AWS application ELB Service discovery

  • Release version: Xanadu
  • Updated August 1, 2024
  • 2 minutes to read
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    Summary of AWS application ELB Service discovery

    The AWS application ELB Service discovery pattern in ServiceNow enables customers to visualize all Elastic Load Balancers (ELBs) in their AWS environment using a top-down discovery approach. ELB automatically distributes incoming application traffic across multiple targets, enhancing performance and availability. This ServiceNow pattern supports features such as ultra-high performance, TLS offloading at scale, centralized certificate deployment, and support for UDP and static IP addresses.

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    The discovery process begins at the HTTP(s) endpoint and establishes outgoing relationships to Amazon EC2 instances. It is compatible with the ServiceNow AI Platform and supports Amazon Commercial Cloud Services (C2S) for government and intelligence community environments. This pattern is available starting with the Kingston release of the ServiceNow platform and later.

    Prerequisites

    • Run a horizontal discovery using Cloud API (CAPI) first because this pattern supports only top-down discovery.
    • After load balancer data is stored in the Configuration Management Database (CMDB), create an application service for each load balancer.
    • Ensure read-only permissions are set for specific AWS REST APIs related to ELB and EC2 instance descriptions to facilitate discovery.
    • Download the Discovery and Service Mapping Patterns from the ServiceNow Store to support Cloud Discovery.
    • Install the MID Server on a host machine that meets or exceeds ServiceNow's system requirements.
    • Verify REST API permissions by consulting the Cloud Discovery patterns spreadsheet, which details required user permissions, CI classes, and vendor documentation links.

    Practical Use and Testing

    The AWS REST APIs used for discovery can be tested with tools like Postman to ensure proper configuration before running discovery jobs. ServiceNow provides knowledge base articles to assist with this testing.

    Data Collected

    Discovery collects key ELB data and stores it in ServiceNow CMDB tables, such as Load Balancer Services [cmdbcilbservice], including:

    • Fully qualified domain name (fqdn): DNS name of the load balancer.
    • Name: Load balancer name formatted as <LB name>:<LB port>.
    • Serial Number: Formatted as ##ObjectID=<LBARN>.
    • Port: Port number used by the load balancer.
    • Object ID: Unique identifier of the load balancer.
    • IP Address: IP address corresponding to the FQDN.

    Benefits for ServiceNow Customers

    By implementing this discovery pattern, ServiceNow customers can gain comprehensive visibility into their AWS ELB infrastructure, establish accurate service relationships, and improve cloud governance and operational efficiency. This enables better monitoring, management, and automation of load balancing resources within the AWS environment.

    Discovery uses the Amazon AWS application ELB Service discovery pattern to show all load balancers in your environment in a map.

    Elastic Load Balancing (ELB) automatically distributes incoming application traffic across multiple targets.

    The Amazon AWS application ELB Service discovery pattern supports top-down discovery. This pattern discovers all load balancers with these characteristics:
    • Use ultra-high performance, TLS offloading at scale, and centralized certificate deployment
    • Support UDP and static IP addresses for your application

    For top-down discovery, the entry point is HTTP(s) Endpoint. Outgoing relations are to Amazon EC2 instances.

    The ServiceNow AI Platform supports Amazon Commercial Cloud Services (C2S) for discovery and cloud governance. C2S is the government program that brings AWS into the Intelligence Community.

    You can use this pattern on the ServiceNow platform using Kingston or later releases.

    Visit the ServiceNow Store website to view all the available apps and for information about submitting requests to the store. For cumulative release notes information for all released apps, see the ServiceNow Store version history release notes.

    Prerequisites

    • Run a horizontal discovery, using Cloud API (CAPI). This is necessary because this discovery pattern supports top-down discovery only. For Cloud Discovery, you can run the horizontal discovery as usual.
    • When the load balancers data has been stored in the Configuration Management Database (CMDB), create an application service for each load balancer.
    • Set read-only permissions for these REST APIs:
      • https://elasticloadbalancing.<REGION>.amazonaws.com/?Action=DescribeLoadBalancers&LoadBalancerArns.member.1=<LB_ARN>&Version=2015-12-01
      • https://elasticloadbalancing.<REGION>.amazonaws.com/?Action=DescribeLoadBalancers&Version=2015-12-01
      • https://elasticloadbalancing.<REGION>.amazonaws.com/?Action=DescribeListeners&LoadBalancerArn=<LB_ARN>&Version=2015-12-01
      • https://elasticloadbalancing.<REGION>.amazonaws.com/?Action=DescribeRules&ListenerArn=<LISTENER_ARN>&Version=2015-12-01
      • https://elasticloadbalancing.<REGION>.amazonaws.com/?Action=DescribeTargetHealth&TargetGroupArn=<TARGET_GROUP_ARN>&Version=2015-12-01
      • https://ec2.<REGION>.amazonaws.com/?Action=DescribeInstances&Version=2016-11-15&Filter.1.Name=instance-state-name&Filter.1.Value=running&Filter.2.Name=instance-id&Filter.2.Value=<INSTANCE_ID>
    • For Cloud Discovery, download the Discovery and Service Mapping Patterns from the ServiceNow Store.
    • When installing the MID Server, ensure that the host machine meets or exceeds the MID Server system requirements published on the ServiceNow documentation site.

    Verify the REST API Permissions

    Download the Cloud Discovery patterns spreadsheet so you can grant user permissions required for running the Discovery patterns. In addition to permissions, the spreadsheet also includes useful information such as pattern names, types, CI Classes, and links to vendor documentation. New patterns are available quarterly, so check periodically to be sure you have the latest version of the spreadsheet.

    Note:
    You can test the AWS REST APIs using Postman API platform. For more information, see the How to test AWS REST API using POSTMAN [KB0782183] article in the Now Support Knowledge Base.

    Data collected by Discovery during horizontal discovery

    The discovered data includes the following tables and fields.

    Table and field Description
    Load Balancer Services [cmdb_ci_lb_service]
    Fully qualified domain name [fqdn] Fully Qualified Domain Name (FQDN) of the load balancer. The DNS name.
    Name [name] Name of the load balancer, in the following format: <LB name>:<LB port>.
    Serial Number [serial_number] Serial number of the load balancer, in the following format: ##Object_ID=<LB_ARN>.
    Port [port] Port of the load balancer.
    Object ID [object_id] Unique identifier of the load balancer.
    IP Address [ip_address] IP address of the FQDN.