Ingo Fahrentholz

Polymer case-study

Sat, 22 Apr 2017 00:00:00 +0000

In this article I want to document how to work with polymer & web components. The goal is to create a fully working webapp.

TODOS:

☑︎ Start 💪
☐ Create the needed web components
☐ Overlay with (iron-overlay-behavior)
☐ Routing & lazy loading
☐ Ajax handling (iron-ajax)
☐ Data-binding
☐ Usage of observables
☐ Event handling
☐ Handle image loading (iron-image & placeholder[base64-image-string])
☐ Implement PRPL pattern
☐ Vulcanize & Crisper
☐ Bundling with Webpack / Grunt

Setup Jenkins server on Raspberry

Fri, 06 Jan 2017 00:00:00 +0000

In this article I want to document how to setup a Jenkins server on raspberry pi (3). The content is heavily borrowed by kubecloud.

Step 1

Choose java jdk-8 as your java.

sudo update-alternatives --config java

There are 2 choices for the alternative java (providing /usr/bin/java).

Step 2

Installation

mkdir jenkins && cd jenkins

wget -q -O - https://jenkins-ci.org/debian/jenkins-ci.org.key | sudo apt-key add -

sudo sh -c 'echo deb http://pkg.jenkins-ci.org/debian binary/ > /etc/apt/sources.list.d/jenkins.list'

sudo apt-get update

sudo apt-get install jenkins

Step 3

Start Jenkins

sudo nano /etc/init.d/jenkins

Define your ports

HTTP_PORT=8000  
JENKINS_ARGS="--httpPort=$HTTP_PORT"

To make sure the new port is used restart Jenkins

sudo /etc/init.d/jenkins restart

Setup Minecraft server on Raspberry

Fri, 06 Jan 2017 00:00:00 +0000

In this article I want to document how to setup a Minecraft server on raspberry pi (3). The content is heavily borrowed by jankarres.

Step 1

First of all you should configure your raspberry pi

sudo raspi-config

Expand Filesystem
Change user password
Change hostname
Set boot to CLI
Set GPU Memory to 16
Update your localisation settings

Step 2 (optional)

Expand your swap file-size.

sudo su -c 'echo "CONF_SWAPSIZE=2048" > /etc/dphys-swapfile'
sudo dphys-swapfile setup
sudo dphys-swapfile swapon

Step 3

Install dependencies.

sudo apt-get install git screen

Step 4

Download & patch the Spigot server.

wget https://hub.spigotmc.org/jenkins/job/BuildTools/lastSuccessfulBuild/artifact/target/BuildTools.jar
java -Xmx1G -jar BuildTools.jar

Step 5

Create a run script to start the Minecraft server.

Keep in mind that you have to update the spigot version number inside the run script @ spigot-1.8.jar.

#!/bin/sh
BINDIR=$(dirname "$(readlink -fn "$0")")
cd "$BINDIR"
java -Xmx1024M -XX:ParallelGCThreads=8 -Xincgc -XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:+CMSIncrementalPacing -XX:+AggressiveOpts -XX:+CMSParallelRemarkEnabled -XX:+DisableExplicitGC -XX:MaxGCPauseMillis=500 -XX:SurvivorRatio=16 -XX:TargetSurvivorRatio=90 -XX:+UseAdaptiveGCBoundary -XX:-UseGCOverheadLimit -Xnoclassgc -XX:UseSSE=3 -XX:LargePageSizeInBytes=4m -jar spigot-1.8.jar nogui

Step 6

Add permission.

sudo chmod +x run.sh

Step 7

Start your server for the first time.

sudo ./run.sh

Step 8

Accept the EULA by setting eula=true in the eula.txt.

vi eula.txt

Step 9

Update the default config of the spigot server to improve the performance.

Config download: spigot_config_2015.02.tar.gz

Step 10 (optional)

Start your Minecraft server in a screen session so it keeps running in the ‘background’.

