[chef] Re: Re: Re: CHEF-4579: should package action install also upgrade?

[Mike < >]

Dan,

The behavior difference makes sense to me.

package 'tmux', when not installed, should install the latest available package, similar to the file resource - populate with the latest available content.

Adding modifiers to constrain the behavior, such as version and create_if_missing, extend the behavior to a subset/specific set of rules.

Etsy had blogged about using package resources with upgrade taking down a significant set of their code, not using the base install method, and devised some foodcritic rules to help them prevent hitting that problem again - by ensuring not using the upgrade action, and requiring use of a version variable to prevent version mismatch.

I think the current behavior works, possibly needs some better documentation for newcomers, but other than that I believe it to be simple and concise.

-M

On Wed, Oct 2, 2013 at 3:56 PM, Daniel DeLeo < " target="_blank"> > wrote:

On Wednesday, October 2, 2013 at 12:33 PM, Brian Hatfield wrote:

No. I strongly object to this.

action :upgrade exists and is sufficient.

The question isn't whether action :install and action :upgrade should exist or have different behavior, but rather one of what default is most desirable given the tradeoffs of each. By comparison, the default action on a file is "create" which really means "create_or_update"; you can use action :create_if_missing if you want to avoid updating the files.

 

If action :install performed upgrades, it would absolutely destroy things, for example running MongoDB using the 10gen repos and having a 2.2 database upgrade to 2.4 behind your back, etc.

The reason we bring this up is the flip side of this coin. If the package in your repo gets updated, then a new machine you bring up with the same recipes will create a different system than your machines you provisioned before the repo update. This seems surprising, no? 

So the question is one of 

* user expectations: What should `package "tmux"` do when there's a newer version available?

* consistency: Is it weird/confusing that files get updated by default, but packages do not? Is it confusing that this default behavior means you can build a box with the exact same recipes and get a different result?

* pragmatic reason to be inconsistent: the risk of upgrading packages by default is so great that it's better if everyone using Chef learns that this is inconsistent, and why, and how to deal with it.

Thoughts?

 

Brian

-- 

Daniel DeLeo