chore: Initial work to add agent config schema

.fleetControl/configurationDefinitions.yml

@@ -17,4 +17,5 @@ configurationDefinitions:
     description: Python agent configuration
     type: agent-config
     version: 1.0.0
-# will add schema information here later
+    schema: ./schemas/config.json
+    format: ini

.fleetControl/schemaGeneration/README.md

@@ -0,0 +1,291 @@
+# Agent Config Schema Generator
+
+This directory contains the Python scripts that walk
+`newrelic.core.config.global_settings()` to produce a JSON Schema
+(`../schemas/config.json`) and to manage version bumps in
+`../configurationDefinitions.yml` for Fleet Control.
+
+## Files
+
+| File | Description |
+|------|-------------|
+| `generate-schema.py` | Per-push regenerator. Reads the live agent settings tree, writes `config.json`. Never touches `configurationDefinitions.yml`. |
+| `bump-schema-version.py` | Release-time version bumper. Compares the schema at a prior git ref to the current schema and writes a new version into `configurationDefinitions.yml`. |
+| `schema_diff.py` | Shared library (no `main`). Holds the diff classification (`classify_changes`), bump arithmetic (`recommend_bump`, `apply_bump`, `bump_version`), and schema loading (`load_existing`). Imported by both top-level scripts. |
+| `dump-settings.py` | Dev helper. Lists every leaf in `global_settings()` and how it appears in the generated schema (or why it was excluded). Not part of the workflow. |
+| `tests/test_generate_schema.py` | Tests for the generator (`infer_type`, `make_property`, `build_properties`, `generate_schema`, anyOf helpers). |
+| `tests/test_schema_diff.py` | Tests for the shared library (`classify_changes`, `recommend_bump`, `apply_bump`, `bump_version`, `load_existing`). |
+| `tests/test_bump_schema_version.py` | Tests for the bump script (parsing helpers + main bootstrap/happy paths with mocked `git_show`). |
+| `../schemas/config.json` | Generated JSON Schema (Draft 2020-12). |
+| `../configurationDefinitions.yml` | Fleet Control metadata, including the schema's semver version. Bumped only at release time. |
+
+## How the generator works
+
+The agent's live settings tree (`newrelic.core.config.global_settings()`)
+is the source of truth for which keys exist, their types, and their
+defaults. `newrelic/newrelic.ini` is consulted only for descriptions
+(comments adjacent to `key = value` lines in the `[newrelic]` section).
+
+`generate-schema.py`:
+
+1. Imports `newrelic.core.config` and walks every leaf whose containing
+   class name ends in `Settings`.
+2. Loads descriptions from `newrelic/newrelic.ini`.
+3. For every leaf, applies (in order): `TYPE_OVERRIDES`, `ENUM_OVERRIDES`,
+   set-typed auto-anyOf, type inference from the live value.
+4. Skips leaves whose path matches `EXCLUDE_KEYS` (exact or `prefix.*`).
+5. Validates the result against the JSON Schema Draft 2020-12 meta-schema.
+6. Deep-merges the freshly generated schema into the existing on-disk
+   `config.json` so the published schema only ever grows.
+7. Writes `config.json` and prints a classified diff summary.
+
+The generator does **not** touch `configurationDefinitions.yml` --
+version bumps live in the next section.
+
+## How versioning works
+
+Schema regeneration runs **per push** on feature branches via
+`.github/workflows/fleet-control-schema.yml`. It writes `config.json`
+and nothing else. Reviewers see schema diffs in PRs.
+
+Version bumps run **manually before each release** via
+`.github/workflows/fleet-control-schema-bump.yml`, which is
+`workflow_dispatch`-only. The bump workflow:
+
+1. Finds the latest `v*` tag on `main` (overridable via the
+   `since_ref` workflow input).
+2. Reads the historical `configurationDefinitions.yml` from that tag --
+   the version stored there is the **starter version** for the bump.
+3. Reads the historical schema using the path declared in that file's
+   `schema:` field.
+4. Compares the historical schema to the current `config.json` on `main`,
+   classifies the cumulative diff, and applies the recommended bump kind
+   (major/minor/patch).
+5. Opens a PR titled `chore: bump agent config schema version` for team
+   review.
