set 'fork' as the default process start method

[MarkintoshZ]

The Runner class depends on 'fork' process start method but this is not the default of multiprocessing lib on Windows and MacOS. This PR ensures 'fork' is the default and it is makes Acto to be compatible with MacOS. In addition, setting the default set method is recommended according to the Python documentation.

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
acto
__main__.py	86	86	0%	1–174
common.py	354	101	71%	97–98, 102–116, 119–126, 129, 132, 136, 138, 140, 142, 144, 148, 153–162, 203, 236, 249, 291, 315–316, 325, 327, 330, 334–343, 363–366, 415, 418, 432, 460–461, 498–503, 505–507, 514–517, 521, 537–538, 544–555, 614–623, 627, 631, 634–639
deploy.py	143	117	18%	29–32, 35–52, 56, 59–69, 77–107, 110–117, 123–145, 148–161, 173–196, 202–211, 219–237
engine.py	532	486	9%	39–56, 63–79, 91–191, 201–226, 229–285, 301–424, 428–529, 539–564, 568–576, 579–592, 617–733, 736–822, 826–916
oracle_handle.py	24	13	46%	15–18, 26–27, 39–46, 54
reproduce.py	121	80	34%	30–40, 48–52, 58–59, 72–93, 96, 99, 102, 106–108, 111, 114, 122–123, 126, 130, 134, 138, 142–176, 179–189, 192–219
serialization.py	30	16	47%	19–27, 33–39
snapshot.py	62	26	58%	32, 48, 58–79, 82–86, 89
acto/checker
checker.py	13	2	85%	12, 19
checker_set.py	57	12	79%	41–42, 67–78
test_checker.py	162	152	6%	13–246
acto/checker/impl
crash.py	30	2	93%	14, 16
health.py	49	3	94%	36, 65, 81
kubectl_cli.py	29	4	86%	32–33, 44–46
operator_log.py	24	2	92%	24, 32
state.py	225	51	77%	55, 63–64, 69–93, 104–105, 133, 140, 147–149, 166, 265, 288, 317, 319–323, 329–336
state_compare.py	76	3	96%	62, 73, 80
state_condition.py	39	13	67%	18, 24, 29–37, 47, 53
acto/input
get_matched_schemas.py	54	22	59%	12, 47–51, 55–74
input.py	609	489	20%	30–37, 74, 92, 112, 123–126, 129, 159–171, 174–185, 189, 193, 200, 206, 210–389, 410–424, 432–437, 441–454, 463, 479, 482–489, 501, 503, 505–507, 510–523, 528, 536–547, 550–556, 564–591, 595–899, 922–935, 939–986
testcase.py	55	20	64%	40–50, 53, 56, 59, 62–66, 95–96, 100, 103, 109, 116, 119
testplan.py	183	137	25%	14–24, 27–29, 32, 35–42, 45, 48–67, 70–74, 78, 82, 85–91, 99–107, 110–121, 124, 127, 130, 133, 136–138, 141–151, 154–164, 167, 174–185, 188–194, 200, 203–219, 222, 225, 231, 239–244, 247, 250, 253, 259–260, 263–269, 272, 275, 278
value_with_schema.py	337	218	35%	16, 20, 24, 28, 32, 36, 40, 54, 58, 61–67, 70–76, 86–114, 117–124, 128–137, 141–149, 152–156, 159, 162, 166, 180, 183, 186–192, 195–201, 211–230, 233–240, 243, 247–256, 260–272, 275–279, 282, 285, 289, 301, 307, 312, 314, 316, 320, 324, 329–333, 337–340, 349–359, 362–369, 373–376, 380–385, 388–391, 405, 408–412, 416, 421–428, 431–434, 437–439, 442–445, 448–451, 462, 465, 468, 485–498
