Add support for Vault 0.10 KV v2

[danlsgiga]

Since Vault 0.10 introduced the secret backend KV v2, the data structure and API endpoints to retrieve certificates has also changed. For now we are keeping our certificates mountpoint on v1 but it would be great to have Fabio supporting KV v2 as well.

[magiconair]

Can you provide a PR?

[pschultz]

@danlsgiga, judging from the patch in #497, it looks like all you have to do to use the V2 backend is to update your Fabio config from

cs=<name>;type=vault;cert=secret/fabio/certs

to

cs=<name>;type=vault;cert=secret/data/fabio/certs

There doesn't seem to be a change required in Fabio itself.

Update: My test runs were false negatives. There are changes required after all.

[danlsgiga]

Hi @pschultz, yeah, before submitting the issue I've tried Fabio with the newer path structure used in v2 but it didn't work. Thanks for looking into it though!

[pschultz]

This is addressed by #497 and can be closed now.

[aaronhurt]

@pschultz Got it, thank you!