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Testing Scheduler Pod Disruption Budget Configuration in Apache Airflow

This test suite validates the Pod Disruption Budget (PDB) functionality for the Apache Airflow scheduler component in Helm deployments. It ensures proper configuration and behavior of PDB settings across different Kubernetes versions and validates component-specific label handling.

Test Coverage Overview

The test suite provides comprehensive coverage of scheduler PDB functionality in Helm charts.

Key areas tested include:

Basic PDB enablement validation for both v1 and v1beta1 API versions
Component-specific label propagation
Configuration validation with minAvailable parameter

Integration points focus on Kubernetes PDB API compatibility and Helm templating.

Implementation Analysis

The testing approach utilizes the render_chart helper function to validate Helm template generation and configuration. Tests employ systematic verification of PDB configurations and label handling, using both direct template rendering and jmespath queries for validation.

Key patterns include:

Template validation without raising exceptions
Kubernetes version-specific testing
Label verification using jmespath

Technical Details

Testing tools and components:

render_chart utility for Helm template testing
jmespath for JSON/YAML parsing and validation
Kubernetes API version compatibility testing (1.16.0)
PDB configuration validation for both v1 and v1beta1 APIs

Best Practices Demonstrated

The test suite exemplifies several testing best practices for Kubernetes manifest validation.

Notable practices include:

Isolated template rendering for focused testing
Version-specific API compatibility checks
Structured validation of configuration parameters
Clear test case organization and naming

apache/airflow

helm_tests/airflow_core/test_pdb_scheduler.py

            
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# to you under the Apache License, Version 2.0 (the
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# with the License.  You may obtain a copy of the License at
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#   http://www.apache.org/licenses/LICENSE-2.0
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# Unless required by applicable law or agreed to in writing,
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# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.
from __future__ import annotations

import jmespath

from tests.charts.helm_template_generator import render_chart


class TestSchedulerPdb:
    """Tests Scheduler PDB."""

    def test_should_pass_validation_with_just_pdb_enabled_v1(self):
        render_chart(
            values={"scheduler": {"podDisruptionBudget": {"enabled": True}}},
            show_only=["templates/scheduler/scheduler-poddisruptionbudget.yaml"],
        )  # checks that no validation exception is raised

    def test_should_pass_validation_with_just_pdb_enabled_v1beta1(self):
        render_chart(
            values={"scheduler": {"podDisruptionBudget": {"enabled": True}}},
            show_only=["templates/scheduler/scheduler-poddisruptionbudget.yaml"],
            kubernetes_version="1.16.0",
        )  # checks that no validation exception is raised

    def test_should_add_component_specific_labels(self):
        docs = render_chart(
            values={
                "scheduler": {
                    "podDisruptionBudget": {"enabled": True},
                    "labels": {"test_label": "test_label_value"},
                },
            },
            show_only=["templates/scheduler/scheduler-poddisruptionbudget.yaml"],
        )

        assert "test_label" in jmespath.search("metadata.labels", docs[0])
        assert jmespath.search("metadata.labels", docs[0])["test_label"] == "test_label_value"

    def test_should_pass_validation_with_pdb_enabled_and_min_available_param(self):
        render_chart(
            values={
                "scheduler": {
                    "podDisruptionBudget": {
                        "enabled": True,
                        "config": {"maxUnavailable": None, "minAvailable": 1},
                    }
                }
            },
            show_only=["templates/scheduler/scheduler-poddisruptionbudget.yaml"],
        )  # checks that no validation exception is raised