.Detail.InstanceId, context);
if (instance != null)
{
HostedZone zone = await GetZone(instance, context);
if (zone == null)
{
return;
}
await DeleteRoute53RecordSet(zone, instance, context);
}
}
/// <summary>
/// Lambda function handler. Triggered by CloudWatch EC2 instance state change.
/// </summary>
/// <param name="cloudWatchEvent"></param>
/// <param name="context"></param>
/// <returns></returns>
public async Task FunctionHandler(EC2InstanceStateChangeEvent cloudWatchEvent, ILambdaContext context)
{
context.Logger.LogLine("EC2 State Change event triggered.");
LogEvent(cloudWatchEvent, context);
switch (cloudWatchEvent.Detail.State)
{
case "running":
await SetShutdownTime(cloudWatchEvent, context);
break;
default:
context.Logger.LogLine($"No action for state: {cloudWatchEvent.Detail.State}");
break;
}
}
/// <summary>
/// Lambda function handler.
/// </summary>
/// <param name="cloudWatchEvent"></param>
/// <param name="context"></param>
/// <returns></returns>
public async Task FunctionHandler(EC2InstanceStateChangeEvent cloudWatchEvent, ILambdaContext context)
{
context.Logger.LogLine("EC2 State Change event triggered.");
LogEvent(cloudWatchEvent, context);
switch (cloudWatchEvent.Detail.State)
{
case "stopping":
await RemoveRoute53Entry(cloudWatchEvent, context);
break;
case "running":
await UpdateRoute53Entry(cloudWatchEvent, context);
break;
default:
context.Logger.LogLine($"No action for state: {cloudWatchEvent.Detail.State}");
break;
}
}
