All posts by nicholas

CLI

Split flac files with shnsplit

April 25, 2019 nicholas Leave a comment

I had a few single FLAC files with cue files I wanted to put into Plex but to my dismay it doesn’t read the CUE files at all. Thus I needed to split the one FLAC file into multiple pieces with shnsplit. Thanks to Stack Exchange for the help.

On my Debian system:

 sudo apt install cuetools shntool flac

With the necessary tools installed you simply have to run the shnsplit command:

 shnsplit -f FILENAME.cue -t "%a - %n %t - %p" FILENAME.flac

the -t parameters formats the filename as desired per the manpage

-t fmt
Name output files in user‐specified format based on CUE sheet fields. The following formatting strings are recognized:

%p
Performer
%a
Album
%t
Track title
%n
Track number

Create local CentOS 7 Repo

April 24, 2019 nicholas Leave a comment

I’ve recently needed to create a local mirror of Cent7 packages. I followed the guide posted on techmint but also made a few tweaks to get it to work to my liking.

Create local repo mirror

Install necessary packages
- sudo yum -y install epel-release nginx createrepo yum-utils moreutils
Create directories that will host your repo
- sudo mkdir -p /usr/share/nginx/html/repos/{base,centosplus,extras,updates,epel}
Use the reposync tool to synchronize to those local directories (repeat for each directory, changing repoid= value to match)
- reposync -g -l -d -m --repoid=base --newest-only --download-metadata --download_path=/usr/share/nginx/html/repos/
Use the createrepo tool to create repodata
- base & epel have a group file, other repos do not.
- For base & epel:
  - createrepo -g comps.xml /usr/share/nginx/html/repos/<FOLDER>
- For the rest:
  - createrepo /usr/share/nginx/html/repos/<FOLDER>

Configure daily synchronization via cron

Copy this script to /etc/cron.daily/ and give it execute rights

#!/bin/bash
##specify all local repositories in a single variable
LOCAL_REPOS="base extras updates epel centosplus"
##a loop to update repos one at a time
for REPO in ${LOCAL_REPOS}; do
reposync -g -l -d -m --repoid=$REPO --newest-only --download-metadata --download_path=/usr/share/nginx/html/repos/Cent7/
if [[ $REPO = 'base' || $REPO = 'epel' ]]; then
        createrepo -g comps.xml /usr/share/nginx/html/repos/Cent7/$REPO/
else
        createrepo /usr/share/nginx/html/repos/Cent7/$REPO/
fi
done

chmod 755 /etc/cron.daily/<script_name>

E-mails from cron became annoying. I wanted to only get e-mailed on error. The solution is to use chronic

Modify /etc/anacrontab to add “chronic” between nice and run-parts

1 5 cron.daily nice chronic run-parts /etc/cron.daily
7 25 cron.weekly nice chronic run-parts /etc/cron.weekly
@monthly 45 cron.monthly nice chronic run-parts /etc/cron.monthly

Success.

Update 4/25/19 I encountered an issue while trying to use repsync to mirror the remi repo.

warning: /usr/share/nginx/html/repos/Cent7/remi/remi/aspell-nl-0.50-1.el7.remi.x86_64.rpm: Header V4 DSA/SHA1 Signature, key ID 00f97f56: NOKEY

I found out from here that it means you need to manually import the package’s key into the RPMDB like so

sudo rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-remi

OS, Virtualization

Proxmox first VM boot delay workaround

April 14, 2019 nicholas 2 Comments

My home lab has an NFS server for storage and a proxmox hypervisor connecting to it. If the power ever goes out for more than my UPS can handle, startup is a bit of a mess. My ProxMox server boots up much faster than my NFS server, so the result is no VMs start automatically (due to storage being unavailable) and I have to manually go in and start everything.

I found this bug report from 2015 which frustratingly doesn’t appear to have any traction to it. Ideally I could just tell the first VM to wait 5 minutes before turning on, and then trigger all the other VMs to turn on once the first one is up, but the devs don’t seem to want to address that issue. So, I got creative.

My solution was to alter the grub menu timeout before booting ProxMox. Simple but effective.

Edit /etc/default/grub and modify GRUB_TIMEOUT

#modify GRUB_TIMEOUT to your liking
GRUB_TIMEOUT=300

Then simply run update-grub

update-grub

Now my proxmox server waits 5 minutes before even booting the OS, by which time the NAS should be up and running. No more manual turning on of VMs after a power outage.

Hardware

IP Camera doorbell without a cloud subscription

March 17, 2019 nicholas 4 Comments

I’ve been on a quest to find a decent looking doorbell camera that is easy on the wallet while also allowing for local storage recording (no cloud subscription.)

