zaterdag 15 september 2018

Location info based on an IP address

Recently redshift broke due to a change in geoclue2.

My solution was to go back to the previous working version of geoclue2 (2.4.7-1) and just wait for a fix upstream. It seems that this compatibility issue will not be fixed in redshift or geoclue2 in their packages, so I neew a beter workarround.

I decided to just enter my location in the startup file, as suggested by several people.

One of the nice suggestions was to use a simple query to get your ip-based location info in json and extract wat was needed for redshift.

curl | jq -j .loc | tr ',' ':'

I decided to just put the result of that query into the redshift desktop-file for my pc at home, not the query itself. I noticed that the json returned by the site looked quite nice.

The location is close enough for use with redshift (well inside a 30 km radius), however it actually suggest another town :-)

zondag 18 maart 2018

Smartmeter P1 in console

De Nederlandse Smartmeters hebben een P1 poort waarmee je de tellerstand kan ophalen. Een geschikte ' kabel' om op een computer aan te sluiten, kan je zelf maken of kant en klaar kopen..

Een makkelijke manier is om een P1 naar USR 'kabel' te kopen en die op een raspberry Pi aan te sluiten. Je kan hier zelfs complete domotica setjes voor kopen, waar ook al leuke software op zit, maar je hebt genoeg aan zo'n kabel en een kale RPi.

Om te testen of het werkt (en zolang je nog geen andere software hebt om wat met de P1 data te doen), zijn de volgende 2 regels (uitvoeren op de commandline) voldoende om te zien wat er uit de meter komt.

sudo stty -F /dev/ttyUSB0 115200
cat /dev/ttyUSB0 | sed '/^$/d'

de eerste regel stelt de snelheid in waar de poort mee werkt (115200)
de tweede regel laat alle binnenkomende regels zien (en sloopt de extra lege regels eruit)

Als je de RPi in de meterkast hebt (en aangesloten op je internet modem/router), kan je overal vanuit je thuisnetwerk inloggen op de RPi en de meterstanden uitlezen. Je kan het natuurlijk zo mooi maken als je zelf wilt, maar dit is het minimum.

Er zijn voldoende sites op internet met info, ' google is your friend'

dinsdag 23 december 2014

Use a MAC address to find a specific network interface

This is an old blogpost, unpublished until now, written in 2014 when windows 2008R2 was widely used and windows 2012 was brand new. Who is stil deploying windows 2008 R2 servers? Now you can use the powershell commands on 2012R2 and 2016 to do  the same tasks.

When deploying VMs in an automated way and your VM has more than one network interface and you need to configure static IP addresses, you need to find the interface that corresponds to a specific network. I also assume you want a static IP address for a server and that your server is a Virtual Machine hosted on vCenter or Hyper-V. On that host, you configured the virtual network interface with a specific VLAN and you know the assigned MAC address. Your task is to find the corresponding interface inside the VM and configure it with the right IP configuration.

The trick is to find the interface with a specific MAC address and then configure it.  This should also work on Windows 2008 R2, so the new PowerShell CmdLets in Windows 2012 cannot be used yet.

WMI to the resque (using Get-WmiObject). Using the Win32_NetworkAdapter class and filtering on AdapterTypeId = 0 gives the list of configured ethernet adapters and the interface index I need.

$wmiResult= Get-WmiObject -Class Win32_NetworkAdapter -Namespace "root\CIMV2"
$wmiResult | Where AdapterTypeId -eq 0 | select Index,MACAddress | ft -AutoSize

Index MACAddress
----- ----------------
   10 00:50:50:A0:2D:D1
   12 00:50:50:A0:2E:D4
   14 00:50:50:A0:2F:D6

The same (and more) data is also available in the Win32_NetworkAdapterConfiguration class, except you cannot filter on 'ethernet adapters' or interface index. On the other hand, if you already know the MAC addresses of the interfaces to configure, then it might still be an option.

When you  know the interfaceindex, you can now configure the interface using netsh (2008R2) or powershell (2012 and up)

zaterdag 6 september 2014

Using .NET to convert a WMI datetime to a powershell datetime

The datetime format for WMI objects (through powershell) is different from the native powershell datetime format, so you need to convert it to PowerShell's native datetime format.

When using 'local' WMI commandlets, this is easy, just call the objects 'ConvertToDatetime' method. But when automating tasks you would collect data using powershell remoting. The powershell object containing the WMI datetime you obtained using remoting, does have all properties available, but not the methods.
You can create a local WMI object and use it's ConvertToDatetime method, but there is an easier way.

I found that solution by looking for something entirely different in this blog: New way to convert WMI time properties
Simply use [System.Management.ManagementDateTimeconverter]::ToDateTime( ) with the WMI time as the parameter.

This .Net method converts a WMI datetime to PowerShell's native DateTime format. So no need the need to create a local WMI object and then us it's conversion method :)

Example code:

$Computer = 'SERVER01'
$wmiResult = Invoke-Command -ComputerName $Computer -ScriptBlock {
 Get-WmiObject -Class Win32_OperatingSystem -Namespace "root\CIMV2"
if ($wmiResult)
    $LastBootTime = [System.Management.ManagementDateTimeconverter]::ToDateTime($wmiResult.LastBootUpTime)
    Write-Output "Server $($wmiResult.PScomputerName) with OS version $($wmiResult.Version), last booted on $LastBootTime"
    Write-Warning "Server $Computer could not be contacted through WS-Man, please check if the server is up and powershell is enabled"

If you are only interested in the last boot time and not in other properties, you can do the conversion at the remote computer (at the expense of a larger scriptblock) and just return the already converted date.