terraform show planfile without -json is incomplete in v0.12.0

[apparentlymart]

The plan rendering from terraform plan was updated to the new structural diff format in v0.12.0, but the corresponding codepath in terraform show (not in JSON mode) was not updated, so it's using a much-reduced version of the old codepath that only shows the top-level actions, and not individual attribute diffs.

To reproduce:

• Run terraform plan -out=tfplan to produce a saved plan file
• Run terraform show tfplan

If the plan contained any create or update actions, notice that they only have the headline of the action and not any details about the individual attributes.

[dayglojesus]

The addition of the -json flag is invaluable, but being able to produce human-readable output from a plan file is critical for the toolchain we use. There appear to be a couple of similar open issues surrounding this regression from 0.11.x. Here is what I have found:

• #21966
• #21949

[dcalhoun]

I agree with @dayglojesus. With my team's process, the inability to see human-readable details of what is changing means we are "flying blind" when reviewing a plan and applying it. Unfortunately 0.12.x is unusable for us without this issue being addressed first.

@apparentlymart are there any plans to prioritize this? If not, is there a specific location in the code you could point to where one might contribute a fix? Thanks.

[mrparkers]

Just want to chime in here and say that this is the only issue preventing the company I work for from switching to Terraform 0.12. Echoing what @dcalhoun mentioned, I'd love to help contribute a fix if someone could point me in the right direction.

[apparentlymart]

This was fixed in #23292. The fix should be included in the next minor release.

[hashibot[bot]]

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