test(health_probes): add pytest for the readiness probe endpoint

Signed-off-by: Niladri Halder <[email protected]>

deployer/src/infra/rest.rs

@@ -44,6 +44,10 @@ impl ComponentAction for Rest {
                 }
             }
 
+            if let Some(core_health_freq) = &options.rest_core_health_freq {
+                binary = binary.with_args(vec!["--core-health-freq", core_health_freq]);
+            }
+
             if cfg.container_exists("jaeger") {
                 let jaeger_config = format!("jaeger.{}:4317", cfg.get_name());
                 binary = binary.with_args(vec!["--jaeger", &jaeger_config])

deployer/src/lib.rs

@@ -136,6 +136,10 @@ pub struct StartOptions {
     #[clap(long, conflicts_with = "no_rest")]
     pub rest_jwk: Option<String>,
 
+    /// Set the rest-to-core health probe frequency on the rest.
+    #[arg(long)]
+    pub rest_core_health_freq: Option<String>,
+
     /// Use the following image pull policy when creating containers from images.
     #[clap(long, default_value = "ifnotpresent")]
     pub image_pull_policy: composer::ImagePullPolicy,

tests/bdd/common/deployer.py

@@ -38,6 +38,7 @@ class StartOptions:
     no_min_timeouts: bool = False
     rust_log: str = None
     rust_log_silence: str = None
+    rest_core_health_freq: str = None
 
     def args(self):
         args = [
@@ -99,13 +100,17 @@ def args(self):
             if rust_log_silence is not None:
                 args.append(f"--rust-log-silence={rust_log_silence}")
 
+        if self.rest_core_health_freq:
+            args.append(f"--rest-core-health-freq={self.rest_core_health_freq}")
+
         agent_arg = "--agents=Core"
         if self.ha_node_agent:
             agent_arg += ",HaNode"
         if self.ha_cluster_agent:
             agent_arg += ",HaCluster"
             if self.ha_cluster_agent_fast is not None:
                 args.append(f"--cluster-fast-requeue={self.ha_cluster_agent_fast}")
+
         args.append(agent_arg)
 
         return args
@@ -139,6 +144,7 @@ def start(
         no_min_timeouts=False,
         rust_log: str = None,
         rust_log_silence: str = None,
+        rest_core_health_freq: str = None,
     ):
         options = StartOptions(
             io_engines,
@@ -165,6 +171,7 @@ def start(
             no_min_timeouts=no_min_timeouts,
             rust_log=rust_log,
             rust_log_silence=rust_log_silence,
+            rest_core_health_freq=rest_core_health_freq,
         )
         pytest.deployer_options = options
         Deployer.start_with_opts(options)

tests/bdd/features/health_probes/readiness_probe.feature

@@ -0,0 +1,12 @@
+Feature: Readiness Probe
+
+  Background:
+    Given a running agent-core service
+    And a running REST service with "--core-health-freq" set to "10s"
+
+  Scenario: The REST API /ready service should not update its readiness status more than once in 10 seconds
+    Given agent-core service is available
+    And the REST service returns a 200 status code for an HTTP GET request to the /ready endpoint
+    When the agent-core service is brought down forcefully
+    Then the REST service returns 200 for /ready endpoint for 5 more seconds
+    And after a delay of 5 seconds the REST service returns 503 for /ready endpoint for the following 12 seconds

tests/bdd/features/health_probes/test_readiness_probe.py

@@ -0,0 +1,99 @@
+"""Readiness Probe feature tests."""
+
+import time
+
+import pytest
+from common.apiclient import REST_SERVER
+from common.deployer import Deployer
+from common.docker import Docker
+from pytest_bdd import given, scenario, then, when
+from requests import get as http_get
+from retrying import retry
+
+READINESS_API_ENDPOINT = REST_SERVER + "/ready"
+
+
+@pytest.fixture(scope="module")
+def setup():
+    Deployer.start(io_engines=1, rest_core_health_freq="10s")
+    yield
+    Deployer.stop()
+
+
+@scenario(
+    "readiness_probe.feature",
+    "The REST API /ready service should not update its readiness status more than once in 10 seconds",
+)
+def test_the_rest_api_ready_service_should_not_update_its_readiness_status_more_than_once_in_5_seconds():
+    """The REST API /ready service should not update its readiness status more than once in 5 seconds."""
+
+
+@given('a running REST service with "--core-health-freq" set to "10s"')
+def a_running_rest_service(setup):
+    """a running REST service with "--core-health-freq" set to "10s"."""
+
+
+@given("a running agent-core service")
+def a_running_agent_core_service(setup):
+    """a running agent-core service."""
+
+
+@given("agent-core service is available")
+def agent_core_service_is_available(setup):
+    """agent-core service is available."""
+
+
+@given(
+    "the REST service returns a 200 status code for an HTTP GET request to the /ready endpoint"
+)
+def the_rest_service_returns_a_200_status_code_for_an_http_get_request_to_the_ready_endpoint(
+    setup,
+):
+    """the REST service returns a 200 status code for an HTTP GET request to the /ready endpoint."""
+
+    # 30 sec retry.
+    @retry(
+        stop_max_attempt_number=150,
+        wait_fixed=200,
+    )
+    def rest_is_ready():
+        response = http_get(READINESS_API_ENDPOINT)
+        assert response.status_code == 200
+
+    rest_is_ready()
+
+
+@when("the agent-core service is brought down forcefully")
+def the_agent_core_service_is_brought_down_forcefully(setup):
+    """the agent-core service is brought down forcefully."""
+    Docker.kill_container("core")
+
+
+@then("the REST service returns 200 for /ready endpoint for 5 more seconds")
+def the_rest_service_returns_200_for_ready_endpoint_for_5_more_seconds(setup):
+    """the REST service returns 200 for /ready endpoint for 5 more seconds."""
+    start_time = time.time()
+    while time.time() - start_time < 5:
+        response = http_get(READINESS_API_ENDPOINT)
+        if response.status_code != 200:
+            raise ValueError(
+                "Expected Readiness probe to return 200 for this duration of 5 seconds"
+            )
+
+
+@then(
+    "after a delay of 5 seconds the REST service returns 503 for /ready endpoint for the following 12 seconds"
+)
+def after_a_delay_of_5_seconds_the_rest_service_returns_503_for_ready_endpoint_for_the_following_12_seconds(
+    setup,
+):
+    """after a delay of 5 seconds the REST service returns 503 for /ready endpoint for the following 12 seconds."""
+    time.sleep(5)
+
+    start_time = time.time()
+    while time.time() - start_time < 12:
+        response = http_get(READINESS_API_ENDPOINT)
+        if response.status_code != 503:
+            raise ValueError(
+                "Expected Readiness probe to return 503 for this duration of 12 seconds"
+            )