Upgrade python3-prometheus-client to v0.18.0.

.circleci/config.yml

@@ -75,12 +75,11 @@ workflows:
           matrix:
             parameters:
                python:
-                 - "3.6"
-                 - "3.7"
                  - "3.8"
                  - "3.9"
                  - "3.10"
                  - "3.11"
+                 - "3.12"
       - test_nooptionals:
           matrix:
             parameters:
@@ -90,4 +89,4 @@ workflows:
           matrix:
             parameters:
                python:
-                 - "3.7"
+                 - "3.8"

README.md

@@ -252,6 +252,20 @@ h = Histogram('request_latency_seconds', 'Description of histogram')
 h.observe(4.7, {'trace_id': 'abc123'})
 ```
 
+Exemplars are only rendered in the OpenMetrics exposition format. If using the
+HTTP server or apps in this library, content negotiation can be used to specify
+OpenMetrics (which is done by default in Prometheus). Otherwise it will be
+necessary to use `generate_latest` from
+`prometheus_client.openmetrics.exposition` to view exemplars.
+
+To view exemplars in Prometheus it is also necessary to enable the the
+exemplar-storage feature flag:
+```
+--enable-feature=exemplar-storage
+```
+Additional information is available in [the Prometheus
+documentation](https://prometheus.io/docs/prometheus/latest/feature_flags/#exemplars-storage).
+
 ### Disabling `_created` metrics
 
 By default counters, histograms, and summaries export an additional series
@@ -590,8 +604,9 @@ To do so you need to create a custom collector, for example:
 
 ```python
 from prometheus_client.core import GaugeMetricFamily, CounterMetricFamily, REGISTRY
+from prometheus_client.registry import Collector
 
-class CustomCollector(object):
+class CustomCollector(Collector):
     def collect(self):
         yield GaugeMetricFamily('my_gauge', 'Help text', value=7)
         c = CounterMetricFamily('my_counter_total', 'Help text', labels=['foo'])
@@ -696,9 +711,10 @@ Gauges have several modes they can run in, which can be selected with the `multi
 - 'min': Return a single timeseries that is the minimum of the values of all processes (alive or dead).
 - 'max': Return a single timeseries that is the maximum of the values of all processes (alive or dead).
 - 'sum': Return a single timeseries that is the sum of the values of all processes (alive or dead).
+- 'mostrecent': Return a single timeseries that is the most recent value among all processes (alive or dead).
 
 Prepend 'live' to the beginning of the mode to return the same result but only considering living processes
-(e.g., 'liveall, 'livesum', 'livemax', 'livemin').
+(e.g., 'liveall, 'livesum', 'livemax', 'livemin', 'livemostrecent').
 
 ```python
 from prometheus_client import Gauge
@@ -722,6 +738,34 @@ for family in text_string_to_metric_families(u"my_gauge 1.0\n"):
     print("Name: {0} Labels: {1} Value: {2}".format(*sample))
 ```
 
+## Restricted registry
+
+Registries support restriction to only return specific metrics.
+If you’re using the built-in HTTP server, you can use the GET parameter "name[]", since it’s an array it can be used multiple times.
+If you’re directly using `generate_latest`, you can use the function `restricted_registry()`.
+
+```python
+curl --get --data-urlencode "name[]=python_gc_objects_collected_total" --data-urlencode "name[]=python_info" http://127.0.0.1:9200/metrics
+```
+
+```python
+from prometheus_client import generate_latest
+
+generate_latest(REGISTRY.restricted_registry(['python_gc_objects_collected_total', 'python_info']))
+```
+
+```python
+# HELP python_info Python platform information
+# TYPE python_info gauge
+python_info{implementation="CPython",major="3",minor="9",patchlevel="3",version="3.9.3"} 1.0
+# HELP python_gc_objects_collected_total Objects collected during gc
+# TYPE python_gc_objects_collected_total counter
+python_gc_objects_collected_total{generation="0"} 73129.0
+python_gc_objects_collected_total{generation="1"} 8594.0
+python_gc_objects_collected_total{generation="2"} 296.0
+```
+
+
 ## Links
 
 * [Releases](https://github.com/prometheus/client_python/releases): The releases page shows the history of the project and acts as a changelog.

prometheus_client/__init__.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 
 from . import (
     exposition, gc_collector, metrics, metrics_core, platform_collector,
@@ -11,7 +11,10 @@
     write_to_textfile,
 )
 from .gc_collector import GC_COLLECTOR, GCCollector
-from .metrics import Counter, Enum, Gauge, Histogram, Info, Summary
+from .metrics import (
+    Counter, disable_created_metrics, enable_created_metrics, Enum, Gauge,
+    Histogram, Info, Summary,
+)
 from .metrics_core import Metric
 from .platform_collector import PLATFORM_COLLECTOR, PlatformCollector
 from .process_collector import PROCESS_COLLECTOR, ProcessCollector
@@ -27,6 +30,8 @@
     'Histogram',
     'Info',
     'Enum',
+    'enable_created_metrics',
+    'disable_created_metrics',
     'CONTENT_TYPE_LATEST',
     'generate_latest',
     'MetricsHandler',

prometheus_client/context_managers.py

@@ -1,13 +1,10 @@
-import sys
 from timeit import default_timer
 from types import TracebackType
 from typing import (
-    Any, Callable, Optional, Tuple, Type, TYPE_CHECKING, TypeVar, Union,
+    Any, Callable, Literal, Optional, Tuple, Type, TYPE_CHECKING, TypeVar,
+    Union,
 )
 
