feat: use content-type provided by prometheus client, pin airflow 2.6.1 dependencies.

.github/workflows/test.yml

@@ -30,23 +30,29 @@ jobs:
         python-version: '3.8'
 
     - name: Setup database
-      run: docker-compose -f tests/docker-compose.yml up -d
+      run: docker compose -f tests/docker-compose.yml up -d
 
     - name: Install Airflow
-      run: pip install "apache-airflow == ${{ matrix.airflow-version }}" mysqlclient==1.4.6 wtforms==2.3.3
+      run: pip install "apache-airflow == ${{ matrix.airflow-version }}" mysqlclient==1.4.6
+
+    - name: Install airflow-exporter for 2.6.1
+      if: matrix.airflow-version == '2.6.1'
+      run: pip install '.[airflow-2.6.1]'
 
     - name: Install airflow-exporter
+      if: matrix.airflow-version != '2.6.1'
       run: pip install .
 
     - name: Init Airflow DB
       run: |
         airflow db init
-        airflow db init
 
     - name: Prepare DAG statuses
       run: |
         airflow dags list
 
+        airflow dags reserialize
+
         airflow dags unpause dummy_dag
         airflow dags unpause slow_dag
 

airflow_exporter/prometheus_exporter.py

@@ -15,7 +15,7 @@
 from airflow.utils.state import State
 
 # Importing base classes that we need to derive
-from prometheus_client import generate_latest, REGISTRY
+from prometheus_client import generate_latest, REGISTRY, CONTENT_TYPE_LATEST
 from prometheus_client.core import GaugeMetricFamily, Metric
 from prometheus_client.samples import Sample
 
@@ -467,7 +467,7 @@ class RBACMetrics(FABBaseView):
 
     @FABexpose('/')
     def list(self):
-        return Response(generate_latest(), mimetype='text')
+        return Response(generate_latest(), mimetype=CONTENT_TYPE_LATEST)
 
 
 # Metrics View for Flask app builder used in airflow with rbac enabled

setup.py

@@ -32,9 +32,20 @@
         "apache-airflow>=2.6.1",
         "prometheus_client>=0.4.2",
     ],
+    extras_require={
+        # NOTE: airflow==2.6.1 has no upper bound on several dependencies. A
+        # new installation brings newer versions which contain breaking
+        # changes, requiring us to explicitly pin these dependencies to
+        # compatible versions.
+        "airflow-2.6.1": [
+            "apache-airflow==2.6.1",
+            "pydantic<2.0.0",
+            "pendulum<3.0.0",
+            "Flask-Session<0.6.0",
+            "connexion<3.0",
+        ],
+    },
     entry_points={
-        "airflow.plugins": [
-            "AirflowPrometheus = airflow_exporter.prometheus_exporter:AirflowPrometheusPlugins"
-        ]
+        "airflow.plugins": ["AirflowPrometheus = airflow_exporter.prometheus_exporter:AirflowPrometheusPlugins"]
     },
 )