Make "legacy" Kibana server aware of connection protocol.

[azasypkin]

It somehow slipped under my radar, but we need to make sure that legacy Kibana is aware of TLS as several places in Kibana rely on server.info.protocol or req.connection.info.protocol (that's basically the same) to build correct external URLs (e.g. SAML in Security plugin and PDF generation in Reporting plugin).

To test, please try to generate PDF reports when ES and Kibana run as shown below:

$ yarn es snapshot --license trial

yarn start --no-base-path --server.ssl.enabled=true \
  --server.ssl.key=/projects/elastic/master/kibana/test/dev_certs/server.key \
  --server.ssl.certificate=/projects/elastic/master/kibana/test/dev_certs/server.crt

and then

$ yarn es snapshot --license trial

yarn start --no-base-path

And yeah, we desperately need TLS-enabled integration/functional tests :)

[elasticmachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request

[epixa]

The comment above says that these values are the same as the new platform configuration, but that's not the case with this tls config. Here tls is a boolean, but in the new platform it's an object with properties. Can you either make them the same or update the comment so this doesn't look like a bug in the future?

[azasypkin]

Yep, sure, I'll update comment

[epixa]

I tested that PDF reporting from visualize works with https enabled.

LGTM once you update the comment

[elasticmachine]

💔 Build Failed

• continuous-integration/kibana-ci/pull-request

[azasypkin]

retest

[spalger]

LGTM

[elasticmachine]

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• continuous-integration/kibana-ci/pull-request

[azasypkin]

flaky selenium test

[azasypkin]

retest

[elasticmachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request

[azasypkin]

6.x\6.4: 2d8ff67