-if sys.version_info >= (3, 8, 0):
-    from typing import Literal
-
 from .decorator import decorate
 
 if TYPE_CHECKING:
@@ -23,7 +20,7 @@ def __init__(self, counter: "Counter", exception: Union[Type[BaseException], Tup
     def __enter__(self) -> None:
         pass
 
-    def __exit__(self, typ: Optional[Type[BaseException]], value: Optional[BaseException], traceback: Optional[TracebackType]) -> "Literal[False]":
+    def __exit__(self, typ: Optional[Type[BaseException]], value: Optional[BaseException], traceback: Optional[TracebackType]) -> Literal[False]:
         if isinstance(value, self._exception):
             self._counter.inc()
         return False

prometheus_client/exposition.py

@@ -38,7 +38,6 @@
 
 CONTENT_TYPE_LATEST = 'text/plain; version=0.0.4; charset=utf-8'
 """Content type of the latest text format"""
-PYTHON376_OR_NEWER = sys.version_info > (3, 7, 5)
 
 
 class _PrometheusRedirectHandler(HTTPRedirectHandler):
@@ -545,10 +544,7 @@ def _use_gateway(
 ) -> None:
     gateway_url = urlparse(gateway)
     # See https://bugs.python.org/issue27657 for details on urlparse in py>=3.7.6.
-    if not gateway_url.scheme or (
-            PYTHON376_OR_NEWER
-            and gateway_url.scheme not in ['http', 'https']
-    ):
+    if not gateway_url.scheme or gateway_url.scheme not in ['http', 'https']:
         gateway = f'http://{gateway}'
 
     gateway = gateway.rstrip('/')

prometheus_client/metrics.py

@@ -3,8 +3,8 @@
 import time
 import types
 from typing import (
-    Any, Callable, Dict, Iterable, List, Optional, Sequence, Tuple, Type,
-    TypeVar, Union,
+    Any, Callable, Dict, Iterable, List, Literal, Optional, Sequence, Tuple,
+    Type, TypeVar, Union,
 )
 
 from . import values  # retain this import style for testability
@@ -70,6 +70,18 @@ def _get_use_created() -> bool:
 _use_created = _get_use_created()
 
 
+def disable_created_metrics():
+    """Disable exporting _created metrics on counters, histograms, and summaries."""
+    global _use_created
+    _use_created = False
+
+
+def enable_created_metrics():
+    """Enable exporting _created metrics on counters, histograms, and summaries."""
+    global _use_created
+    _use_created = True
+
+
 class MetricWrapperBase(Collector):
     _type: Optional[str] = None
     _reserved_labelnames: Sequence[str] = ()
@@ -346,7 +358,8 @@ def f():
         d.set_function(lambda: len(my_dict))
     """
     _type = 'gauge'
-    _MULTIPROC_MODES = frozenset(('all', 'liveall', 'min', 'livemin', 'max', 'livemax', 'sum', 'livesum'))
+    _MULTIPROC_MODES = frozenset(('all', 'liveall', 'min', 'livemin', 'max', 'livemax', 'sum', 'livesum', 'mostrecent', 'livemostrecent'))
+    _MOST_RECENT_MODES = frozenset(('mostrecent', 'livemostrecent'))
 
     def __init__(self,
                  name: str,
@@ -357,7 +370,7 @@ def __init__(self,
                  unit: str = '',
                  registry: Optional[CollectorRegistry] = REGISTRY,
                  _labelvalues: Optional[Sequence[str]] = None,
-                 multiprocess_mode: str = 'all',
+                 multiprocess_mode: Literal['all', 'liveall', 'min', 'livemin', 'max', 'livemax', 'sum', 'livesum', 'mostrecent', 'livemostrecent'] = 'all',
                  ):
         self._multiprocess_mode = multiprocess_mode
         if multiprocess_mode not in self._MULTIPROC_MODES:
@@ -373,6 +386,7 @@ def __init__(self,
             _labelvalues=_labelvalues,
         )
         self._kwargs['multiprocess_mode'] = self._multiprocess_mode
+        self._is_most_recent = self._multiprocess_mode in self._MOST_RECENT_MODES
 
     def _metric_init(self) -> None:
         self._value = values.ValueClass(
@@ -382,18 +396,25 @@ def _metric_init(self) -> None:
 
     def inc(self, amount: float = 1) -> None:
         """Increment gauge by the given amount."""
+        if self._is_most_recent:
+            raise RuntimeError("inc must not be used with the mostrecent mode")
         self._raise_if_not_observable()
         self._value.inc(amount)
 
     def dec(self, amount: float = 1) -> None:
         """Decrement gauge by the given amount."""
+        if self._is_most_recent:
+            raise RuntimeError("dec must not be used with the mostrecent mode")
         self._raise_if_not_observable()
         self._value.inc(-amount)
 
     def set(self, value: float) -> None:
         """Set gauge to the given value."""
         self._raise_if_not_observable()
-        self._value.set(float(value))
+        if self._is_most_recent:
+            self._value.set(float(value), timestamp=time.time())
+        else:
+            self._value.set(float(value))
 
     def set_to_current_time(self) -> None:
         """Set gauge to the current unixtime."""