Navigate to your server’s directory.
Run the command: screen -S ScreenNameGoesHere
Then you’ll be in your screen session, so run the server startup script.
To leave the screen session (and leave it running) press and hold CTRL, A, D (in that order).
To resume the screen session run the command: screen -r ScreenNameGoesHere
To kill the screen session run the command: screen -S ScreenNameGoesHere -X kill

Availability

If you want to make your server public available you need to use a dynip service like: noip.com

Install Nextcloud on Raspberry

Sat, 13 Aug 2016 00:00:00 +0000

UPDATE 2016-08-13: Use MariaDB and PHP7

In the following steps I’ll document how the nextcloud setup works.

Configure your Pi

sudo raspi-config

Expand Filesystem
Change user password
Change hostname
Set boot to CLI
Set GPU Memory to 16
Update your localisation settings

Update your system

sudo apt-get update && sudo apt-get upgrade && sudo apt-get dist-upgrade

Add the www-data user to the www-data group:

sudo usermod -a -G www-data www-data

Install the required packages

sudo apt-get install nginx openssl ssl-cert curl libapr1 libtool curl libcurl4-openssl-dev memcached varnish

Install PHP7

Edit sources:

sudo nano /etc/apt/sources.list

Add

deb http://mirrordirector.raspbian.org/raspbian/ stretch main contrib non-free rpi

Edit

sudo nano /etc/apt/preferences

Add

Package: *
Pin: release n=jessie
Pin-Priority: 600

Fetch and install

wget https://www.dotdeb.org/dotdeb.gpg
sudo apt-key add dotdeb.gpg
sudo apt-get update
sudo apt-get install php7.0-fpm php7.0-mysql php7.0-common php7.0-gd php7.0-json php7.0-cli php7.0-curl php7.0-xml php7.0-zip php7.0-mbstring

Install MariaDB

MariaDB is a drop-in replacement for MySQL.

sudo apt-get install -y mariadb-server mariadb-client

Check MariaDB version

mysql --version

Now run the security script (But don’t delete the root user yet!)

sudo mysql_secure_installation

Now we need to setup our database

sudo mysql -u root -p
CREATE DATABASE nextcloud;
CREATE USER 'nextcloud'@'localhost' IDENTIFIED BY 'SecurePassword';
GRANT ALL PRIVILEGES ON nextcloud.* TO 'nextcloud'@'localhost';
FLUSH PRIVILEGES;

Create the SSL certificat

sudo openssl req $@ -new -x509 -days 730 -nodes -out /etc/nginx/cert.pem -keyout /etc/nginx/cert.key

Protect the certificat

sudo chmod 600 /etc/nginx/cert.pem
sudo chmod 600 /etc/nginx/cert.key

Update the nginx configuration

sudo mv /etc/nginx/sites-available/default /etc/nginx/sites-available/default_old
sudo nano /etc/nginx/sites-available/default

Paste the following configuration. Make sure you substitue IPAdress with your Raspberry Pi IPAdress

upstream php-handler {
    server 127.0.0.1:9000;
}

server {
    listen 80;
    server_name IPaddress;
    return 301 https://$server_name$request_uri; # enforce https
}

server {
    listen 443 ssl;
    server_name IPaddress;
    ssl_certificate /etc/nginx/cert.pem;
    ssl_certificate_key /etc/nginx/cert.key;
    # Path to the root of your installation
    root /var/www/nextcloud;
    client_max_body_size 1000M; # set max upload size
    fastcgi_buffers 64 4K;
    rewrite ^/caldav(.*)$ /remote.php/caldav$1 redirect;
    rewrite ^/carddav(.*)$ /remote.php/carddav$1 redirect;
    rewrite ^/webdav(.*)$ /remote.php/webdav$1 redirect;
    index index.php;
    error_page 403 /core/templates/403.php;
    error_page 404 /core/templates/404.php;
    location = /robots.txt {
        allow all;
        log_not_found off;
        access_log off;
    }
    location ~ ^/(?:\.htaccess|data|config|db_structure\.xml|README) {
        deny all;
    }
    location / {
        # The following 2 rules are only needed with webfinger
        rewrite ^/.well-known/host-meta /public.php?service=host-meta last;
        rewrite ^/.well-known/host-meta.json /public.php?service=host-meta-json last;
        rewrite ^/.well-known/carddav /remote.php/carddav/ redirect;
        rewrite ^/.well-known/caldav /remote.php/caldav/ redirect;
        rewrite ^(/core/doc/[^\/]+/)$ $1/index.html;
        try_files $uri $uri/ index.php;
    }
    location ~ \.php(?:$|/) {
        fastcgi_split_path_info ^(.+\.php)(/.+)$;
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_param PATH_INFO $fastcgi_path_info;
        fastcgi_param HTTPS on;
        fastcgi_pass unix:/run/php/php7.0-fpm.sock;
    }
    # Optional: set long EXPIRES header on static assets
    location ~* \.(?:jpg|jpeg|gif|bmp|ico|png|css|js|swf)$ {
         expires 30d;
         # Optional: Don't log access to assets
         access_log off;
    }
}

