Add release automation script

.release/README.md

@@ -0,0 +1,93 @@
+# PyTorch Documentation Release Automation
+
+Automates the mechanical steps of the PyTorch docs release checklist.
+
+## Prerequisites
+
+- Git push access to `pytorch/tutorials` and `pytorch/docs`
+- CUDA version suffix from the RC announcement on [dev-discuss.pytorch.org](https://dev-discuss.pytorch.org)
+- Optional: `lintrunner` installed for lint checks (skipped if not available)
+
+## Phases
+
+### Phase 1: `enable-nightly` (after first RC)
+
+Run after the first release candidate is available. Creates PRs in both repos.
+
+**Tutorials repo (`pytorch/tutorials`):**
+- Enables nightly CI workflow triggers (pull_request + push to main)
+- Updates torch RC version in `.jenkins/build.sh`
+
+**Docs repo (`pytorch/docs`):**
+- Adds `v{version}.0 (release candidate)` entry to `pytorch-versions.json`
+- Bumps the `(unstable)` label to the next version
+
+### Phase 2: `pre-release` (a few days before release)
+
+Single command that creates four PRs across both repos.
+
+**Tutorials repo (`pytorch/tutorials`):**
+- Updates `torch==` pin in `requirements.txt`
+- Updates torch version in `.jenkins/build.sh`
+- Pushes branch `release-{version}` with these changes
+
+**Docs repo (`pytorch/docs`):**
+- Promotes RC to `(stable)` with `"preferred": true` in `pytorch-versions.json` (branch: `update-stable-{version}`)
+- Updates `stable` symlink to new version (branch: `update-stable-symlink-{version}`)
+- Adds noindex tags to previous version docs (branch: `add-noindex-{prev_version}`)
+
+### Phase 3: `post-release` (day after release)
+
+**Tutorials repo (`pytorch/tutorials`):**
+- Disables nightly CI workflow triggers
+- Updates torch version in `.ci/docker/requirements.txt`
+
+## Usage
+
+```bash
+# 1. After first RC is available
+python .release/release_docs.py --version 2.12 --cuda 130 --phase enable-nightly
+
+# 2. A few days before release (creates 4 PRs: 1 tutorials + 3 docs)
+python .release/release_docs.py --version 2.12 --cuda 130 --prev-version 2.11 --phase pre-release
+
+# 3. Day after release
+python .release/release_docs.py --version 2.12 --prev-version 2.11 --phase post-release
+```
+
+The cross-repo phases (`update-versions`, `stable-symlink`, `noindex`) can also be run individually if needed:
+
+```bash
+python .release/release_docs.py --version 2.12 --phase update-versions
+python .release/release_docs.py --version 2.12 --phase stable-symlink
+python .release/release_docs.py --version 2.12 --prev-version 2.11 --phase noindex
+```
+
+## Options
+
+| Flag | Description |
+|------|-------------|
+| `--version` | New PyTorch version (e.g., `2.12`) |
+| `--prev-version` | Previous version (e.g., `2.11`). Required for `pre-release`, `post-release`, and `noindex` |
+| `--cuda` | CUDA version suffix (e.g., `130` for `cu130`). Required for `enable-nightly` and `pre-release`. Get this from the [dev-discuss RC announcement](https://dev-discuss.pytorch.org) |
+| `--clean` | Remove existing `pytorch/docs` clone at `/tmp/pytorch-docs` and start fresh |
+| `--dry-run` | Show what would change without modifying files |
+| `--phase list` | Show all phases with descriptions |
+
+## How it works
+
+- **Tutorials repo changes**: Creates a branch, commits, and pushes. You create the PR via the printed GitHub compare link.
+- **Docs repo changes**: Shallow-clones `pytorch/docs` to `/tmp/pytorch-docs` (reuses if already present). Each phase creates a separate branch and pushes it. You create PRs via the printed links.
+- **Validation**: `pytorch-versions.json` is validated after every modification (valid JSON, required fields, exactly one preferred entry, no duplicates).
+- **Re-runnable**: Safe to run multiple times. Stale local branches are deleted before re-creating, and remote branches are force-pushed.
+
+## What it does NOT do
+
+- Merge any PRs (you review and merge manually)
+- Update ecosystem package versions (`torchrl`, `torchao`, etc.) in `requirements.txt`
+- Update the "What's New" section in `index.rst`
+- Review proposed features or attend meetings
+
+## Full checklist
+
+See the [PyTorch Documentation Release Checklist](https://www.internalfb.com/wiki/PyTorch/Teams/PyTorch_Doc_Engineering/PyTorch_Documentation_Release_Checklist/) for the complete process.