Audit and Update Modules for Idempotent Prereqs and Caching

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Context

We discussed making modules faster without relying on prebuilds by ensuring all prerequisite installs are idempotent and skip work when a dependency is already present. Our goal is to reduce startup time, minimize egress, and keep modules usable standalone and in air‑gapped/cached environments.

Objectives

• Idempotent installs: Detect pre-installed tools and skip work; no repeated downloads when unchanged.
• Opt‑in installs for heavy dependencies: Provide install_ flags with customizable defaults.
• Offline/caching support: Support offline and cached modes; respect proxy settings; allow custom download base URL or mirror.
• Version pinning: Optional version variables; install only when version mismatch.
• Paths: Allow customizable install paths.
• Extension/assets: Install only missing extensions/assets.
• Non‑blocking installs: Prefer non‑blocking methods where safe.

Initial Audit (High‑impact areas)

1. code-server module: Change logic to install only when necessary and respect proxy settings.
2. vscode-web module: Add logic to avoid redundant extension installs.
3. Templates using curl installs: Replace with module usage or document caching/mirrors.
4. filebrowser module: Introduce version pinning and respect proxy settings.
5. jupyter-related modules: Continue good practices, add version pinning.
6. devcontainers-cli: Document proxy settings, allow version pinning.
7. kasmvnc, vault, git modules: Add version pins and respect proxy/mirror options.

Proposed Standards

• Utilize helpers.sh for common functions.
• Specify required variables for installation logic.
• Define default behaviors for heavy network installs.

Acceptance Criteria

• No redundant module downloads when unchanged.
• Modules operate fully offline and in mirror environments.
• Templates avoid curl installs, favoring modules or pre-installs.

Open Questions

• Decide default behavior for heavy installs.
• Determine templates that need updates versus guidance for baking into images.

Next Steps

• Update code-server module for idempotency.
• Introduce extension caching logic to vscode-web.
• Remove curl installers from templates.
• Begin helpers.sh implementation.
• Add relevant documentation on caching and proxies.

References

• Examples from existing modules and templates.

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Assignees/labels: Please triage and distribute tasks accordingly. This issue can be broken down into per-module tasks if necessary.