chore: extract module with builtin metrics

query_exporter/config.py

@@ -28,51 +28,9 @@
     Query,
     QueryMetric,
 )
+from .metrics import BUILTIN_METRICS, get_builtin_metric_configs
 from .yaml import load_yaml_config
 
-# metric for counting database errors
-DB_ERRORS_METRIC_NAME = "database_errors"
-_DB_ERRORS_METRIC_CONFIG = MetricConfig(
-    name=DB_ERRORS_METRIC_NAME,
-    description="Number of database errors",
-    type="counter",
-    config={"increment": True},
-)
-
-# metric for counting performed queries
-QUERIES_METRIC_NAME = "queries"
-_QUERIES_METRIC_CONFIG = MetricConfig(
-    name=QUERIES_METRIC_NAME,
-    description="Number of database queries",
-    type="counter",
-    labels=("query", "status"),
-    config={"increment": True},
-)
-# metric for tracking last query execution timestamp
-QUERY_TIMESTAMP_METRIC_NAME = "query_timestamp"
-_QUERY_TIMESTAMP_METRIC_CONFIG = MetricConfig(
-    name=QUERY_TIMESTAMP_METRIC_NAME,
-    description="Query last execution timestamp",
-    type="gauge",
-    labels=("query",),
-)
-# metric for counting queries execution latency
-QUERY_LATENCY_METRIC_NAME = "query_latency"
-_QUERY_LATENCY_METRIC_CONFIG = MetricConfig(
-    name=QUERY_LATENCY_METRIC_NAME,
-    description="Query execution latency",
-    type="histogram",
-    labels=("query",),
-)
-GLOBAL_METRICS = frozenset(
-    (
-        DB_ERRORS_METRIC_NAME,
-        QUERIES_METRIC_NAME,
-        QUERY_LATENCY_METRIC_NAME,
-        QUERY_TIMESTAMP_METRIC_NAME,
-    )
-)
-
 # regexp for validating environment variables names
 _ENV_VAR_RE = re.compile(r"[a-zA-Z_][a-zA-Z0-9_]*$")
 
@@ -189,22 +147,7 @@ def _get_metrics(
     metrics: dict[str, dict[str, t.Any]], extra_labels: frozenset[str]
 ) -> dict[str, MetricConfig]:
     """Return a dict mapping metric names to their configuration."""
-    configs = {}
-    # global metrics
-    for metric_config in (
-        _DB_ERRORS_METRIC_CONFIG,
-        _QUERIES_METRIC_CONFIG,
-        _QUERY_LATENCY_METRIC_CONFIG,
-        _QUERY_TIMESTAMP_METRIC_CONFIG,
-    ):
-        configs[metric_config.name] = MetricConfig(
-            metric_config.name,
-            metric_config.description,
-            metric_config.type,
-            labels=set(metric_config.labels) | extra_labels,
-            config=metric_config.config,
-        )
-    # other metrics
+    configs = get_builtin_metric_configs(extra_labels)
     for name, config in metrics.items():
         _validate_metric_config(name, config, extra_labels)
         metric_type = config.pop("type")
@@ -221,7 +164,7 @@ def _validate_metric_config(
     name: str, config: dict[str, t.Any], extra_labels: frozenset[str]
 ) -> None:
     """Validate a metric configuration stanza."""
-    if name in GLOBAL_METRICS:
+    if name in BUILTIN_METRICS:
         raise ConfigError(f'Label name "{name} is reserved for builtin metric')
     labels = set(config.get("labels", ()))
     overlap_labels = labels & extra_labels
@@ -437,7 +380,7 @@ def _warn_if_unused(
             entries=unused_dbs,
         )
     if unused_metrics := sorted(
-        set(config.metrics) - GLOBAL_METRICS - used_metrics
+        set(config.metrics) - BUILTIN_METRICS - used_metrics
     ):
         logger.warning(
             "unused config entries",

query_exporter/loop.py

@@ -23,10 +23,6 @@
 )
 
 from .config import (
-    DB_ERRORS_METRIC_NAME,
-    QUERIES_METRIC_NAME,
-    QUERY_LATENCY_METRIC_NAME,
-    QUERY_TIMESTAMP_METRIC_NAME,
     Config,
 )
 from .db import (
@@ -37,6 +33,12 @@
     Query,
     QueryTimeoutExpired,
 )
+from .metrics import (
+    DB_ERRORS_METRIC_NAME,
+    QUERIES_METRIC_NAME,
+    QUERY_LATENCY_METRIC_NAME,
+    QUERY_TIMESTAMP_METRIC_NAME,
+)
 
 
 class MetricsLastSeen:

