nicholasjackson/golang-opa-rego-language

Rego is the declarative policy language used by Open Policy Agent (OPA) for writing and enforcing policies across cloud-native stacks, featuring data-driven rules, comprehensions, and 200+ built-in functions for infrastructure, security, and compliance automation.

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CI/CD Pipeline Policies

Name: nicholasjackson/golang-opa-rego-language
Author: nicholasjackson

This document provides comprehensive examples of using Rego to enforce policies and validation in CI/CD pipelines. These policies help automate quality gates, security checks, and compliance requirements throughout the software delivery lifecycle.

1. File Validation

1.1 YAML and JSON Syntax Validation

Validates configuration file syntax to catch errors before deployment.

package cicd.validation

import rego.v1

# METADATA
# description: Validates YAML and JSON file syntax in pull requests
# entrypoint: true

deny contains sprintf("%s is an invalid YAML file: %s", [filename, content]) if {
    some filename, content in yaml_file_contents
    changes[filename].status in {"added", "modified"}
    not yaml.is_valid(content)
}

deny contains sprintf("%s is an invalid JSON file: %s", [filename, content]) if {
    some filename, content in json_file_contents
    changes[filename].status in {"added", "modified"}
    not json.is_valid(content)
}

yaml_file_contents[filename] := file_content if {
    some filename in filenames
    extension(filename) in {"yml", "yaml"}
    file_content := files[filename]
}

json_file_contents[filename] := file_content if {
    some filename in filenames
    extension(filename) == "json"
    file_content := files[filename]
}

extension(filename) := ext if {
    parts := split(filename, ".")
    ext := parts[count(parts) - 1]
}

1.2 TOML Configuration Validation

Validates TOML configuration files commonly used in CI/CD pipelines.

package cicd.validation

import rego.v1

deny contains sprintf("%s contains invalid TOML syntax", [filename]) if {
    some filename in filenames
    extension(filename) == "toml"
    content := files[filename]
    changes[filename].status in {"added", "modified"}
    not is_valid_toml(content)
}

# Helper to validate TOML by attempting to parse as structured data
is_valid_toml(content) if {
    # TOML validation would typically use an external parser
    # This is a simplified check for basic structure
    lines := split(content, "\n")
    every line in lines {
        valid_toml_line(line)
    }
}

valid_toml_line(line) if trim_space(line) == ""
valid_toml_line(line) if startswith(trim_space(line), "#")
valid_toml_line(line) if contains(line, "=")
valid_toml_line(line) if startswith(trim_space(line), "[")

1.3 Configuration File Schema Validation

Ensures configuration files follow required schemas.

package cicd.validation

import rego.v1

required_package_json_fields := ["name", "version", "description", "license"]

deny contains sprintf("package.json missing required field: %s", [field]) if {
    "package.json" in filenames
    changes["package.json"].status in {"added", "modified"}
    content := json.unmarshal(files["package.json"])
    some field in required_package_json_fields
    not content[field]
}

deny contains msg if {
    "package.json" in filenames
    changes["package.json"].status in {"added", "modified"}
    content := json.unmarshal(files["package.json"])
    not is_valid_semver(content.version)
    msg := sprintf("package.json version '%s' is not valid semver", [content.version])
}

is_valid_semver(version) if {
    semver.is_valid(version)
}

2. PR Change Detection and Test Routing

2.1 Smart Test Selection Based on Changed Files

Determines which test suites to run based on file changes.

package cicd.test_routing

import rego.v1

go_change_prefixes := [
    "internal/",
    "pkg/",
    "cmd/",
    "api/",
]

frontend_change_prefixes := [
    "ui/",
    "web/",
    "frontend/",
]

changes["backend"] if {
    some changed_file in input.files
    endswith(changed_file.filename, ".go")
}

changes["backend"] if {
    some changed_file in input.files
    strings.any_prefix_match(changed_file.filename, go_change_prefixes)
}

changes["frontend"] if {
    some changed_file in input.files
    strings.any_prefix_match(changed_file.filename, frontend_change_prefixes)
}

changes["frontend"] if {
    some changed_file in input.files
    extension(changed_file.filename) in {"ts", "tsx", "jsx", "js", "vue"}
}

changes["infrastructure"] if {
    some changed_file in input.files
    extension(changed_file.filename) in {"tf", "tfvars"}
}

changes["docker"] if {
    some changed_file in input.files
    contains(changed_file.filename, "Dockerfile")
}

changes["docs"] if {
    some changed_file in input.files
    startswith(changed_file.filename, "docs/")
}

changes["docs"] if {
    some changed_file in input.files
    extension(changed_file.filename) == "md"
}

extension(filename) := ext if {
    parts := split(filename, ".")
    ext := parts[count(parts) - 1]
}

# Test matrix output
required_tests contains "backend-unit" if changes["backend"]
required_tests contains "backend-integration" if changes["backend"]
required_tests contains "frontend-unit" if changes["frontend"]
required_tests contains "frontend-e2e" if changes["frontend"]
required_tests contains "terraform-validate" if changes["infrastructure"]
required_tests contains "docker-build" if changes["docker"]

2.2 Conditional Integration Test Requirements

Requires integration tests only when critical paths are modified.

package cicd.test_requirements

import rego.v1

critical_paths := [
    "services/payment/",
    "services/auth/",
    "database/migrations/",
    "api/",
]

require_integration_tests if {
    some changed_file in input.files
    some critical_path in critical_paths
    startswith(changed_file.filename, critical_path)
}

deny contains "Integration tests must be run for changes to critical services" if {
    require_integration_tests
    not input.tests_run.integration
}

deny contains sprintf("Modified critical file: %s requires integration test evidence", [filename]) if {
    require_integration_tests
    some changed_file in input.files
    filename := changed_file.filename
    some critical_path in critical_paths
    startswith(filename, critical_path)
    not has_integration_test_for(filename)
}

has_integration_test_for(filename) if {
    test_file := integration_test_path(filename)
    test_file in input.test_files_executed
}

integration_test_path(filename) := test_path if {
    dir := substring(filename, 0, last_index_of(filename, "/"))
    base := substring(filename, last_index_of(filename, "/") + 1, count(filename))
    name := trim_suffix(base, sprintf(".%s", [extension(filename)]))
    test_path := sprintf("%s/%s_integration_test.go", [dir, name])
}

last_index_of(str, search) := idx if {
    indices := indexof_n(str, search)
    idx := indices[count(indices) - 1]
}

