During a fresh deployment, the default dashboard zip file is malformatted

[Garrett Neugent]

When adding the prometheus-libvirt-exporter charm to a customer cloud, we found that the default dashboard zip file was not being zipped correctly. Looking at an example unit log, one can see the failure during the install hook:

tracer: set flag libvirt-exporter.started
tracer: -- dequeue handler reactive/prometheus-libvirt-exporter.py:34:install_packages
tracer: -- dequeue handler reactive/prometheus-libvirt-exporter.py:59:start_snap
2021-06-28 15:53:30 INFO juju-log juju-info:483: start_snap() libvirt-exporter.started
2021-06-28 15:53:30 DEBUG juju-log juju-info:483: Installing dashboards from resource
2021-06-28 15:53:31 ERROR juju-log juju-info:483: BadZipFile: File is not a zip file

Investigating the files themselves, one can see:

ubuntu@REDACTED:/var/lib/juju/agents/unit-prometheus-libvirt-exporter-3/resources/dashboards$ sudo zcat grafana-dashboards.zip

gzip: grafana-dashboards.zip: unexpected end of file

and

ubuntu@REDACTED:/var/lib/juju/agents/unit-prometheus-libvirt-exporter-3/charm/files/grafana-dashboards$ sudo zcat grafana-dashboards.zip

gzip: grafana-dashboards.zip: unexpected end of file

Commands to deploy the charm:

juju deploy prometheus-libvirt-exporter
juju relate prometheus-libvirt-exporter nova-compute-kvm
juju relate prometheus-libvirt-exporter:scrape prometheus:target
juju relate prometheus-libvirt-exporter:dashboards grafana:dashboards
juju relate prometheus-libvirt-exporter:nrpe-external-master nrpe-host:nrpe-external-master

Charm info:

  prometheus:
    charm: cs:prometheus2-19
    series: bionic
    os: ubuntu
    charm-origin: jujucharms
    charm-name: prometheus2
    charm-rev: 19
    charm-version: ae30894
    can-upgrade-to: cs:prometheus2-22
    exposed: false
    application-status:
      current: active
      message: Ready
      since: 28 Jun 2021 15:59:41Z
    relations:
      grafana-source:
      - grafana
      juju-info:
      - canonical-livepatch
      - filebeat
      - landscape-client
      - logrotate
      - ntp
      - telegraf-prometheus
      nrpe-external-master:
      - nrpe-host
      target:
      - prometheus-ceph-exporter
      - prometheus-libvirt-exporter
      - prometheus-openstack-exporter
      - telegraf
      - telegraf-maas-infra
      - telegraf-prometheus

$ juju config keystone openstack-origin
cloud:bionic-ussuri

As a workaround, reattaching the dashboard solved this issue:

1) clone the libvirt.json file on the cloud in question
2) zip grafana-dashboards.zip libvirt.json
3) juju attach-resource prometheus-libvirt-exporter dashboards=./grafana-dashboards.zip