CODEWITHSUNDEEP
google-bigqueryterraformterraform-provider-gcp
RobotEyes
RobotEyes

Reputation: 5250

Updating Terraform Google provider forces replacement

I am trying to update terraform google provider to 3.58 from 3.55 to add big query deletion protection.

When running a terraform plan I get # forces replacement warnings:

# google_bigquery_table.my_table must be replaced
...
+ deletion_protection = true
...
~ schema              = jsonencode(
          ~ [ # forces replacement
              ~ {
                  ~ fields      = [
                        # (6 unchanged elements hidden)
                        {
                            description = "Location of the data schema."
                            name        = "dataSchema"
                            type        = "STRING"
                        },
                      ~ {
                          ~ type        = "BOOLEAN" -> "BOOL"
                            # (2 unchanged elements hidden)
                        },
                    ]
                  ~ type        = "RECORD" -> "STRUCT"
                    # (2 unchanged elements hidden)
                } # forces replacement,
              ~ {
                  ~ type        = "RECORD" -> "STRUCT"
                    # (3 unchanged elements hidden)
                } # forces replacement,
              ~ {
                  ~ type        = "RECORD" -> "STRUCT"
                    # (3 unchanged elements hidden)
                } # forces replacement,
            ]
        )

Can anyone help me understand (a) why am I getting a forced replacement on this update when I haven't changed my schemas and (b) how can I update my google provider without deleting the data in my table.

Any help would be much appreciated.

Upvotes: 0

Views: 1794

Answers (1)

Foghorn
Foghorn

Reputation: 2326

Sometimes it seems that Terraform is aggressive on flagging needs replacement. I am not sure if it is related, but I have seen sometimes a more 'conservative' flagging of this when changing versions of Terraform (by conservative, I mean it appears to try to replace more often - I am unsure if the upgraded versions don't realize that settings that were not previously settable in TF, but are now, are flagged as potentially changed and thus need replacement). I agree that if your schema hasn't changed, there is no need to replace the resource.

Solution

Identify the resource as ignore_changes by ensuring it is specified in the lifecycle block within the resource body.

From the Terraform documentation:

The ignore_changes feature is intended to be used when a resource is created with references to data that may change in the future, but should not affect said resource after its creation. In some rare cases, settings of a remote object are modified by processes outside of Terraform, which Terraform would then attempt to "fix" on the next run. In order to make Terraform share management responsibilities of a single object with a separate process, the ignore_changes meta-argument specifies resource attributes that Terraform should ignore when planning updates to the associated remote object.

Some example code from that:

resource "aws_instance" "example" {
  # ...
  lifecycle {
    ignore_changes = [
      # Ignore changes to tags, e.g. because a management agent
      # updates these based on some ruleset managed elsewhere.
      tags,
    ]
  }
}

Also note that you can use the keyword all instead of a list in ignore_changes to ignore all attributes.

Upvotes: 1

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