Adjust the php.ini

sudo nano /etc/php/7.0/fpm/php.ini

Use Ctrl+W to search for the lines below TO disable max_sizes use 0

upload_max_filesize = 2000M
post_max_size = 2000M

Find the the following line:

;cgi.fix_pathinfo=1

remove the preceeding semicolon and set it’s value to 0

cgi.fix_pathinfo=0

Adjust the www.conf

sudo nano /etc/php/7.0/fpm/pool.d/www.conf

Change listen = /var/run/php7-fpm.sock to listen = 127.0.0.1:9000

Adjust the Swapsize

sudo nano /etc/dphys-swapfile

CONF_SWAPSIZE=100 to CONF_SWAPSIZE=512

Restart your pi

sudo reboot

Install Nextcloud

sudo mkdir -p /var/www/nextcloud
sudo wget https://download.nextcloud.com/server/releases/nextcloud-9.0.53.tar.bz2
sudo tar xvf nextcloud-9.0.53.tar.bz2
sudo mv nextcloud/ /var/www/
sudo chown -R www-data:www-data /var/www
rm -rf nextcloud nextcloud-9.0.53.tar.bz2

Mount your drive

Install the following packages

sudo apt-get install ntfs-3g exfat-utils

Create a directory we can mount to

sudo mkdir /media/nextclouddrive

Get your gid, uid and UUID

id -g www-data

id -u www-data

UUID

ls -l /dev/disk/by-uuid

Adjust fstab

sudo nano /etc/fstab

At the bottom paste the following

UUID=F6941E59941E1D25 /media/nextclouddrive auto nofail,uid=33,gid=33,umask=0027,dmask=0027,noatime 0 0

Test if everything is ok

sudo mount -a

If you don’t get any errors reboot

sudo reboot

Now you can open your webbrowser and setup Nextcloud. Please make sure you configure your Data folder below Storage & database

Appendix

If you’ve trouble with large folders and run into a timeout you need to make the following adjustments.

For Nginx + FastCGI (php-fpm), you should try to tweak nginx configuration in this way:

Open:

sudo nano /etc/php/7.0/fpm/php.ini

Set:

max_execution_time = 300

Open :

sudo nano /etc/php/7.0/fpm/pool.d/www.conf

Set:

request_terminate_timeout = 300

Now set the fastcgi_read_timeout

sudo nano /etc/nginx/sites-available/default

Set:

fastcgi_read_timeout 300;

Restart Nginx:

sudo service nginx reload

Mount USB HDD on Raspberry

Tue, 09 Aug 2016 10:00:00 +0000

In this article I want to document how to mount a external HDD device on a Raspberry Pi.

Configure your Pi

sudo raspi-config

Expand Filesystem
Change user password
Change hostname
Set boot to CLI
Set GPU Memory to 16
Update your localisation settings

Update your system

sudo apt-get update && sudo apt-get upgrade && sudo apt-get dist-upgrade

Mount your external HDD

Now we can mount our storage. Please not that I’m using in this tutorial usbstorage, sda1 and as user pi. These are variables which you have to adjust depending on your system configuration and needs.

