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Testing DAGs Persistent Volume Claim Configuration in Apache Airflow

This test suite validates the Persistent Volume Claim (PVC) functionality for DAGs in Apache Airflow’s Helm chart implementation. It ensures proper storage configuration and persistence behavior when deploying Airflow using Kubernetes.

Test Coverage Overview

The test suite provides comprehensive coverage of DAGs PVC configuration scenarios.

Validates PVC document generation based on persistence settings
Tests behavior with existing claims
Verifies storage class configuration
Checks access mode settings
Validates annotation handling

Implementation Analysis

The testing approach utilizes the Helm template generator to render and validate chart configurations. It employs a systematic pattern of testing different PVC configurations using the render_chart function with various input values and assertions.

The implementation leverages jmespath for JSON path queries to verify specific configuration elements within the rendered templates.

Technical Details

Uses render_chart helper for Helm template testing
Implements jmespath for YAML document traversal
Tests storage configuration parameters including size, class, and access modes
Validates template interpolation for dynamic values

Best Practices Demonstrated

The test suite exhibits strong testing practices through isolated test cases and comprehensive assertion coverage.

Separate test methods for distinct functionality
Clear test method naming conventions
Thorough validation of configuration parameters
Proper handling of template rendering edge cases

apache/airflow

helm_tests/other/test_dags_persistent_volume_claim.py

            
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# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
#
#   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 TestDagsPersistentVolumeClaim:
    """Tests DAGs PVC."""

    def test_should_not_generate_a_document_if_persistence_is_disabled(self):
        docs = render_chart(
            values={"dags": {"persistence": {"enabled": False}}},
            show_only=["templates/dags-persistent-volume-claim.yaml"],
        )

        assert len(docs) == 0

    def test_should_not_generate_a_document_when_using_an_existing_claim(self):
        docs = render_chart(
            values={"dags": {"persistence": {"enabled": True, "existingClaim": "test-claim"}}},
            show_only=["templates/dags-persistent-volume-claim.yaml"],
        )

        assert len(docs) == 0

    def test_should_generate_a_document_if_persistence_is_enabled_and_not_using_an_existing_claim(self):
        docs = render_chart(
            values={"dags": {"persistence": {"enabled": True, "existingClaim": None}}},
            show_only=["templates/dags-persistent-volume-claim.yaml"],
        )

        assert len(docs) == 1

    def test_should_set_pvc_details_correctly(self):
        docs = render_chart(
            values={
                "dags": {
                    "persistence": {
                        "enabled": True,
                        "size": "1G",
                        "existingClaim": None,
                        "storageClassName": "MyStorageClass",
                        "accessMode": "ReadWriteMany",
                    }
                }
            },
            show_only=["templates/dags-persistent-volume-claim.yaml"],
        )

        assert jmespath.search("spec", docs[0]) == {
            "accessModes": ["ReadWriteMany"],
            "resources": {"requests": {"storage": "1G"}},
            "storageClassName": "MyStorageClass",
        }

    def test_single_annotation(self):
        docs = render_chart(
            values={
                "dags": {
                    "persistence": {
                        "enabled": True,
                        "size": "1G",
                        "existingClaim": None,
                        "storageClassName": "MyStorageClass",
                        "accessMode": "ReadWriteMany",
                        "annotations": {"key": "value"},
                    }
                }
            },
            show_only=["templates/dags-persistent-volume-claim.yaml"],
        )

        annotations = jmespath.search("metadata.annotations", docs[0])
        assert annotations.get("key") == "value"

    def test_multiple_annotations(self):
        docs = render_chart(
            values={
                "dags": {
                    "persistence": {
                        "enabled": True,
                        "size": "1G",
                        "existingClaim": None,
                        "storageClassName": "MyStorageClass",
                        "accessMode": "ReadWriteMany",
                        "annotations": {"key": "value", "key-two": "value-two"},
                    }
                }
            },
            show_only=["templates/dags-persistent-volume-claim.yaml"],
        )

        annotations = jmespath.search("metadata.annotations", docs[0])
        assert annotations.get("key") == "value"
        assert annotations.get("key-two") == "value-two"

    def test_dags_persistent_volume_claim_template_storage_class_name(self):
        docs = render_chart(
            values={
                "dags": {
                    "persistence": {
                        "existingClaim": None,
                        "enabled": True,
                        "storageClassName": "{{ .Release.Name }}-storage-class",
                    }
                }
            },
            show_only=["templates/dags-persistent-volume-claim.yaml"],
        )
        assert jmespath.search("spec.storageClassName", docs[0]) == "release-name-storage-class"