Create custom service for ElasticSearch

[sauloperez]

It turns out that the systemd service the elasticsearch role creates (introduced in #82) doesn't work with the old version of ES we're running in production, 2.4.6.

We can either follow the approach we followed in #84 or find out if we can skip the service creation by using a variable and do it ourselves.

If we follow the second approach, please provide also these variables we've been playing with:

es_version: 2.4.6
es_use_repository: false

[sauloperez]

I just provisioned with the branch install-ES-2.6.4 and indeed the systemd complaints about the unit file:

● timeoverflow_elasticsearch.service - Elasticsearch-timeoverflow
   Loaded: loaded (/usr/lib/systemd/system/timeoverflow_elasticsearch.service; enabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Wed 2019-10-09 16:48:36 CEST; 3min 16s ago
     Docs: http://www.elastic.co
 Main PID: 3565 (code=exited, status=64)

Oct 09 16:48:35 staging systemd[1]: Starting Elasticsearch-timeoverflow...
Oct 09 16:48:35 staging systemd[1]: Started Elasticsearch-timeoverflow.
Oct 09 16:48:36 staging elasticsearch[3565]: ERROR: Parameter [-Edefault.path.data=/var/lib/elasticsearch/staging.timeoverflow.org-timeoverflow]does not start with --
Oct 09 16:48:36 staging systemd[1]: timeoverflow_elasticsearch.service: Main process exited, code=exited, status=64/n/a
Oct 09 16:48:36 staging systemd[1]: timeoverflow_elasticsearch.service: Failed with result 'exit-code'.

I can confirm the right version was installed:

$ ll /tmp/elasticsearch-2.4.6.deb 
-rw-r--r-- 1 root root 27234396 Oct  9 16:37 /tmp/elasticsearch-2.4.6.deb

There's no other way than writing a custom unit ourselves, I'm afraid.

[markets]

@sauloperez I think this issue will be deprecated by coopdevs/timeoverflow#551. Just adding the comment for linking both issues.

[sauloperez]

I actually think we implemented the service to provision the new production server with the current ES version but I didn't check.

[markets]

@sauloperez so time close this?

[sauloperez]

Yep, confirmed