fix(chart): allow revisionHistoryLimit to be set to 0

chart/templates/_helpers.yaml

@@ -1172,3 +1172,23 @@ This helper function returns true if the executor can launch pods (Kubernetes-ba
     {{- print "true" -}}
   {{- end -}}
 {{- end -}}
+
+{{/*
+Get revisionHistoryLimit with nil-aware fallback.
+Unlike `or`, this properly handles 0 as a valid value.
+Pass a list of values to check in order of priority.
+
+Usage:
+  include "airflow.revisionHistoryLimit" (list .Values.scheduler.revisionHistoryLimit .Values.revisionHistoryLimit)
+*/}}
+{{- define "airflow.revisionHistoryLimit" -}}
+  {{- $result := "" -}}
+  {{- $found := false -}}
+  {{- range . -}}
+    {{- if and (not $found) (not (kindIs "invalid" .)) -}}
+      {{- $result = . -}}
+      {{- $found = true -}}
+    {{- end -}}
+  {{- end -}}
+  {{- $result -}}
+{{- end -}}

chart/templates/api-server/api-server-deployment.yaml

@@ -25,7 +25,7 @@
 {{- $affinity := or .Values.apiServer.affinity .Values.affinity }}
 {{- $tolerations := or .Values.apiServer.tolerations .Values.tolerations }}
 {{- $topologySpreadConstraints := or .Values.apiServer.topologySpreadConstraints .Values.topologySpreadConstraints }}
-{{- $revisionHistoryLimit := or .Values.apiServer.revisionHistoryLimit .Values.revisionHistoryLimit }}
+{{- $revisionHistoryLimit := include "airflow.revisionHistoryLimit" (list .Values.apiServer.revisionHistoryLimit .Values.revisionHistoryLimit) }}
 {{- $securityContext := include "airflowPodSecurityContext" (list . .Values.apiServer) }}
 {{- $containerSecurityContext := include "containerSecurityContext" (list . .Values.apiServer) }}
 {{- $containerSecurityContextWaitForMigrations := include "containerSecurityContext" (list . .Values.apiServer.waitForMigrations) }}
@@ -48,7 +48,7 @@ metadata:
   {{- end }}
 spec:
   replicas: {{ .Values.apiServer.replicas }}
-  {{- if $revisionHistoryLimit }}
+  {{- if ne $revisionHistoryLimit "" }}
   revisionHistoryLimit: {{ $revisionHistoryLimit }}
   {{- end }}
   strategy:

chart/templates/dag-processor/dag-processor-deployment.yaml

@@ -30,7 +30,7 @@
 {{- $affinity := or .Values.dagProcessor.affinity .Values.affinity }}
 {{- $tolerations := or .Values.dagProcessor.tolerations .Values.tolerations }}
 {{- $topologySpreadConstraints := or .Values.dagProcessor.topologySpreadConstraints .Values.topologySpreadConstraints }}
-{{- $revisionHistoryLimit := or .Values.dagProcessor.revisionHistoryLimit .Values.revisionHistoryLimit }}
+{{- $revisionHistoryLimit := include "airflow.revisionHistoryLimit" (list .Values.dagProcessor.revisionHistoryLimit .Values.revisionHistoryLimit) }}
 {{- $securityContext := include "airflowPodSecurityContext" (list . .Values.dagProcessor) }}
 {{- $containerSecurityContext := include "containerSecurityContext" (list . .Values.dagProcessor) }}
 {{- $containerSecurityContextLogGroomerSidecar := include "containerSecurityContext" (list . .Values.dagProcessor.logGroomerSidecar) }}
@@ -54,7 +54,7 @@ metadata:
   {{- end }}
 spec:
   replicas: {{ .Values.dagProcessor.replicas }}
-  {{- if $revisionHistoryLimit }}
+  {{- if ne $revisionHistoryLimit "" }}
   revisionHistoryLimit: {{ $revisionHistoryLimit }}
   {{- end }}
   selector:

