Note to myself: when you try to configure a system using DSC, do not forget to configure the Local Configuration Manager first!
Today I caught myself in “troubleshooting” an issue with Desired State Configuration. The issue looked like that
- when I tried to apply a new DSC Configuration, it was applied fine.
- if I changed the systems configuration later, the change was caught by DSC and if I ran the get-DSCConfiguration cmdlet the configuration issue was shown in the resultset properly
But the system did not get reconfigured by the set-procedure.
If you ever notice an issue like that, check your event logs first! You may take a note of your Event ID 4257 entries in your “Microsoft-Windows-Desired State Configuration/Operational” Event Log and check the ConfigurationMode setting.By default this is set to “ApplyAndMonitor” (see also https://msdn.microsoft.com/en-us/powershell/dsc/metaconfig). This will apply your configuration once and monitor for changes, but it will not re-apply your configuration! Unfortunately, this is true as well for machines deployed in Microsoft Azure.
Once you ran this configuration by using the set-dscLocalConfigurationManager cmdlet, you will find your configuration applied. DSC now will run the set Scripts when your test scripts return “false”.