+
+If the latest release tag predates the schema (the `.fleetControl/`
+directory or the `schema:` field in `configurationDefinitions.yml`),
+`bump-schema-version.py` exits 0 with a bootstrap message and no PR
+is opened. The first release that includes the schema ships at whatever
+version is currently in `configurationDefinitions.yml`.
+
+### Release ordering -- run the bump workflow before cutting the tag
+
+The bump PR is a separate review/merge step from the agent's `vX.Y.Z`
+release tag. Run the workflows in this order:
+
+1. Trigger `Fleet Control Config Schema Bump` (manual `workflow_dispatch`).
+2. Wait for the PR to open (or the workflow to report that no bump is needed).
+3. Review and merge the bump PR if one was opened.
+4. Cut the GitHub Release from the post-merge `main`.
+
+If the release tag is cut before the bump PR merges, the tag's
+`configurationDefinitions.yml` will still say the pre-bump version,
+even though the schema itself (`config.json`) at that tag reflects the
+new keys. Consumers see a mismatch. The next release will compute its
+bump correctly from this tag's metadata, but the tag itself ships
+mismatched.
+
+## Quick start
+
+Regenerate the schema, run tests, and surface excluded settings in one
+command:
+
+```bash
+tox -e fleet-schema
+```
+
+This runs the unit tests, regenerates `.fleetControl/schemas/config.json`
+(deep-merged into the existing schema), prints the classified diff, and
+dumps any settings that didn't make it into the schema. Exit code matches
+`generate-schema.py`: `0` if no schema changes, `1` if the schema changed
+(commit before pushing), `2` on a hard failure.
+
+> **Run with a clean shell.** `import newrelic.core.config` reads
+> `NEW_RELIC_*` env vars at import time and bakes them into the live
+> defaults. The tox env unsets them defensively; if you invoke the
+> generator directly, do the same (`env -i PATH="$PATH" HOME="$HOME"
+> python3 ...`).
+
+### Lower-level commands
+
+If you want to invoke a single step directly without going through tox:
+
+```bash
+# Regenerate schema only (from repo root)
+python3 .fleetControl/schemaGeneration/generate-schema.py
+
+# Force-regenerate without comparing to existing on-disk schema
+python3 .fleetControl/schemaGeneration/generate-schema.py --force
+
+# Dry-run a release-time bump against a tag
+python3 .fleetControl/schemaGeneration/bump-schema-version.py --since=v10.21.0
+
+# Apply a release-time bump (writes configurationDefinitions.yml)
+python3 .fleetControl/schemaGeneration/bump-schema-version.py --since=v10.21.0 --ci
+
+# Dump every live setting alongside how it appears in the schema
+python3 .fleetControl/schemaGeneration/dump-settings.py
+
+# Filter the dump to settings missing from the schema
+python3 .fleetControl/schemaGeneration/dump-settings.py --missing
+```
+
+## Adding new configuration keys
+
+When new settings land in `newrelic/core/config.py`, the generator
+picks them up automatically on the next push -- no manual schema edit
+needed for the common case.
+
+**Special handling is required for certain key types**, configured via
+override maps in `generate-schema.py`.
+
+### Array-or-string keys (`_environ_as_set`-backed)
+
+Many agent config keys accept either a structured array OR a delimited
+string (the INI form):
+
+```ini
+attributes.include = request.parameters.* response.headers.content-type
+```
+
+These keys are parsed via `_environ_as_set` /
+`_environ_as_comma_separated_set` in `newrelic/core/config.py`. For the
+JSON Schema to correctly represent both forms, set-typed live values
+auto-detect into the right shape -- you don't need a per-key entry
+unless the live default is empty (in which case `set` vs. `list` cannot
+be distinguished from the value alone). Empty defaults need an explicit
+override:
+
+```python
+'new_feature.include': string_array_or_delimited(default=[]),
+'new_feature.exclude': string_array_or_delimited(default=[]),
+```
+
+The auto-detection covers the long tail (the seven `*.attributes.*`
+subtrees, `opentelemetry.traces.*`, etc.) because their live values
+arrive as Python `set` objects.
