Feature - Manage schedules with cron (1/3)

[sasirven]

This is the part of the schedule management that replaces cron.

Linked Merge Requests:
#3026
mitre/magma#61

• Manage schedules with cron:
  • Replace time management with cron syntax for better control.
• Add conversion from old format to new one:
  • Replace the old date with the new cron syntax to create a new operation each day at the same hour and minute as before.

[elegantmoose]

@sasirven picking this up now. Sorry for delay.

[uruwhy]

Tested using both the proposed and latest version (3.0.3) of croniter and confirmed scheduled operations are still kicking off as expected:

curl -H "KEY: ADMIN123" -H "Content-Type: application/json" -X POST http://192.168.56.7:8888/api/v2/schedules --data '{
    "schedule": "13:17:00.000000",
    "id": "123456",
    "task": {
        "id": "234567",
        "name": "testop",
        "adversary": {
            "adversary_id": "01d77744-2515-401a-a497-d9f7241aac3c"
        },
        "planner": {
            "id": "aaa7c857-37a0-4c4a-85f7-4e9f7f30e31a"
        },
        "autonomous": 1,
        "use_learning_parsers": true,
        "group": "red",
        "source": {
            "id": "ed32b9c3-9593-4c33-b0db-e2007315096b"
        }
    }
}' | jq

[uruwhy]

some suggestions and comments (see above)

[elegantmoose]

Thank you @guillaume-duong-bib and @sasirven !