Troubleshooting Invalid Metric Filter Pattern Error in Terraform for AWS CloudWatch Log Metric Filter

Question

I'm encountering an error while trying to configure an AWS CloudWatch Log Metric Filter using Terraform. My goal is to create a metric filter that captures specific log data based on the level and logger fields. However, I keep getting an "Invalid metric filter pattern" error, and I'm unsure how to correct the pattern syntax.

Here's my Terraform configuration:

resource "aws_cloudwatch_log_metric_filter" "log_count_metric_filter" {
  name           = "logGroupCount"
  pattern        = "{ $.level = * } { $.logger = <*> }"
  log_group_name = "myLogGroup"

  metric_transformation {
    name      = "logErrorCount"
    namespace = "logSpace"
    value     = "1"
    dimensions = {
      level  = "$.level"
      logger = "$.logger"
      #      message = "$.message"
    }
  }
}

The error I receive is:

Error: putting CloudWatch Logs Metric Filter (logGroupCount: InvalidParameterException: Invalid metric filter pattern
with module.data-retention.aws_cloudwatch_log_metric_filter.log_count_metric_filter
on <> line 21, in resource "aws_cloudwatch_log_metric_filter" "log_count_metric_filter":

I've tried several variations of the pattern(pattern = "{$.level $.logger}" ), such as removing commas, changing the structure, but I keep encountering the same error. I'm looking for guidance on how to correctly format this pattern according to AWS CloudWatch Logs filter pattern syntax.

Answer 1

Probably that will work:

pattern = "{ ($.level = *) && ($.logger = *) }"

Take a look that tutorial for filters and pattern Syntax: https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/FilterAndPatternSyntax.html