3. Test Coverage Requirements

3.1 Minimum Coverage Thresholds

Enforces minimum test coverage percentages.

package cicd.coverage

import rego.v1

minimum_coverage := 80
minimum_new_code_coverage := 90

deny contains msg if {
    coverage := input.test_results.coverage_percent
    coverage < minimum_coverage
    msg := sprintf("Test coverage %v%% is below minimum %v%%", [coverage, minimum_coverage])
}

deny contains msg if {
    new_code_coverage := input.test_results.new_code_coverage_percent
    new_code_coverage < minimum_new_code_coverage
    msg := sprintf("New code coverage %v%% is below minimum %v%%", [new_code_coverage, minimum_new_code_coverage])
}

deny contains sprintf("Package '%s' has coverage %v%% below minimum %v%%", [pkg, cov, minimum_coverage]) if {
    some pkg, cov in input.test_results.package_coverage
    cov < minimum_coverage
}

3.2 Coverage Trend Validation

Ensures coverage doesn't decrease between builds.

package cicd.coverage

import rego.v1

deny contains msg if {
    current := input.current_coverage
    previous := input.previous_coverage
    decrease := previous - current
    decrease > 0
    msg := sprintf("Coverage decreased by %.2f%% (from %.2f%% to %.2f%%)", [decrease, previous, current])
}

warning contains msg if {
    current := input.current_coverage
    previous := input.previous_coverage
    increase := current - previous
    increase < 1.0
    increase >= 0
    msg := sprintf("Coverage increased by only %.2f%% - consider adding more tests", [increase])
}

3.3 Test File Requirements

Requires test files for new source files.

package cicd.test_requirements

import rego.v1

test_required_extensions := {"go", "py", "js", "ts", "java"}

deny contains sprintf("New file %s requires corresponding test file %s", [filename, test_file]) if {
    some changed_file in input.files
    changed_file.status == "added"
    filename := changed_file.filename
    ext := extension(filename)
    ext in test_required_extensions
    not is_test_file(filename)
    test_file := expected_test_file(filename)
    not test_file_exists(test_file)
}

is_test_file(filename) if contains(filename, "_test")
is_test_file(filename) if contains(filename, ".test")
is_test_file(filename) if startswith(filename, "test_")

expected_test_file(filename) := test_file if {
    ext := extension(filename)
    ext == "go"
    base := trim_suffix(filename, ".go")
    test_file := sprintf("%s_test.go", [base])
}

expected_test_file(filename) := test_file if {
    ext := extension(filename)
    ext in {"js", "ts"}
    base := trim_suffix(filename, sprintf(".%s", [ext]))
    test_file := sprintf("%s.test.%s", [base, ext])
}

expected_test_file(filename) := test_file if {
    ext := extension(filename)
    ext == "py"
    parts := split(filename, "/")
    file := parts[count(parts) - 1]
    base := trim_suffix(file, ".py")
    test_file := sprintf("test_%s.py", [base])
}

test_file_exists(test_file) if {
    some changed_file in input.files
    changed_file.filename == test_file
}

test_file_exists(test_file) if {
    test_file in input.existing_files
}

4. Branch Protection Policies

4.1 Protected Branch Enforcement

Prevents direct commits to protected branches.

package cicd.branch_protection

import rego.v1

protected_branches := {"main", "master", "production", "release"}

deny contains sprintf("Direct commits to protected branch '%s' are not allowed", [branch]) if {
    branch := input.target_branch
    branch in protected_branches
    input.event_type == "push"
    not input.via_pull_request
}

deny contains msg if {
    input.target_branch in protected_branches
    input.via_pull_request
    approvals := count(input.pull_request.approvals)
    approvals < 2
    msg := sprintf("Pull request requires at least 2 approvals, found %d", [approvals])
}

deny contains sprintf("Pull request to '%s' requires approval from code owner", [branch]) if {
    branch := input.target_branch
    branch in protected_branches
    not has_codeowner_approval
}

has_codeowner_approval if {
    some approval in input.pull_request.approvals
    approval.user in input.codeowners
}

4.2 Branch Naming Convention

Enforces branch naming standards.

package cicd.branch_naming

import rego.v1

valid_prefixes := {"feature/", "bugfix/", "hotfix/", "release/", "chore/"}

deny contains sprintf("Branch name '%s' must start with one of: %v", [branch, valid_prefixes]) if {
    branch := input.branch_name
    not branch in {"main", "master", "develop"}
    not has_valid_prefix(branch)
}

has_valid_prefix(branch) if {
    some prefix in valid_prefixes
    startswith(branch, prefix)
}

deny contains sprintf("Branch name '%s' contains invalid characters (use lowercase, hyphens, slashes)", [branch]) if {
    branch := input.branch_name
    not regex.match(`^[a-z0-9/_-]+$`, branch)
}

deny contains sprintf("Branch name '%s' exceeds maximum length of 64 characters", [branch]) if {
    branch := input.branch_name
    count(branch) > 64
}

5. Commit Message Validation

5.1 Conventional Commit Format

Enforces conventional commit message format.

