pants-plugins/uses_services: follow new conventions in redis rules too

These changes were already made for MongoDB and RabbitMQ rules.
This removes a TODO comment and slightly refactors to follow the same convention.

pants-plugins/uses_services/redis_rules.py

@@ -28,6 +28,7 @@
     rules as pex_rules,
 )
 from pants.core.goals.test import TestExtraEnv
+from pants.engine.env_vars import EnvironmentVars
 from pants.engine.fs import CreateDigest, Digest, FileContent
 from pants.engine.rules import collect_rules, Get, MultiGet, rule
 from pants.engine.process import FallibleProcessResult, ProcessCacheScope
@@ -54,17 +55,30 @@ class UsesRedisRequest:
 
     # These config opts for integration tests are in:
     #   conf/st2.dev.conf (copied to conf/st2.ci.conf)
-    # TODO: for int tests: set url by either modifying st2.{dev,ci}.conf on the fly or via env vars.
-
-    #   with our version of oslo.config (newer are slower) we can't directly override opts w/ environment variables.
+    # These can also be updated via the ST2TESTS_REDIS_* env vars.
+    # Integration tests should pass these changes onto subprocesses using the
+    # ST2_COORDINATION__* env vars (which oslo_config reads).
 
     host: str = "127.0.0.1"
-    port: str = "6379"
+    port: int = 6379
 
     @property
     def coord_url(self) -> str:
         return f"redis://{self.host}:{self.port}?namespace=_st2_test"
 
+    @classmethod
+    def from_env(cls, env: EnvironmentVars) -> UsesRedisRequest:
+        default = cls()
+        host = env.get("ST2TESTS_REDIS_HOST", default.host)
+        port_raw = env.get("ST2TESTS_REDIS_PORT", str(default.port))
+
+        try:
+            port = int(port_raw)
+        except (TypeError, ValueError):
+            port = default.port
+
+        return cls(host=host, port=port)
+
 
 @dataclass(frozen=True)
 class RedisIsRunning:
@@ -88,11 +102,8 @@ async def redis_is_running_for_pytest(
     request: PytestUsesRedisRequest,
     test_extra_env: TestExtraEnv,
 ) -> PytestPluginSetup:
-    redis_host = test_extra_env.env.get("ST2TESTS_REDIS_HOST", "127.0.0.1")
-    redis_port = test_extra_env.env.get("ST2TESTS_REDIS_PORT", "6379")
-
     # this will raise an error if redis is not running
-    _ = await Get(RedisIsRunning, UsesRedisRequest(host=redis_host, port=redis_port))
+    _ = await Get(RedisIsRunning, UsesRedisRequest.from_env(env=test_extra_env.env))
 
     return PytestPluginSetup()
 
@@ -161,7 +172,7 @@ async def redis_is_running(
             not_installed_clause_deb="this is one way to install it:",
             install_instructions_deb=dedent(
                 """\
-                sudo apt-get install -y mongodb redis
+                sudo apt-get install -y redis
                 # Don't forget to start redis.
                 """
             ),
@@ -170,7 +181,8 @@ async def redis_is_running(
                 """\
                 You can also export the ST2TESTS_REDIS_HOST and ST2TESTS_REDIS_PORT
                 env vars to automatically use any redis host, local or remote,
-                while running unit and integration tests.
+                while running unit and integration tests. Tests do not use any
+                ST2_COORDINATION__* vars at this point.
                 """
             ),
         ),

pants-plugins/uses_services/redis_rules_test.py

@@ -51,7 +51,14 @@ def run_redis_is_running(
             "--backend-packages=uses_services",
             *(extra_args or ()),
         ],
-        env_inherit={"PATH", "PYENV_ROOT", "HOME"},
+        env_inherit={
+            "PATH",
+            "PYENV_ROOT",
+            "HOME",
+            "ST2TESTS_REDIS_HOST",
+            "ST2TESTS_REDIS_PORT",
+            "ST2TESTS_PARALLEL_SLOT",
+        },
     )
     result = rule_runner.request(
         RedisIsRunning,
@@ -62,7 +69,7 @@ def run_redis_is_running(
 
 # Warning this requires that redis be running
 def test_redis_is_running(rule_runner: RuleRunner) -> None:
-    request = UsesRedisRequest()
+    request = UsesRedisRequest.from_env(env=rule_runner.environment)
     mock_platform = platform(os="TestMock")
 
     # we are asserting that this does not raise an exception
@@ -74,7 +81,7 @@ def test_redis_is_running(rule_runner: RuleRunner) -> None:
 def test_redis_not_running(rule_runner: RuleRunner, mock_platform: Platform) -> None:
     request = UsesRedisRequest(
         host="127.100.20.7",
-        port="10",  # 10 is an unassigned port, unlikely to be used
+        port=10,  # 10 is an unassigned port, unlikely to be used
     )
 
     with pytest.raises(ExecutionError) as exception_info:

pants-plugins/uses_services/scripts/is_redis_running.py

@@ -39,8 +39,8 @@ def _is_redis_running(coord_url: str) -> bool:
 if __name__ == "__main__":
     args = dict((k, v) for k, v in enumerate(sys.argv))
 
-    # unit tests do not use redis, they use use an in-memory coordinator: "zake://"
-    # integration tests use this url with a conf file derived from conf/st2.dev.conf
+    # unit and integration tests require a coordinator, and mostly use this redis url.
+    # In some cases, unit tests can also use an in-memory coordinator: "zake://"
     coord_url = args.get(1, "redis://127.0.0.1:6379?namespace=_st2_test")
 
     is_running = _is_redis_running(coord_url)