[MESOS-7429] Allow isolators to inject task-specific environment variables.

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.2.0
• Fix Version/s: 1.2.1, 1.3.1, 1.4.0
• Labels: containerizer isolator mesosphere
• Target Version/s: 1.2.1, 1.3.1, 1.4.0
• Sprint: Mesosphere Sprint 56
• Assignee: Till Toenshoff
• Reporter: Till Toenshoff
• Shepherd: Gilbert Song
• Created: 26/Apr/17 18:48
• Updated: 08/May/17 22:09
• Resolved: 08/May/17 17:29

Description

For command tasks, we currently have no way for isolators to inject task specific environments into data path.

Isolators in their prepare implementation can return a ContainerLaunchInfo which currently supports setting the member environment - but that is effective for the executor already and will get inherited by the task environment.

Given that the command-executor is active in the host-fs context but the task may be running in a container-fs context (has_rootfs=true), using the above will possibly cause failures, depending on the nature of the variables set – consider e.g. LD_LIBRARY_PATH as a fatal one.

The command-executor does support the flag task_environment to receive environment variables which are meant exclusively for the task itself but not the executor.

Runtime isolators (docker/runtime, appc/runtime) already make use of this flag. However, they do it in a way that is a bit unfortunate as it does not allow for other isolators to make use of it - there is no merging taking place in the containerizer.

Issue Links

• depends upon: MESOS-7027 CommandExecutor ENV overwritten by Docker Image ENV in Unified Containerizer