Trestle Task System

The trestle task system converts external data formats (CSV, XLSX, XCCDF, Tanium, CIS benchmarks) into OSCAL documents and vice versa. Tasks are configured via config.ini sections and run with trestle task <name>.

Available Tasks

Into OSCAL

Task Name	Input Format	Output OSCAL Type
csv-to-oscal-cd	CSV	Component Definition
xlsx-to-oscal-cd	XLSX	Component Definition
xlsx-to-oscal-profile	XLSX	Profile
xccdf-result-to-oscal-ar	XCCDF XML results	Assessment Results
tanium-result-to-oscal-ar	Tanium JSON results	Assessment Results
cis-xlsx-to-oscal-catalog	CIS benchmark XLSX	Catalog
cis-xlsx-to-oscal-cd	CIS benchmark XLSX	Component Definition
ocp4-cis-profile-to-oscal-catalog	OCP4 CIS profile YAML	Catalog
ocp4-cis-profile-to-oscal-cd	OCP4 CIS profile YAML	Component Definition

From OSCAL

Task Name	Input OSCAL Type	Output Format
oscal-catalog-to-csv	Catalog	CSV
oscal-profile-to-osco-profile	Profile	OSCO YAML

Configuration Format

Tasks are configured in .trestle/config.ini using INI-style sections:

[task.csv-to-oscal-cd]
title = My Component Definition
version = 1.0
csv-file = data/controls.csv
output-dir = component-definitions/my-component
output-overwrite = true

The section name follows the pattern [task.<task-name>].

Task-Specific Configuration

csv-to-oscal-cd

The most commonly used task. Converts a CSV file with control mappings into an OSCAL Component Definition.

Required keys:

• title — Component definition title
• version — Component definition version
• csv-file — Path to the CSV file
• output-dir — Output directory for the generated OSCAL JSON

Optional keys:

• component-definition — Path to existing component-definition to merge with
• class.column-name — Class to associate with a CSV column name
• output-overwrite — true (default) or false
• validate-controls — on, warn, or off (default)

CSV Column Mapping: The CSV file should contain columns that map to OSCAL control implementation fields. The task reads column headers and maps them to the component definition structure. Common columns include: Rule_Id, Rule_Description, Component_Title, Control_Id_List, Parameter_Id, Parameter_Value.

xccdf-result-to-oscal-ar

Converts XCCDF scan results (e.g., from OpenSCAP) into OSCAL Assessment Results.

Required keys:

• input-dir — Directory containing XCCDF result XML files
• output-dir — Output directory

Optional keys:

• checking — true/false (default: false)
• output-overwrite — true/false (default: true)
• quiet — true/false (default: false)
• title — Title for the assessment results (default: "XCCDF")
• description — Description (default: "XCCDF Scan Results")
• type — Assessor type (default: "Validator")
• timestamp — ISO 8601 timestamp override

tanium-result-to-oscal-ar

Converts Tanium compliance scan results into OSCAL Assessment Results.

Required keys:

• input-dir — Directory containing Tanium result JSON files
• output-dir — Output directory

Optional keys:

• blocksize — Lines per CPU for parallel processing
• cpus-max — Maximum CPUs (default: 1)
• cpus-min — Minimum CPUs
• aggregate — true (default) or false
• caching — true (default) or false
• checking — true/false (default: false)
• output-overwrite — true/false (default: true)
• quiet — true/false (default: false)
• timestamp — ISO 8601 timestamp override

oscal-catalog-to-csv

Exports an OSCAL Catalog to CSV format.

Required keys:

• input-file — Path to the catalog JSON/YAML file
• output-dir — Output directory

Optional keys:

• output-name — CSV filename
• output-overwrite — true/false (default: true)
• level — control or statement (default: statement)

cis-xlsx-to-oscal-cd

Converts CIS benchmark spreadsheets into OSCAL Component Definitions.