chart/templates/flower/flower-deployment.yaml

@@ -26,7 +26,7 @@
 {{- $affinity := or .Values.flower.affinity .Values.affinity }}
 {{- $tolerations := or .Values.flower.tolerations .Values.tolerations }}
 {{- $topologySpreadConstraints := or .Values.flower.topologySpreadConstraints .Values.topologySpreadConstraints }}
-{{- $revisionHistoryLimit := or .Values.flower.revisionHistoryLimit .Values.revisionHistoryLimit }}
+{{- $revisionHistoryLimit := include "airflow.revisionHistoryLimit" (list .Values.flower.revisionHistoryLimit .Values.revisionHistoryLimit) }}
 {{- $securityContext := include "airflowPodSecurityContext" (list . .Values.flower) }}
 {{- $containerSecurityContext := include "containerSecurityContext" (list . .Values.flower) }}
 {{- $containerLifecycleHooks := or .Values.flower.containerLifecycleHooks .Values.containerLifecycleHooks }}
@@ -48,7 +48,7 @@ metadata:
   {{- end }}
 spec:
   replicas: 1
-  {{- if $revisionHistoryLimit }}
+  {{- if ne $revisionHistoryLimit "" }}
   revisionHistoryLimit: {{ $revisionHistoryLimit }}
   {{- end }}
   selector:

chart/templates/pgbouncer/pgbouncer-deployment.yaml

@@ -25,7 +25,7 @@
 {{- $affinity := or .Values.pgbouncer.affinity .Values.affinity }}
 {{- $tolerations := or .Values.pgbouncer.tolerations .Values.tolerations }}
 {{- $topologySpreadConstraints := or .Values.pgbouncer.topologySpreadConstraints .Values.topologySpreadConstraints }}
-{{- $revisionHistoryLimit := or .Values.pgbouncer.revisionHistoryLimit .Values.revisionHistoryLimit }}
+{{- $revisionHistoryLimit := include "airflow.revisionHistoryLimit" (list .Values.pgbouncer.revisionHistoryLimit .Values.revisionHistoryLimit) }}
 {{- $securityContext := include "localPodSecurityContext" .Values.pgbouncer }}
 {{- $containerSecurityContext := include "externalContainerSecurityContext" .Values.pgbouncer }}
 {{- $containerSecurityContextMetricsExporter := include "externalContainerSecurityContext" .Values.pgbouncer.metricsExporterSidecar }}
@@ -49,7 +49,7 @@ metadata:
   {{- end }}
 spec:
   replicas: {{ .Values.pgbouncer.replicas | default "1" }}
-  {{- if $revisionHistoryLimit }}
+  {{- if ne $revisionHistoryLimit "" }}
   revisionHistoryLimit: {{ $revisionHistoryLimit }}
   {{- end }}
   strategy:

chart/templates/scheduler/scheduler-deployment.yaml

@@ -40,7 +40,7 @@
 {{- $affinity := or .Values.scheduler.affinity .Values.affinity }}
 {{- $tolerations := or .Values.scheduler.tolerations .Values.tolerations }}
 {{- $topologySpreadConstraints := or .Values.scheduler.topologySpreadConstraints .Values.topologySpreadConstraints }}
-{{- $revisionHistoryLimit := or .Values.scheduler.revisionHistoryLimit .Values.revisionHistoryLimit }}
+{{- $revisionHistoryLimit := include "airflow.revisionHistoryLimit" (list .Values.scheduler.revisionHistoryLimit .Values.revisionHistoryLimit) }}
 {{- $securityContext := include "airflowPodSecurityContext" (list . .Values.scheduler) }}
 {{- $containerSecurityContext := include "containerSecurityContext" (list . .Values.scheduler) }}
 {{- $containerSecurityContextWaitForMigrations := include "containerSecurityContext" (list . .Values.scheduler.waitForMigrations) }}
@@ -69,7 +69,7 @@ spec:
   serviceName: {{ include "airflow.fullname" . }}-scheduler
   {{- end }}
   replicas: {{ .Values.scheduler.replicas }}
-  {{- if $revisionHistoryLimit }}
+  {{- if ne $revisionHistoryLimit "" }}
   revisionHistoryLimit: {{ $revisionHistoryLimit }}
   {{- end }}
   {{- if and $stateful .Values.scheduler.updateStrategy }}

