tongueroo / terraspace-debug-local-file

Terraspace project example to debug local file creation between stacks

Terraspace Project

This is a Terraspace project to help debug

• Terraspace all up and Terraform local-file Resource

Works: simple terraspace up

• app/stacks/demo1: creates local file foo1.txt
• app/stacks/demo2: creates local file foo2.txt

app/stacks/demo1

$ terraspace clean all -y
$ terraspace up demo1 -y
$ ls .terraspace-cache/us-west-2/dev/stacks/demo1/foo1.txt
.terraspace-cache/us-west-2/dev/stacks/demo1/foo1.txt
$

app/stacks/demo2

$ terraspace clean all -y
$ terraspace up demo1 -y
$ ls .terraspace-cache/us-west-2/dev/stacks/demo2/foo2.txt
.terraspace-cache/us-west-2/dev/stacks/demo2/foo2.txt
$

Reproduce the Issue: terraspace all

The issue is when terraspace all up vs terraspace up is used.

$ terraspace clean all -y
$ terraspace all up -y
Building one stack to build all stacks
Building .terraspace-cache/us-west-2/dev/stacks/demo1
Built in .terraspace-cache/us-west-2/dev/stacks/demo1
Running:
    terraspace up demo1 # batch 1
    terraspace up demo2 # batch 2
Batch Run 1:
Running: terraspace up demo1 Logs: log/up/demo1.log
terraspace up demo1:  Apply complete! Resources: 1 added, 0 changed, 0 destroyed.
Batch Run 2:
Running: terraspace up demo2 Logs: log/up/demo2.log
terraspace up demo2:  Apply complete! Resources: 1 added, 0 changed, 0 destroyed.
Time took: 28s
$ tree .terraspace-cache/us-west-2/dev/stacks/
.terraspace-cache/us-west-2/dev/stacks/
├── demo1
│   ├── backend.tf
│   ├── main.tf
│   ├── outputs.tf
│   ├── provider.tf
│   └── variables.tf
└── demo2
    ├── 1-base.auto.tfvars
    ├── backend.tf
    ├── foo2.txt
    ├── main.tf
    ├── outputs.tf
    ├── provider.tf
    └── variables.tf

2 directories, 12 files
$

Notice how foo1.txt is missing.

Why?

Terraform only creates local files as part of an terraform apply. So the first batch 1 run will create foo1.txt

terraspace up demo1 # batch 1

But between the second run

terraspace up demo2 # batch 2

Terraspace cleans out the .terraspace-cache files and rebuilds them. One of the reasons Terraspace does this is because outputs are recalculated for dependencies. The current implementation clears out files and recomputes the output values for the tfvars. Unsure if can make this recalculation smarter.

Remove or Workaround Issue

There's a build.clean_cache config that can be set to false to disable the clean step between the batch runs.

• Terraspace Docs: Config Reference

config/app.rb

Terraspace.configure do |config|
  config.logger.level = :info
  config.test_framework = "rspec"

  # Setting `clean_cache = false` disables cleaning the .terraspace-cache between runs.
  # This allows terraspace all up to work where there are modules that generate local files.
  # Wondering if relying on generated local files from different stacks is an good, okay, or bad thing.
  config.build.clean_cache = false
end

Here's the terraspace all up again

$ terraspace clean all -y
$ terraspace all up -y
Building one stack to build all stacks
Building .terraspace-cache/us-west-2/dev/stacks/demo1
Built in .terraspace-cache/us-west-2/dev/stacks/demo1
Running:
    terraspace up demo1 # batch 1
    terraspace up demo2 # batch 2
Batch Run 1:
Running: terraspace up demo1 Logs: log/up/demo1.log
terraspace up demo1:  Apply complete! Resources: 1 added, 0 changed, 0 destroyed.
Batch Run 2:
Running: terraspace up demo2 Logs: log/up/demo2.log
terraspace up demo2:  Apply complete! Resources: 1 added, 0 changed, 0 destroyed.
Time took: 28s
$ tree .terraspace-cache/us-west-2/dev/stacks/
.terraspace-cache/us-west-2/dev/stacks/
├── demo1
│   ├── backend.tf
│   ├── foo1.txt
│   ├── main.tf
│   ├── outputs.tf
│   ├── provider.tf
│   └── variables.tf
└── demo2
    ├── 1-base.auto.tfvars
    ├── backend.tf
    ├── foo2.txt
    ├── main.tf
    ├── outputs.tf
    ├── provider.tf
    └── variables.tf

2 directories, 13 files
$

Both foo1.txt and foo2.txt exist here.