add verify_latency_percentile_from_load_test probe

Signed-off-by: Sylvain Hellegouarch <sh@defuze.org>

CHANGELOG.md

@@ -2,15 +2,24 @@
 
 ## [Unreleased][]
 
-[Unreleased]: https://github.com/chaostoolkit-incubator/chaostoolkit-reliably/compare/0.74.0...HEAD
+[Unreleased]: https://github.com/chaostoolkit-incubator/chaostoolkit-reliably/compare/0.75.0...HEAD
+
+## [0.75.0][]
+
+[0.75.0]: https://github.com/chaostoolkit-incubator/chaostoolkit-reliably/compare/0.74.0...0.75.0
+
+### Added
+
+* The `verify_latency_percentile_from_load_test`  probeto perform a verification of a
+  load test from `run_load_test`
 
 ## [0.74.0][]
 
 [0.74.0]: https://github.com/chaostoolkit-incubator/chaostoolkit-reliably/compare/0.73.0...0.74.0
 
 ### Added
 
-* The `run_load_test` to perform a load test using the excellent [oha](https://github.com/hatoo/oha)
+* The `run_load_test` action to perform a load test using the excellent [oha](https://github.com/hatoo/oha)
 
 ### Changed
 

chaosreliably/activities/load/__init__.py

@@ -0,0 +1,15 @@
+import threading
+from typing import Any, Dict
+
+lock = threading.Lock()
+RESULTS = {}
+
+
+def store_results(name: str, results: Dict[str, Any]) -> None:
+    with lock():
+        RESULTS[name] = results
+
+
+def get_results(name: str) -> Dict[str, Any]:
+    with lock():
+        RESULTS.get("name", {})

chaosreliably/activities/load/actions.py

@@ -5,6 +5,7 @@
 import shutil
 import subprocess  # nosec
 import tempfile
+from threading import Lock
 from typing import Any, Dict, Optional, cast
 from urllib.parse import urlparse
 
@@ -13,6 +14,8 @@
 from chaoslib.types import Configuration, Secrets
 from logzero import logger
 
+from chaosreliably.activities.load import store_results
+
 try:
     from opentelemetry.context import get_current
     from opentelemetry.propagate import inject
@@ -22,6 +25,8 @@
     HAS_OTEL = False
 
 __all__ = ["inject_gradual_traffic_into_endpoint", "run_load_test"]
+lock = Lock()
+RESULTS = dict()
 
 
 def inject_gradual_traffic_into_endpoint(
@@ -166,13 +171,14 @@ def run_load_test(
     url: str,
     duration: int = 30,
     qps: int = 5,
-    use_dns_servers: str = "",
+    connect_to: str = "",
     insecure: bool = False,
     host: str = "None",
     method: str = "GET",
     headers: str = "",
     body: str = "",
     content_type: str = "",
+    test_name: str = "load test",
 ) -> Dict[str, Any]:
     """
     Run a load test against the given URL.
@@ -181,21 +187,27 @@ def run_load_test(
     It produces a different set of results. Please make sure to have it
     installed in your `PATH`.
 
+    Set the `test_name` so you can use one of the probe against this action
+    to retrieve its results.
+
     Use the following parameters to adjust the default:
 
-    * `use_dns_servers` pass a comma-separated list of DNS servers to connect
-      to instead of the default ones
+    * `connect_to` pass a column seperated list of addresses `host:port`
+       to connect to instead of the DNS values for the domain
     * `insecure` set to False to communicate with a non-secure TLS server
     * `host` set a different `HOST` header
     * `method` the HTTP method to use
     * `headers` a comma-separated list of headers "foo: bar,other: thing"
     * `body` the content of the request to send if any
     * `content_type` the content-type of the request to send if any
+
     """
     oha_path = shutil.which("oha")
     if not oha_path:
         raise ActivityFailed("missing load test dependency")
 
+    results = {}  # Dict[str, Any]
+
     cmd = [
         oha_path,
         "--json",
@@ -209,8 +221,8 @@ def run_load_test(
         f"{qps}",
     ]
 
-    if use_dns_servers:
-        cmd.extend(["--connect-to", use_dns_servers])
+    if connect_to:
+        cmd.extend(["--connect-to", connect_to])
 
     if insecure:
         cmd.extend(
@@ -261,9 +273,12 @@ def run_load_test(
         logger.debug(f"locust stderr: {stderr}")
 
         try:
-            results = json.loads(stdout)
+            results = cast(Dict[str, Any], json.loads(stdout))
         except json.decoder.JSONDecodeError:
             logger.error("failed to parse oha results")
             raise ActivityFailed("failed to parse oha results")
 
-    return cast(Dict[str, Any], results)
+    if test_name:
+        store_results(test_name, results)
+
+    return results

chaosreliably/activities/load/probes.py

@@ -2,10 +2,13 @@
 import os.path
 from typing import Optional, cast
 
+from chaosreliably.activities.load import get_results
+
 __all__ = [
     "load_test_result_field_should_be",
     "load_test_result_field_should_be_less_than",
     "load_test_result_field_should_be_greater_than",
+    "verify_latency_percentile_from_load_test",
 ]
 
 
@@ -103,3 +106,21 @@ def load_test_result_field_should_be_greater_than(
         return cast(bool, data[0][field] > int(expect))
 
     return False
+
+
+def verify_latency_percentile_from_load_test(
+    lower_than: float, percentile: str = "p99", test_name: str = "load test"
+) -> bool:
+    """
+    Verify that the percentile of a load test result, generated with the
+    `run_load_test` action, is lower than the expected value.
+    """
+    results = get_results("test_name")
+    if not results:
+        return False
+
+    p = results.get("latencyPercentilesSuccessful", {}).get(percentile)
+    if not p:
+        return False
+
+    return p <= lower_than