chart/templates/statsd/statsd-deployment.yaml

@@ -25,7 +25,7 @@
 {{- $affinity := or .Values.statsd.affinity .Values.affinity }}
 {{- $tolerations := or .Values.statsd.tolerations .Values.tolerations }}
 {{- $topologySpreadConstraints := or .Values.statsd.topologySpreadConstraints .Values.topologySpreadConstraints }}
-{{- $revisionHistoryLimit := or .Values.statsd.revisionHistoryLimit .Values.revisionHistoryLimit }}
+{{- $revisionHistoryLimit := include "airflow.revisionHistoryLimit" (list .Values.statsd.revisionHistoryLimit .Values.revisionHistoryLimit) }}
 {{- $securityContext := include "localPodSecurityContext" .Values.statsd }}
 {{- $containerSecurityContext := include "externalContainerSecurityContext" .Values.statsd }}
 {{- $containerLifecycleHooks := .Values.statsd.containerLifecycleHooks }}
@@ -47,7 +47,7 @@ metadata:
   {{- end }}
 spec:
   replicas: 1
-  {{- if $revisionHistoryLimit }}
+  {{- if ne $revisionHistoryLimit "" }}
   revisionHistoryLimit: {{ $revisionHistoryLimit }}
   {{- end }}
   selector:

chart/templates/triggerer/triggerer-deployment.yaml

@@ -29,7 +29,7 @@
 {{- $affinity := or .Values.triggerer.affinity .Values.affinity }}
 {{- $tolerations := or .Values.triggerer.tolerations .Values.tolerations }}
 {{- $topologySpreadConstraints := or .Values.triggerer.topologySpreadConstraints .Values.topologySpreadConstraints }}
-{{- $revisionHistoryLimit := or .Values.triggerer.revisionHistoryLimit .Values.revisionHistoryLimit }}
+{{- $revisionHistoryLimit := include "airflow.revisionHistoryLimit" (list .Values.triggerer.revisionHistoryLimit .Values.revisionHistoryLimit) }}
 {{- $securityContext := include "airflowPodSecurityContext" (list . .Values.triggerer) }}
 {{- $containerSecurityContext := include "containerSecurityContext" (list . .Values.triggerer) }}
 {{- $containerSecurityContextWaitForMigrations := include "containerSecurityContext" (list . .Values.triggerer.waitForMigrations) }}
@@ -59,7 +59,7 @@ spec:
   {{- if not $keda }}
   replicas: {{ .Values.triggerer.replicas }}
   {{- end }}
-  {{- if $revisionHistoryLimit }}
+  {{- if ne $revisionHistoryLimit "" }}
   revisionHistoryLimit: {{ $revisionHistoryLimit }}
   {{- end }}
   selector:

chart/templates/webserver/webserver-deployment.yaml

@@ -25,7 +25,7 @@
 {{- $affinity := or .Values.webserver.affinity .Values.affinity }}
 {{- $tolerations := or .Values.webserver.tolerations .Values.tolerations }}
 {{- $topologySpreadConstraints := or .Values.webserver.topologySpreadConstraints .Values.topologySpreadConstraints }}
-{{- $revisionHistoryLimit := or .Values.webserver.revisionHistoryLimit .Values.revisionHistoryLimit }}
+{{- $revisionHistoryLimit := include "airflow.revisionHistoryLimit" (list .Values.webserver.revisionHistoryLimit .Values.revisionHistoryLimit) }}
 {{- $securityContext := include "airflowPodSecurityContext" (list . .Values.webserver) }}
 {{- $containerSecurityContext := include "containerSecurityContext" (list . .Values.webserver) }}
 {{- $containerSecurityContextWaitForMigrations := include "containerSecurityContext" (list . .Values.webserver.waitForMigrations) }}
@@ -50,7 +50,7 @@ spec:
   {{- if not .Values.webserver.hpa.enabled }}
   replicas: {{ .Values.webserver.replicas }}
   {{- end}}
-  {{- if $revisionHistoryLimit }}
+  {{- if ne $revisionHistoryLimit "" }}
   revisionHistoryLimit: {{ $revisionHistoryLimit }}
   {{- end }}
   strategy:

