required ceph-dashboard plugins can't be installed behind a proxy

[Drew Freiberger]

When deploying the charm ceph-dashboard per it's README.md, the operator must add the following plugins to grafana:

juju config grafana install_plugins="https://storage.googleapis.com/plugins-community/vonage-status-panel/release/1.0.11/vonage-status-panel-1.0.11.zip,https://storage.googleapis.com/plugins-community/grafana-piechart-panel/release/1.6.2/grafana-piechart-panel-1.6.2.zip"

The grafana charm's install_plugins config utilizes charmhelpers.fetch.remote_install to pull down the bits.

Charmhelpers has the following bug which notes that there are parts of charmhelpers.fetch that do not properly reference the juju-http(s)-proxy environment variables from the model.

https://github.com/juju/charm-helpers/issues/614

This should be solved in charmhelpers.

[Drew Freiberger (afreiberger)]

Workaround for ceph-dashboard is to download the zip files manually, place them on the grafana unit, and unzip them into /var/lib/grafana/plugins/ directory and `systemctl restart grafana-server.service`

[Vern Hart (vern)]

I've encountered this issue on a customer deployment. Had to blank the install_plugins config option and install the zips by hand:

juju config -m lma grafana --reset install_plugins
juju ssh -m lma grafana/leader "sudo apt install unzip;
cd /tmp;
https_proxy=http://10.49.12.10:8000 wget https://storage.googleapis.com/plugins-community/vonage-status-panel/release/1.0.11/vonage-status-panel-1.0.11.zip;
https_proxy=http://10.49.12.10:8000 wget https://storage.googleapis.com/plugins-community/grafana-piechart-panel/release/1.6.2/grafana-piechart-panel-1.6.2.zip;
sudo unzip vonage-status-panel-1.0.11.zip -d /var/snap/grafana/common/data/plugins;
sudo unzip grafana-piechart-panel-1.6.2.zip -d /var/snap/grafana/common/data/plugins;
sudo sudo snap restart grafana"

[Marcelo Subtil Marcal (msmarcal)]

When deploying grafana channel stable rev 66, the charm gets stuck on `(install) Installing plugins` state.

As a workaround, I set the install_plugins as an empty string and then:

```
juju run -m lma-maas -u grafana/0 "sudo https_proxy=http://10.243.173.4:8000 grafana.grafana-cli plugins install vonage-status-panel"

juju run -m lma-maas -u grafana/0 "sudo https_proxy=http://10.243.173.4:8000 grafana.grafana-cli plugins install grafana-piechart-panel"

juju run -m lma-maas -u grafana/0 "sudo systemctl restart snap.grafana.grafana"
```