Improve coverage in modules

[IanHoang]

Is your feature request related to a problem? Please describe

When users run pytest --cov=. within the OSB repository, they get the following output.

---------- coverage: platform darwin, python 3.9.6-final-0 -----------
Name                                                                                          Stmts   Miss Branch BrPart  Cover
-------------------------------------------------------------------------------------------------------------------------------
benchmarks/__init__.py                                                                            0      0      0      0   100%
benchmarks/worker_coordinator/__init__.py                                                         0      0      0      0   100%
benchmarks/worker_coordinator/parsing_test.py                                                   113    113      0      0     0%
benchmarks/worker_coordinator/runner_test.py                                                     18     18      2      0     0%
benchmarks/workload/__init__.py                                                                   0      0      0      0   100%
benchmarks/workload/bulk_params_test.py                                                          62     62      0      0     0%
it/__init__.py                                                                                  149    149     26      0     0%
it/distribution_test.py                                                                          14     14      4      0     0%
it/download_test.py                                                                               8      8      2      0     0%
it/info_test.py                                                                                  17     17      0      0     0%
it/list_test.py                                                                                  18     18      0      0     0%
it/proxy_test.py                                                                                 50     50      2      0     0%
it/sources_test.py                                                                                8      8      0      0     0%
it/tracker_test.py                                                                               27     27      2      0     0%
osbenchmark/__init__.py                                                                          15      2      2      0    76%
osbenchmark/actor.py                                                                            120     90     36      0    19%
osbenchmark/aggregator.py                                                                       172     66     68     14    60%
osbenchmark/async_connection.py                                                                 140     67     34      4    49%
osbenchmark/benchmark.py                                                                        511    511    124      0     0%
osbenchmark/benchmarkd.py                                                                        62     62     24      0     0%
osbenchmark/builder/__init__.py                                                                   1      0      0      0   100%
osbenchmark/builder/builder.py                                                                  444    302    104      0    29%
osbenchmark/builder/cluster.py                                                                    9      1      0      0    89%
osbenchmark/builder/cluster_builder.py                                                           10     10      0      0     0%
osbenchmark/builder/configs/__init__.py                                                           0      0      0      0   100%
osbenchmark/builder/configs/listers/__init__.py                                                   0      0      0      0   100%
osbenchmark/builder/configs/listers/plugin_config_instance_lister.py                             40      0      6      0   100%
osbenchmark/builder/configs/utils/__init__.py                                                     0      0      0      0   100%
osbenchmark/builder/configs/utils/config_path_resolver.py                                        27      0      4      0   100%
osbenchmark/builder/downloaders/__init__.py                                                       0      0      0      0   100%
osbenchmark/builder/downloaders/builders/__init__.py                                              0      0      0      0   100%
osbenchmark/builder/downloaders/builders/binary_builder.py                                        5      1      0      0    80%
osbenchmark/builder/downloaders/builders/source_binary_builder.py                                27      0      2      0   100%
osbenchmark/builder/downloaders/core_plugin_source_downloader.py                                 19      0      2      1    95%
osbenchmark/builder/downloaders/downloader.py                                                     7      1      0      0    86%
osbenchmark/builder/downloaders/external_plugin_source_downloader.py                             23      0      2      1    96%
osbenchmark/builder/downloaders/opensearch_distribution_downloader.py                            45      3      2      0    94%
osbenchmark/builder/downloaders/opensearch_source_downloader.py                                  36      0      2      1    97%
osbenchmark/builder/downloaders/plugin_distribution_downloader.py                                 9      0      0      0   100%
osbenchmark/builder/downloaders/repositories/__init__.py                                          0      0      0      0   100%
osbenchmark/builder/downloaders/repositories/opensearch_distribution_repository_provider.py      22      0      2      0   100%
osbenchmark/builder/downloaders/repositories/plugin_distribution_repository_provider.py           8      0      0      0   100%
osbenchmark/builder/downloaders/repositories/repository_url_provider.py                          18      0      2      0   100%
osbenchmark/builder/downloaders/repositories/source_repository_provider.py                       64      0     12      1    99%
osbenchmark/builder/executors/__init__.py                                                         0      0      0      0   100%