valuegenerator.py	620	389	37%	20, 24, 28, 32, 43, 47, 51, 55, 76–86, 90–104, 107, 110, 114, 117, 121–130, 133–139, 142, 145, 148, 151, 154, 157–167, 194–199, 202–213, 216, 219, 223, 226–231, 234–237, 240, 243–248, 251–254, 257, 260, 263, 266, 269, 273–282, 285, 288, 291, 294–304, 331–343, 346–347, 350, 353, 357, 360–365, 368–371, 374, 377–382, 385–388, 391, 394, 397, 400, 403, 406, 409–419, 450–482, 485–496, 499–502, 505–508, 512–520, 523, 526, 529, 532, 535, 538–548, 573–589, 592–609, 612, 615, 619–621, 624–628, 631–632, 635–644, 647–653, 656–657, 660–670, 673, 676, 679, 682, 685, 688–698, 710–711, 714–724, 727–730, 733–736, 740, 748, 751–752, 755–765, 768–771, 774–777, 781, 794–797, 800–814, 817, 820, 824, 827–832, 835, 838, 841–846, 849, 852, 855, 858, 861–871, 881, 884, 887, 890, 894, 913, 919, 931, 933, 936–940, 943–946, 951, 955, 957, 961–962
acto/input/known_schemas
base.py	53	13	75%	17–18, 28, 37, 46–47, 56–57, 66, 75, 84–85, 93
cronjob_schemas.py	76	33	57%	13, 16–19, 22, 25, 36–39, 42–47, 50, 53, 59, 62–65, 68, 71, 82, 85–90, 93, 96, 113, 117–119, 131, 137, 140
deployment_schemas.py	59	25	58%	16, 22–27, 30–32, 35, 38, 54–57, 65–67, 70, 78–81, 91, 94
known_schema.py	75	39	48%	28, 31–34, 37, 43, 46–48, 51, 54, 81–84, 102–113, 117–135
pod_disruption_budget_schemas.py	56	22	61%	14–17, 21, 25–27, 30, 41–44, 48, 54, 57, 68–71, 81, 84
pod_schemas.py	797	271	66%	16–19, 23, 28, 32, 40–43, 47, 51–53, 61–64, 68, 73, 83, 92, 151, 156, 160, 167, 171, 178, 182, 238, 242, 247, 251, 294, 298, 303, 307, 335, 338, 341, 344, 347, 350, 353, 356, 359, 362, 365, 368, 393, 397, 400–405, 408, 414, 417, 420, 428, 431, 434, 437, 445, 453, 481, 488–494, 503, 507, 539, 543, 572, 575, 578, 581, 584, 587, 590, 619, 623, 626–631, 634, 642, 645, 648, 664–667, 670–672, 675, 684, 690, 693–696, 699, 702, 713–714, 717–719, 722, 725, 736, 739, 742, 745–748, 752, 756–758, 761–765, 768, 774, 777, 780, 783, 786, 789, 792, 795, 798, 801, 804, 807, 810, 813, 816, 840, 845, 849–857, 860, 866, 869, 872, 875, 878, 881, 884, 887, 890, 893, 896, 899, 902, 905, 908, 929, 933–935, 938–943, 946, 959, 964, 974, 980, 986, 989, 992, 1032, 1036–1038, 1041, 1054, 1059, 1065, 1068–1071, 1074, 1077, 1088–1091, 1094–1096, 1102, 1108, 1111–1114, 1117, 1120, 1133–1136, 1139–1141, 1147, 1153, 1156–1159, 1162, 1165, 1176–1179, 1182–1184, 1190, 1196, 1199–1202, 1205, 1212, 1215–1217, 1223, 1238, 1243, 1247, 1274, 1278, 1291, 1296, 1302, 1305, 1308, 1314, 1317, 1320–1322, 1325, 1342, 1345, 1348, 1374, 1378–1381, 1384, 1402, 1408, 1411, 1414, 1421, 1427, 1469, 1473
resource_schemas.py	149	50	66%	15–19, 22, 25, 28–32, 35, 38, 45, 49, 54, 57–59, 62, 76, 78, 82, 96, 102–105, 108, 111, 121, 134, 147, 154, 159–162, 165, 173–176, 179, 187, 194, 199, 213, 231, 236
service_schemas.py	178	67	62%	13, 16, 19, 25–30, 33, 36, 42, 45–48, 51, 54, 64–67, 70–73, 79, 85, 88–91, 94, 101–102, 105–108, 111, 114, 127, 142, 180, 184, 208, 214, 217, 220, 228–231, 235, 240, 244–246, 249, 257–258, 261, 264, 277–280, 284, 288–290, 293