Prepare the Mount Point

First make a directory where your storage should be mounted.

sudo mkdir /mnt/usbstorage

Set the user permissions

sudo chown -R pi:pi /mnt/usbstorage
sudo chmod -R 775 /mnt/usbstorage

Set all future permissions for the mount point.

sudo setfacl -Rdm g:pi:rwx /mnt/usbstorage
sudo setfacl -Rm g:pi:rwx /mnt/usbstorage

Determine the USB Hard Drive Format

You need to knwo the file system the drive is formatted with

sudo blkid

/dev/mmcblk0p1: SEC_TYPE="msdos" LABEL="boot" UUID="787C-2FD4" TYPE="vfat"
/dev/mmcblk0p2: UUID="3d81d9e2-7d1b-4015-8c2c-29ec0875f762" TYPE="ext4"
/dev/sda1: LABEL="TrekStor" UUID="3d9d92e2-7d1b-4015-8c2c" TYPE="exfat"

Note the TYPE=”exfat” at the end, you will need this for the fstab file.

Now mount the usb stick. If it is NTFS you will need to install some utilities first.

sudo apt-get install ntfs-3g -y

If the drive is exfat install these utilities

sudo apt-get install exfat-utils -y

For all drive types mount the usb with this command, -o insures pi is the owner which should avoid permission issues

sudo mount -o uid=pi,gid=pi /dev/sda1 /mnt/usbstorage

If you get an error use this syntax

sudo mount -t uid=pi,gid=pi /dev/sda1 /mnt/usbstorage

If the mount -t command returns an error then use this syntax

sudo mount uid=pi,gid=pi /dev/sda1 /mnt/usbstorage

Automount the USB Hard Drive

/mnt/usbstorage will be the folder in which you store your media. We want it to be automounted on boot The best way to do this is through the UUID. Get the UUID by using this commmand

sudo ls -l /dev/disk/by-uuid/

You will see some output like this. The UUID you want is formatted like this XXXX-XXXX for the sda1 drive. If the drive is NTFS it can have a longer format like UUID=”BABA3C2CBA3BE413”. Note this UUID, for me it is BA8F-FFE8

total 0
lrwxrwxrwx 1 root root 15 Jan  1  1970 3d81d9e2-7d1b-4015-8c2c-29ec0875f762 -> ../../mmcblk0p2
lrwxrwxrwx 1 root root 15 Jan  1  1970 787C-2FD4 -> ../../mmcblk0p1
lrwxrwxrwx 1 root root 10 Oct 26 21:10 BA8F-FFE8 -> ../../sda1

Now we will edit fstab to mount the USB by UUID on boot

sudo nano /etc/fstab

Add the line in red to the bottom, replace XXXX-XXXX with your UUID and exfat with your type if it is different (e.g. ntfs, vfat, ext4). You may or may not need the quotation marks wrapped around the UID, you do not need quotation marks wrapped around the file system type (ext4, vfat, NTFS etc).

The umask 0002 sets 775 permissions so the pi user and group can read, write and execute files on the external USB drive. To completely eliminate permission issues you can set the umask to 0000 which equals 777 permissions so anybody can read, write and execute. Note that 777 permissions are considered a security risk.

If you have issues here then try replacing uid=pi,gid=pi with just the word defaults (typical for ext4). You can also try replacing the UUID with the /dev/sda1 line.

This is an example for exfat

/dev/mmcblk0p1 /boot vfat defaults 0 2
/dev/mmcblk0p2 / ext4 errors=remount-ro,noatime 0 1

UUID=XXXX-XXXX  /mnt/usbstorage exfat   nofail,uid=pi,gid=pi   0   0

For NTFS, note that it is ntfs and not ntfs-3g

/dev/mmcblk0p1 /boot vfat defaults 0 2
/dev/mmcblk0p2 / ext4 errors=remount-ro,noatime 0 1

UUID=XXXX-XXXX    /mnt/usbstorage    ntfs   nofail,uid=pi,gid=pi    0   0

for ext4 using uid and gid is not recommended so use at your own risk as it could cause issues.

