tests: include Elasticsearch 5 in Travis-CI

[hjhsalo]

• include Elasticsearch5 in Travis-CI tests.

Signed-off-by: Harri Hirvonsalo harri.hirvonsalo@cern.ch

[hjhsalo]

ES5 tests in Travis are failing but I think otherwise the tasks defined in #103 are done, so I guess this is ready for review?

If the reviewer has knowledge about .travis.yml, could you suggest a way to reduce the repetion of ES_DOWNLOAD_URL=https://download.elasticsearch.org/elasticsearch/release/org/elasticsearch/distribution/tar/elasticsearch/${ES_VERSION}/elasticsearch-${ES_VERSION}.tar.gz to something like ES_DOWNLOAD_URL=ES_2_DOWNLOAD_URL? The same also applies to download URL of ES5.
I couldn't come up with solutions by myself...

[hjhsalo]

Please note that files https://github.com/inveniosoftware/invenio/blob/master/scripts/provision-elasticsearch.sh and https://github.com/inveniosoftware/invenio/blob/master/elasticsearch/Dockerfile should probably be prepared for ES5.

Maybe something like this could be used in Dockerfile and then change behaviour of provision-elasticsearch.sh based on value of $ES_VERSION:

ARG ES_VERSION=2
ENV ES_VERSION ${ES_VERSION:-2}

FROM elasticsearch:$ES_VERSION
...

Also note that mapper-attachment -plugin is deprecated in ES5 in favor of ingest-attachment -plugin and that name of the binary that is used to install plugins changes in ES5 as well ($ elasticsearch-plugin install ... VS $ plugin install ...)

https://www.elastic.co/guide/en/elasticsearch/plugins/5.6/mapper-attachments.html
https://www.elastic.co/guide/en/elasticsearch/plugins/5.6/ingest-attachment.html

[nharraud]

The current state of this PR does not enable to support elasticsearch 5.

• index init fails because the mappings provided by invenio-marc21 are not elasticsearch 5 compatible (see the breaking changes)
• The percolator API changed and breaks the tests (see the breaking changes)

Currently invenio-search uses all the mappings provided. However if we want to support both elasticsearch-5 and elasticsearch-2 we would need to provide two different set of mappings. Thus we would need to refactor invenio-search.

@inveniosoftware/architects Another issue pointed out by @slint : Elasticsearch version 2 End Of Life is 2018-02-28. We might want to go for version 5 or 6 immediately and drop version 2.

[slint]

There's also an official migration helper plugin that goes over some basic checks of the cluster. I've added the output of running the tool on the relevant issue #103

[slint]

Dependencies (PR merged and released):

• global: addition of ES5 support invenio-marc21#56
  • global: add elasticsearch 5 compatibility invenio-records-rest#177
• config: add a variable to control created aliases  invenio-search#119

[krzysztof]

PERCROLATOR -> PERCOLATOR