prometheus_client/mmap_dict.py

@@ -6,25 +6,26 @@
 
 _INITIAL_MMAP_SIZE = 1 << 16
 _pack_integer_func = struct.Struct(b'i').pack
-_pack_double_func = struct.Struct(b'd').pack
+_pack_two_doubles_func = struct.Struct(b'dd').pack
 _unpack_integer = struct.Struct(b'i').unpack_from
-_unpack_double = struct.Struct(b'd').unpack_from
+_unpack_two_doubles = struct.Struct(b'dd').unpack_from
 
 
 # struct.pack_into has atomicity issues because it will temporarily write 0 into
 # the mmap, resulting in false reads to 0 when experiencing a lot of writes.
 # Using direct assignment solves this issue.
 
-def _pack_double(data, pos, value):
-    data[pos:pos + 8] = _pack_double_func(value)
+
+def _pack_two_doubles(data, pos, value, timestamp):
+    data[pos:pos + 16] = _pack_two_doubles_func(value, timestamp)
 
 
 def _pack_integer(data, pos, value):
     data[pos:pos + 4] = _pack_integer_func(value)
 
 
 def _read_all_values(data, used=0):
-    """Yield (key, value, pos). No locking is performed."""
+    """Yield (key, value, timestamp, pos). No locking is performed."""
 
     if used <= 0:
         # If not valid `used` value is passed in, read it from the file.
@@ -41,9 +42,9 @@ def _read_all_values(data, used=0):
         encoded_key = data[pos:pos + encoded_len]
         padded_len = encoded_len + (8 - (encoded_len + 4) % 8)
         pos += padded_len
-        value = _unpack_double(data, pos)[0]
-        yield encoded_key.decode('utf-8'), value, pos
-        pos += 8
+        value, timestamp = _unpack_two_doubles(data, pos)
+        yield encoded_key.decode('utf-8'), value, timestamp, pos
+        pos += 16
 
 
 class MmapedDict:
@@ -53,7 +54,8 @@ class MmapedDict:
     Then 4 bytes of padding.
     There's then a number of entries, consisting of a 4 byte int which is the
     size of the next field, a utf-8 encoded string key, padding to a 8 byte
-    alignment, and then a 8 byte float which is the value.
+    alignment, and then a 8 byte float which is the value and a 8 byte float
+    which is a UNIX timestamp in seconds.
 
     Not thread safe.
     """
@@ -76,7 +78,7 @@ def __init__(self, filename, read_mode=False):
             _pack_integer(self._m, 0, self._used)
         else:
             if not read_mode:
-                for key, _, pos in self._read_all_values():
+                for key, _, _, pos in self._read_all_values():
                     self._positions[key] = pos
 
     @staticmethod
@@ -95,7 +97,7 @@ def _init_value(self, key):
         encoded = key.encode('utf-8')
         # Pad to be 8-byte aligned.
         padded = encoded + (b' ' * (8 - (len(encoded) + 4) % 8))
-        value = struct.pack(f'i{len(padded)}sd'.encode(), len(encoded), padded, 0.0)
+        value = struct.pack(f'i{len(padded)}sdd'.encode(), len(encoded), padded, 0.0, 0.0)
         while self._used + len(value) > self._capacity:
             self._capacity *= 2
             self._f.truncate(self._capacity)
@@ -105,30 +107,28 @@ def _init_value(self, key):
         # Update how much space we've used.
         self._used += len(value)
         _pack_integer(self._m, 0, self._used)
-        self._positions[key] = self._used - 8
+        self._positions[key] = self._used - 16
 
     def _read_all_values(self):
         """Yield (key, value, pos). No locking is performed."""
         return _read_all_values(data=self._m, used=self._used)
 
     def read_all_values(self):
-        """Yield (key, value). No locking is performed."""
-        for k, v, _ in self._read_all_values():
-            yield k, v
+        """Yield (key, value, timestamp). No locking is performed."""
+        for k, v, ts, _ in self._read_all_values():
+            yield k, v, ts
 
     def read_value(self, key):
         if key not in self._positions:
             self._init_value(key)
         pos = self._positions[key]
-        # We assume that reading from an 8 byte aligned value is atomic
-        return _unpack_double(self._m, pos)[0]
+        return _unpack_two_doubles(self._m, pos)
 
-    def write_value(self, key, value):
+    def write_value(self, key, value, timestamp):
         if key not in self._positions:
             self._init_value(key)
         pos = self._positions[key]
-        # We assume that writing to an 8 byte aligned value is atomic
-        _pack_double(self._m, pos, value)
+        _pack_two_doubles(self._m, pos, value, timestamp)
 
     def close(self):
         if self._f: