Add simple test for sharding

test_runner/regress/test_sharding.py

@@ -0,0 +1,19 @@
+from fixtures.neon_fixtures import NeonEnvBuilder
+import pytest
+
+@pytest.mark.parametrize("shard_count", [2])
+def test_sharding(neon_env_builder: NeonEnvBuilder, shard_count: int):
+    neon_env_builder.enable_generations = True
+    neon_env_builder.initial_shard_count = shard_count
+    neon_env_builder.num_pageservers = shard_count
+    env = neon_env_builder.init_start()
+
+    for pageserver in env.pageservers:
+        # FIXME: attachment_service is not yet sharding aware, so generation validation is broken.
+        pageserver.allowed_errors.append(".*Dropped remote consistent LSN updates.*")
+        pageserver.allowed_errors.append(".*Dropping stale deletions for tenant.*")
+
+    endpoint = env.endpoints.create_start("main", pageserver_ids=[p.id for p in env.pageservers])
+    endpoint.safe_psql("create table t(t bigint, payload text default repeat('?',200))")
+    endpoint.safe_psql("insert into t values(generate_series(1,10000000))")
+    assert endpoint.safe_psql("select count(*) from t")[0][0] == 10000000