Cinder Spec Generator

Cinder Driver Spec Generator

Automates the pipeline: Cinder driver source → YAML driver spec → Sunbeam charm.

Prerequisites

• Python 3.12+
• Access to a Cinder source tree (default: ../cinder relative to this repo)
• PyYAML installed (pip install pyyaml or available in the project venv)
• sunbeam-cinder-factory repo (this repo) with charm_generator available

Quick Start (All Drivers)

# Step 1: Extract config options from all Cinder drivers
python .agents/skills/cinder-spec-generator/scripts/extract_opts.py \
    /path/to/cinder/cinder/volume/drivers \
    -o /tmp/cinder_drivers_extracted.json

# Step 2: Generate YAML specs from extracted data
python .agents/skills/cinder-spec-generator/scripts/generate_spec.py \
    /tmp/cinder_drivers_extracted.json \
    -o driver-specs/

# Step 3: Generate charms from specs (one at a time or batch)
for spec in driver-specs/*.yaml; do
    python -m charm_generator generate "$spec" || echo "FAILED: $spec"
done

# Step 4: Validate generated charms
for spec in driver-specs/*.yaml; do
    vendor=$(python -c "import yaml; print(yaml.safe_load(open('$spec'))['charm']['name'])")
    python -m charm_generator validate "$vendor" --spec "$spec" || echo "INVALID: $spec"
done

Detailed Workflow

Step 1: Extract Driver Configuration

Run extract_opts.py against the Cinder drivers directory.

python .agents/skills/cinder-spec-generator/scripts/extract_opts.py \
    /path/to/cinder/cinder/volume/drivers \
    -o extracted.json \
    --verbose

The script uses Python AST parsing (not regex) for accuracy. It extracts:

• All cfg.*Opt declarations with name, type, default, help, secret flag, choices
• Class hierarchies and base class inheritance
• Protocol support by detecting @interface.volumedriver decorated classes
• SUPPORTED flag (for unsupported drivers)
• SUPPORTS_ACTIVE_ACTIVE flag (for HA)
• Base opts referenced via get_driver_options() and append_config_values()

Single driver extraction:

python .agents/skills/cinder-spec-generator/scripts/extract_opts.py \
    /path/to/cinder/cinder/volume/drivers \
    --driver pure \
    -o pure_extracted.json

Step 2: Generate YAML Specs

Run generate_spec.py to classify options and produce YAML:

python .agents/skills/cinder-spec-generator/scripts/generate_spec.py \
    extracted.json \
    -o driver-specs/ \
    --verbose

The script applies these classification rules automatically:

Type mapping: See references/type-mapping.md

Secret detection:

• secret=True in oslo.config → type: secret in YAML
• Backup: field names matching *_password, *_token, *_key (auth keys only)

Required detection (conservative — only high-confidence fields):

• Secret fields without defaults → required
• Fields explicitly without defaults that are connection-critical
• san_ip is auto-injected as required by the factory

Enum detection:

• choices=[...] in oslo.config → enum: [...] in YAML
• Vendor-prefixed enum fields get enum_class for StrEnum generation

Validation detection:

• item_type=types.IPAddress() → validation: ip_address
• Field names containing cidr + StrOpt → validation: ip_network
• Field names containing cidr + ListOpt → validation: ip_network_list

type_overrides generation:

• Secret + required → {type: secret, secret_key: ..., required: true}
• Vendor-prefixed enum → {type: enum, enum_class: ...}
• Vendor-prefixed IP/CIDR → {type: ip_network} or {type: ip_network_list}
• Required non-string types → {type: required, python_type: ...}
• Protocol with literal choices + required → {type: literal, values: [...]}

Unsupported driver: SUPPORTED = False → unsupported_driver: true

Base config removal: If driver doesn't reference driver_ssl_cert options → remove_base_config: [driver-ssl-cert]

Step 3: Review Generated Specs

Before running the charm generator, review the YAML specs for:

1. Vendor name and display_name — Verify they match expected conventions
2. Required fields — The script is conservative; you may need to mark additional fields as required
3. cli_prompt fields — Should include required fields + protocol selector
4. type_overrides — Verify secret_key values, enum_class names, group assignments
5. Grouping — Secondary/failover fields may need required_group/secret_group type_overrides with a shared group name

Step 4: Run the Charm Generator

python -m charm_generator generate driver-specs/newvendor.yaml

Step 5: Validate

python -m charm_generator validate cinder-volume-newvendor --spec driver-specs/newvendor.yaml

Fix any validation errors and re-generate if needed.

Reference Files

• Type Mapping Table — Complete oslo.config → YAML type mapping
• Worked Examples — Pure Storage and Dell SC end-to-end examples

Known Limitations

1. Complex default values: Expressions, variable references, and computed defaults are represented as null in the YAML spec. Review help text for intended defaults.
2. Grouping heuristics: Fields with secondary_ prefix are auto-grouped, but other grouping patterns need manual review.
3. Display names: Derived from docstrings and class names — verify for accuracy.
4. Deprecated options: Options with deprecated_for_removal=True are excluded by default.
5. Imported opts from other packages: The script resolves opts within the driver's own files and the san.py base module. Opts imported from third-party packages are not extracted.