eventsapi: Add JWT signing support

New argument added to accept secret to generate JWT token. This patch
does not affect the backward compatibility.

Usage:

    gluster-eventsapi webhook-add <url> [-t <TOKEN>] \
        [-s SECRET]

With `--token` argument, Token header will be added as is.

    Authorization: Bearer <TOKEN>

In case of shared secret, Gluster will generate JWT token using the
secret and then add it to Authorization header.

    Authorization: Bearer <GENERATED_TOKEN>

Secret/Token can be updated using `webhook-mod` command.

Generated token will include the following payload,

    {
       "iss": "gluster",
       "exp": EXPIRY_TIME,
       "sub": EVENT_TYPE,
       "iat": EVENT_TIME
     }

Where: iss - Issuer, exp - Expiry Time, sub - Event Type
       used as Subject, iat - Event Time used as Issue Time

BUG: 1501864
Change-Id: Ib6b6fab23fb212d7f5e9bbc9e1416a9e9813ab1b
Signed-off-by: Aravinda VK <avishwan@redhat.com>
(cherry picked from commit add7116efa1f31e86f9c00c72c71872b1161370f)

0 files changed, 0 insertions, 0 deletions