chart/templates/workers/worker-deployment.yaml

@@ -28,7 +28,7 @@
 {{- $affinity := or .Values.workers.affinity .Values.affinity }}
 {{- $tolerations := or .Values.workers.tolerations .Values.tolerations }}
 {{- $topologySpreadConstraints := or .Values.workers.topologySpreadConstraints .Values.topologySpreadConstraints }}
-{{- $revisionHistoryLimit := or .Values.workers.celery.revisionHistoryLimit .Values.workers.revisionHistoryLimit .Values.revisionHistoryLimit }}
+{{- $revisionHistoryLimit := include "airflow.revisionHistoryLimit" (list .Values.workers.celery.revisionHistoryLimit .Values.workers.revisionHistoryLimit .Values.revisionHistoryLimit) }}
 {{- $securityContext := include "airflowPodSecurityContext" (list . .Values.workers) }}
 {{- $containerSecurityContext := include "containerSecurityContext" (list . .Values.workers) }}
 {{- $containerSecurityContextPersistence := include "containerSecurityContext" (list . .Values.workers.persistence) }}
@@ -65,7 +65,7 @@ spec:
   {{- if and (not $keda) (not $hpa) }}
   replicas: {{ .Values.workers.celery.replicas | default .Values.workers.replicas }}
   {{- end }}
-  {{- if $revisionHistoryLimit }}
+  {{- if ne $revisionHistoryLimit "" }}
   revisionHistoryLimit: {{ $revisionHistoryLimit }}
   {{- end }}
   {{- if and $persistence (or .Values.workers.celery.persistence.persistentVolumeClaimRetentionPolicy .Values.workers.persistence.persistentVolumeClaimRetentionPolicy) }}

helm-tests/tests/helm_tests/airflow_core/test_api_server.py

@@ -50,6 +50,25 @@ def test_revision_history_limit(self, revision_history_limit, global_revision_hi
         expected_result = revision_history_limit if revision_history_limit else global_revision_history_limit
         assert jmespath.search("spec.revisionHistoryLimit", docs[0]) == expected_result
 
+    @pytest.mark.parametrize(
+        ("revision_history_limit", "global_revision_history_limit", "expected"),
+        [(0, None, 0), (None, 0, 0), (0, 10, 0)],
+    )
+    def test_revision_history_limit_zero(
+        self, revision_history_limit, global_revision_history_limit, expected
+    ):
+        """Test that revisionHistoryLimit can be set to 0."""
+        values = {"apiServer": {}}
+        if revision_history_limit is not None:
+            values["apiServer"]["revisionHistoryLimit"] = revision_history_limit
+        if global_revision_history_limit is not None:
+            values["revisionHistoryLimit"] = global_revision_history_limit
+        docs = render_chart(
+            values=values,
+            show_only=["templates/api-server/api-server-deployment.yaml"],
+        )
+        assert jmespath.search("spec.revisionHistoryLimit", docs[0]) == expected
+
     def test_should_add_scheme_to_liveness_and_readiness_and_startup_probes(self):
         docs = render_chart(
             values={

helm-tests/tests/helm_tests/airflow_core/test_dag_processor.py

@@ -624,6 +624,25 @@ def test_revision_history_limit(self, revision_history_limit, global_revision_hi
         expected_result = revision_history_limit or global_revision_history_limit
         assert jmespath.search("spec.revisionHistoryLimit", docs[0]) == expected_result
 
