What is the proper configuration to persist edgeAgent storage? - azure

Question

I am working on an Azure IoT Edge project. Currently I am going through the production readiness checklist. I followed the documentation to use storage on the host filesystem for the edgeAgent and edgeHub modules.
When I run sudo iotedge check edgeHub is OK but edgeAgent raises a warning:
‼ production readiness: Edge Agent's storage directory is persisted on the host filesystem - Warning
The edgeAgent module is not configured to persist its /tmp/edgeAgent directory on the host filesystem.
Data might be lost if the module is deleted or updated.
Please see https://aka.ms/iotedge-storage-host for best practices.
√ production readiness: Edge Hub's storage directory is persisted on the host filesystem - OK
Here is a snippet from the deployment template:
"systemModules": {
"edgeAgent": {
"type": "docker",
"settings": {
"image": "mcr.microsoft.com/azureiotedge-agent:1.0",
"createOptions": {
"HostConfig": {
"Binds": [
"/home/pi/iotedge/edgeAgent/storage/:/iotedge/storage/"
]
}
}
},
"env": {
"storageFolder": {
"value": "/iotedge/storage/"
}
}
},
"edgeHub": {
"type": "docker",
"status": "running",
"restartPolicy": "always",
"settings": {
"image": "mcr.microsoft.com/azureiotedge-hub:1.0",
"createOptions": {
"HostConfig": {
"Binds": [
"/home/pi/iotedge/edgeHub/storage:/iotedge/storage/"
],
"PortBindings": {
"5671/tcp": [
{
"HostPort": "5671"
}
],
"8883/tcp": [
{
"HostPort": "8883"
}
],
"443/tcp": [
{
"HostPort": "443"
}
]
}
}
}
},
"env": {
"storageFolder": {
"value": "/iotedge/storage/"
}
}
}
},

Answer 1

As of release 1.0.9, there's an issue where edgeAgent's configuration doesn't update unless its image tag is updated. Two options from your current state:
Use a specific tag in the image settings (always recommended). E.g. mcr.microsoft.com/azureiotedge-agent:1.0.9
Delete the edgeAgent container on the device: docker rm -f edgeAgent. It will get restarted in under 30 secs and the new storageFolder env var will be picked up.
Run 'iotedge check' again after the container is update, and this warning should go away.

Answer 2

I have followed the same documentation and was able to avoid the production readiness checklist warnings on my Raspberry Pi 3.
1) I have configured the "Binds" as per the documentation Link module storage to device storage
"Binds":["/etc/iotedge/storage/:/iotedge/storage/"]
2) I have provided the user access on the HostStoragePath, from SSH terminal.
sudo chown 1000 /etc/iotedge/storage/
sudo chmod 700 /etc/iotedge/storage/
3) Restarted Raspberry Pi 3, to make sure the grant access takes into effect.
Make sure you have host storage folders available on your edge device.
Make sure to provide the user full access on those folders.
Try the deployment with your updated manifest, it should probably work.