Required keys:

• benchmark-file — Path to the CIS benchmark .xlsx file
• benchmark-title — CIS benchmark title
• benchmark-version — Benchmark version
• component-name — Component name
• component-description — Component description
• component-type — Component type
• namespace — Namespace for properties
• output-dir — Output directory
• profile-version — Profile version
• profile-source — Profile source
• profile-description — Profile description

Optional keys:

• benchmark-control-prefix — Default: cisc-
• benchmark-rule-prefix — Default: CIS-
• benchmark-sheet-name — Default: Combined Profiles
• output-overwrite — true/false (default: true)

Running Tasks

# List available tasks
trestle task -l

# Show config requirements for a task
trestle task csv-to-oscal-cd -i

# Run a task (uses .trestle/config.ini by default)
trestle task csv-to-oscal-cd

# Run with a specific config file
trestle task csv-to-oscal-cd -c my-config.ini

Common Patterns

Import scan results for continuous monitoring

[task.xccdf-result-to-oscal-ar]
input-dir = scan-results/latest
output-dir = assessment-results/latest-scan
output-overwrite = true
title = Weekly Compliance Scan
description = Automated XCCDF scan results

Build component definitions from spreadsheets

[task.csv-to-oscal-cd]
title = Application Controls
version = 1.0
csv-file = data/app-controls.csv
output-dir = component-definitions/my-app
validate-controls = warn

Export catalog for review

[task.oscal-catalog-to-csv]
input-file = catalogs/nist-800-53/catalog.json
output-dir = exports
output-name = nist-controls.csv
level = control

CSV Column Reference for csv-to-oscal-cd

The csv-to-oscal-cd task reads specific column headers from the CSV file to build the component definition. All column names are case-sensitive.

Column Header	Required	Description
Rule_Id	Yes	Unique identifier for the rule (e.g., rule-ac-1)
Rule_Description	Yes	Human-readable description of what the rule checks
Component_Title	Yes	Name of the component this rule belongs to
Component_Type	No	Component type (default: Service). Valid: Software, Hardware, Service, Policy, Process, Plan, Guidance, Standard, Validation
Control_Id_List	Yes	OSCAL control IDs this rule maps to (comma-separated, e.g., ac-1,ac-2)
Parameter_Id	No	Parameter identifier for the rule
Parameter_Description	No	Human-readable description of the parameter
Parameter_Value_Alternatives	No	Allowed values for the parameter (comma-separated)
Profile_Source	No	Profile href (e.g., trestle://profiles/my-profile/profile.json)
Profile_Description	No	Description of the profile being referenced
Namespace	No	Namespace for rule properties (e.g., https://my-org.com/ns/oscal)
Check_Id	No	Identifier for automated check (e.g., XCCDF check ID)
Check_Description	No	Description of the automated check

Example CSV

Rule_Id,Rule_Description,Component_Title,Component_Type,Control_Id_List,Parameter_Id,Parameter_Value_Alternatives,Profile_Source,Namespace
rule-ac-1,Ensure access control policy exists,My Application,Service,ac-1,,,trestle://profiles/nist-800-53/profile.json,https://my-org.com/ns/oscal
rule-ac-2-a,Validate account types are defined,My Application,Service,ac-2,,,,https://my-org.com/ns/oscal
rule-ac-2-timeout,Check session timeout,My Application,Service,ac-2,ac-2-timeout-param,"15,30,60",trestle://profiles/nist-800-53/profile.json,https://my-org.com/ns/oscal
rule-cm-1,Configuration management policy review,My Application,Service,cm-1,,,trestle://profiles/nist-800-53/profile.json,https://my-org.com/ns/oscal
rule-ia-2,MFA for privileged accounts,Identity Provider,Service,"ia-2,ia-2.1",,,trestle://profiles/nist-800-53/profile.json,https://my-org.com/ns/oscal

Note: When Control_Id_List contains multiple controls, wrap the value in quotes if it contains commas.

Testing Tasks Before Full Runs

Before running a task against production data:

1. Check required configuration — use -i (info) to see what config keys are needed:

   trestle task csv-to-oscal-cd -i
   

   This prints all required and optional configuration keys with descriptions.

2. Use a small test input — create a 3-5 row CSV or a minimal XML/JSON file to verify the mapping works before processing full datasets.