/dev/mmcblk0p1 /boot vfat defaults 0 2
/dev/mmcblk0p2 / ext4 errors=remount-ro,noatime 0 1

UUID=XXXX-XXXX    /mnt/usbstorage    ext4   nofail,uid=pi,gid=pi    0   0

If you get any errors you can replace uid=pi,gid=pi with defaults or remove it entirely

/dev/mmcblk0p1 /boot vfat defaults 0 2
/dev/mmcblk0p2 / ext4 errors=remount-ro,noatime 0 1

UUID=XXXX-XXXX    /mnt/usbstorage    ext4   nofail,defaults    0   0

For using /dev/sda1 and defaults if you have troubles with UUID

/dev/mmcblk0p1 /boot vfat defaults 0 2
/dev/mmcblk0p2 / ext4 errors=remount-ro,noatime 0 1

/dev/sda1    /mnt/usbstorage    ext4   nofail    0   0

Now test if the fstab file works

sudo mount -a

If you didn’t get errors reboot, otherwise try the suggestions above to get it working then mount -a again until it succeeds

sudo reboot

You should be able to access the mounted USB drive and list its contents

cd /mnt/usbstorage
ls

Every time you reboot, the drives will be mounted as long as the UUID remains the same. If you delete the partitions or format the USB hard drive or stick the UUID changes so bear this in mind. You can always repeat the process for additional hard drives in the future.

If you have multiple hard drives you will have to make separate mount points (e.g. /mnt/usbstorage2) for each drive’s partition

Fix Raspberry Pi 2 Mounting Issues

Apparently there is a bug in the Pi 2 that messes up automounting. You can fix it by creating a delay.

Open up the /boot/cmdline.txt files

sudo nano /boot/cmdline.txt

Add this line to the bottom, you can increase this delay if necessary

rootdelay=5

Hit Ctrl+X, Y and Enter to save and exit, then reboot to see if it automounts now. If the Raspberry Pi hard drive still does not automount we can use rc.local

sudo nano /etc/rc.local

Add this lines before the exit line

sleep 30
sudo mount -a
exit

Ctrl+X, Y and Enter to save

Reboot again to test

Appendix

Unmount the disk
```
sudo umount /mnt/usbstorage
```

Use the Raspberry Pi as NAS server

Fri, 08 Jan 2016 15:04:23 +0000

First of all - due to the crapy data throughput of the Raspberry Pi you should not expect high performance data transfer. A 1GB file will take ~20 minutes to be transfered.

That said lets dive directly into the setup.

Prerequisites:

sudo rights on your working station
external hard disks (one or more)
OpenMediaVault image for your Pi

Install OMV OS

Insert the SD card onto your computer
Get the device name of the SD card - should be something like: /dev/disk2

➜  ~ diskutil list
/dev/disk2 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     FDisk_partition_scheme                        *31.9 GB    disk2
   1:             Windows_FAT_32 boot                    58.7 MB    disk2s1
   2:                      Linux                         3.5 GB     disk2s2
   3:                      Linux                         67.1 MB    disk2s3

Open the terminal and open the folder where you downloaded your OMV Os to.
Unzip the file:

gunzip omv_3.0.24_beta_rpi2_rpi3.img.gz

Now you need to unmount your SD card an install the img (be sure you substitue /dev/disk2 with your device name of the SD card):

sudo diskutil unmountDisk /dev/disk2
sudo dd bs=1m if=omv_3.0.24_beta_rpi2_rpi3.img of=/dev/disk2

Put the SD card into your Raspberry Pi and start it - but make sure the external hard disks and the ethernet cable are connected
Now you’ll be prompted with the login:

raspberrypi login: root
Password: openmediavault

Get the IP address of your Raspberry Pi (ifconfig):

root@raspberrypi:~# ifconfig
eth0      Link encap:Ethernet  HWaddr b8:27:eb:f0:ea:18
          inet addr:***.***.*.**  Bcast:***.***.*.***  Mask:***.***.***.*

On your workstation you can open a webbrowser and as url type: http://[your-ip]
The default weblogin is:

Username: admin
Password: openmediavault

The first thing you should do is to change the default password to something secure:

sudo passwd