query_exporter/metrics.py

@@ -0,0 +1,65 @@
+from prometheus_aioexporter import MetricConfig
+
+# metric for counting database errors
+DB_ERRORS_METRIC_NAME = "database_errors"
+_DB_ERRORS_METRIC_CONFIG = MetricConfig(
+    name=DB_ERRORS_METRIC_NAME,
+    description="Number of database errors",
+    type="counter",
+    config={"increment": True},
+)
+
+# metric for counting performed queries
+QUERIES_METRIC_NAME = "queries"
+_QUERIES_METRIC_CONFIG = MetricConfig(
+    name=QUERIES_METRIC_NAME,
+    description="Number of database queries",
+    type="counter",
+    labels=("query", "status"),
+    config={"increment": True},
+)
+# metric for tracking last query execution timestamp
+QUERY_TIMESTAMP_METRIC_NAME = "query_timestamp"
+_QUERY_TIMESTAMP_METRIC_CONFIG = MetricConfig(
+    name=QUERY_TIMESTAMP_METRIC_NAME,
+    description="Query last execution timestamp",
+    type="gauge",
+    labels=("query",),
+)
+# metric for counting queries execution latency
+QUERY_LATENCY_METRIC_NAME = "query_latency"
+_QUERY_LATENCY_METRIC_CONFIG = MetricConfig(
+    name=QUERY_LATENCY_METRIC_NAME,
+    description="Query execution latency",
+    type="histogram",
+    labels=("query",),
+)
+BUILTIN_METRICS = frozenset(
+    (
+        DB_ERRORS_METRIC_NAME,
+        QUERIES_METRIC_NAME,
+        QUERY_LATENCY_METRIC_NAME,
+        QUERY_TIMESTAMP_METRIC_NAME,
+    )
+)
+
+
+def get_builtin_metric_configs(
+    extra_labels: frozenset[str],
+) -> dict[str, MetricConfig]:
+    """Return configuration for builtin metrics."""
+    return {
+        metric_config.name: MetricConfig(
+            metric_config.name,
+            metric_config.description,
+            metric_config.type,
+            labels=set(metric_config.labels) | extra_labels,
+            config=metric_config.config,
+        )
+        for metric_config in (
+            _DB_ERRORS_METRIC_CONFIG,
+            _QUERIES_METRIC_CONFIG,
+            _QUERY_LATENCY_METRIC_CONFIG,
+            _QUERY_TIMESTAMP_METRIC_CONFIG,
+        )
+    }

tests/config_test.py

@@ -8,15 +8,17 @@
 import yaml
 
 from query_exporter.config import (
-    DB_ERRORS_METRIC_NAME,
-    GLOBAL_METRICS,
-    QUERIES_METRIC_NAME,
     ConfigError,
     _get_parameters_sets,
     _resolve_dsn,
     load_config,
 )
 from query_exporter.db import QueryMetric
+from query_exporter.metrics import (
+    BUILTIN_METRICS,
+    DB_ERRORS_METRIC_NAME,
+    QUERIES_METRIC_NAME,
+)
 
 
 @pytest.fixture
@@ -437,7 +439,7 @@ def test_load_metrics_section(self, write_config: ConfigWriter) -> None:
             "states": ["on", "off"],
             "expiration": 100,
         }
-        # global metrics
+        # builtin metrics
         assert result.metrics.get(DB_ERRORS_METRIC_NAME) is not None
         assert result.metrics.get(QUERIES_METRIC_NAME) is not None
 
@@ -473,20 +475,20 @@ def test_load_metrics_overlap_database_label(
             == 'Labels for metric "m" overlap with reserved/database ones: l1'
         )
 
-    @pytest.mark.parametrize("global_name", list(GLOBAL_METRICS))
+    @pytest.mark.parametrize("builtin_metric_name", list(BUILTIN_METRICS))
     def test_load_metrics_reserved_name(
         self,
         config_full: dict[str, t.Any],
         write_config: ConfigWriter,
-        global_name: str,
+        builtin_metric_name: str,
     ) -> None:
-        config_full["metrics"][global_name] = {"type": "counter"}
+        config_full["metrics"][builtin_metric_name] = {"type": "counter"}
         config_file = write_config(config_full)
         with pytest.raises(ConfigError) as err:
             load_config([config_file])
         assert (
             str(err.value)
-            == f'Label name "{global_name} is reserved for builtin metric'
+            == f'Label name "{builtin_metric_name} is reserved for builtin metric'
         )
 
     def test_load_metrics_unsupported_type(
@@ -1006,7 +1008,7 @@ def test_load_multiple_files_combine(
         )
         config = load_config([file1, file2])
         assert set(config.databases) == {"db1", "db2"}
-        assert set(config.metrics) == {"m1", "m2"} | GLOBAL_METRICS
+        assert set(config.metrics) == {"m1", "m2"} | BUILTIN_METRICS
         assert set(config.queries) == {"q1", "q2"}
 
     def test_load_multiple_files_duplicated_database(