+    @pytest.mark.parametrize(
+        ("revision_history_limit", "global_revision_history_limit", "expected"),
+        [(0, None, 0), (None, 0, 0), (0, 10, 0)],
+    )
+    def test_revision_history_limit_zero(
+        self, revision_history_limit, global_revision_history_limit, expected
+    ):
+        """Test that revisionHistoryLimit can be set to 0."""
+        values = {"dagProcessor": {"enabled": True}}
+        if revision_history_limit is not None:
+            values["dagProcessor"]["revisionHistoryLimit"] = revision_history_limit
+        if global_revision_history_limit is not None:
+            values["revisionHistoryLimit"] = global_revision_history_limit
+        docs = render_chart(
+            values=values,
+            show_only=["templates/dag-processor/dag-processor-deployment.yaml"],
+        )
+        assert jmespath.search("spec.revisionHistoryLimit", docs[0]) == expected
+
     @pytest.mark.parametrize("command", [None, ["custom", "command"]])
     @pytest.mark.parametrize("args", [None, ["custom", "args"]])
     def test_command_and_args_overrides(self, command, args):

helm-tests/tests/helm_tests/airflow_core/test_scheduler.py

@@ -348,6 +348,25 @@ def test_revision_history_limit(self, revision_history_limit, global_revision_hi
         expected_result = revision_history_limit or global_revision_history_limit
         assert jmespath.search("spec.revisionHistoryLimit", docs[0]) == expected_result
 
+    @pytest.mark.parametrize(
+        ("revision_history_limit", "global_revision_history_limit", "expected"),
+        [(0, None, 0), (None, 0, 0), (0, 10, 0)],
+    )
+    def test_revision_history_limit_zero(
+        self, revision_history_limit, global_revision_history_limit, expected
+    ):
+        """Test that revisionHistoryLimit can be set to 0."""
+        values = {"scheduler": {}}
+        if revision_history_limit is not None:
+            values["scheduler"]["revisionHistoryLimit"] = revision_history_limit
+        if global_revision_history_limit is not None:
+            values["revisionHistoryLimit"] = global_revision_history_limit
+        docs = render_chart(
+            values=values,
+            show_only=["templates/scheduler/scheduler-deployment.yaml"],
+        )
+        assert jmespath.search("spec.revisionHistoryLimit", docs[0]) == expected
+
     def test_should_create_valid_affinity_tolerations_and_node_selector(self):
         docs = render_chart(
             values={

helm-tests/tests/helm_tests/airflow_core/test_triggerer.py

@@ -75,6 +75,25 @@ def test_revision_history_limit(self, revision_history_limit, global_revision_hi
         expected_result = revision_history_limit or global_revision_history_limit
         assert jmespath.search("spec.revisionHistoryLimit", docs[0]) == expected_result
 
+    @pytest.mark.parametrize(
+        ("revision_history_limit", "global_revision_history_limit", "expected"),
+        [(0, None, 0), (None, 0, 0), (0, 10, 0)],
+    )
+    def test_revision_history_limit_zero(
+        self, revision_history_limit, global_revision_history_limit, expected
+    ):
+        """Test that revisionHistoryLimit can be set to 0."""
+        values = {"triggerer": {"enabled": True}}
+        if revision_history_limit is not None:
+            values["triggerer"]["revisionHistoryLimit"] = revision_history_limit
+        if global_revision_history_limit is not None:
+            values["revisionHistoryLimit"] = global_revision_history_limit
+        docs = render_chart(
+            values=values,
+            show_only=["templates/triggerer/triggerer-deployment.yaml"],
+        )
+        assert jmespath.search("spec.revisionHistoryLimit", docs[0]) == expected
+
     def test_disable_wait_for_migration(self):
         docs = render_chart(
             values={

helm-tests/tests/helm_tests/airflow_core/test_worker.py

@@ -133,6 +133,29 @@ def test_revision_history_limit_overwrite(self, worker_values, global_limit, exp
 
