[MESOS-7643] The order of isolators provided in '--isolation' flag is not preserved and instead sorted alphabetically

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.1.2, 1.2.0, 1.3.0
• Fix Version/s: 1.6.0
• Component/s: containerization
• Labels: isolation
• Epic Link: Unified Container
• Sprint: Mesosphere Sprint 78
• Story Points: 2
• Assignee: James Peach
• Reporter: Michael Cherny
• Shepherd: Gilbert Song
• Created: 08/Jun/17 16:42
• Updated: 23/Apr/18 16:04
• Resolved: 20/Apr/18 18:10

Description

According to documentation and comments in code the order of the entries in the --isolation flag should specify the ordering of the isolators. Specifically, the `create` and `prepare` calls for each isolator should run serially in the order in which they appear in the --isolation flag, while the `cleanup` call should be serialized in reverse order (with exception of filesystem isolator which is always first).
But in fact, the isolators provided in '--isolation' flag are sorted alphabetically.
That happens in this line of code. In this line use of 'set<string>' is done (apparently instead of list or vector) and set is a sorted container.

Issue Links

• is duplicated by: MESOS-8818 VolumeSandboxPathIsolatorTest.SharedParentTypeVolume fails on macOS
• is related to: MESOS-7909 Ordering dependency between 'linux/capabilities' and 'docker/runtime' isolator.
• is related to: MESOS-5581 Guarantee ordering between Isolators
• relates to: MESOS-8083 Mesos containerizer should run isolate() sequentially.