Add hostname in monitoring data

[fgiannar]

Adds veriflier/jetmon hostname in monitoring data we send to WPCOM.

Testing instructions

Pre-requisites

• A JN site with Jetpack plugin active and fully connected
• Downtime monitoring should be also on (Jetpack settings -> Downtime monitoring )

Jetmon status running

• Update your test site's site_status in the DB to be 0: update jetpack_monitor_subscription set site_status=0 where blog_id=WPCOM_SITE_ID
• Make sure your site is up and running
• Restart jetmon with docker compose stop jetmon and docker compose start jetmon
• Monitor ES and verify that host is now logged

Jetmon status down

• You'll need to manually update PEER_OFFLINE_LIMIT to 1 in jetmon.js here: This determines how many peers have to confirm that the site is down before a notification email is sent. By default it's 3, however on our local envs we only run a single veriflier service, therefore we need to set this to 1 to actually send the monitoring data to WPCOM
• Update your test site's site_status in the DB to be 1: update jetpack_monitor_subscription set site_status=1 where blog_id=WPCOM_SITE_ID
• Bring your site down
• Restart jetmon with docker compose stop jetmon and docker compose start jetmon
• Monitor ES and verify that host is now logged in both Jetmon and Veriflier checks results

[darssen]

Tested and able to verify that host is now logged in ES both for
Jetmon status running

[{"type":1,"host":"docker.jetmon.dev.com","status":1,"rtt":563,"code":200}]

Jetmon status down

[{"type":1,"host":"docker.jetmon.dev.com","status":0,"rtt":735,"code":503},{"type":1,"host":"docker.jetmon.dev.com","status":0,"rtt":818,"code":503},{"type":1,"host":"docker.jetmon.dev.com","status":0,"rtt":509,"code":503},{"type":2,"host":"veriflier","status":0,"rtt":564,"code":503}]

[darssen]

LGTM!