如何使用Ansible删除AWS Lambda时同步删除关联的CloudWatch Event

To tackle your problem of deleting the corresponding CloudWatch Event when removing a Lambda function (especially since your current setup creates Events tied to specific Lambda versions), here are two practical approaches tailored to your scenario:

Approach 1: Use a Fixed Naming Convention (Simplest) #

If your CloudWatch Event rule follows a predictable naming pattern (e.g., lambdaNameevent for a Lambda named lambdaName), you can directly delete the Event rule by name before removing the Lambda. This avoids dealing with version-specific ARNs entirely.

First, adjust your creation tasks to use the version-agnostic Lambda ARN (instead of the versioned one returned by the lambda module) to ensure your Event targets the Lambda's latest version:

- name: Deploy Lambda function
  lambda:
    name: 'lambdaName'
    state: present
    # Add your runtime, handler, code package, etc. here
  register: lambdaResult

- name: Build version-agnostic Lambda ARN
  set_fact:
    lambda_base_arn: "arn:aws:lambda:{{ aws_region }}:{{ aws_account_id }}:function:{{ lambdaResult.configuration.function_name }}"

- name: Create CloudWatch Event rule targeting Lambda
  cloudwatchevent_rule:
    name: 'lambdaNameevent'
    schedule_expression: 'rate(5 minutes)'  # Adjust to your trigger logic
    targets:
      - arn: '{{ lambda_base_arn }}'
        id: "1"
    state: present

Then, when you need to clean up resources:

- name: Delete associated CloudWatch Event rule
  cloudwatchevent_rule:
    name: 'lambdaNameevent'
    state: absent
    # Including the target ID ensures we cleanly remove the target before deleting the rule
    targets:
      - id: "1"

- name: Delete Lambda function
  lambda:
    name: 'lambdaName'
    state: absent

Approach 2: Dynamically Find and Delete Associated Events #

If your CloudWatch Event rules don't follow a fixed naming pattern, or multiple Events target the same Lambda, you can query all Event rules, filter those targeting your Lambda, and delete them programmatically.

- name: Get all CloudWatch Event rules in the region
  cloudwatchevent_rule_info:
    region: '{{ aws_region }}'
  register: all_cwe_rules

- name: Filter rules targeting our Lambda function
  set_fact:
    target_rules: >
      {{ all_cwe_rules.rules 
         | selectattr('targets', 'defined') 
         | selectattr('targets', '!=', []) 
         | selectattr('targets.0.arn', 'search', lambdaResult.configuration.function_name) 
         | map(attribute='name') 
         | list }}

- name: Delete all matching CloudWatch Event rules
  cloudwatchevent_rule:
    name: '{{ item }}'
    state: absent
  loop: '{{ target_rules }}'

- name: Delete the Lambda function
  lambda:
    name: 'lambdaName'
    state: absent

Key Notes: #

• Version-Agnostic ARNs: Using the base Lambda ARN (without version suffix) ensures your CloudWatch Event always triggers the latest Lambda version, and simplifies cleanup since you don't have to track versioned ARNs.
• Order Matters: Always delete the CloudWatch Event rule first before removing the Lambda to avoid "target not found" errors in AWS.
• Filter Logic: The search filter in the second approach matches any Event target ARN that includes your Lambda's name, which works for both versioned and base ARNs.

内容的提问来源于stack exchange，提问作者Sumanth Kumar Mora