Amazon.EC2.Model.Filter inverse search

Question

I'm trying to get hold of all NACLs that do not have the word "public" in the value of the tag called Name.

I can see on this page https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/Using_Filtering.html that it is possible to carry out an inverse search.

However, everything I'm trying is failing.

For example, I declare the object and the tag:

        $inverseNameFilter = new-object Amazon.EC2.Model.Filter
        $inverseNameFilter.name = 'tag:Name'

And then these are the results I receive, for various methods I've tried:

        $inverseNameFilter.Value = '!public'
        (Get-EC2NetworkAcl -region $region -filter $inverseNameFilter).count

result: 0

        $inverseNameFilter.Value = '!*public*'
        (Get-EC2NetworkAcl -region $region -filter $inverseNameFilter).count

result: 0

        $inverseNameFilter.Value = '*public*'
        (Get-EC2NetworkAcl -region $region -filter $inverseNameFilter).count

result: 3 (So there are clearly three NACLs with Name tags containing public)

        (Get-EC2NetworkAcl -region $region).count

result: 18 (so there are clearly 18 NACLs in this region)

How do I carry out an inverse search to find the 15 NACLs that do not contain the word "public"?

Answer 1

It looks like the filter doesn't actually support negation (see comment by Mathias R. Jessen)

However, I've found a way to exclude the results using this PowerShell filtering rather than AWS filtering. It means the processing occurs at the client rather than at AWS, but gives me sufficient results:

(Get-EC2NetworkAcl -region $region | Where-Object -FilterScript { ([string]$_.tags.Value) -notmatch "public"}).count

15