Allow selecting attribute of all elements of a collection in ignore_changes

[jhyot]

I could not get ignore_changes to work with a property of a nested list of blocks in Terraform 1.0.

In this example I would like to ignore any prop_b changes in any example_block:

resource "example_resource" {
  example_block {
    prop_a = "abc"
    prop_b = "123"
  }

  example_block {
    prop_a = "xyz"
    prop_b = "999"
  }

  lifecycle {
    ignore_changes = [
    // -------- what to put here? ---------
    ]
  }
}

Searching on the internet there are many suggestions, but none of them seem to work, including:

• "example_block.%.prop_b" --> Error: "Dot must be followed by attribute name."
• example_block[*].prop_b --> Error: "A single static variable reference is required"
• example_block.0.prop_b --> Ignores it for the first item, but not "all" items
• example_block[0].prop_b --> Seems to be same as above
• example_block["prop_b"] --> Seems to ignore the whole example_block, in particular adding a new example_block does not add it in the Terraform plan.

[andyli]

looks like a duplicate of #5666