Proposal: ability to install features in different regions in single command

[Владимир Коньков <vk...@citc.ru>]

Hi there!

Use case:

Environment: clean Karaf 4.x instance.

Requirements:

Multiple software modules should be install according to accepted deployment plan. Deployment plan consist 3 modules in different regions: ActiveMQ (root/broker), business module A (root), business module B (root). Some bundle requirements for ActiveMQ and business modules are same or compatible.

How it works now:

Operation engineer should install modules in 2 steps: one for root region and one for root/broker region. Because of shared bundle deps optimal way is to install into root region first.

Whats wrong:

1. Service provider (ActiveMQ) should be installed after consumer. Consumer can fail to start before provider appears.
2. Operation engineer should know such deps semantics or it should be documented by developers.
3. There is 2 deployment steps for one deployment plan. Such deployment not atomic and can fail in the middle of installation reducing usefulness of new Karaf 4 resolver (you can’t do: feature:install -t feaure_list ).
4. If order of installation is reversed refreshes and ActiveMQ restart if follows because of uninstall/install of shared bundles in performed.

How it should work:

Operation engineer issue one install command where features tarted regions is specified by feature basis. Something like: feature:install {root/broker}actimemq-broker/5.13.2 business-module-a/1.1.12 business-module-b/5.0


I can provide PR if proposal is accepted.

Regards,
Vladimir Konkov
CIT Consulting LLC