support base64 encoded api key

[jsvd]

fixes #1064

[yaauie]

build failure is unrelated; something in our dependency graph no longer causes this plugin's open-ended development dependency on elasticsearch to resolve to 7.x, so we get 8.x and fail.

EDIT: it's logstash-core 8.17+ that now relies on elasticsearch ~>8 😩, so the build is just plain broken.

We'll need to either:

• (a) update this code to use the v8 es client (which is not backward-compatible with older ES's); OR
• (b) update all tests to http at elasticsearch manually.

[mashhurs]

build failure is unrelated; something in our dependency graph no longer causes this plugin's open-ended development dependency on elasticsearch to resolve to 7.x, so we get 8.x and fail.

EDIT: it's logstash-core 8.17+ that now relies on elasticsearch ~>8 😩, so the build is just plain broken.

We'll need to either:

• (a) update this code to use the v8 es client (which is not backward-compatible with older ES's); OR
• (b) update all tests to http at elasticsearch manually.

Sorry for that! #1208 fixes the CI failures.
I have opened an issue to remove elasticsearch-ruby v7 sources once LS-core fully moves to v8 version.