app-sam.json

{
  "AWSTemplateFormatVersion": "2010-09-09",
  "Transform": "AWS::Serverless-2016-10-31",
  "Parameters": {
    "ExportName": {
      "Type": "String",
      "Default": "Function::CloudWatch-Alarm-To-Slack::Arn"
    },
    "UnencryptedHookUrl": {
      "Type": "String",
      "Default": ""
    },
    "KmsEncryptedHookUrl": {
      "Type": "String",
      "Default": ""
    },
    "SlackChannel": {
      "Type": "String",
      "Default": ""
    },
    "SlackUsername": {
      "Type": "String",
      "Default": "Slack-CloudWatch-Bot"
    },
    "EmojiIcon": {
      "Type": "String",
      "Default": ":robot_face:"
    },
    "OrgIcon": {
      "Type": "String",
      "Default": ""
    },
    "OrgName": {
      "Type": "String",
      "Default": ""
    }
  },
  "Resources": {
    "Topic": {
      "Type": "AWS::SNS::Topic",
      "Properties": {
        "DisplayName": {
          "Fn::Sub": "${AWS::StackName}-topic"
        }
      }
    },
    "LambdaErrorAlarm": {
      "Type": "AWS::CloudWatch::Alarm",
      "Properties": {
        "AlarmName": {
          "Fn::Sub": "${AWS::StackName}-lambda-errors"
        },
        "MetricName": "Errors",
        "Namespace": "AWS/Lambda",
        "Statistic": "Sum",
        "Threshold": 1,
        "Period": 60,
        "EvaluationPeriods": 1,
        "ComparisonOperator": "GreaterThanOrEqualToThreshold",
        "TreatMissingData": "notBreaching",
        "AlarmActions": [
          {
            "Ref": "Topic"
          }
        ]
      }
    },
    "CloudWatchFunction": {
      "Type": "AWS::Serverless::Function",
      "Properties": {
        "FunctionName": {
          "Ref": "AWS::StackName"
        },
        "Runtime": "nodejs22.x",
        "Handler": "lambda.handler",
        "Timeout": 60,
        "MemorySize": 192,
        "CodeUri": "build",
        "Environment": {
          "Variables": {
            "UNENCRYPTED_HOOK_URL": {
              "Fn::Sub": "${UnencryptedHookUrl}"
            },
            "KMS_ENCRYPTED_HOOK_URL": {
              "Fn::Sub": "${KmsEncryptedHookUrl}"
            },
            "SLACK_CHANNEL": {
              "Fn::Sub": "${SlackChannel}"
            },
            "SLACK_USERNAME": {
              "Fn::Sub": "${SlackUsername}"
            },
            "EMOJI_ICON": {
              "Fn::Sub": "${EmojiIcon}"
            },
            "ORG_ICON": {
              "Fn::Sub": "${OrgIcon}"
            },
            "ORG_NAME": {
              "Fn::Sub": "${OrgName}"
            }
          }
        },
        "Events": {
          "NotificationTopic": {
            "Type": "SNS",
            "Properties": {
              "Topic": {
                "Ref": "Topic"
              }
            }
          }
        }
      }
    }
  },
  "Outputs": {
    "FunctionArn": {
      "Value": {
        "Fn::GetAtt": [
          "CloudWatchFunction",
          "Arn"
        ]
      },
      "Export": {
        "Name": {
          "Fn::Sub": "${ExportName}"
        }
      }
    }
  }
}