package cicd.commit_validation

import rego.v1

conventional_types := {
    "feat", "fix", "docs", "style", "refactor",
    "perf", "test", "build", "ci", "chore", "revert"
}

deny contains sprintf("Commit message must follow conventional format: <type>: <description>") if {
    message := input.commit.message
    not is_conventional_commit(message)
}

is_conventional_commit(message) if {
    lines := split(message, "\n")
    subject := lines[0]
    regex.match(`^[a-z]+(\([a-z0-9-]+\))?!?: .+`, subject)
    type := extract_type(subject)
    type in conventional_types
}

extract_type(subject) := type if {
    parts := regex.find_all_string_submatch_n(`^([a-z]+)`, subject, 1)
    type := parts[0][1]
}

deny contains "Commit message subject line must be 72 characters or less" if {
    message := input.commit.message
    lines := split(message, "\n")
    subject := lines[0]
    count(subject) > 72
}

deny contains "Commit message must have blank line between subject and body" if {
    message := input.commit.message
    lines := split(message, "\n")
    count(lines) > 2
    lines[1] != ""
}

5.2 Commit Message Content Requirements

Ensures commit messages reference issue tracking.

package cicd.commit_validation

import rego.v1

deny contains "Commit message must reference an issue (e.g., 'fixes #123' or 'relates to PROJ-456')" if {
    message := lower(input.commit.message)
    not contains_issue_reference(message)
    not input.commit.is_merge_commit
}

contains_issue_reference(message) if {
    regex.match(`(fixes|closes|resolves|relates to|refs?) #[0-9]+`, message)
}

contains_issue_reference(message) if {
    regex.match(`[A-Z]+-[0-9]+`, message)
}

deny contains "Commit message must not contain 'WIP' or 'TODO' in subject line" if {
    message := input.commit.message
    lines := split(message, "\n")
    subject := lower(lines[0])
    contains(subject, "wip")
}

deny contains "Commit message must not contain 'WIP' or 'TODO' in subject line" if {
    message := input.commit.message
    lines := split(message, "\n")
    subject := lower(lines[0])
    contains(subject, "todo")
}

6. Deployment Approval Workflows

6.1 Environment-Based Approval Requirements

Requires different approval levels for different environments.

package cicd.deployment

import rego.v1

environment_approvals := {
    "production": 2,
    "staging": 1,
    "development": 0,
}

deny contains sprintf("Deployment to '%s' requires %d approvals, found %d", [env, required, actual]) if {
    env := input.deployment.environment
    required := environment_approvals[env]
    actual := count(input.deployment.approvals)
    actual < required
}

deny contains sprintf("Deployment to production requires approval from security team") if {
    input.deployment.environment == "production"
    not has_security_approval
}

has_security_approval if {
    some approval in input.deployment.approvals
    approval.team == "security"
}

deny contains "Production deployments must occur during approved maintenance window" if {
    input.deployment.environment == "production"
    not in_maintenance_window
}

in_maintenance_window if {
    [hour, _, _] := time.clock(time.now_ns())
    day := time.weekday(time.now_ns())
    day in {"Saturday", "Sunday"}
    hour >= 2
    hour <= 6
}

6.2 Deployment Change Window Validation

Ensures deployments happen during approved time windows.

package cicd.deployment

import rego.v1

# Block deployments during business hours on weekdays
deny contains "Production deployments not allowed during business hours (9 AM - 5 PM weekdays)" if {
    input.deployment.environment == "production"
    not input.deployment.emergency
    is_business_hours
}

is_business_hours if {
    [hour, _, _] := time.clock(time.now_ns())
    day := time.weekday(time.now_ns())
    day in {"Monday", "Tuesday", "Wednesday", "Thursday", "Friday"}
    hour >= 9
    hour < 17
}

# Require change ticket for production
deny contains "Production deployment requires approved change ticket number" if {
    input.deployment.environment == "production"
    not input.deployment.emergency
    not input.deployment.change_ticket
}

deny contains sprintf("Change ticket '%s' is not in approved status", [ticket]) if {
    input.deployment.environment == "production"
    ticket := input.deployment.change_ticket
    not change_ticket_approved(ticket)
}

change_ticket_approved(ticket) if {
    ticket_status := input.change_tickets[ticket].status
    ticket_status == "approved"
}

7. Artifact Scanning and Signing

7.1 Container Image Scanning Requirements

Ensures container images are scanned for vulnerabilities.

package cicd.artifact_scanning

import rego.v1

critical_severity_threshold := 0
high_severity_threshold := 5

deny contains sprintf("Container image has %d critical vulnerabilities (max: %d)", [count, critical_severity_threshold]) if {
    count := input.scan_results.critical_count
    count > critical_severity_threshold
}

deny contains sprintf("Container image has %d high vulnerabilities (max: %d)", [count, high_severity_threshold]) if {
    count := input.scan_results.high_count
    count > high_severity_threshold
}

deny contains sprintf("Container image vulnerability scan is outdated (scanned: %s)", [scan_time]) if {
    scan_time := input.scan_results.scanned_at
    scan_age_hours := (time.now_ns() - time.parse_rfc3339_ns(scan_time)) / 1000000000 / 3600
    scan_age_hours > 24
}

deny contains "Container image must be scanned before deployment" if {
    not input.scan_results
}

7.2 Artifact Signing Verification

Ensures artifacts are properly signed.

package cicd.artifact_signing

import rego.v1

deny contains "Container image must be signed before deployment to production" if {
    input.deployment.environment == "production"
    not input.artifact.signed
}

deny contains sprintf("Artifact signature verification failed: %s", [error]) if {
    input.artifact.signed
    not input.artifact.signature_valid
    error := input.artifact.signature_error
}

deny contains "Artifact must be signed by trusted key" if {
    input.artifact.signed
    input.artifact.signature_valid
    not signer_is_trusted
}

signer_is_trusted if {
    signer := input.artifact.signer
    signer in data.trusted_signers
}

deny contains sprintf("Artifact signature timestamp %s is too old", [timestamp]) if {
    timestamp := input.artifact.signature_timestamp
    age_hours := (time.now_ns() - time.parse_rfc3339_ns(timestamp)) / 1000000000 / 3600
    age_hours > 168  # 1 week
}

