Add metric for cluster.max_shards_per_node

[TheMeier]

First draft, still need to do some testing. Also want to clean up and put the test json strings in separte fixture files.

fixes #271

Signed-off-by: Christoph Maser [email protected]

[zwopir]

nice, thanks a lot! Looks good so far. Ping me if you want to merge

[TheMeier]

So, turns out i forgot to encode the query params and the ?include_defaults=true was never send. This was a bug also for the existing shard allocation metric.

I also moved the test json content into files under a new fixtures directory. Probably we should consider a util package to make it easy to setup test strings from fixture files and then refactor the existing tests to use fixture files instead of inline json strings.

@zwopir BTW its quite easy to generate arbitrary test fixtures by simply firing up a container eg

docker run --rm -p 9200:9200 -p 9300:9300 -e "discovery.type=single-node" docker.elastic.co/elasticsearch/elasticsearch:7.3.0

And then fetching the data, eg:

curl "http://localhost:9200/_cluster/settings?include_defaults=true" | jq .> fixtures/settings-7.3.0.json

@zwopir so i think this is ready to review :)

[zwopir]

looks good to me, except a little thing in opening the fixture files. Thanks a lot! The proposed change makes the fixture opening code so short that it doesn't make sense to exclude it to a utils package IMO.

[zwopir]

thank you!

[tetianakravchenko]

Any chance to get it released?

[KevW7]

Hi, I'm really interested in this functionality - do you have any plans to create a new release?