cloudwatch metric filter alert with logs - amazon-web-services

We are using cloudwatch metrics filter and setup alarm and send notification through SNS - Email.
We are wondering if it is possible to also see logs that triggers the alarm in the email? or is it possible to do so with the help with a custom lambda function?
Thanks

Locally, you may try to have the following set up.
CloudWatch Alarm
SNS-log-reader with lambda as a subscriber
SNS-send-mails with e-mails as a subscriber
So the logic would be - Alarm trigger SNS-log-reader. Then lambda which is mapped to *SNS-log-reader can read the logs from LogGroup, build the message in needed format and send to e-mail/s via SNS-send-mails (or Simple Email Service (Amazon SES))

Related

AWS cloudwatch alerting poll API

I can see that in AWS alerting works with SNS where protocols are available as Email, https and SMS...Basically push mechanisms..
Is it possible to make these alerts pull-based? any ideas around how this could be tried?
You would need to create a solution for this, natively when an alert triggers it can be configured to go to either an SNS topic which has 1 or more subscriptions to notify.
Instead you would need to use the describe-alarms function to retrieve a list of alarms, this can be narrowed down to alarming only by using the --state-value parameter such as the example below
aws cloudwatch describe-alarms --state-value ALARM
Does this fit your needs https://awscli.amazonaws.com/v2/documentation/api/latest/reference/cloudwatch/describe-alarm-history.html ?
Please check aws cloudwatch there are several options for alarms.

Send log data from ec2 logs to eventbridge

I want to send logs data from my EC2 instance (Ubuntu) to an AWS eventbridge where I can then send them to multiple endpoints. e.g. if someone performs a root user operation on the server this is written to/var/log/auth.log, I would then like this change in the log to be sent to eventbridge where it can then be routed to other locations, how can achieve this?
cheers
N.B.
I have tried using the cloudwatch agent but I can't figure how to get the logs to eventbridge once they're in a log group, so if there is a way I can this that would also work.
I can't figure how to get the logs to eventbridge once they're in a log group, so if there is a way I can this that would also work.
Once your CloudWatch Agent writes relevant logs to CloudWatch logs, you can setup a subscription filter on your log group.
The filter would stream logs of interest (e.g. those that contain ssh) into a lambda function. How to set it up is shown in:
Example 2: Subscription Filters with AWS Lambda
The lambda, using events api, e.g. in boto3, could process the log stream, filter out messages, construct events and publish them to the event bridge.

AWS CloudWatch Rule triggered by Log Event

I want to create CloudWatch Rule that would be triggered upon creation of Log Event. For that reason as an event pattern I selected CloudWatch Logs service but when I try to generate some Cloud Watch logs the rule is not getting triggered. I can not find any example of using aws.logs as a source for an event and hence my question if I'm doing something wrong.
This is because the only events for logs available are AWS API Call via CloudTrail. CloudWatch Logs does not generate CloudWatch events on receiving new log entries.
For the Logs API call events to work, you need to setup CloudTrial trial.
However, if you want to trigger your lambda function based on log entries, I can recommend using subscription filters for lambda:
You can use subscriptions to get access to a real-time feed of log events from CloudWatch Logs and have it delivered to other services such as a Amazon Kinesis stream, Amazon Kinesis Data Firehose stream, or AWS Lambda for custom processing, analysis, or loading to other systems.

Want SNS alert repeatedly

I had setup an Alert for CPU utilization on EC2 instance. Created one SNS topic to send alerts on mail. It sends me an alert when CPU utilization goes to ALARM state but I want repeated alerts till ALARM state get resolved. Please help me... I'm newbie to AWS.
What you can do is setup a Lambda function with a CloudWatch event trigger so that it runs periodically, and inside it call the CloudWatch GetMetricStatistics API. Then, simply check if it is above or below your preferred threshold (or if you want, whether or not it's in Alarm state) and publish a message to SNS. There are a lot of SDK documentations on how to use these API's with your preferred language.
It is not possible to get repeated notifications after getting into the ALARM state. As the alarm is entering the ALARM state only once that means the notification via Amazon SNS will be sent only once.
Autoscaling policy will be triggered by the same alarm. But mail will be sent only once.

How can I get aws cloudwatch to fire alarm notifications repeatedly

We have aws alarms set up to email on alarm but we would like to continue to get the alarm notification even if the state is in Alarm without a state change. How could I achieve this (would be happy to use a lambda but no idea how to do it)
Amazon CloudWatch alarm notifications are only sent when the state of the alarm changes. It is not possible to configure CloudWatch to continually send notifications while in the ALARM state.
You would need to write your own code to send such notifications. This could be accomplished via a cron job, scheduled AWS Lambda function or your own application.
Try with a script using Cloudwatch API for example with Boto3 + Python or a Lambda running every X minutes. I have a python script to get values from cloudwatch you can adapt it. http://www.dbigcloud.com/cloud-computing/230-integrando-metricas-de-aws-cloudwatch-en-zabbix.html
One alternative is, to create a Lambda function to send email and host that function using CloudWatch Rule with Scheduled option and target as Lambda function that you have created. In Schedule option, you can set the frequency of time that you expect to receive email. In defined frequency, the Rule will trigger Lambda Function to send email.