instance manager logs to stdout/stderr during test run?

[davepacheco]

During cargo test I noticed:

     Running unittests src/lib.rs (target/debug/deps/omicron_sled_agent-cc40d5e98ba6d39c)

running 44 tests
test bootstrap::agent::tests::test_mac_to_socket_addr ... ok
test bootstrap::trust_quorum::rack_secret::tests::secret_splitting_fails_with_threshold_larger_than_total_shares ... ok
test common::instance::test::test_destroy_from_running_stops_first ... ok
test common::instance::test::test_destroy_from_stopped_destroys_immediately ... ok
test common::instance::test::test_migrating_from_running ... ok
test common::instance::test::test_migrating_missing_params_fails ... ok
test common::instance::test::test_migrating_inconsistent_internal_state ... ok
test common::instance::test::test_migrating_with_new_migration_fails ... ok
test common::instance::test::test_migrating_with_same_migration ... ok
test common::instance::test::test_migrating_from_invalid_states_fails ... ok
test common::instance::test::test_reboot ... ok
test common::instance::test::test_migrating_with_same_migration_different_propolis_fails ... ok
test common::instance::test::test_reboot_skip_starting_converges_to_running ... ok
test common::instance::test::test_running_from_creating ... ok
test common::instance::test::test_reboot_skip_stopping_converges_to_running ... ok
test illumos::vnic::test::test_allocate_within_scopes ... ok
test illumos::vnic::test::test_allocate ... ok
test illumos::zpool::test::test_parse_zpool_missing_column ... ok
test illumos::zpool::test::test_parse_zpool ... ok
test illumos::zpool::test::test_parse_zpool_name ... ok
test illumos::zpool::test::test_parse_bad_zpool_names ... ok
test rack_setup::config::test::test_subnets ... ok
test serial::tests::test_continuous_buffer_range_abstraction ... ok
test bootstrap::params::tests::json_serialization_round_trips ... ok
test sim::collection::test::test_sim_disk_transition_to_detached_states ... ok
test sim::collection::test::test_sim_instance_creating_to_stop ... ok
test sim::collection::test::test_sim_disk_attach_then_destroy ... ok
test sim::collection::test::test_sim_disk_attach_then_fault ... ok
test updates::test::test_write_artifact_to_filesystem ... ignored
test storage_manager::test::serialize_dataset_info ... ok
test bootstrap::agent::tests::persistent_sled_agent_request_serialization_round_trips ... ok
Jul 12 18:43:10.399 INFO Instance::new w/initial HW: InstanceHardware { runtime: InstanceRuntimeState { run_state: Creating, sled_id: 3f65a96d-ca00-4954-b053-4288f0ed8e03, propolis_id: ed895b13-55d5-4e0b-88e9-3f4e74d0d936, dst_propolis_id: None, propolis_addr: Some([fd00:1de::74]:12400), migration_id: None, ncpus: InstanceCpuCount(2), memory: ByteCount(536870912), hostname: "myvm", gen: Generation(1), time_updated: 2022-07-12T18:43:10.398411470Z }, nics: [], external_ip: ExternalIp { ip: 10.0.0.1, first_port: 0, last_port: 8192 }, disks: [], cloud_init_bytes: None }
Jul 12 18:43:10.400 INFO transition to InstanceRuntimeStateRequested { run_state: Running, migration_params: None }; action: Run, instance_id: e398c5d5-5059-4e55-beac-3a1071083aaa
Jul 12 18:43:10.400 INFO Taking action: Run, instance_id: e398c5d5-5059-4e55-beac-3a1071083aaa
test sim::collection::test::test_sim_instance_preempt_transition ... ok
test instance::test::transition_before_start - should panic ... ok
test sim::collection::test::test_sim_instance_running_then_destroyed ... ok
Jul 12 18:43:10.407 INFO instance_ensure e398c5d5-5059-4e55-beac-3a1071083aaa -> InstanceRuntimeStateRequested { run_state: Running, migration_params: None }, component: InstanceManager
Jul 12 18:43:10.407 INFO new instance, component: InstanceManager
test instance_manager::test::ensure_instance ... ok
Jul 12 18:43:10.410 INFO instance_ensure e398c5d5-5059-4e55-beac-3a1071083aaa -> InstanceRuntimeStateRequested { run_state: Running, migration_params: None }, component: InstanceManager
Jul 12 18:43:10.410 INFO new instance, component: InstanceManager
Jul 12 18:43:10.410 INFO instance_ensure e398c5d5-5059-4e55-beac-3a1071083aaa -> InstanceRuntimeStateRequested { run_state: Running, migration_params: None }, component: InstanceManager
Jul 12 18:43:10.410 INFO instance already exists, component: InstanceManager
Jul 12 18:43:10.410 INFO instance_ensure e398c5d5-5059-4e55-beac-3a1071083aaa -> InstanceRuntimeStateRequested { run_state: Running, migration_params: None }, component: InstanceManager
Jul 12 18:43:10.410 INFO instance already exists, component: InstanceManager
test instance_manager::test::ensure_instance_repeatedly ... ok
test sim::collection::test::test_sim_instance_reboot ... ok
test bootstrap::trust_quorum::rack_secret::tests::create_and_verify ... ok
test services::test::test_ensure_service ... ok
test services::test::test_ensure_service_which_already_exists ... ok
test services::test::test_services_are_recreated_on_reboot ... ok
test services::test::test_services_do_not_persist_without_config ... ok
test bootstrap::trust_quorum::rack_secret::tests::combine_deserialized_shares ... ok
test rack_setup::service::tests::test_generate_rack_secret ... ok

We seem to be getting log output from both InstanceManager and something else up there. Like in #1260 I think we probably want to be using a LogContext.