8. Environment Promotion Rules

8.1 Sequential Environment Promotion

Ensures code progresses through environments in order.

package cicd.promotion

import rego.v1

environment_order := ["development", "staging", "production"]

deny contains sprintf("Cannot deploy to '%s' without successful deployment to '%s'", [target, previous]) if {
    target := input.deployment.environment
    some i, env in environment_order
    env == target
    i > 0
    previous := environment_order[i - 1]
    not deployed_to_environment(previous)
}

deployed_to_environment(env) if {
    some deployment in input.deployment_history
    deployment.environment == env
    deployment.status == "success"
    deployment.git_sha == input.deployment.git_sha
}

deny contains sprintf("Deployment to '%s' requires at least 24 hours soak time in staging", [env]) if {
    env := input.deployment.environment
    env == "production"
    staging_deployment_time := get_staging_deployment_time
    soak_hours := (time.now_ns() - staging_deployment_time) / 1000000000 / 3600
    soak_hours < 24
}

get_staging_deployment_time := deployment_time if {
    some deployment in input.deployment_history
    deployment.environment == "staging"
    deployment.git_sha == input.deployment.git_sha
    deployment.status == "success"
    deployment_time := time.parse_rfc3339_ns(deployment.completed_at)
}

8.2 Production Promotion Gates

Enforces quality gates before production deployment.

package cicd.promotion

import rego.v1

deny contains "All automated tests must pass before production deployment" if {
    input.deployment.environment == "production"
    not all_tests_passing
}

all_tests_passing if {
    input.test_results.unit.status == "passed"
    input.test_results.integration.status == "passed"
    input.test_results.e2e.status == "passed"
}

deny contains sprintf("Performance benchmarks degraded by %.2f%%", [degradation]) if {
    input.deployment.environment == "production"
    baseline := input.performance_benchmarks.baseline
    current := input.performance_benchmarks.current
    degradation := ((baseline - current) / baseline) * 100
    degradation > 10  # More than 10% degradation
}

deny contains "Production deployment requires sign-off from product owner" if {
    input.deployment.environment == "production"
    not has_product_owner_signoff
}

has_product_owner_signoff if {
    some approval in input.deployment.approvals
    approval.role == "product_owner"
}

9. Rollback Policies and Safeguards

9.1 Automated Rollback Triggers

Defines conditions for automatic rollback.

package cicd.rollback

import rego.v1

require_rollback contains "Error rate exceeds 5% threshold" if {
    error_rate := input.metrics.error_rate_percent
    error_rate > 5.0
}

require_rollback contains sprintf("Response time degraded by %.2f%%", [degradation]) if {
    baseline := input.metrics.baseline_response_time_ms
    current := input.metrics.current_response_time_ms
    degradation := ((current - baseline) / baseline) * 100
    degradation > 50
}

require_rollback contains "Health check failures exceed threshold" if {
    failures := input.metrics.health_check_failures
    total := input.metrics.health_check_total
    failure_rate := (failures / total) * 100
    failure_rate > 10
}

require_rollback contains "Critical alerts triggered" if {
    some alert in input.alerts
    alert.severity == "critical"
    alert.status == "firing"
}

9.2 Rollback Approval Requirements

Ensures rollbacks follow proper procedures.

package cicd.rollback

import rego.v1

deny contains "Rollback must include incident ticket reference" if {
    input.action == "rollback"
    not input.incident_ticket
}

deny contains "Rollback requires approval from on-call engineer" if {
    input.action == "rollback"
    input.environment == "production"
    not has_oncall_approval
}

has_oncall_approval if {
    some approval in input.approvals
    approval.is_oncall
}

warning contains "Consider creating postmortem for production rollback" if {
    input.action == "rollback"
    input.environment == "production"
    not input.postmortem_created
}

10. Build Configuration Validation

10.1 Dockerfile Best Practices

Validates Dockerfile security and best practices.

package cicd.dockerfile

import rego.v1

deny contains "Dockerfile must not use latest tag for base images" if {
    some instruction in input.dockerfile.instructions
    instruction.cmd == "FROM"
    contains(instruction.value, ":latest")
}

deny contains sprintf("Dockerfile must not run as root user (found USER %s)", [user]) if {
    not has_user_instruction
    not uses_nonroot_base_image
}

deny contains "Dockerfile should use specific package versions" if {
    some instruction in input.dockerfile.instructions
    instruction.cmd == "RUN"
    contains(instruction.value, "apt-get install")
    not contains(instruction.value, "=")
}

has_user_instruction if {
    some instruction in input.dockerfile.instructions
    instruction.cmd == "USER"
    instruction.value != "root"
    instruction.value != "0"
}

deny contains "Dockerfile must include HEALTHCHECK instruction" if {
    not has_healthcheck
}

has_healthcheck if {
    some instruction in input.dockerfile.instructions
    instruction.cmd == "HEALTHCHECK"
}

deny contains "Dockerfile should use multi-stage builds to reduce image size" if {
    from_count := count([i | some i in input.dockerfile.instructions; i.cmd == "FROM"])
    from_count == 1
    final_size_mb := input.image_size_bytes / 1024 / 1024
    final_size_mb > 500
}

10.2 CI Pipeline Configuration Validation

Validates GitHub Actions or GitLab CI configuration.

package cicd.pipeline_config

import rego.v1

deny contains "CI pipeline must include security scanning job" if {
    not has_security_scan_job
}

has_security_scan_job if {
    some job_name, job in input.workflow.jobs
    contains(lower(job_name), "security")
}

has_security_scan_job if {
    some job_name, job in input.workflow.jobs
    some step in job.steps
    contains(lower(step.name), "security scan")
}

deny contains "CI pipeline must run tests before build" if {
    test_job := get_job_by_name("test")
    build_job := get_job_by_name("build")
    not "test" in build_job.needs
}

deny contains sprintf("Job '%s' missing required timeout", [job_name]) if {
    some job_name, job in input.workflow.jobs
    not job.timeout_minutes
}

deny contains sprintf("Job '%s' timeout exceeds maximum of 60 minutes", [job_name]) if {
    some job_name, job in input.workflow.jobs
    job.timeout_minutes > 60
}