3. Validate the output — after the task completes, run validation on the generated OSCAL:

   trestle validate -f <output-dir>/component-definition.json
   

4. Import into workspace — only after validation passes, import the result:

   trestle import -f <output-dir>/component-definition.json -o my-component
   

Troubleshooting Task Failures

Error	Cause	Fix
KeyError: 'csv-file'	Missing required config key in .trestle/config.ini	Add the missing key to the [task.<name>] section. Run trestle task <name> -i to see all required keys
FileNotFoundError or File not found	Input file path doesn't exist. Relative paths resolve from the workspace root	Use absolute paths or verify the path relative to the directory containing .trestle/
No controls found	CSV column headers don't match expected names (case-sensitive)	Check column names exactly match the reference table above (e.g., Rule_Id not rule_id)
Validation error in output	Input data references invalid control IDs or malformed UUIDs	Verify control IDs exist in the target catalog/profile. Fix UUIDs with python -c "import uuid; print(uuid.uuid4())"
UnicodeDecodeError	File uses non-UTF-8 encoding (e.g., Windows Latin-1)	Re-save the file as UTF-8. In Python: open(f, encoding='utf-8-sig') handles BOM
XML parse error (XCCDF tasks)	Malformed or incomplete XCCDF XML file	Validate the XML with xmllint --noout <file>. Ensure the file is a complete XCCDF result, not a partial extract
JSON decode error (Tanium tasks)	Malformed Tanium JSON output or truncated file	Validate JSON with python -m json.tool <file>. Check for truncation from export tools
configparser.NoSectionError	Task section missing from config.ini	Ensure the section header matches [task.<exact-task-name>]

Debugging tip: Run trestle with the --verbose flag for detailed logging:

trestle -v task csv-to-oscal-cd

Dual Component Definition Pattern

The csv-to-oscal-cd task supports two distinct component types that together bridge compliance controls to automated assessment. This pattern originates from the COMPASS architecture for end-to-end compliance automation.

Service Component CSV (Control-to-Rule)

Service components declare which rules implement a regulation control for a specific product:

Column	Example Value	Purpose
Rule_Id	rule-ac-2-accounts	Unique rule identifier
Rule_Description	Manage account lifecycle	What the rule checks
Component_Title	My Cloud Service	Product or service name
Component_Type	Service	Marks this as a service component
Control_Id_List	ac-2	Regulation controls this rule implements
Parameter_Id	timeout-minutes	Configurable parameter for the rule

Owner: Product vendors and service providers.

Validation Component CSV (Rule-to-Check)

Validation components declare which PVP checks validate a rule:

Column	Example Value	Purpose
Rule_Id	rule-ac-2-accounts	Must match a Service component rule
Rule_Description	Manage account lifecycle	Same rule, different perspective
Component_Title	Auditree PVP	Assessment tool name
Component_Type	Validation	Marks this as a validation component
Control_Id_List	ac-2	Same controls as the service rule
Check_Id	demo.checks.test_github.GitHubOrgs.test_members	PVP-specific check identifier
Check_Description	Verify org members exist	What the check validates

Owner: Assessment tool vendors, PVP providers, compliance engineers.

Example Validation CSV

Rule_Id,Rule_Description,Component_Title,Component_Type,Control_Id_List,Check_Id,Check_Description,Profile_Source,Namespace
rule-ac-2-accounts,Manage account lifecycle,Auditree PVP,Validation,ac-2,demo.checks.test_github.GitHubOrgs.test_members_is_not_empty,Verify GitHub org members exist,trestle://profiles/nist-high/profile.json,https://my-org.com/ns
rule-ac-2-timeout,Enforce session timeout,Auditree PVP,Validation,ac-2,demo.checks.test_github.GitHubOrgs.test_timeout,Verify timeout is configured,trestle://profiles/nist-high/profile.json,https://my-org.com/ns
rule-sc-7-boundary,Protect network boundaries,Kyverno PVP,Validation,sc-7,kyverno.check-network-boundary,Verify boundary protection policies,trestle://profiles/nist-high/profile.json,https://my-org.com/ns

When to Use the Dual Pattern

Use the dual pattern when connecting OSCAL compliance artifacts to automated assessment:

• Auditree: Check_Id = full Python module path of the check method
• OCM/Kubernetes: Check_Id = policy resource directory name
• XCCDF/OpenSCAP: Check_Id = XCCDF rule identifier
• Custom tools: Check_Id = whatever identifier the tool uses to select checks

The Check_Id semantics depend on the PVP. Trestle stores it in the component definition; C2P (Compliance-to-Policy) interprets it when generating PVP-specific configuration.

For the full pipeline context, see the trestle-compliance-pipeline skill.

Cross-References

• trestle-assessment: Using XCCDF/Tanium task output in the assessment-results workflow (import → split → edit → merge)
• trestle-validation: Validating task output before importing into the workspace
• trestle-control-implementation: Understanding the component-definition structure that csv-to-oscal-cd produces
• trestle-compliance-pipeline: End-to-end pipeline, persona ownership, and C2P bridge