What I ended up with was the Hikvision DS-KB6003-WIP. It’s been great so far. The OEM version I got had a different firmware on it, so I flashed the official HikVision firmware just to stay proper.

Spec sheet:
HikVision Website
Alternate Link

Manual:
HikVision Website
Alternate Link

Device as listed on HikVisions website:
https://www.hikvision.com/Products/Video-Intercom/Wi-Fi-Door-Bell/DS-KB6003-WIP

Note this doorbell will ONLY work with MECHANICAL wired chimes. I could not get it to work with my digital chime (it would just chime incessantly or not power up the doorbell camera properly depending on how I used the dummy resistor provided.)

Installation was pretty straightforward. Make sure you have a good transformer and not a terrible one like I had. Connecting it to your WiFi network is a bit different. You have to use the Hik-Connect app to create a QR code with your wifi settings. The you simply need to point the QR code to the camera, and after a moment it will announce it connected to your network.

Once connected you can access the device via web browser by IP address (or continue using the hik-connect app.) The web interface requires a stupid plugin to work properly. Make sure you use IE or older Firefox version for plugin to work. The default username is admin, and the default password is admin+verification code found on the device sticker. For example, “adminHLPVTL”

Sign in on https://www.hik-connect.com/ and register device with hik-connect to get the doorbell button to do something instead of just saying “no account found.”

To configure with Zoneminder or other DVR software, the RTSP URL is as follows:

rtsp://USERNAME:PASSWORD@IP_ADDRESS:554/ch1/main/av_stream

CLI, OS, Virtualization

Fix Proxmox swapping issue

March 9, 2019 nicholas 1 Comment

I recently had an issue with one of my Proxmox hosts where it would max out all swap and slow down to a crawl despite having plenty of physical memory free. After digging and tweaking, I found this post which directed to set the kernel swappiness setting to 0. More reading suggested I should set it to 1, which is what I did.

Append to /etc/sysctl.conf:

#Fix excessive swap usage
vm.swappiness = 1

Apply settings with:

sysctl --system

This did the trick for me.

CLI, Hardware, OS

Rasbperry Pi as a dashboard computer

March 8, 2019 nicholas Leave a comment

Here are my raw, unpolished notes on how I set up a raspberry pi to serve as a dashboard display:

Use Raspbian OS

Autostart Chrome in kiosk mode

Eliminate Chrome crash bubble thanks to this post

mkdir -p ~/.config/lxsession/LXDE-pi/
nano ~/.config/lxsession/LXDE-pi/autostart

Add this line:
@chromium-browser --kiosk --app=<URL>

Mouse removal

sudo apt-get install unclutter

in ~/.config/lxsession/LXDE-pi/autostart add

@unclutter -idle 5

Disable screen blank:

in /etc/lightdm/lightdm.conf add

[SeatDefaults]
xserver-command=X -s 0 -dpms

Open up SSH & VNC

Pi / Preferences / Raspberry Pi Configuration: Interfaces tab

SSH: Enable
VNC: Enable

Increase swap file

sudo nano /etc/dphys-swapfile
CONF_SWAPSIZE=2048M

Configure NTP

sudo apt-get install openntpd ntpdate
sudo systemctl enable openntpd
sudo ntpdate <IP of NTP server>

edit /etc/openntpd/ntpd.conf and modify servers lines to fit your NTP server

Disable overscan

Pi / Preferences / Raspberry Pi Configuration: System tab
Overscan: Disable

Hardware

Installing Android Auto / Apple Carplay retrofit in Mazda CX3

February 10, 2019 nicholas 15 Comments

I just finished installing the Android Auto / Apple CarPlay retrofit kit into my 2016 Mazda CX-3 Grand Touring AWD. It’s sweet! The process to get it installed was a learning experience for me.

The CX-3 is not as popular as its bigger brother the CX-5 and therefore there wasn’t nearly as much information on how to do the retrofit. Of great help were various posts over at CX3 forum and this youtube video.