11. Dependency Vulnerability Scanning

11.1 Dependency Vulnerability Thresholds

Blocks builds with vulnerable dependencies.

package cicd.dependency_scanning

import rego.v1

deny contains sprintf("Found %d critical vulnerabilities in dependencies", [count]) if {
    count := count([v | some v in input.vulnerabilities; v.severity == "critical"])
    count > 0
}

deny contains sprintf("Found %d high vulnerabilities in dependencies", [count]) if {
    count := count([v | some v in input.vulnerabilities; v.severity == "high"])
    count > 5
}

deny contains sprintf("Dependency '%s' has known vulnerability %s", [dep, cve]) if {
    some vuln in input.vulnerabilities
    vuln.severity in {"critical", "high"}
    not has_exception(vuln.cve)
    dep := vuln.package
    cve := vuln.cve
}

has_exception(cve) if {
    some exception in input.vulnerability_exceptions
    exception.cve == cve
    exception.status == "approved"
    not is_expired(exception.expires_at)
}

is_expired(expires_at) if {
    expiry := time.parse_rfc3339_ns(expires_at)
    expiry < time.now_ns()
}

11.2 Dependency Update Requirements

Ensures dependencies are kept up to date.

package cicd.dependency_scanning

import rego.v1

deny contains sprintf("Dependency '%s' is %d days behind latest version", [dep, days]) if {
    some dependency in input.dependencies
    dep := dependency.name
    current := dependency.current_version
    latest := dependency.latest_version
    current != latest
    days := dependency.days_behind_latest
    days > 90
    not is_major_version_change(current, latest)
}

is_major_version_change(current, latest) if {
    current_parts := split(current, ".")
    latest_parts := split(latest, ".")
    current_parts[0] != latest_parts[0]
}

warning contains sprintf("Dependency '%s' has available security update", [dep]) if {
    some dependency in input.dependencies
    dep := dependency.name
    dependency.security_update_available
}

12. License Compliance Checking

12.1 Allowed License Validation

Ensures dependencies use approved licenses.

package cicd.license_compliance

import rego.v1

approved_licenses := {
    "MIT",
    "Apache-2.0",
    "BSD-2-Clause",
    "BSD-3-Clause",
    "ISC",
}

copyleft_licenses := {
    "GPL-2.0",
    "GPL-3.0",
    "AGPL-3.0",
    "LGPL-2.1",
    "LGPL-3.0",
}

deny contains sprintf("Dependency '%s' uses unapproved license: %s", [dep, license]) if {
    some dependency in input.dependencies
    dep := dependency.name
    license := dependency.license
    not license in approved_licenses
    not license in copyleft_licenses
}

deny contains sprintf("Dependency '%s' uses copyleft license '%s' which may require legal review", [dep, license]) if {
    some dependency in input.dependencies
    dep := dependency.name
    license := dependency.license
    license in copyleft_licenses
    not has_legal_exception(dep)
}

deny contains sprintf("Dependency '%s' has no license information", [dep]) if {
    some dependency in input.dependencies
    dep := dependency.name
    not dependency.license
}

has_legal_exception(dep) if {
    some exception in input.legal_exceptions
    exception.package == dep
    exception.status == "approved"
}

12.2 License Header Validation

Ensures source files contain required license headers.

package cicd.license_compliance

import rego.v1

required_header := `Copyright (c) 2024 Example Corp. All rights reserved.
Licensed under the Apache License, Version 2.0`

source_file_extensions := {"go", "py", "js", "ts", "java", "rs"}

deny contains sprintf("File '%s' missing required license header", [filename]) if {
    some changed_file in input.files
    changed_file.status == "added"
    filename := changed_file.filename
    ext := extension(filename)
    ext in source_file_extensions
    content := changed_file.content
    not has_license_header(content)
}

has_license_header(content) if {
    lines := split(content, "\n")
    header_lines := [l | some l in lines; count(l) > 0][0:5]
    header_text := concat("\n", header_lines)
    contains(header_text, "Copyright")
    contains(header_text, "License")
}

13. Code Quality Gate Enforcement

13.1 Code Quality Metrics

Enforces quality thresholds on code metrics.

package cicd.quality_gates

import rego.v1

deny contains sprintf("Code complexity score %.2f exceeds maximum of 10", [complexity]) if {
    some file in input.quality_metrics.files
    complexity := file.complexity_score
    complexity > 10
}

deny contains sprintf("Function '%s' exceeds maximum length of 50 lines", [func]) if {
    some file in input.quality_metrics.files
    some function in file.functions
    func := function.name
    function.line_count > 50
}

deny contains sprintf("File '%s' has %d code smells", [filename, count]) if {
    some file in input.quality_metrics.files
    filename := file.name
    count := count(file.code_smells)
    count > 10
}

deny contains "Code duplication exceeds 5% threshold" if {
    duplication := input.quality_metrics.duplication_percent
    duplication > 5.0
}

deny contains sprintf("Technical debt ratio %.2f%% exceeds maximum of 10%%", [ratio]) if {
    ratio := input.quality_metrics.technical_debt_ratio
    ratio > 10.0
}

13.2 Static Analysis Requirements

Ensures static analysis tools are run and pass.

package cicd.quality_gates

import rego.v1

deny contains sprintf("Static analysis tool '%s' found %d issues", [tool, count]) if {
    some tool, results in input.static_analysis
    count := count(results.issues)
    count > 0
}

deny contains "ESLint must pass with no errors" if {
    eslint := input.static_analysis.eslint
    eslint.error_count > 0
}

deny contains sprintf("Found %d linting warnings (max: 10)", [count]) if {
    eslint := input.static_analysis.eslint
    count := eslint.warning_count
    count > 10
}

deny contains "Go code must be formatted with gofmt" if {
    gofmt := input.static_analysis.gofmt
    count(gofmt.unformatted_files) > 0
}

