Add docker files for easier development setup

[ssaarinen]

Helps to whip up elasticsearch with freshly built raudikko plugin.

Maybe even better would be to run some integration tests in the build w/ e.g. https://www.testcontainers.org/modules/docker_compose/ but this helped me do manual testing with ES8 support.

[komu]

Wouldn't it be sufficient to just say ARG ES_VERSION here without repeating the version?

[ssaarinen]

looks like it from the docs I linked but apparently did not read :D Will fix that

[komu]

It would probably be useful to have actually exercise the code path of the plugin here. Perhaps making the same call as in the example of README.md:

GET http://localhost:9200/_analyze
Content-Type: application/json

{
    "tokenizer": "finnish",
    "filter": [
        {
            "type": "raudikko"
        }
    ],
    "text": "Testataan raudikon analyysiä tällä tavalla yksinkertaisesti."
}

[ssaarinen]

Isn't that the exact copy of this already?

elasticsearch-analysis-raudikko/README.md

Lines 28 to 33 in 003d1a4

	curl -XGET 'localhost:9200/_analyze' -H 'Content-Type: application/json' -d '
	{
	"tokenizer" : "finnish",
	"filter" : [{"type": "raudikko"}],
	"text" : "Testataan raudikon analyysiä tällä tavalla yksinkertaisesti."
	}'

[komu]

Yes it is. I actually generated the request by pasting the original curl request into IDEA.

My point is that if we're going to have a file of executable http-requests, why not include this there? It would feel silly to first run a bunch of requests in one way and then perform additional request in another way.

[ssaarinen]

So I should merge this file with https://github.com/EvidentSolutions/elasticsearch-analysis-raudikko/blob/master/etc/test-analyzer.http ?

[ssaarinen]

There is a slight difference in "filter" [{"type": "raudikko"}] vs ["raudikko"] but that might not matter

[komu]

Oh, right. I completely forgot about the other file. Yeah, it's probably a good idea to have just one file for requests.

[komu]

Thanks!