raspberry pi – Paul Bastide

Raspberry Pi: Setting up backup

I have a Raspberry Pi providing household automation and productivity services – WebDav, Backups and Calendar. I always worry about a jolt of power, a failed byte and something that is unrecoverable. Time for a Backup solution.

I plugged in a USB stick – 64GB, and immediately checked the file system is there and visible as SDA (unmounted).

pi@raspberrypi:~# sudo su - 

root@raspberrypi:~# lsblk 
 NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
 sda           8:0    1 58.2G  1 disk 
 └─sda1        8:1    1 58.2G  1 part 
 mmcblk0     179:0    0 14.9G  0 disk 
 ├─mmcblk0p1 179:1    0 43.9M  0 part /boot
 └─mmcblk0p2 179:2    0 14.8G  0 part /

I check to see which one is assigned to the SD card slot (mmc), I really don’t want to reformat Raspbian. I see the USB stick is on /dev/sda. All of my subsequent commands use /dev/sda as part of the command.

root@raspberrypi:~# parted -ls
Warning: The driver descriptor says the physical block size is 2048 bytes, but Linux says it is 512 bytes.
 Model: JetFlash Transcend 64GB (scsi)
 Disk /dev/sda: 62.5GB
 Sector size (logical/physical): 512B/512B
 Partition Table: unknown
 Disk Flags: 

 Model: SD SC16G (sd/mmc)
 Disk /dev/mmcblk0: 15.9GB
 Sector size (logical/physical): 512B/512B
 Partition Table: msdos
 Disk Flags: 
 Number  Start   End     Size    Type     File system  Flags
  1      4194kB  50.2MB  46.0MB  primary  fat32        lba
  2      50.3MB  15.9GB  15.9GB  primary  ext4

If you don’t see the relevant information on your HD or run into issues formatting the hard-drive, install hdparm. and check with hdparm -r0 /dev/sda .

TIP: I did run into an issue with an ISO written to a USB drive which locks the partition table and makes it unwriteable.

root@raspberrypi:~# apt-get install hdparm
 Reading package lists… Done
 Building dependency tree       
 Reading state information… Done
 The following package was automatically installed and is no longer required:
   realpath
 Use 'apt autoremove' to remove it.
 The following additional packages will be installed:
   powermgmt-base
 Suggested packages:
   apmd
 The following NEW packages will be installed:
   hdparm powermgmt-base
 0 upgraded, 2 newly installed, 0 to remove and 148 not upgraded.
 Need to get 114 kB of archives.
 After this operation, 278 kB of additional disk space will be used.
 Do you want to continue? [Y/n] y
 Get:1 http://raspbian.mirror.constant.com/raspbian stretch/main armhf hdparm armhf 9.51+ds-1+deb9u1 [105 kB]
 Get:2 http://raspbian-us.ngc292.space/raspbian stretch/main armhf powermgmt-base all 1.31+nmu1 [9,240 B]
 Fetched 114 kB in 0s (120 kB/s)           
 Selecting previously unselected package hdparm.
 (Reading database … 135688 files and directories currently installed.)
 Preparing to unpack …/hdparm_9.51+ds-1+deb9u1_armhf.deb …
 Unpacking hdparm (9.51+ds-1+deb9u1) …
 Selecting previously unselected package powermgmt-base.
 Preparing to unpack …/powermgmt-base_1.31+nmu1_all.deb …
 Unpacking powermgmt-base (1.31+nmu1) …
 Setting up powermgmt-base (1.31+nmu1) …
 Setting up hdparm (9.51+ds-1+deb9u1) …
 Processing triggers for man-db (2.7.6.1-2) …
Preparing to unpack …/hdparm_9.51+ds-1+deb9u1_armhf.deb …

Unpacking hdparm (9.51+ds-1+deb9u1) …

Selecting previously unselected package powermgmt-base.

Preparing to unpack …/powermgmt-base_1.31+nmu1_all.deb …

Unpacking powermgmt-base (1.31+nmu1) …

Setting up powermgmt-base (1.31+nmu1) …

Setting up hdparm (9.51+ds-1+deb9u1) …

Processing triggers for man-db (2.7.6.1-2) …

root@raspberrypi:~# hdparm -r0 /dev/sda
 /dev/sda:
  setting readonly to 0 (off)
  readonly      =  0 (off)

Now that I know the drive is writeable, I need to create the partition. I used

cfdisk

Navigate through the menu and select the maximum size

                                                                                        Disk: /dev/sda
                                                                     Size: 58.2 GiB, 62495129600 bytes, 122060800 sectors
                                                                              Label: dos, identifier: 0x00000000

    Device                    Boot                               Start                      End                  Sectors                Size               Id Type
>>  /dev/sda1                                                     2048                122060799                122058752               58.2G               83 Linux

Once you see “Syncing disks.”, you can format the disk. I formatted the partition sda1 with ext4 (I may want to encrypt in the future). Unmount and then format.

root@raspberrypi:~# umount /dev/sda1
root@raspberrypi:~# mkfs.ext4 /dev/sda1
mke2fs 1.43.4 (31-Jan-2017)
Found a dos partition table in /dev/sda1
Proceed anyway? (y,N) y
Creating filesystem with 2828032 4k blocks and 707136 inodes
Filesystem UUID: 363f1b4a-b0f5-4c7b-bf91-66f3823032d6
Superblock backups stored on blocks: 
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208

Allocating group tables: done 
Writing inode tables: done 
Creating journal (16384 blocks): done
Writing superblocks and filesystem accounting information: done

root@raspberrypi:~#

Make the backup directory, edit fstab and mount the directory. Insert into fstab with your uuid “UUID=363f1b4a-b0f5-4c7b-bf91-66f3823032d6 /backups auto nosuid,nodev,nofail 0 0
” The second to last avoids backup and the last one enables fsck on reboot.