14. Container Image Scanning in CI

14.1 Base Image Compliance

Validates base images meet security requirements.

package cicd.container_scanning

import rego.v1

approved_base_images := {
    "alpine:3.18",
    "ubuntu:22.04",
    "debian:bookworm-slim",
    "gcr.io/distroless/base-debian12",
}

deny contains sprintf("Base image '%s' is not in approved list", [image]) if {
    base_image := input.dockerfile.base_image
    not base_image in approved_base_images
    not is_approved_registry(base_image)
}

is_approved_registry(image) if {
    startswith(image, "mycompany.azurecr.io/")
}

is_approved_registry(image) if {
    startswith(image, "gcr.io/mycompany/")
}

deny contains "Container image must not contain high-risk packages" if {
    some package in input.scan_results.packages
    package.name in high_risk_packages
}

high_risk_packages := {"telnet", "ftp", "rsh", "wget"}

deny contains sprintf("Container image contains %d unnecessary packages", [count]) if {
    count := count([p | some p in input.scan_results.packages;
                    p.name in unnecessary_packages])
    count > 0
}

unnecessary_packages := {"vim", "nano", "curl", "netcat"}

14.2 Container Security Scanning

Validates container security configuration.

package cicd.container_scanning

import rego.v1

deny contains "Container must not run privileged" if {
    input.container_config.privileged == true
}

deny contains "Container must not use host network" if {
    input.container_config.network_mode == "host"
}

deny contains "Container should define resource limits" if {
    not input.container_config.resources.limits.memory
}

deny contains "Container should define resource limits" if {
    not input.container_config.resources.limits.cpu
}

deny contains sprintf("Container exposes privileged port %d", [port]) if {
    some port in input.container_config.exposed_ports
    port < 1024
}

deny contains "Container should use read-only root filesystem" if {
    not input.container_config.read_only_root_filesystem
}

15. Secrets Detection in Code

15.1 Secret Pattern Detection

Detects potential secrets in code changes.

package cicd.secrets_detection

import rego.v1

secret_patterns := {
    "aws_key": `AKIA[0-9A-Z]{16}`,
    "github_token": `ghp_[a-zA-Z0-9]{36}`,
    "private_key": `-----BEGIN (RSA |EC |OPENSSH )?PRIVATE KEY-----`,
    "password": `(password|passwd|pwd)\s*=\s*['"][^'"]{8,}['"]`,
    "api_key": `api[_-]?key\s*[:=]\s*['"][^'"]{20,}['"]`,
}

deny contains sprintf("File '%s' contains potential %s", [filename, secret_type]) if {
    some changed_file in input.files
    filename := changed_file.filename
    content := changed_file.content
    some secret_type, pattern in secret_patterns
    regex.match(pattern, content)
}

deny contains sprintf("File '%s' contains high-entropy string that may be a secret", [filename]) if {
    some changed_file in input.files
    filename := changed_file.filename
    changed_file.status in {"added", "modified"}
    some line in split(changed_file.content, "\n")
    has_high_entropy_string(line)
}

has_high_entropy_string(line) if {
    strings := extract_quoted_strings(line)
    some str in strings
    count(str) > 20
    entropy(str) > 4.5
}

extract_quoted_strings(line) := strings if {
    matches := regex.find_all_string_submatch_n(`["']([^"']{20,})["']`, line, -1)
    strings := [m[1] | some m in matches]
}

# Simplified entropy calculation
entropy(str) := score if {
    chars := {c | some c in str}
    score := count(chars) / count(str) * 10
}

15.2 Secrets File Detection

Prevents committing common secret files.

package cicd.secrets_detection

import rego.v1

forbidden_files := {
    ".env",
    ".env.local",
    ".env.production",
    "secrets.yml",
    "secrets.yaml",
    "credentials.json",
    "service-account.json",
    "id_rsa",
    "id_dsa",
    ".pem",
    ".key",
}

deny contains sprintf("File '%s' should not be committed to repository", [filename]) if {
    some changed_file in input.files
    filename := changed_file.filename
    base_name := base_filename(filename)
    base_name in forbidden_files
}

deny contains sprintf("File '%s' with extension '.%s' should not be committed", [filename, ext]) if {
    some changed_file in input.files
    filename := changed_file.filename
    ext := extension(filename)
    ext in {"pem", "key", "p12", "pfx", "jks"}
}

base_filename(path) := name if {
    parts := split(path, "/")
    name := parts[count(parts) - 1]
}

16. Performance Regression Detection

16.1 Benchmark Performance Gates

Detects performance regressions in benchmarks.

package cicd.performance

import rego.v1

max_regression_percent := 10

deny contains sprintf("Benchmark '%s' regressed by %.2f%%", [name, regression]) if {
    some benchmark in input.benchmarks
    name := benchmark.name
    baseline := benchmark.baseline_ns_per_op
    current := benchmark.current_ns_per_op
    regression := ((current - baseline) / baseline) * 100
    regression > max_regression_percent
}

deny contains sprintf("Memory usage increased by %.2f%% for '%s'", [increase, name]) if {
    some benchmark in input.benchmarks
    name := benchmark.name
    baseline_mem := benchmark.baseline_bytes_per_op
    current_mem := benchmark.current_bytes_per_op
    increase := ((current_mem - baseline_mem) / baseline_mem) * 100
    increase > 15
}

warning contains sprintf("Allocations increased for '%s': %d -> %d", [name, baseline, current]) if {
    some benchmark in input.benchmarks
    name := benchmark.name
    baseline := benchmark.baseline_allocs_per_op
    current := benchmark.current_allocs_per_op
    current > baseline
}

16.2 Load Test Thresholds

Validates load test results meet SLA requirements.

