Add compatibility for PostgreSQL 9.6

[MichaelConrad]

Replaces #204

• Add configuration template for PostgreSQL 9.6
• Update variables and comments in defaults/main.yml
• Update test.yml to use 9.6
• Add role options for 9.6 to .travis.yml
• Update the 2.x version of Ansible in .travis.yml to 2.1.2.0
• Use specific release numbers for each distribution / version

[MichaelConrad]

Hi @arturmartins, regarding your comment on #204:

Could you add [*] as default value of postgresql_synchronous_standby_names, please?

Wouldn't this default to synchronous mode being enforced on all standbys?

By default, I believe this should be an empty string (or list, in this case) per the PostgreSQL default:

If no synchronous standby names are specified here, then synchronous replication is not enabled and transaction commits will not wait for replication.

I may have added another commit after your first comment which addressed the issue with the defaults in a different manor:

defaults/main.yml

postgresql_synchronous_standby_num_sync: ''
postgresql_synchronous_standby_names: [] # '*' means 'all'

templates/postgresql.conf-9.6.j2

synchronous_standby_names = '{{postgresql_synchronous_standby_num_sync}}{% if postgresql_synchronous_standby_names != [] %} ({{postgresql_synchronous_standby_names|join(',')}}){% endif %}'    # standby servers that provide sync rep
                # number of sync standbys and comma-separated list of application_name
                # from standby(s); '*' = all

The default would now be:

synchronous_standby_names = ''  # standby servers that provide sync rep
                                # number of sync standbys and comma-separated list of application_name
                                # from standby(s); '*' = all

Which would match the PostgreSQL default.

This will also have no impact on the defaults which are set for prior versions of PostgreSQL that use synchronous_standby_names.

[sebalix]

👍 Thanks for the work

[lhoss]

any chance getting this nice upgrade PR merged to master soon ? @otakup0pe ?

[sebalix]

Indeed, the 9.6 release will be heavily asked/required by people soon. Minor fixes could be applied after the PR is merged.

[bcoe]

@otakup0pe any chance of seeing this land soon? would love to roll this out at work without working from a fork.

[MichaelConrad]

I have been running PostgreSQL 9.6 with this for a few weeks and have yet to encounter any issues. If anyone discovers any changes to be made please let me know and I will update the PR.

[thbar]

@MichaelConrad thanks for your feedback on this, will try it out very soon. I wonder if you used a playbook to handle the upgrade? (or maybe it wasn't an upgrade in your case).

[lhoss]

nice to hear @MichaelConrad !
will myself test it ASAP (mostly for the 9.6 configure part) using n a custom branch merging your PR and ontop #213 to test for our postgres(9.6)-in-docker deployments

I hope after 1-2 more positive feedbacks here, we can get @otakup0pe to merge this finally (requiring less custom branches etc)

[lhoss]

Actually, it works nicely for me (tested with the 3 tags -t postgresql-configure,postgresql-users,postgresql-databases , deploying an updated config in our 9.6 postgres(+postgis) docker container) !

@MichaelConrad After I compared the diffs (ansible --diff to the rescue) between the default pg 9.6 config and the one deployed by the role, I found a number of diffs, but only one of these was introduced with the new 9.6 config settings:

• +wal_log_hints = False
  I propose to use on/off as done for the (pre-9.6) wal_compression in the 9.6 template:

wal_compression = {{ 'on' if postgresql_wal_compression else 'off' }}
wal_log_hints = {{postgresql_wal_log_hints}}			# also do full page writes of non-critical updates

not really changing the logic though 👍
Also I found an existing case (found in the templates back to v9.4), that does not do the 'on/off' mapping either:

ssl_prefer_server_ciphers = {{postgresql_ssl_prefer_server_ciphers}}		# (change requires restart)

Finally found 2 default postgres settings, that got removed, because not in the 9.6 template (It seems these were only supported by the role upto v9.2. No idea why, as these are still in the original postgres configs) :

-#gin_fuzzy_search_limit = 0
-#gin_pending_list_limit = 4MB

[vividvilla]

Works fine for me. Any idea when this will be merged with the master?

[vividvilla]

I am actually getting error while copying the postgresql.conf template. Its looking for config template in my local directory.

TASK [MichaelConrad.postgresql : PostgreSQL | Update configuration - pt. 2 (postgresql.conf)] ***
fatal: [127.0.0.1]: FAILED! => {"changed": false, "failed": true, "msg": "IOError: [Errno 2] No such file or directory: u'/Users/vivek/ansible/ubuntu/postgresql.conf-9.6.j2'"}

[lhoss]

yes plz get it merged (maybe if some more people review it)
I just found a minor thing to improve ( @MichaelConrad could you fix wal_log_hints , see my review above)

@vividvilla btw what ansible version?
I recommend to double-check that your local role/branch copy (I assume you used ansible-galaxy with a git+httpsurl) really has the right branch, and thus the required template file postgresql.conf-9.6.j2 .
Note that the ansible No such file or directory: can get confusing, as ansible tries multiple folders that could contain a file from a role, and usually checks the current working directory last..

[Envek]

Actually ansible-galaxy won't notice that you've changed requirements.yml and will not reinstall a role (what the shame!).

So to use it version you need to have in your requirements.yml:

- src: https://github.com/MichaelConrad/postgresql
  version: implement_postgresql_9_6
  name: ANXS.postgresql

and then execute:

ansible-galaxy remove ANXS.postgresql
ansible-galaxy install -r requirements.yml

I'm using this branch too and it works fine for me.

[lhoss]

Actually ansible-galaxy won't notice that you've changed requirements.yml and will not reinstall a role (what the shame!).

Yeah! (I guess we are thousands of ansible users shaking their head on that)
Or you force ansible in kind of an upgrade mode using -f/--force ! (but WHY not making this existing logic more explicit, without 'forcing' any unplanned behaviour!?)

[ernestas-poskus]

when this will be merged ?

[MichaelConrad]

@lhoss, I went ahead and implemented the changes you recommended for the postgresql_wal_log_hints and postgresql_ssl_prefer_server_ciphers variables.

Please let me know if you find anything else and I will make changes as necessary. Thanks again for your detailed analysis!

[lhoss]

LGTM now, thx @MichaelConrad 👍
now let's get this PR merged !
@otakup0pe ?! (this repos needs more 'owners' , maybe @ernestas-poskus ? who is managing a number of ANXS repos' like zookeeper, mesos, marathon... )

[pinak1180]

@MichaelConrad thanks for your awesome work, Any idea when this will be merged with the master?

[ernestas-poskus]

ping @pjan @farridav @jesselang @sebalix

[otakup0pe]

This is amazing work! I don't have time to personally validate this, but there seems to be a ton of interest so.... It seems like others have tested this and it works, so unless someone tells me otherwise I'm going to merge it.

As well.... We are looking for people to help maintain some Ansible roles! A few people who are interested in helping with the backlog of this particular role would be very much appreciated...

[MichaelConrad]

@otakup0pe, I would be very much willing to help contribute / maintain this role (and potentially others) in any capacity. Please let me know how I can help.

[lhoss]

I'ld also be willing but I am sure others qualified (like this PR's owner Michael) are better suited (+have more capacity) as I'm already quite busy contributing to https://github.com/AnsibleShipyard roles (mainly zookeeper, mesos, marathon) 👍

[otakup0pe]

@MichaelConrad if you can email me, we can get you setup as a maintainer :)