How to do a 'not' tag filter?

I am trying to figure out how to write a filter that will match on ‘not equal’ to a value.

For example, this works great to filter out all instances with Environment = “Prod”

policies:
  - name: list-prod-ec2-instances
    resource: ec2
    filters:
      - tag:Environment: "Prod"

But, how do I write a filter that will list all instances where Environment is NOT “Prod”?

I can see from http://capitalone.github.io/cloud-custodian/docs/filters.html that I should be able to use ‘value filters’ for ‘not-equal’, but I don’t know how to write them in the policy together with ‘tag:Environment’.

I tried the following which did not work:

policies:
  - name: list-all-non-prod-ec2-instances
    resource: ec2
    filters:
      - tag:Environment
        value: "Prod"
        op: ne


policies:
  - name: list-all-non-prod-ec2-instances
    resource: ec2
    filters:
      - type: tag
        key: Environment
        value: "Prod"
        op: ne

[kapilt]

short hand form for value is primarily equality, long hand form allows for many other additional operators (not-equal, contains, etc) and value conversions (space/case normalization, date time conversion, etc).

policies:
  - name: list-non-prod-ec2-instances
    resource: ec2
    filters:
        - type: value
          key: "tag:Environment"
          value: "prod"
          value_type: normalize
          op: not-equal

[rahuldivakar]

how do we check for a tag:value as follows. tag is Owner Value: [e-mail] … @xyz.com has to be checked