package cicd.performance

import rego.v1

sla_response_time_ms := 200
sla_error_rate_percent := 0.1

deny contains sprintf("Average response time %.2fms exceeds SLA of %dms", [avg, sla_response_time_ms]) if {
    avg := input.load_test.avg_response_time_ms
    avg > sla_response_time_ms
}

deny contains sprintf("P95 response time %.2fms exceeds threshold of %dms", [p95, threshold]) if {
    p95 := input.load_test.p95_response_time_ms
    threshold := sla_response_time_ms * 2
    p95 > threshold
}

deny contains sprintf("Error rate %.2f%% exceeds SLA of %.2f%%", [rate, sla_error_rate_percent]) if {
    rate := input.load_test.error_rate_percent
    rate > sla_error_rate_percent
}

deny contains sprintf("Throughput %d req/s is below minimum of 1000 req/s", [throughput]) if {
    throughput := input.load_test.requests_per_second
    throughput < 1000
}

17. Documentation Requirements

17.1 Documentation Update Requirements

Ensures documentation is updated with code changes.

package cicd.documentation

import rego.v1

significant_change_threshold := 10  # files

deny contains "Significant changes require documentation updates" if {
    changed_files := count(input.files)
    changed_files > significant_change_threshold
    not has_doc_changes
}

has_doc_changes if {
    some changed_file in input.files
    extension(changed_file.filename) == "md"
}

has_doc_changes if {
    some changed_file in input.files
    startswith(changed_file.filename, "docs/")
}

deny contains sprintf("New API endpoint '%s' requires documentation", [endpoint]) if {
    some changed_file in input.files
    contains(changed_file.filename, "routes")
    changed_file.status in {"added", "modified"}
    some line in split(changed_file.content, "\n")
    endpoint := extract_endpoint(line)
    not endpoint_documented(endpoint)
}

extract_endpoint(line) := endpoint if {
    regex.match(`@(Get|Post|Put|Delete|Patch)\(['"]([^'"]+)['"]`, line)
    matches := regex.find_all_string_submatch_n(`@(Get|Post|Put|Delete|Patch)\(['"]([^'"]+)['"]`, line, 1)
    endpoint := matches[0][2]
}

endpoint_documented(endpoint) if {
    some doc_file in input.files
    contains(doc_file.filename, "README")
    contains(doc_file.content, endpoint)
}

endpoint_documented(endpoint) if {
    some doc_file in input.files
    extension(doc_file.filename) == "md"
    contains(doc_file.content, endpoint)
}

17.2 README Completeness Check

Validates README contains required sections.

package cicd.documentation

import rego.v1

required_readme_sections := {
    "Installation",
    "Usage",
    "Configuration",
    "Contributing",
    "License",
}

deny contains sprintf("README.md missing required section: %s", [section]) if {
    readme := get_readme_content
    some section in required_readme_sections
    not contains_section(readme, section)
}

get_readme_content := content if {
    some file in input.files
    contains(file.filename, "README.md")
    content := file.content
}

contains_section(content, section) if {
    contains(content, sprintf("## %s", [section]))
}

contains_section(content, section) if {
    contains(content, sprintf("# %s", [section]))
}

18. Release Note Generation Validation

18.1 Release Notes Required for Version Bumps

Ensures release notes accompany version changes.

package cicd.release_notes

import rego.v1

deny contains "Version bump requires release notes" if {
    version_changed
    not has_release_notes
}

version_changed if {
    some changed_file in input.files
    changed_file.filename in {"package.json", "pom.xml", "Cargo.toml", "pyproject.toml"}
    changed_file.status == "modified"
}

has_release_notes if {
    some changed_file in input.files
    contains(changed_file.filename, "CHANGELOG")
}

has_release_notes if {
    some changed_file in input.files
    startswith(changed_file.filename, "release-notes/")
}

deny contains "CHANGELOG.md must include version number and date" if {
    has_release_notes
    changelog := get_changelog
    not contains_version_header(changelog)
}

get_changelog := content if {
    some file in input.files
    contains(file.filename, "CHANGELOG")
    content := file.content
}

contains_version_header(content) if {
    regex.match(`## \[?\d+\.\d+\.\d+\]? - \d{4}-\d{2}-\d{2}`, content)
}

18.2 Release Notes Content Validation

Validates quality and completeness of release notes.

package cicd.release_notes

import rego.v1

changelog_sections := {"Added", "Changed", "Deprecated", "Removed", "Fixed", "Security"}

warning contains sprintf("CHANGELOG missing recommended section: %s", [section]) if {
    changelog := get_changelog
    some section in changelog_sections
    not contains(changelog, sprintf("### %s", [section]))
    has_relevant_changes(section)
}

has_relevant_changes("Added") if {
    some file in input.files
    file.status == "added"
}

has_relevant_changes("Fixed") if {
    some file in input.files
    commit_message := input.commit.message
    contains(lower(commit_message), "fix")
}

has_relevant_changes("Security") if {
    some file in input.files
    commit_message := input.commit.message
    contains(lower(commit_message), "security")
}

deny contains "Release notes must include breaking changes section if major version bumped" if {
    is_major_version_bump
    changelog := get_changelog
    not contains(lower(changelog), "breaking")
}

is_major_version_bump if {
    old_version := input.version_info.old_version
    new_version := input.version_info.new_version
    old_parts := split(old_version, ".")
    new_parts := split(new_version, ".")
    old_parts[0] != new_parts[0]
}

19. Feature Flag Validation

19.1 Feature Flag Configuration Validation

Ensures feature flags are properly configured.

