This task is to track the upgrade of node-exporter to >= 0.16. Note that we'd want to upgrade to a version that matches Debian Buster, to ease migration (Buster tracking task is T213527).
Prior upgrades: T152580 and T166561. Though in this case there's a bunch of metrics renamed, so we'll have to be backwards compatible with the old names at least for a little while, see also https://github.com/prometheus/node_exporter/blob/v0.16.0/docs/V0_16_UPGRADE_GUIDE.md.
Proposed plan of attack:
[x] Make sure Buster/Stretch/Jessie all have the same node-exporter version available (in practice this means backporting 0.17 to jessie, which shouldn't pose particular problems)
[x] Test the upgrade in beta:
[x] Deploy the compatibility recording rules above
[x] Upgrade node-exporter
[] Verify dashboards still report data as expected under old names
[] Extend the upgrade to production, one site at a time (if easy to do)
[] (Optional, can be postponed) audit/change dashboards to use new metric names, and retire compatibility recording rules