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IS_EMPTY_LOOKUP

IS_EMPTY_LOOKUP: { lookupPath }

Description​

The IS_EMPTY_LOOKUP operation specifically checks whether a lookup field, or a chain of lookups, resolves to an empty value. This operation is designed to address scenarios described in the Object Relationships documentation, where a FIELD operation might return null not just because the field is empty, but also because a lookup in the path is broken or incomplete.

IS_EMPTY_LOOKUP helps distinguish between a truly empty field and a null value resulting from a broken lookup chain. It returns true if the lookup path leads to a null or empty object at any point, indicating an incomplete or broken relationship. It returns false if the lookup path is fully resolved and the final field is not empty (or if the final field itself is null, which is not considered an empty lookup).

This operation is crucial for policies that need to verify the existence and completeness of related objects, especially when dealing with potentially inconsistent or partially collected data in Cloudaware CMDB.

Parameters​

  • lookupPath (string, required):
    • Specifies the lookup path to be checked for emptiness.
    • The path is a string that can include relationship names to traverse lookups (e.g., CA10__vpc__r.CA10__subnet__r).
    • The path should point to a lookup field or a chain of lookup fields. Only lookup__r fields can be used in the chain of lookups.
    • Example paths:
      • CA10__vpc__r
      • CA10__vpc__r.CA10__subnet__r

Return Type​

Boolean

Examples​

  1. Checking if a lookup field CA10__vpc__r is empty:

    IS_EMPTY_LOOKUP: CA10__vpc__r

    This example checks if the VPC lookup on an EC2 instance is empty, which could indicate that the instance is not associated with a VPC or that VPC data is not available.

  2. Checking a chain of lookups CA10__vpc__r.CA10__subnet__r for emptiness:

    IS_EMPTY_LOOKUP: CA10__vpc__r.CA10__subnet__r

    This example checks if the subnet lookup, accessed through the VPC lookup, is empty or the VPC lookup itself is empty. This could indicate issues at any point in the lookup chain (instance -> VPC -> subnet).

  3. Using IS_EMPTY_LOOKUP in a condition to set status to UNDETERMINED when a lookup is empty:

    - status: UNDETERMINED
      currentStateMessage: "VPC information is not available, status cannot be determined."
      check:
        IS_EMPTY_LOOKUP: CA10__vpc__r

    This condition sets the policy status to UNDETERMINED if the VPC lookup is empty, acknowledging the lack of necessary data for evaluation.