package cicd.feature_flags

import rego.v1

deny contains sprintf("Feature flag '%s' missing required metadata", [flag]) if {
    some flag, config in input.feature_flags
    not config.description
}

deny contains sprintf("Feature flag '%s' missing owner", [flag]) if {
    some flag, config in input.feature_flags
    not config.owner
}

deny contains sprintf("Feature flag '%s' missing expiration date", [flag]) if {
    some flag, config in input.feature_flags
    not config.expires_at
}

deny contains sprintf("Feature flag '%s' has expired", [flag]) if {
    some flag, config in input.feature_flags
    expires_at := time.parse_rfc3339_ns(config.expires_at)
    expires_at < time.now_ns()
}

warning contains sprintf("Feature flag '%s' expires in less than 30 days", [flag]) if {
    some flag, config in input.feature_flags
    expires_at := time.parse_rfc3339_ns(config.expires_at)
    days_until_expiry := (expires_at - time.now_ns()) / 1000000000 / 86400
    days_until_expiry < 30
    days_until_expiry > 0
}

19.2 Feature Flag Cleanup Detection

Identifies stale feature flags that should be removed.

package cicd.feature_flags

import rego.v1

deny contains sprintf("Feature flag '%s' enabled at 100%% for over 60 days - consider removing", [flag]) if {
    some flag, config in input.feature_flags
    config.rollout_percentage == 100
    created_at := time.parse_rfc3339_ns(config.created_at)
    age_days := (time.now_ns() - created_at) / 1000000000 / 86400
    age_days > 60
}

deny contains sprintf("Feature flag '%s' never used in code", [flag]) if {
    some flag, config in input.feature_flags
    not flag_referenced_in_code(flag)
}

flag_referenced_in_code(flag) if {
    some file in input.source_files
    contains(file.content, flag)
}

warning contains sprintf("Feature flag '%s' used in %d places - consider refactoring", [flag, count]) if {
    some flag, config in input.feature_flags
    references := [1 | some file in input.source_files;
                   some line in split(file.content, "\n");
                   contains(line, flag)]
    count := count(references)
    count > 10
}

20. Pipeline Dependency Validation

20.1 Job Dependency Requirements

Ensures CI/CD jobs have proper dependencies.

package cicd.pipeline_dependencies

import rego.v1

# Test must run before build
deny contains "Build job must depend on test job" if {
    some job_name, job in input.pipeline.jobs
    job_name == "build"
    not has_dependency(job, "test")
}

# Deployment must depend on build and scan
deny contains sprintf("Deploy job '%s' must depend on build and security-scan", [job_name]) if {
    some job_name, job in input.pipeline.jobs
    startswith(job_name, "deploy")
    not has_dependency(job, "build")
}

deny contains sprintf("Deploy job '%s' must depend on security-scan", [job_name]) if {
    some job_name, job in input.pipeline.jobs
    startswith(job_name, "deploy")
    not has_dependency(job, "security-scan")
}

has_dependency(job, dep_name) if {
    some dep in job.depends_on
    dep == dep_name
}

has_dependency(job, dep_name) if {
    some dep in job.needs
    dep == dep_name
}

# Prevent circular dependencies
deny contains sprintf("Circular dependency detected: %v", [cycle]) if {
    cycle := detect_cycle
    count(cycle) > 0
}

detect_cycle := cycle if {
    some job_name, job in input.pipeline.jobs
    cycle := find_cycle(job_name, [])
    count(cycle) > 0
}

find_cycle(job_name, visited) := cycle if {
    job_name in visited
    cycle := array.concat(visited, [job_name])
}

find_cycle(job_name, visited) := cycle if {
    not job_name in visited
    job := input.pipeline.jobs[job_name]
    some dep in job.depends_on
    cycle := find_cycle(dep, array.concat(visited, [job_name]))
}

default find_cycle(_, _) := []

20.2 Parallel Job Optimization

Identifies opportunities for parallel execution.

package cicd.pipeline_dependencies

import rego.v1

warning contains sprintf("Jobs '%s' and '%s' can run in parallel", [job1, job2]) if {
    some job1, config1 in input.pipeline.jobs
    some job2, config2 in input.pipeline.jobs
    job1 < job2  # Avoid duplicate pairs
    not jobs_have_dependency(job1, job2)
    not jobs_have_dependency(job2, job1)
    jobs_can_parallelize(config1, config2)
}

jobs_have_dependency(job1, job2) if {
    config := input.pipeline.jobs[job1]
    some dep in config.depends_on
    dep == job2
}

jobs_can_parallelize(config1, config2) if {
    # Jobs that don't share resources can run in parallel
    not shares_resources(config1, config2)
}

shares_resources(config1, config2) if {
    config1.runner == config2.runner
    config1.concurrent == false
}

shares_resources(config1, config2) if {
    config2.concurrent == false
}

Summary

These 20 examples demonstrate comprehensive CI/CD pipeline policy enforcement using Rego:

File Validation - Syntax checking for YAML, JSON, TOML
PR Change Detection - Smart test routing based on changes
Test Coverage - Minimum thresholds and trend validation
Branch Protection - Protected branch and naming enforcement
Commit Messages - Conventional commits and content requirements
Deployment Approvals - Environment-based approval workflows
Artifact Scanning - Container vulnerability and signature verification
Environment Promotion - Sequential progression and quality gates
Rollback Policies - Automated triggers and approval requirements
Build Configuration - Dockerfile and pipeline validation
Dependency Scanning - Vulnerability and update requirements
License Compliance - Approved licenses and header validation
Code Quality Gates - Metrics and static analysis enforcement
Container Scanning - Base image and security validation
Secrets Detection - Pattern matching and file prevention
Performance Regression - Benchmark and load test validation
Documentation - Update requirements and completeness checks
Release Notes - Version bump and content validation
Feature Flags - Configuration and cleanup detection
Pipeline Dependencies - Job ordering and parallel optimization

Each policy can be customized to match your organization's specific requirements and integrated into GitHub Actions, GitLab CI, Jenkins, or other CI/CD platforms using OPA's eval command.

Install with Tessl CLI

npx tessl i nicholasjackson/golang-opa-rego-language@1.15.0

nicholasjackson/golang-opa-rego-language