The steps to accomplish the retrofit are as follows, taken from the official Mazda guide

Update Mazda firmware to latest 70.00+ version
1. Firmware can be found here
Remove glove compartment
Remove Audio Panel 1
Remove Audio Panel 2
Remove Central display
1. Be careful here. This will scratch up your dashboard. Do not ignore recommendations to lay down protective tape/other layer
Remove Center Console Tray (or, in my case, the armrest attachment)
Remove shift bezel
Remove upper panel
Remove/detach shift panel (Removal not necessary)
1. I didn’t want to undo the shift knob, so I just unplugged the panel and rotated the whole assembly to the side. It was enough for the installation – no removal required.
Remove console side panels
Remove front console box
Remove DVD/CD Player (if installed)
1. Removal keys were not easy to find. I ended up using two small cutting knives I found in my kitchen. Insert into keyholes, angle them slightly, and pull.
Remove Front Console
Remove old USB hub from front console
Replace USB hub in front console
Wrap wiring in foam
Route wiring and add zip ties
Replace components in reverse order from how you removed them

The biggest challenges for me were the armrest and CD player. The rest of it was pretty straightforward. Here are some pictures of the process:

CLI

Installing Gears of War 4 in Windows 10

January 31, 2019 nicholas 1 Comment

Installing Gears of War 4 on Windows can only be described as a hellish nightmare. Here are my notes on how I finally got it to install and run.

Download file with fiddler and a download accelerator, as outlined here:

[GUIDE v2.0] How to download install package for Windows Store games (bypass Store download issues or for install on another PC)
byu/ShadowStealer7 inpcgaming

Once you have the file, begin installing / downloading the game from the Windows store. Get several hundred MB / a few GB, then pause download.
Open powershell (no need to be an admin) and run the following:
- ```
Add-AppxPackage -path "<PATH TO GEARS FILE>"
```

After finish, close windows store and re-open, launch from there.

You may need to repeat removal and installation process many times, but now that you have the EAPPX file, it should be much less painful.

CLI, OS

Recover files from ZFS snapshot of ProxMox VM

January 6, 2019 nicholas Leave a comment

I recently needed to restore a specific file from one of my ProxMox VMs that had been deleted. I didn’t want to roll back the entire VM from a previous snapshot – I just wanted a single file from the snapshot. My snapshots are handled via ZFS using FreeNAS.

Since my VM was CentOS 7 it uses XFS, which made things a bit more difficult. I couldn’t find a way to crash-mount a read-only XFS snapshot – it simply resufed to mount, so I had to make everything read/write. Below is the process I used to recover my file:

On the FreeNAS server, find the snapshot you wish to clone:

sudo zfs list -t snapshot -o name -s creation -r DATASET_NAME

Next, clone the snapshot

sudo zfs clone SNAPSHOT_NAME CLONED_SNAPSHOT_NAME

Next, on a Linux box, use SSHFS to mount the snapshot:

mkdir Snapshot
sshfs -o allow_other user@freenas:/mnt/CLONED_SNAPSHOT_NAME Snapshot/

Now create a read/write loopback device following instructions found here:

sudo -i #easy lazy way to get past permissions issues
cd /path/to/Snapshot/folder/created/above
losetup -P -f VM_DISK_FILENAME.raw
losetup 
#Take note of output, it's likely set to /dev/loop0 unless you have other loopbacks

Note if your VM files are not in RAW format, extra steps will need to be taken in order to convert it to RAW format.

Now we have an SSH-mounted loopback device ready for mounting. Things are complicated if your VM uses LVM, which mine does (CentOS 7). Once the loopback device is set, lvscan should see the image’s logical volumes. Make the desired volume active

sudo lvscan
sudo lvchange -ay /dev/VG_NAME/LV_NAME

Now you can mount your volume:

mkdir Restore
mount /dev/VG_NAME/LV_NAME Restore/

Note: for XFS you must have read/write capability on the loopback device for this to work.

When you’re done, do your steps in reverse to unmount the snaspshot:

#Unmount snapshot
umount Restore
#Deactivate LVM
lvchange -an /dev/VG_NAME/LV_NAME
Remove loopback device
losetup -d /dev/loop0 #or whatever the loopback device was
#Unmount SSHfs mount to ZFS server
umount Snapshot

Finally, on the ZFS server, delete the snapshot:

sudo zfs destroy CLONED_SNAPSHOT_NAME

Troubleshooting

When I tried to mount the LVM partition at this point I got this error message:

mount: /dev/mapper/centos_plexlocal-root: can't read superblock

It ended up being because I was accidentally creating a read-only loopback device. I destroy the loopback device and re-created with write support and all was well.

CLI

Batch crop images with imagemagick

December 25, 2018 nicholas Leave a comment

My scanner adds annoying borders on everything it scans. I wanted to find a way to fix this with the command line. Enter Imagemagick (thanks to this site for the help.)

I found one picture and selected the area I wanted to crop it from. I used IrfanView to tell me the dimensions of the desired crop, then passed that info onto the command line. I used a bash for loop to get the job done on the entire directory:

for file in *.jpg; do convert $file -crop 4907x6561+53+75 $file; done

It worked beautifully.

Technicus