osbenchmark/builder/executors/exception_handling_shell_executor.py                               10      0      0      0   100%
osbenchmark/builder/executors/local_shell_executor.py                                            10      0      4      0   100%
osbenchmark/builder/executors/shell_executor.py                                                   5      1      0      0    80%
osbenchmark/builder/installers/__init__.py                                                        0      0      0      0   100%
osbenchmark/builder/installers/bare_installer.py                                                 56      3     16      1    92%
osbenchmark/builder/installers/docker_installer.py                                               66     16      4      0    74%
osbenchmark/builder/installers/exception_handling_installer.py                                   16     16      0      0     0%
osbenchmark/builder/installers/installer.py                                                      10      2      0      0    80%
osbenchmark/builder/installers/preparers/__init__.py                                              0      0      0      0   100%
osbenchmark/builder/installers/preparers/opensearch_preparer.py                                  63      3      4      1    94%
osbenchmark/builder/installers/preparers/plugin_preparer.py                                      32      4      4      1    86%
osbenchmark/builder/installers/preparers/preparer.py                                             19      5      0      0    74%
osbenchmark/builder/java_resolver.py                                                             32      7     10      1    76%
osbenchmark/builder/launcher.py                                                                 185     12     42      7    92%
osbenchmark/builder/launchers/__init__.py                                                         0      0      0      0   100%
osbenchmark/builder/launchers/docker_launcher.py                                                 58      0      8      0   100%
osbenchmark/builder/launchers/exception_handling_launcher.py                                     16     16      0      0     0%
osbenchmark/builder/launchers/launcher.py                                                        10      2      0      0    80%
osbenchmark/builder/launchers/local_process_launcher.py                                         132     11     26      5    90%
osbenchmark/builder/launchers/no_op_launcher.py                                                   6      6      0      0     0%
osbenchmark/builder/models/__init__.py                                                            0      0      0      0   100%
osbenchmark/builder/models/architecture_types.py                                                 13      1      4      1    88%
osbenchmark/builder/models/bootstrap_phase.py                                                    12     12      4      0     0%
osbenchmark/builder/models/cluster.py                                                             7      7      0      0     0%
osbenchmark/builder/models/cluster_flavors.py                                                     4      0      0      0   100%
osbenchmark/builder/models/cluster_infra_providers.py                                             4      0      0      0   100%
osbenchmark/builder/models/config_instance_types.py                                               7      0      0      0   100%
osbenchmark/builder/models/host.py                                                                8      0      0      0   100%
osbenchmark/builder/models/node.py                                                               14      0      0      0   100%
osbenchmark/builder/models/plugin_config_instance.py                                             26      3      2      0    89%
osbenchmark/builder/models/provision_config_instance.py                                          30     30      2      0     0%
osbenchmark/builder/models/provision_config_instance_descriptor.py                               15     15      0      0     0%
osbenchmark/builder/models/provision_config_instance_types.py                                     4      4      0      0     0%
osbenchmark/builder/provision_config.py                                                         334     55    116      6    83%
osbenchmark/builder/provisioner.py                                                              304    100     60      9    65%
osbenchmark/builder/provisioners/__init__.py                                                      0      0      0      0   100%
osbenchmark/builder/provisioners/provisioner.py                                                  10     10      0      0     0%
osbenchmark/builder/supplier.py                                                                 515     83    128     15    82%
osbenchmark/builder/utils/__init__.py                                                             0      0      0      0   100%
osbenchmark/builder/utils/artifact_variables_provider.py                                         12      0      0      0   100%
osbenchmark/builder/utils/binary_keys.py                                                          3      0      0      0   100%
osbenchmark/builder/utils/config_applier.py                                                      32      0      8      0   100%
osbenchmark/builder/utils/git_manager.py                                                         16      7      0      0    56%
osbenchmark/builder/utils/host_cleaner.py                                                        14      0      4      0   100%
osbenchmark/builder/utils/java_home_resolver.py                                                  33      4      6      1    87%
osbenchmark/builder/utils/jdk_resolver.py                                                        54      1     22      3    95%
osbenchmark/builder/utils/path_manager.py                                                        20      0      4      1    96%
osbenchmark/builder/utils/template_renderer.py                                                   27      0      0      0   100%
osbenchmark/client.py                                                                           256     92     62     10    64%
