📦 Demo pack pipeline

Goal: explain how pack_demo produces a runnable demo/ directory, including where app.py comes from and what files are written/copied/symlinked.

🔗 Entry points

• Stage: pack_demo → espnet3/systems/base/system.py:System.pack_demo
• Implementation: espnet3/demo/pack.py:pack_demo

🗂 Output layout

pack_demo produces a runnable directory. Typical output:

demo
├── app.py
├── demo.yaml
├── requirements.txt
├── README.md
├── config
│   └── infer.yaml
├── data -> ../data/
├── exp -> ../exp/
└── (optional files from pack.files ...)

Notes:

• demo.yaml is rewritten so infer_config points to config/infer.yaml and demo_dir is set.
• README.md may be generated if missing.
• Entries under pack.files in demo.yaml are typically added as symlinks into the demo directory (implementation detail in espnet3/demo/pack.py).

🏭 How each file is generated

• app.py

  • Written by espnet3/demo/setup.py:_write_app_py() via espnet3/demo/setup.py:setup_demo_assets()
  • Contents come from espnet3/demo/setup.py:_APP_TEMPLATE and call espnet3/demo/app_builder.py:build_demo_app(demo_dir)

• requirements.txt

  • Written by espnet3/demo/setup.py:_write_requirements() via espnet3/demo/setup.py:setup_demo_assets()
  • Uses requirements: in demo.yaml if present, otherwise writes a small default
  • To add system/recipe-specific dependencies (e.g., extra tokenizers, GPU libs), set requirements: in demo.yaml to the full list you want shipped with the demo package. pack_demo will write it into the packed directory.

• demo.yaml

  • Prepared by espnet3/demo/pack.py:_prepare_demo_config():
    • sets demo_dir
    • rewrites infer_config to config/infer.yaml for the packed demo
    • sets ui.article_path to README.md when missing
  • Written by espnet3/demo/pack.py:_write_demo_config()

• config/infer.yaml

  • Loaded/resolved from the source infer_config by:
    • espnet3/demo/resolve.py:resolve_infer_path()
    • espnet3/demo/resolve.py:load_infer_config()
  • Written to the demo directory by espnet3/demo/pack.py:_write_infer_config()

• README.md

  • Created only if missing by espnet3/demo/pack.py:_write_readme_if_missing()
  • Template resolution happens in espnet3/demo/pack.py:_load_demo_readme_template()

• data, exp, and any other entries under pack.files in demo.yaml

  • Added by espnet3/demo/pack.py:_copy_pack_files() (typically as symlinks via espnet3/demo/pack.py:_copy_path(..., symlink=True))