Configure AWS functions

Functionbeat runs as a function in your serverless environment.

Before deploying Functionbeat, you need to configure one or more functions and specify details about the services that will trigger the functions.

You configure the functions in the the functionbeat.yml configuration file. When you’re done, you can deploy the functions to your serverless environment.

The aws functions require AWS credentials configuration in order to make AWS API calls. Users can either use AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY and/or AWS_SESSION_TOKEN, or use shared AWS credentials file. Please see AWS credentials options for more details.

The following example configures two functions: cloudwatch and sqs. The cloudwatch function collects events from CloudWatch Logs. The sqs function collects messages from Amazon Simple Queue Service (SQS). Both functions forward the events to Elasticsearch.

functionbeat.provider.aws.endpoint: "s3.amazonaws.com"
functionbeat.provider.aws.deploy_bucket: "functionbeat-deploy"
functionbeat.provider.aws.functions:
  - name: cloudwatch
    enabled: true
    type: cloudwatch_logs
    description: "lambda function for cloudwatch logs"
    triggers:
      - log_group_name: /aws/lambda/my-lambda-function
        #filter_pattern: mylog_
  - name: sqs
    enabled: true
    type: sqs
    description: "lambda function for SQS events"
    triggers:
      - event_source_arn: arn:aws:sqs:us-east-1:123456789012:myevents

cloud.id: "MyESDeployment:SomeLongString=="
cloud.auth: "elastic:SomeLongString"

processors:
  - add_host_metadata: ~
  - add_cloud_metadata: ~

You can specify the following options to configure the functions that you want to deploy.

A unique name for the S3 bucket that the Lambda artifact will be uploaded to.

A unique name for the Lambda function. This is the name of the function as it will appear in the Lambda console on AWS.

The type of service to monitor. For this release, the supported types are:

A description of the function. This description is useful when you are running multiple functions and need more context about how each function is used.

A list of triggers that will cause the function to execute. The list of valid triggers depends on the type:

A regular expression that matches the events you want to collect. Setting this option may reduce execution costs because the function only executes if there is data that matches the pattern.

The reserved number of instances for the function. Setting this option may reduce execution costs by limiting the number of functions that can execute in your serverless environment. The default is unreserved.

The maximum amount of memory to allocate for this function. Specify a value that is a factor of 64. There is a hard limit of 3008 MiB for each function. The default is 128 MiB.

The custom execution role to use for the deployed function. For example:

    role: arn:aws:iam::123456789012:role/MyFunction

Make sure the custom role has the permissions required to run the function. For more information, see IAM permissions required for deployment.

If role is not specified, the function uses the default role and policy created during deployment.

Specifies additional settings required to connect to private resources in an Amazon Virtual Private Cloud (VPC). For example:

    virtual_private_cloud:
      security_group_ids:
        - mySecurityGroup
        - anotherSecurityGroup
      subnet_ids:
        - myUniqueID

The dead letter queue to use for messages that can’t be processed successfully. Set this option to an ARN that points to an SQS queue.

The number of events to read from a Kinesis stream, the minimum value is 100 and the maximum is 10000. The default is 100.

The starting position to read from a Kinesis stream, valids values are trim_horizon and latest. The default is trim_horizon.

The number of batches to process from each shard concurrently, the minimum value is 1 and the maximum is 10 The default is 1.

If this option is set to true, fields with null values will be published in the output document. By default, keep_null is set to false.

If present, this formatted string overrides the index for events from this function (for elasticsearch outputs), or sets the raw_index field of the event’s metadata (for other outputs). This string can only refer to the agent name and version and the event timestamp; for access to dynamic fields, use output.elasticsearch.index or a processor.

Example value: "%{[agent.name]}-myindex-%{+yyyy.MM.dd}" might expand to "functionbeat-myindex-2019.12.13".

To configure AWS credentials, either put the credentials into the Functionbeat configuration, or use a shared credentials file, as shown in the following examples.

Users can either put the credentials into the Metricbeat module configuration or use environment variable AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY and/or AWS_SESSION_TOKEN instead.

If running on Docker, these environment variables should be added as a part of the docker command. For example, with Metricbeat:

$ docker run -e AWS_ACCESS_KEY_ID=abcd -e AWS_SECRET_ACCESS_KEY=abcd -d --name=metricbeat --user=root --volume="$(pwd)/metricbeat.aws.yml:/usr/share/metricbeat/metricbeat.yml:ro" docker.elastic.co/beats/metricbeat:7.11.1 metricbeat -e -E cloud.auth=elastic:1234 -E cloud.id=test-aws:1234

Sample metricbeat.aws.yml looks like:

metricbeat.modules:
- module: aws
  period: 5m
  access_key_id: ${AWS_ACCESS_KEY_ID}
  secret_access_key: ${AWS_SECRET_ACCESS_KEY}
  session_token: ${AWS_SESSION_TOKEN}
  metricsets:
    - ec2

Environment variables can also be added through a file. For example:

$ cat env.list
AWS_ACCESS_KEY_ID=abcd
AWS_SECRET_ACCESS_KEY=abcd

$ docker run --env-file env.list -d --name=metricbeat --user=root --volume="$(pwd)/metricbeat.aws.yml:/usr/share/metricbeat/metricbeat.yml:ro" docker.elastic.co/beats/metricbeat:7.11.1 metricbeat -e -E cloud.auth=elastic:1234 -E cloud.id=test-aws:1234

If access_key_id, secret_access_key and role_arn are all not given, then functionbeat will check for credential_profile_name. If you use different credentials for different tools or applications, you can use profiles to configure multiple access keys in the same configuration file. If there is no credential_profile_name given, the default profile will be used.

shared_credential_file is optional to specify the directory of your shared credentials file. If it’s empty, the default directory will be used. In Windows, shared credentials file is at C:\Users\<yourUserName>\.aws\credentials. For Linux, macOS or Unix, the file is located at ~/.aws/credentials. When running as a service, the home path depends on the user that manages the service, so the shared_credential_file parameter can be used to avoid ambiguity. Please see Create Shared Credentials File for more details.

role_arn is used to specify which AWS IAM role to assume for generating temporary credentials. If role_arn is given, functionbeat will check if access keys are given. If not, functionbeat will check for credential profile name. If neither is given, default credential profile will be used. Please make sure credentials are given under either a credential profile or access keys.

