Adding present option for version

[bigmstone]

Name says it all.

Fixes #111

[m4dcoder]

LGTM but i should let @humblearner or @armab approve since they're more familiar with this.

[arm4b]

Instead of introducing another keyword present, I'd like us to use existing state: present block and improve existing logic. See also the following issues for more context to understand the history:
#142 and #111

Ideally is to have the following syntax working:

• st2_version: latest - as before, always tries to auto-update the package.
• st2_version: * - this is exactly what's you're requesting, just make * working instead of present naming. (see UPDATE in the next message)
• st2_version: 2.2.1 - pin st2 version, but use latest st2_revision.
• st2_version: 2.2.1, st2_revision: 5 - pin both package version and revision.

[arm4b]

We already have state: present logic here.

Thinking about how to use that block, instead of introducing another st2_version: present keyword.

[arm4b]

After playing a bit with st2_version: * st2_version: 2.3dev + st2_revision: * it looks like * works for auto-updating, despite Ansible explicit state: present flag.

Le me think a little & dig in further, including how Ansible package module works to make sure the syntax we'll use will be consistent enough across the use cases for st2_version & st2_revision.

[arm4b]

UPDATE:

So after further research and things like https://github.com/ansible/ansible/blob/6dd8a4cf78d4fe4216a842a461871bade9a9b5a2/lib/ansible/modules/packaging/os/apt.py#L496-L501 and https://github.com/ansible/ansible/blob/6dd8a4cf78d4fe4216a842a461871bade9a9b5a2/lib/ansible/modules/packaging/os/apt.py#L1000, here is an updated alternative syntax which I believe will work better, comparing to introducing new present keyword:

• st2_version: null = just install st2 package (equivalent: apt/yum install st2) (no upgrade, NEW default). Exactly what you're requesting.
• st2_version: latest = always auto-upgrade to use latest package (OLD default)
• st2_version: 2.3 = pinned st2 package (equivalent: apt/yum install st2=2.3-*)

@bigmstone @humblearner @lakshmi-kannan WDYT?

[bigmstone]

@armab thoughts?
https://github.com/StackStorm/ansible-st2/pull/148/files#diff-555e17548189fd960a2fbb76681e59d9R13

If you like the direction I'll make the rest match.

[arm4b]

@bigmstone We've talked about the st2_version: null as var value, not st2_version: present.

So with st2_version: null we do apt/yum install st2.

[arm4b]

I'm more about leaving latest block as is for less jinja hackery.

[arm4b]

Looks there is no easy fix for #111

For example this construction will pin the version, but always try to update the package once there is a new revision available in a repo. So no real pinning happens here:

st2_version: 2.2.1
st2_revision: *

Another idea is that we could check if package is installed for apt/yum separately, parse the version, extract the revision and compare with the user input st2_version & st2_revision. But this logic easily breaks by the fact that user is free to specify anything like st2_version: 2.2.*. Also, it's probably a bad show http://blog.jasonantman.com/2014/07/how-yum-and-rpm-compare-versions/ without wrapping the logic as a custom Ansible plugin with some Python.

[arm4b]

After check, needs an adjustement as well, since it's apt format: apt install st2=2.2.1-5.
yum is different: yum install st2-2.2.1-5.

It's interesting that revision is not a requirement for yum. It's possible to do: yum install st2-2.2.1, while it's not possible to specify version without revision in apt: apt install st2=2.2.1

---

In short: this block never worked in CentOS/EL. Something that we missed in a big v0.6.0

[arm4b]

@bigmstone FYI I reverted back to your initial commit with present.
Sorry for the cofusion, but I initially wanted us to improve the versioning story here, which is already confusing and requires a good overhaul considering corner cases with apt/yum and package versioning.

Will see/experiment what I can do in this and next PRs.

[arm4b]

Alright, merging initial Matt's present proposal.

Fixed also one apt/yum-related corner case. But as said before, initially thought abount fixing more here, but moving entire version overhaul into another issue: #150 which will probably be the breaking change.