58 lines
1.4 KiB
Markdown
58 lines
1.4 KiB
Markdown
# Local Path Inputs
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This note covers `40-path-inputs/`, which uses `inputs.catalog.url = "path:./catalog";` to pull another local flake into the parent flake.
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---
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## 1. What a Local Path Input Looks Like
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A local input is declared with a `path:` flake reference:
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```nix
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inputs.catalog.url = "path:./catalog";
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```
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The target directory must itself be a flake, so `catalog/` contains its own `flake.nix`.
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---
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## 2. What the Child Flake Exposes
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The child flake in this example does not build packages. It exports pure data through `lib`:
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- one release name,
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- one service-owner map, and
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- one rollout plan.
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The parent flake reads those values and turns them into a runnable script.
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---
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## 3. Why This Example Uses `lib`
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Using `lib` keeps the focus on the input boundary, not on packaging details in both flakes.
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That is the important part of `path:` inputs: once the child is a flake, its outputs are consumed the same way as any other flake input.
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---
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## 4. The Git-Tracked File Rule Still Applies
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This is still a flake input, so Nix reads it from the flake source tree. Files inside `catalog/` must be tracked, or the parent flake will not see
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them during pure evaluation.
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That rule is easy to miss when the child flake lives in the same repository.
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---
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## 5. Commands to Try
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```bash
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cd 40-path-inputs
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nix flake metadata
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nix build
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./result/bin/show-local-plan
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nix flake check
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```
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