         assert jmespath.search("spec.revisionHistoryLimit", docs[0]) == expected
 
+    @pytest.mark.parametrize(
+        ("worker_values", "global_limit", "expected"),
+        [
+            ({}, 0, 0),
+            ({"revisionHistoryLimit": 0}, None, 0),
+            ({"celery": {"revisionHistoryLimit": 0}}, None, 0),
+            ({"revisionHistoryLimit": 0}, 10, 0),
+            ({"celery": {"revisionHistoryLimit": 0}}, 10, 0),
+            ({"revisionHistoryLimit": 0, "celery": {"revisionHistoryLimit": 0}}, 10, 0),
+        ],
+    )
+    def test_revision_history_limit_zero(self, worker_values, global_limit, expected):
+        """Test that revisionHistoryLimit can be set to 0."""
+        values = {"workers": worker_values}
+        if global_limit is not None:
+            values["revisionHistoryLimit"] = global_limit
+        docs = render_chart(
+            values=values,
+            show_only=["templates/workers/worker-deployment.yaml"],
+        )
+
+        assert jmespath.search("spec.revisionHistoryLimit", docs[0]) == expected
+
     def test_should_add_extra_containers(self):
         docs = render_chart(
             values={

helm-tests/tests/helm_tests/other/test_flower.py

@@ -69,6 +69,25 @@ def test_revision_history_limit(self, revision_history_limit, global_revision_hi
         expected_result = revision_history_limit or global_revision_history_limit
         assert jmespath.search("spec.revisionHistoryLimit", docs[0]) == expected_result
 
+    @pytest.mark.parametrize(
+        ("revision_history_limit", "global_revision_history_limit", "expected"),
+        [(0, None, 0), (None, 0, 0), (0, 10, 0)],
+    )
+    def test_revision_history_limit_zero(
+        self, revision_history_limit, global_revision_history_limit, expected
+    ):
+        """Test that revisionHistoryLimit can be set to 0."""
+        values = {"flower": {"enabled": True}}
+        if revision_history_limit is not None:
+            values["flower"]["revisionHistoryLimit"] = revision_history_limit
+        if global_revision_history_limit is not None:
+            values["revisionHistoryLimit"] = global_revision_history_limit
+        docs = render_chart(
+            values=values,
+            show_only=["templates/flower/flower-deployment.yaml"],
+        )
+        assert jmespath.search("spec.revisionHistoryLimit", docs[0]) == expected
+
     @pytest.mark.parametrize(
         ("airflow_version", "expected_arg"),
         [

helm-tests/tests/helm_tests/other/test_pgbouncer.py

@@ -129,6 +129,25 @@ def test_revision_history_limit(self, revision_history_limit, global_revision_hi
         expected_result = revision_history_limit or global_revision_history_limit
         assert jmespath.search("spec.revisionHistoryLimit", docs[0]) == expected_result
 
+    @pytest.mark.parametrize(
+        ("revision_history_limit", "global_revision_history_limit", "expected"),
+        [(0, None, 0), (None, 0, 0), (0, 10, 0)],
+    )
+    def test_revision_history_limit_zero(
+        self, revision_history_limit, global_revision_history_limit, expected
+    ):
+        """Test that revisionHistoryLimit can be set to 0."""
+        values = {"pgbouncer": {"enabled": True}}
+        if revision_history_limit is not None:
+            values["pgbouncer"]["revisionHistoryLimit"] = revision_history_limit
+        if global_revision_history_limit is not None:
+            values["revisionHistoryLimit"] = global_revision_history_limit
+        docs = render_chart(
+            values=values,
+            show_only=["templates/pgbouncer/pgbouncer-deployment.yaml"],
+        )
+        assert jmespath.search("spec.revisionHistoryLimit", docs[0]) == expected
+
     def test_scheduler_name(self):
         docs = render_chart(
             values={"pgbouncer": {"enabled": True}, "schedulerName": "airflow-scheduler"},