datadog_monitor - Removal of 'tags' from resource has no effect

[MattHodge]

Terraform Version

• Terraform v0.11.1
• provider.datadog v1.0.2

Affected Resource(s)

• datadog_monitor

If this issue appears to affect multiple resources, it may be an issue with Terraform's core, so please mention this.

Terraform Configuration Files

resource "datadog_monitor" "foo" {
  name = "..."
  type = "metric alert"
  ...

  # The significant bit.
  tags = [ "foo:bar"]
}

Then remove the tags block:

resource "datadog_monitor" "foo" {
  name = "..."
  type = "metric alert"
  ...
}

Expected Behavior

• Terraform removes the monitors tags.

Actual Behavior

Terraform says it is removing the tag, but it doesn't happen:

datadog_monitor.foo: Modifying... (ID: 3734291)
  tags.#: "1" => "0"
  tags.0: "foo:bar" => ""
datadog_monitor.foo: Modifications complete after 1s (ID: 3734291)

Re-run terraform plan and it still detects the tag:

An execution plan has been generated and is shown below.
Resource actions are indicated with the following symbols:
  ~ update in-place

Terraform will perform the following actions:

  ~ datadog_monitor.script_runtime
      tags.#: "1" => "0"
      tags.0: "foo:bar" => ""


Plan: 0 to add, 1 to change, 0 to destroy.

Subsequent terraform plan invocations show the resources as out-of-sync, and subsequent terraform apply invocations end in the same result.

Steps to Reproduce

Please list the steps required to reproduce the issue, for example:

1. Create a new Datadog monitor using Terraform with a tag.
2. Remove the tag and do an apply, which will not remove the tag.

[masci]

Fixed in #70