If running on Docker, the credential file needs to be provided via a volume mount. For example, with Metricbeat:

docker run -d --name=metricbeat --user=root --volume="$(pwd)/metricbeat.aws.yml:/usr/share/metricbeat/metricbeat.yml:ro" --volume="/Users/foo/.aws/credentials:/usr/share/metricbeat/credentials:ro" docker.elastic.co/beats/metricbeat:7.11.1 metricbeat -e -E cloud.auth=elastic:1234 -E cloud.id=test-aws:1234

Sample metricbeat.aws.yml looks like:

metricbeat.modules:
- module: aws
  period: 5m
  credential_profile_name: elastic-beats
  shared_credential_file: /usr/share/metricbeat/credentials
  metricsets:
    - ec2

There are two different types of AWS credentials can be used: access keys and temporary security credentials.

AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY are the two parts of access keys. They are long-term credentials for an IAM user or the AWS account root user. Please see AWS Access Keys and Secret Access Keys for more details.

An IAM role is an IAM identity that you can create in your account that has specific permissions that determine what the identity can and cannot do in AWS. A role does not have standard long-term credentials such as a password or access keys associated with it. Instead, when you assume a role, it provides you with temporary security credentials for your role session. IAM role Amazon Resource Name (ARN) can be used to specify which AWS IAM role to assume to generate temporary credentials. Please see AssumeRole API documentation for more details.

Here are the steps to set up IAM role using AWS CLI for Metricbeat. Please replace 123456789012 with your own account ID.

Step 1. Create example-policy.json file to include all permissions:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "VisualEditor0",
            "Effect": "Allow",
            "Action": [
                "s3:GetObject",
                "sqs:ReceiveMessage"
            ],
            "Resource": "*"
        },
        {
            "Sid": "VisualEditor1",
            "Effect": "Allow",
            "Action": "sqs:ChangeMessageVisibility",
            "Resource": "arn:aws:sqs:us-east-1:123456789012:test-fb-ks"
        },
        {
            "Sid": "VisualEditor2",
            "Effect": "Allow",
            "Action": "sqs:DeleteMessage",
            "Resource": "arn:aws:sqs:us-east-1:123456789012:test-fb-ks"
        },
        {
            "Sid": "VisualEditor3",
            "Effect": "Allow",
            "Action": [
                "sts:AssumeRole",
                "sqs:ListQueues",
                "tag:GetResources",
                "ec2:DescribeInstances",
                "cloudwatch:GetMetricData",
                "ec2:DescribeRegions",
                "iam:ListAccountAliases",
                "sts:GetCallerIdentity",
                "cloudwatch:ListMetrics"
            ],
            "Resource": "*"
        }
    ]
}

Step 2. Create IAM policy using the aws iam create-policy command:

$ aws iam create-policy --policy-name example-policy --policy-document file://example-policy.json

Step 3. Create the JSON file example-role-trust-policy.json that defines the trust relationship of the IAM role

{
    "Version": "2012-10-17",
    "Statement": {
        "Effect": "Allow",
        "Principal": { "AWS": "arn:aws:iam::123456789012:root" },
        "Action": "sts:AssumeRole"
    }
}

Step 4. Create the IAM role and attach the policy:

$ aws iam create-role --role-name example-role --assume-role-policy-document file://example-role-trust-policy.json
$ aws iam attach-role-policy --role-name example-role --policy-arn "arn:aws:iam::123456789012:policy/example-policy"

After these steps are done, IAM role ARN can be used for authentication in Metricbeat aws module.

Temporary security credentials has a limited lifetime and consists of an access key ID, a secret access key, and a security token which typically returned from GetSessionToken. MFA-enabled IAM users would need to submit an MFA code while calling GetSessionToken. default_region identifies the AWS Region whose servers you want to send your first API request to by default. This is typically the Region closest to you, but it can be any Region. Please see Temporary Security Credentials for more details. sts get-session-token AWS CLI can be used to generate temporary credentials. For example. with MFA-enabled:

aws> sts get-session-token --serial-number arn:aws:iam::1234:mfa/your-email@example.com --token-code 456789 --duration-seconds 129600

Because temporary security credentials are short term, after they expire, the user needs to generate new ones and modify the aws.yml config file with the new credentials. Unless live reloading feature is enabled for Metricbeat, the user needs to manually restart Metricbeat after updating the config file in order to continue collecting Cloudwatch metrics. This will cause data loss if the config file is not updated with new credentials before the old ones expire. For Metricbeat, we recommend users to use access keys in config file to enable aws module making AWS api calls without have to generate new temporary credentials and update the config frequently.

IAM policy is an entity that defines permissions to an object within your AWS environment. Specific permissions needs to be added into the IAM user’s policy to authorize Metricbeat to collect AWS monitoring metrics. Please see documentation under each metricset for required permissions.