Comment 13 for bug 1639981

I've run into the same issue.

* Node is in Asia
* snap info grafana takes "real 0m50.056s".
* snap_layer_proxy.conf looks like (no no_proxy env var):
"""
~# cat /etc/systemd/system/snapd.service.d/snap_layer_proxy.conf
# Managed by Juju
[Service]
Environment=https_proxy=http://192.168.x.x:8000/
Environment=http_proxy=http://192.168.x.x:8000/
"""

* snap versions
"""
~# snap version
snap 2.45
snapd 2.45
series 16
ubuntu 16.04
kernel 4.15.0-91-generic
"""

* snap refresh grafana returns:
"""
error: cannot refresh "grafana": cannot refresh snap-declaration for "core18": Get
       https://api.snapcraft.io/api/v1/snaps/assertions/snap-declaration/16/<a-long-id>?max-format=4:
       net/http: request canceled while waiting for connection (Client.Timeout exceeded while
       awaiting headers)
"""