Charge HP Stream 7 while using it with an OTG cable

After a quite frustrating experience with an HP Stream 7 tablet, which refused to get charged while having a USB stick connected to it via an OTG cable, I found an extremly easy solution:

Just disable the Microsoft AC Power Supply which can be found in the device manager under Batteries.

Voila – that’s it.

I have the German version only where it says Microsoft Ladegerät and can be found under Akkus.

Installing Debian Jessie on an APU1D4

To install Debian Jessie on an APU1D4, it is easiest to go for a network installation. You need
– a TFTP server
– a DHCP server
– the Debian file structure in the TFTP server’s root directory

For DHCP you will need something like the following configuration:

For the TFTP server you need something like the following configuration:

Then simply extract the debian installer files into /src/tftp . I have included my working configuration into netboot_serial_20150107.tar. Should you want to change its configuration, simply edit the file pxelinux.cfg/default file. Mine looks as follows and is preconfigured for serial console output:

Attach a serial console cable and fire it up!

Frontend for openssl to check key chains

Since checking SSL key chains with openssl is sometimes a bit tricky, I have written a little perl script as wrapper around it.

Just download check_chain.zip, unzip it and run it as follows:

./check_chain.pl -p server port

-p (optional) prints out the certificates as well
server is the server to check
port (optional) is the port to connect to.

Here is the code:

Its output is as follows:

Install most basic Debian Jessie container for use as a template for LXC or similar

To create a most basic Debian Jessie container, you can follow these steps:

You should not forget to set the root password as it is good to have a known value later.

Now that we are within the container, we can configure the most basic settings that we will need for all containers:

Here I am usually generating

and set the default to en_US.UTF-8 .

To get the full repository contents, you should change your repository sources to look as below:

and then do an aptitude update .

You should also install an SSH server by entering

Enable root logins via SSH by changing one line in its configuration:

Unfortunately systemd is not yet working easily with LXC, so it should be replaced by the old sysvinit:

Edit initial DNS resolver configuration so it looks like this:

Then also configure the main network interface configuration:

Replace /etc/inittab with the following short version which is enough for a container:

Should the network not come up automatically, you can set the IP address in the config file of the container:

After a first start, you should also configure the mail server so it can send all system mail to your main mail server:

and answer all the questions.

Shut the machine down again, cleanup all the log files and make a copy which you can then use as your template for further containers.