+
+### Status code keys
+
+Keys that accept integers, arrays of integers, or range strings (e.g.,
+`"100-102 200-208 226 300-308 404"`) should use:
+
+```python
+'error_collector.new_status_codes': status_code_array_or_range(),
+'error_collector.new_status_codes_with_default': status_code_array_or_range(default=[404]),
+```
+
+### Enum keys
+
+Keys with a fixed set of allowed values should be added to `ENUM_OVERRIDES`:
+
+```python
+ENUM_OVERRIDES = {
+    'new_feature.mode': ['option1', 'option2', 'option3'],
+}
+```
+
+### None-defaulted leaves
+
+Settings whose live default is `None` cannot have their type inferred,
+so they're skipped from the schema with a warning. To surface them, add
+an explicit type in `TYPE_OVERRIDES`:
+
+```python
+'proxy_user': {'type': 'string'},
+```
+
+## Excluding keys
+
+Add keys to `EXCLUDE_KEYS` to drop them from the schema:
+
+```python
+EXCLUDE_KEYS = {
+    'agent_run_id',                # exact match
+    'cross_application_tracer.*',  # subtree exclusion
+}
+```
+
+The `.*` suffix matches both the prefix itself and any descendant.
+
+## Checklist for new config keys
+
+1. Add the setting to `newrelic/core/config.py` as you would any other.
+2. **Run the generator locally** (`python3 .fleetControl/schemaGeneration/generate-schema.py`) to pick up the new key.
+3. **Check the inferred type** in the generated schema.
+4. **If the live default is `None`** → add an entry to `TYPE_OVERRIDES`.
+5. **If the key uses `_environ_as_set` and the default is empty** → add to `TYPE_OVERRIDES` with `string_array_or_delimited()`.
+6. **If the key has enum values** → add to `ENUM_OVERRIDES`.
+7. **If the key should be hidden** → add to `EXCLUDE_KEYS`.
+8. **Run the generator again**; verify the schema entry looks correct.
+9. **Run the tests** (`python3 -m unittest discover .fleetControl/schemaGeneration/tests`).
+10. The next release will pick up the bump when the maintainer runs the
+    bump workflow as part of release prep.
+
+## CLI options
+
+### Generator CLI (`generate-schema.py`)
+
+| Option | Description |
+|--------|-------------|
+| `--force` | Overwrite the schema without comparing to the existing one. Always exits 0. |
+
+### Bumper CLI (`bump-schema-version.py`)
+
+| Option | Description |
+|--------|-------------|
+| `--since=<ref>` | Required. Compare the current schema to the schema at `<ref>` and recommend a bump. |
+| `--ci` | Write the bumped version to `configurationDefinitions.yml`. Without this, the script just prints the recommendation. |
+
+## Exit codes
+
+### Generator exit codes (`generate-schema.py`)
+
+| Code | Meaning |
+|------|---------|
+| 0 | No schema changes (or first run, or `--force` mode). |
+| 1 | Schema regenerated and on-disk differed (CI should commit). |
+| 2 | Generator failure (invalid schema, malformed inputs). |
+
+### Bumper exit codes (`bump-schema-version.py`)
+
+| Code | Meaning |
+|------|---------|
+| 0 | No bump needed (no schema diff, or bootstrap case where `<ref>` predates the schema). |
+| 1 | Bump applied (`--ci`) or recommended (without `--ci`). |
+| 2 | Bump failure (uncaught exception, missing args, malformed historical inputs). |
+
+## Version bumping rules
+
+`bump-schema-version.py` classifies each schema change and the bump
+kind is the highest severity across all changes:
+
+| Change type | Severity | Bump |
+|-------------|----------|------|
+| Property removed | Breaking | Major |
+| Type changed | Breaking | Major |
+| Enum value removed | Breaking | Major |
+| Enum newly introduced | Breaking | Major |
+| Required field added | Breaking | Major |
+| `additionalProperties` tightened (true → false) | Breaking | Major |
+| Property added | Additive | Minor |
+| Enum value added | Additive | Minor |
+| Enum removed entirely | Additive | Minor |
+| Required field removed | Additive | Minor |
+| Default changed | Additive | Minor |
+| `additionalProperties` loosened (false → true) | Additive | Minor |
+| Description changed | Cosmetic | Patch |
+
+## Running the tests
+
+```bash
+# All schema-generation tests in one shot
+python3 -m unittest discover .fleetControl/schemaGeneration/tests
+
+# Individual files
+python3 -m unittest .fleetControl.schemaGeneration.tests.test_generate_schema
+python3 -m unittest .fleetControl.schemaGeneration.tests.test_schema_diff
+python3 -m unittest .fleetControl.schemaGeneration.tests.test_bump_schema_version
+```