Category: Linux

Running octoprint on raspberry pi 4 model b. Part 1

For some time we have a Tevo Tarantula 3d printer. Usually we keep it connected to a desktop computer and while we were printing we didn’t do much on it. However last night while printing a piece that took a long time to print we decided that we should use the computer. Big mistake. Computer hanged ( We assume something related to video card but that remains to be tested), printer hanged so we have to print that piece again.

You can imagine the frustration. Luckily we have several raspberry pi 4 around ( for a Kubernetes cluster project ) and we decided to take one and build a print server.

All good . There is a good tutorial here: https://howchoo.com/g/y2rhnzm3odz/control-your-3d-printer-with-octoprint-and-raspberry-pi

However this tutorial is for Rpi 3 . Rpi 4 is a different kind of beast. First octoprint normal image ( at this point in time ) does not work with Rpi 4 . You need to flash the night build image from here: https://storage.googleapis.com/octoprint/2019-06-24_2019-06-20-octopi-buster-lite-0.17.0.zip

Second rpi4 has wireless . So you need to edit from the start octopi-wpa-supplicant.txt and setup SID and wifi pass .

We managed to do that after 3 flashed of the SD card (due to the fact that we were flashing the wrong image). Now comes the configuration part. But that will be in another post.

Unifi controller in ubuntu 18.04 fix

To my disappointment Unifi Controller install on Ubuntu 18.04 fails big time. Their packages … Error message is somehow cryptic enough :

[2018-06-22 16:18:14,046]  INFO  db     - waiting for db connection...
[2018-06-22 16:18:14,546]  INFO  db     - Connecting to mongodb://127.0.0.1:27117
[2018-06-22 16:18:15,164]  ERROR system - [exec] error, rc=2
[2018-06-22 16:18:15,164]  INFO  db     - DbServer stopped
[2018-06-22 16:18:19,209]  ERROR system - [exec] error, rc=2
[2018-06-22 16:18:19,211]  INFO  db     - DbServer stopped
[2018-06-22 16:18:23,247]  ERROR system - [exec] error, rc=2

However i needed Unifi controller in order to control / setup an UniFi AP-AC-Pro ( we have one testing for one of our clients ). After some searching and tweaking around here how we fixed it:

cd /usr/bin
sudo mv mongod mongod.bin

And replace mongod with:

#!/bin/bash
cleaned_args=$(echo $* | sed -e 's/--nohttpinterface//')
exec /usr/bin/mongod.bin ${cleaned_args}

then

chmod +x mongod

Restart unifi service and point your browser to: http://localhost:8843/ and enjoy.

Create a maintainable Centos 7 box for web hosting

Goal: Create Centos 7 box for web hosting  ( LAMP stack / monitoring software code versioning software ) that will be easy to install , maintainable in time , easy to add functionality .

 

First things first: install the centos 7 minimal.

After instalation:

update OS

yum update
yum upgrade

generic tools

yum install perl perl-core ntpl nmap sudo libidn gmp libaio libstdc++ unzip sysstat sqlite net-tools mc bind-utils telnet

Remove iptables wrapper and install plain iptables service

yum remove firewalld

yum install iptables-services

Adding more useful software repositories

yum install https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
yum install http://rpms.famillecollet.com/enterprise/remi-release-7.rpm
yum install https://www.percona.com/redir/downloads/percona-release/redhat/latest/percona-release-0.1-3.noarch.rpm

Installing php 5.6

yum –enablerepo=remi-php56 install php php-gd php-mysql php-mcrypt

Installing mysql DB and backup tools

yum install Percona-Server-server-57 percona-xtrabackup

git

For Centos 7 we didn’t find (yet) a decent software repository for GIT 2.7 . Most probably we will make one and try to maintain it.  ( will be covered in another article )

Monitoring

yum install collectd collectd-apache

 

 

Installing Ricoh Aficio SG3100SNw in linux

So , you have decided to purchase a Ricoh Aficio SG3100SNw printer. Good. It’s a good choice for small / medium companies. What we like about it is that it comes with wireless interface and that is quite nice . Less cables more fun. I’m not going to get into details on how to unbox it and make the initial setup. I leave that as an exercise for the reader ( it’s not easy but up to a point it’s fun ) .   Continue reading Installing Ricoh Aficio SG3100SNw in linux

Resize VM images in proxmox

When you really need to resize a VM disk image ( and free space to be allocated into partitions inside the vm) you might want to read this:

Step-by-step guide

  1. Poweroff you VM from proxmox
  2. Grow the disk allocation from proxmox GUIresize-proxmox
  3. Open a shell to proxmox and use parted to resize the partitions ( for qcow you might need to mount it first on nbd )
    root@proxmox:~# qemu-nbd -c /dev/nbd0 /mnt/pve/gogu/images/108/vm-108-disk-1.qcow2
    root@proxmox:~# parted /dev/nbd0
    (parted) p
    Model: Unknown (unknown)
    Disk /dev/nbd0: 82.9GB
    Sector size (logical/physical): 512B/512B
    Partition Table: msdos
    Disk Flags:
    Number  Start   End     Size    Type     File system  Flags
     1      1049kB  525MB   524MB   primary  ext4         boot
     2      525MB   42.9GB  42.4GB  primary               lvm
    (parted) resizepart 2 82.8G
    root@proxmox:~# nbd-client -d /dev/nbd0
  4. Power on the VM and login to it. Time to put the free space to good use.
    pvdisplay
    pvresize /dev/vda2
    lvextend -l +100%FREE /dev/mapper/vg_webtest01-lv_root
    resize2fs /dev/mapper/vg_webtest01-lv_root
    # In case of xfs use:
    # xfs_growfs /dev/mapper/centos_template-root
  5. Job done . Enjoy