[Data plugin] Wrong caching for Index pattern fields

[alexwizp]

Closes: #84666

Summary

[Data plugin] Wrong caching for Index pattern fields. Index pattern cache should be local instance, not global

[alexwizp]

@mattkime @ppisljar it looks like an issue while unifying client/server code.

This approach unacceptable for server side code. indexPatternCache variable should not declared as instance variable.

[alexwizp]

also I think it should be backported into 7.10, 7.11 as a security issue.

[elasticmachine]

Pinging @elastic/kibana-app (Team:KibanaApp)

[alexwizp]

have no idea how it worked before but if I'm not wrong users should not be able to change field name/type.

[mattkime]

Approved pending passing tests and more accurate description - 'Index pattern cache should be local instance, not global'

[alexwizp]

@mattkime could you please help me with understanding our indexPatterns API.
Please see my example with sending 2 queries.

# First query create a new indexpattern with 2 fields: foo, bar. 

const response = await supertest.post('/api/index_patterns/index_pattern').send({
        index_pattern: {
          title,
          fields: {
            foo: {
              name: 'foo',
              type: 'string',
            },
            bar: {
              name: 'bar',
              type: 'number',
              count: 123,
              script: '',
              esTypes: ['test-type'],
              scripted: true,
            },
          },
        },
      });

in response I see that index was successfully created with 2 fields.

Next query just a getting an indexPattern by id from step 1;

   const response1 = await supertest
        .get('/api/index_patterns/index_pattern/' + response.body.index_pattern.id)
        .send();

I expect to see 2 fields like in response from step 1. But I see only one:

What is the correct behavior? I honestly think these are just poorly written integration tests cause user should not be able somehow to modify fields (except scripted fields).

[mattkime]

@alexwizp You are correct - the user can't add fields aside from scripted fields.

Its valid to ignore the non scripted fields.

[stratoula]

Nice catch @alexwizp, LGTM

[alexwizp]

@elasticmachine merge upstream

[kibanamachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: b9e4376

Metrics [docs]

Distributable file count

id	before	after	diff
default	47252	48012	+760

Page load bundle

Size of the bundles that are downloaded on every page load. Target size is below 100kb

id	before	after	diff
data	1003.4KB	1003.5KB	+111.0B

History

• 💔 Build #96948 failed 60543b1
• 💔 Build #96621 failed 086f421
• 💔 Build #96569 failed 67298aa

To update your PR or re-run it, just comment with:
@elasticmachine merge upstream