Upgrading from preview to GA version of IoT Edge

Article
06/28/2018

The wait is finally over with todays announcement that Azure IoT Edge is now out of preview and in GA. The new installation process is quite different than it was in preview and there are detailed instructions available for the wide variety of supported platform. But you may hit some speedbumps if you install the GA version over the top of the preview version.

The Problem

The IoT Edge runtime should automatically instantiate the edgeAgent module to orchestrate the deployment and lifecycle of the other modules. For some reason this wasn't happening so running the "iotedge list" command returned a depressing blank result. This occurred on both my windows and Linux dev machines.

 iotedge list
NAME STATUS DESCRIPTION CONFIG

Looking at the logs for the IoT Edge service (iotedged) revealed a not overly helpful error.

 
PS C:\WINDOWS\system32> Get-WinEvent -ea SilentlyContinue  -FilterHashtable @{ProviderName= "iotedged";
>> LogName = "application"; StartTime = [datetime]::Today} |  select TimeCreated, Message | Sort-Object -Descending

TimeCreated Message
----------- -------
28/06/2018 4:54:16 PM info: edgelet_core::watchdog -- Updating identity for module $edgeAgent
28/06/2018 4:54:19 PM warn: edgelet_core::watchdog -- Error in watchdog when checking for edge runtime status:
28/06/2018 4:54:19 PM warn: edgelet_utils::logging -- A module runtime error occurred. 
28/06/2018 4:53:59 PM info: edgelet_http::logging -- [mgmt] - - - [2018-06-28 06:53:59.809207100 UTC] "GET /modules?...
28/06/2018 4:54:16 PM info: edgelet_core::watchdog -- Checking edge runtime status
28/06/2018 4:54:16 PM info: edgelet_core::watchdog -- Creating and starting edge runtime module edgeAgent
28/06/2018 4:54:19 PM warn: edgelet_utils::logging -- caused by: Conflict with current operation
28/06/2018 4:55:16 PM info: edgelet_core::watchdog -- Updating identity for module $edgeAgent
28/06/2018 4:55:19 PM warn: edgelet_core::watchdog -- Error in watchdog when checking for edge runtime status:
28/06/2018 4:55:19 PM warn: edgelet_utils::logging -- A module runtime error occurred.

The Solution

It seems that the existence of the preview versions of the edgeAgent images in the local Docker registry was the source of my grief. A spring clean was therefore required.

Windows (Linux containers) Fix

Start a powershell as Adminstrator
Stop the IoT Edge Service
```
 Stop-Service iotedge
```

Create and run a batch file to delete the existing images and containers

  @echo off
FOR /f "tokens=*" %%i IN ('docker ps -aq') DO docker rm %%i
FOR /f "tokens=*" %%i IN ('docker images --format "{{.ID}}"') DO docker rmi %%i -f

Restart the IoT Edge service and give it a minute to pull down the images
```
 Start-Service iotedge
```

List the running modules to make sure all is good

 PS C:\WINDOWS\system32> iotedge list
NAME      STATUS  DESCRIPTION   CONFIG
edgeAgent running Up 41 minutes mcr.microsoft.com/azureiotedge-agent:1.0

Linux Fix

Stop the IoT Edge Service
```
 sudo systemctl stop iotedge
```
Run commands to delete the existing images and containers
```
 rm $(docker ps -a -q) 
rmi $(docker images -q) -f
```
Restart the IoT Edge service and give it a minute to pull down the images
```
 sudo systemctl start iotedge
```