Support different Elasticsearch versions

[geerlingguy]

Currently there's just Elasticsearch 2.x... which is ancient. I want to introduce an elasticsearch_version variable, and make it default to the current major version, 6.x. Should also fix #36.

[esseti]

how can I install 2.4?

[gioy]

Hello,
I tried to install elasticsearch 2.x, but it failed with the following message:

TASK [geerlingguy.elasticsearch : Install Elasticsearch.]
task path: /etc/ansible/roles/geerlingguy.elasticsearch/tasks/main.yml:8
Using module file /usr/local/lib/python2.7/dist-packages/ansible/modules/packaging/os/apt.py
ESTABLISH LOCAL CONNECTION FOR USER: vagrant
EXEC /bin/sh -c 'echo ~ && sleep 0'
EXEC /bin/sh -c '( umask 77 && mkdir -p "echo /home/vagrant/.ansible/tmp/ansible-tmp-1546192520.79-237011690349350" && echo ansible-tmp-1546192520.79-237011690349350="echo /home/vagrant/.ansible/tmp/ansible-tmp-1546192520.79-237011690349350" ) && sleep 0'
PUT /tmp/tmpJCbsC2 TO /home/vagrant/.ansible/tmp/ansible-tmp-1546192520.79-237011690349350/apt.py
EXEC /bin/sh -c 'chmod u+x /home/vagrant/.ansible/tmp/ansible-tmp-1546192520.79-237011690349350/ /home/vagrant/.ansible/tmp/ansible-tmp-1546192520.79-237011690349350/apt.py && sleep 0'
EXEC /bin/sh -c 'sudo -H -S -n -u root /bin/sh -c '"'"'echo BECOME-SUCCESS-pmkmivtbjvpkfjltgzzmgziwotlverok; /usr/bin/python /home/vagrant/.ansible/tmp/ansible-tmp-1546192520.79-237011690349350/apt.py; rm -rf "/home/vagrant/.ansible/tmp/ansible-tmp-1546192520.79-237011690349350/" > /dev/null 2>&1'"'"' && sleep 0'
The full traceback is:
File "/tmp/ansible_O9eckZ/ansible_module_apt.py", line 333, in package_status
pkg = cache[pkgname]
File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 262, in getitem
raise KeyError('The cache has no package named %r' % key)
fatal: [myhost]: FAILED! => {
"changed": false,
"failed": true,
"invocation": {
"module_args": {
"allow_unauthenticated": false,
"autoclean": false,
"autoremove": false,
"cache_valid_time": 0,
"deb": null,
"default_release": null,
"dpkg_options": "force-confdef,force-confold",
"force": false,
"force_apt_get": false,
"install_recommends": null,
"name": "elasticsearch",
"only_upgrade": false,
"package": [
"elasticsearch"
],
"purge": false,
"state": "present",
"update_cache": null,
"upgrade": null
}
},
"msg": "No package matching 'elasticsearch' is available"
}

So I checked the current set apt repository and it actually does not have any release for elasticsearch 2.x.
Looking for an open issue, I found the following suggested patch: #26 (comment)).
I based the following pull request on it: #43

Thank you for your work.