statefulset_schemas.py	186	61	67%	15–18, 21, 31–36, 42, 49–53, 56–58, 61–63, 66–70, 73–75, 78–80, 83, 90–93, 99–102, 105, 132, 149, 154, 158, 164, 167–170, 173, 176, 190–193, 196–201, 207, 225, 230, 234, 262, 266, 290
storage_schemas.py	179	79	56%	13, 16, 25–30, 33, 36, 42, 48–53, 59, 67–70, 74, 79–80, 83, 89, 92–95, 98, 104–105, 108–111, 114–116, 122, 130–131, 135, 140, 145–148, 154–155, 158, 164, 181–184, 193, 197, 203–205, 211, 214, 228–231, 244, 250–252, 255, 258, 266–269, 273, 277–279, 282
acto/kubectl_client
kubectl.py	23	18	22%	8–14, 23–29, 37–44
acto/kubernetes_engine
base.py	53	30	43%	28, 32, 36, 40, 44, 47–65, 72–86
k3d.py	85	68	20%	17, 21–39, 45, 54–78, 81–97, 100–110, 117–133, 137–139
kind.py	94	76	19%	20–21, 25–56, 62, 71–108, 111–123, 126–139, 146–160
minikube.py	3	3	0%	1–5
acto/monkey_patch
monkey_patch.py	79	24	70%	9, 18, 36, 39, 41, 45–56, 76, 90–95, 106
acto/parse_log
parse_log.py	78	19	76%	71–74, 84–86, 89–91, 96–98, 116–124
acto/post_process
post_diff_test.py	390	231	41%	40, 54–55, 94–95, 166, 176, 180, 185–194, 229, 231, 233–237, 243–260, 268–276, 279–302, 309–318, 321–380, 392–396, 416, 424–454, 457–474, 478–527, 539, 543, 549–550, 552–573, 583–619
post_process.py	104	22	79%	51, 55, 67, 77–88, 100, 103, 138–142, 146, 150, 158, 162
test_post_process.py	28	1	96%	53
acto/runner
runner.py	286	258	10%	24–44, 73–119, 122–131, 134–165, 172–199, 206–229, 232–238, 241–260, 263–268, 279–284, 298–303, 316–392, 397–401, 407–417, 428–451, 456–489
acto/schema
anyof.py	44	20	55%	26, 30–38, 41, 44, 47–49, 52, 55–60
array.py	70	29	59%	31, 43–52, 57, 59–62, 71–78, 81–83, 86–88, 91, 94, 97, 103
base.py	102	57	44%	13–15, 18–20, 23, 26–37, 40, 43, 46–48, 51–61, 64–74, 77, 80–86, 95, 100, 105, 110, 114, 118, 142, 145–149
boolean.py	27	10	63%	16, 20, 23, 26, 29–32, 35, 38
integer.py	26	9	65%	17, 21–23, 26, 29, 32, 35, 38
number.py	30	11	63%	30–32, 35–37, 40, 43, 46, 49, 52
object.py	117	48	59%	44, 46, 51, 66–75, 80, 83, 94–109, 112–120, 123–126, 129, 132, 148, 151–158, 168
oneof.py	44	30	32%	13–19, 22, 25–27, 30–38, 41, 44, 47–49, 52, 55–60
opaque.py	17	6	65%	13, 16, 19, 22, 25, 28
schema.py	42	8	81%	21, 25, 31–34, 49–50
string.py	27	9	67%	25, 29–31, 34, 37, 40, 43, 46
acto/utils
__init__.py	13	1	92%	11
acto_timer.py	31	22	29%	10–15, 19, 22–33, 38–40, 44–47
error_handler.py	43	33	23%	13–30, 38–52, 56–74
k8s_helper.py	64	51	20%	21–27, 39–45, 57–61, 73–79, 83–91, 95–102, 106–127
preprocess.py	69	58	16%	17–73, 93–141, 147–192
process_with_except.py	9	9	0%	1–13
thread_logger.py	15	3	80%	9, 18, 28
TOTAL	8103	4268	47%

Tests	Skipped	Failures	Errors	Time
138	0 💤	0 ❌	0 🔥	1m 6s ⏱️

[tianyin]

@ThrivikramanV can you review this commit and merge it?

[ThrivikramanV]

Verified @MarkintoshZ's comments and code. Will run the e2e tests on the cloudlab systems and then merge this PR.

[ThrivikramanV]

Passed the e2e test. Merging this PR.