## Context
`infra/stacks/mailserver/modules/mailserver/variables.tf` carried a
130-line historical scaffolding variable
`postfix_cf_reference_DO_NOT_USE` containing a reference copy of an
older Postfix `main.cf` layout. The variable name itself signalled
dead-code intent ("DO_NOT_USE"), and a repo-wide
`grep -rn postfix_cf_reference infra/` confirmed zero consumers — no
module, no stack, no script, no doc ever referenced it. Carrying dead
Terraform variables costs nothing at runtime but actively wastes
reviewer attention on every `git blame`, drives up `variables.tf` read
time, and lets drift calcify.
Trade-offs considered:
- Keep it "just in case" → rejected; the file it mirrored
(`/usr/share/postfix/main.cf.dist`) is already canonical upstream and
reproducible inside any docker-mailserver container.
- Move it to a comment block → rejected; same noise cost, no value
over deletion (authoritative source is in the image).
## This change
Drops the entire `variable "postfix_cf_reference_DO_NOT_USE" { ... }`
block (136 lines incl. trailing blank). No other variable touched, no
resource touched, no comment elsewhere touched. `variables.tf` now
contains only the single live variable `postfix_cf` that is actually
consumed by the module.
## What is NOT in this change
- No Terraform state modification — variable was never read, so state
has no record of it.
- No Postfix runtime behaviour change — `postfix_cf` (the live one) is
untouched.
- No fix for the pre-existing `kubernetes_deployment.mailserver` /
`kubernetes_service.mailserver` drift that `terragrunt plan` surfaces
independently. Those 2 in-place updates are known and tracked
separately; this commit explicitly avoids conflating cleanup with
drift resolution.
- No apply needed — pure source hygiene.
## Test Plan
### Automated
Reference check before edit:
```
$ grep -rn postfix_cf_reference /home/wizard/code/infra/
infra/stacks/mailserver/modules/mailserver/variables.tf:41:variable "postfix_cf_reference_DO_NOT_USE" {
```
(single match — the declaration itself)
Reference check after edit:
```
$ grep -rn postfix_cf_reference /home/wizard/code/infra/
(no matches)
```
`terragrunt validate` (from `infra/stacks/mailserver/`):
```
Success! The configuration is valid, but there were some
validation warnings as shown above.
```
(warnings are pre-existing `kubernetes_namespace` → `_v1` deprecation
notices, unrelated)
`terragrunt plan` (from `infra/stacks/mailserver/`):
```
# module.mailserver.kubernetes_deployment.mailserver will be updated in-place
# module.mailserver.kubernetes_service.mailserver will be updated in-place
Plan: 0 to add, 2 to change, 0 to destroy.
```
Both in-place updates are the known pre-existing drift
(volume_mount ordering + stale `metallb.io/ip-allocated-from-pool`
annotation). No change is attributable to this commit — the dead
variable was never referenced, so removing it leaves state untouched.
### Manual Verification
1. `cd infra/stacks/mailserver/modules/mailserver/`
2. `grep -c postfix_cf_reference variables.tf` → expected `0`
3. `wc -l variables.tf` → expected `39` (was `175`; 136 lines removed
including the trailing blank after the EOT)
4. Open `variables.tf` → expected: only `variable "postfix_cf"` remains
5. `cd ../..` (stack root) → `terragrunt validate` → expected:
`Success! The configuration is valid`
6. `terragrunt plan` → expected: `Plan: 0 to add, 2 to change, 0 to
destroy.` (the 2 are the pre-existing drift, not from this commit).
Closes: code-o3q
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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