osbenchmark/config.py                                                                           149     30     40      5    79%
osbenchmark/create_workload/__init__.py                                                           0      0      0      0   100%
osbenchmark/create_workload/config.py                                                            20      0      0      0   100%
osbenchmark/create_workload/extractors.py                                                       128     31     32      5    72%
osbenchmark/create_workload/helpers.py                                                          108    108     30      0     0%
osbenchmark/create_workload/workload_generator.py                                                50     50      4      0     0%
osbenchmark/exceptions.py                                                                        31      1      0      0    97%
osbenchmark/log.py                                                                               41     28     10      0    25%
osbenchmark/metrics.py                                                                         1149    159    360     65    83%
osbenchmark/paths.py                                                                             21      5      4      0    72%
osbenchmark/results_publisher.py                                                                418    296    122      7    25%
osbenchmark/telemetry.py                                                                       1050    148    308     36    83%
osbenchmark/test_execution_orchestrator.py                                                      223    142     30      1    35%
osbenchmark/time.py                                                                              52      4     12      5    86%
osbenchmark/utils/__init__.py                                                                     0      0      0      0   100%
osbenchmark/utils/collections.py                                                                 12      0     10      0   100%
osbenchmark/utils/console.py                                                                    117     21     20      6    80%
osbenchmark/utils/convert.py                                                                     46     16     14      4    63%
osbenchmark/utils/dataset.py                                                                    206     33     64     20    78%
osbenchmark/utils/git.py                                                                         76      7     18      4    88%
osbenchmark/utils/io.py                                                                         330    116     80      7    61%
osbenchmark/utils/jvm.py                                                                         61     14     24      2    76%
osbenchmark/utils/modules.py                                                                     55     38     20      0    23%
osbenchmark/utils/net.py                                                                        159    102     40      0    30%
osbenchmark/utils/opts.py                                                                       125     16     32      2    86%
osbenchmark/utils/parse.py                                                                       33     12     24      5    60%
osbenchmark/utils/periodic_waiter.py                                                             14      0      4      0   100%
osbenchmark/utils/process.py                                                                     86     30     16      1    64%
osbenchmark/utils/repo.py                                                                        93     27     32      1    70%
osbenchmark/utils/sysstats.py                                                                    39      6      6      3    80%
osbenchmark/utils/versions.py                                                                    95      5     40      3    94%
osbenchmark/version.py                                                                           29     10      8      2    57%
osbenchmark/worker_coordinator/__init__.py                                                        1      0      0      0   100%
osbenchmark/worker_coordinator/errors.py                                                         47     37     26      0    14%
osbenchmark/worker_coordinator/runner.py                                                       1632    182    470     46    86%
osbenchmark/worker_coordinator/scheduler.py                                                     121     13     18      3    88%
osbenchmark/worker_coordinator/worker_coordinator.py                                           1253    410    306     23    66%
osbenchmark/workload/__init__.py                                                                  2      0      0      0   100%
osbenchmark/workload/loader.py                                                                 1081    258    434     44    76%
osbenchmark/workload/params.py                                                                 1098     78    368     41    91%
osbenchmark/workload/workload.py                                                                658     87    232      5    86%
scripts/expand-data-corpus.py                                                                   119     67     28      5    39%
-------------------------------------------------------------------------------------------------------------------------------
TOTAL                                                                                         15846   4715   4292    435    69%

Only 69% of the repository is covered with some modules lacking coverage.

Describe the solution you'd like

Add more unittests to improve coverage. This will help give us peace of mind when refactoring in the future or making changes for OSB 2.0.0 because we will know if we are introducing breaking changes. For areas with low coverage, we should aim to bring them up to at least 60-75% coverage.

It's important to note that high code coverage percentage does not guarantee high quality code coverage. However, low code coverage percentage informs us that areas of the code are untested. More importantly, we should ensure that the essential areas are properly covered by high quality tests.