root@raspberrypi:~# blkid 
/dev/mmcblk0p1: LABEL="boot" UUID="DDAB-3A15" TYPE="vfat" PARTUUID="b53687e8-01"
/dev/mmcblk0p2: LABEL="rootfs" UUID="5fa1ec37-3719-4b25-be14-1f7d29135a13" TYPE="ext4" PARTUUID="b53687e8-02"
/dev/mmcblk0: PTUUID="b53687e8" PTTYPE="dos"
/dev/sdb: UUID="363f1b4a-b0f5-4c7b-bf91-66f3823032d6" TYPE="ext4"

root@raspberrypi:~# mkdir /backups 
root@raspberrypi:~# vim /etc/fstab
root@raspberrypi:~# mount -a 
root@raspberrypi:~# mount 
UUID=363f1b4a-b0f5-4c7b-bf91-66f3823032d6 /backups auto nosuid,nodev,nofail 0 0

You should see backups listed. (Note: I bricked my Raspberry Pi with a bad FSTAB entry, and mounted it on my Mac using Paragon and removed the bad fstab entry. )

Update Crontab with daily backups.

crontab -e

Setup an editor for crontab.

root@raspberrypi:~# crontab -e
no crontab for root - using an empty one

Select an editor. To change later, run 'select-editor'.
1. /bin/ed
2. /bin/nano <---- easiest
3. /usr/bin/vim.basic
4. /usr/bin/vim.tiny

Choose 1-4 [2]: 3
crontab: installing new crontab

I added this line and copied it to /etc/cron.daily/

0 1 * * * /usr/bin/rsync -r /data/ /backups/`date +%w-%A`

crontab -l > pi-backup
mv /root/pi-backup /etc/cron.daily 
run-parts /etc/cron.daily

Note, I had to add #!/bin/bash after I copied and remove the timing of the job.

Also, check to see if rsync is installed with which rsync and apt-get install rsync.

This enables backups on a daily basis rotating every 7 days.

Check back on the following day to see your backups

root@raspberrypi:~# /usr/bin/rsync -r /data/ /backups/`date +%w-%A`
root@raspberrypi:~# find /backups
/backups
/backups/lost+found
/backups/0-Sunday
/backups/0-Sunday/startup.sh

Good luck, I hope this helps you with your Raspberry Pi.

References

HDParam https://askubuntu.com/a/138051
Formatting in Debian https://www.thomas-krenn.com/en/wiki/Hard_Disk_Formatting/Partitioning_and_Mounting_in_Debian_Linux
Rsync http://www.mikerubel.org/computers/rsync_snapshots/
Fstab https://wiki.debian.org/fstab
Rsync Trick https://stackoverflow.com/questions/29784625/how-do-i-rotate-daily-backups-using-rsync
(If you run into cron issues) https://askubuntu.com/questions/216692/where-is-the-user-crontab-stored
CronTab Test https://superuser.com/questions/402781/what-is-run-parts-in-etc-crontab-and-how-do-i-use-it

2019-07-21

Cups and Raspberry Pi – How to setup your print server

Print Server is one of those things that makes life easier. I hooked up my Raspberry Pi and a Docker image in order to have a CUPS server and the Bonjour configuration.

Login to the Raspberry Pi and switch to root (sudo -s or sudo su –)

Check lsusb to see if you can see the USB device.

 root@raspberrypi:~# lsusb 
 Bus 001 Device 005: ID 046d:c52b Logitech, Inc. Unifying Receiver 
 Bus 001 Device 004: ID 8564:1000 Transcend Information, Inc. JetFlash
 Bus 001 Device 006: ID 0424:7800 Standard Microsystems Corp.
 Bus 001 Device 003: ID 0424:2514 Standard Microsystems Corp. USB 2.0 Hub 
 Bus 001 Device 002: ID 0424:2514 Standard Microsystems Corp. USB 2.0 Hub
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
 root@raspberryp:~#

If you don’t see it, check to see that the device is properly plugged in.

Check again, and you’ll see your manufacture for your printer listed. (highlighted in red)

 root@raspberrypi:~# lsusb 
 Bus 001 Device 007: ID 03f0:7411 Hewlett-Packard 
 Bus 001 Device 005: ID 046d:c52b Logitech, Inc. Unifying Receiver
 Bus 001 Device 004: ID 8564:1000 Transcend Information, Inc. JetFlash
 Bus 001 Device 006: ID 0424:7800 Standard Microsystems Corp. 
 Bus 001 Device 003: ID 0424:2514 Standard Microsystems Corp. USB 2.0 Hub
 Bus 001 Device 002: ID 0424:2514 Standard Microsystems Corp. USB 2.0 Hub
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
 root@raspberrypi:~#

Further, I am able to see the exact model that is connected:

 root@raspberrypi:~# lsusb -v | grep -A 20 Hewlett-Packard 
 Bus 001 Device 007: ID 03f0:7411 Hewlett-Packard 
 Device Descriptor:
   bLength                18
   bDescriptorType         1
   bcdUSB               2.00
   bDeviceClass            0 (Defined at Interface level)
   bDeviceSubClass         0 
   bDeviceProtocol         0 
   bMaxPacketSize0        64
   idVendor           0x03f0 Hewlett-Packard
   idProduct          0x7411 
   bcdDevice            1.00
   iManufacturer           1 HP
   iProduct                2 Photosmart C4600 series
   iSerial                 3 |||MASKED|||MASKED|||MASKED|||

I’ll use these details downstream in order to install and use the HP driver.

If you still don’t see the USB device, you should check dmesg and look at the pattern for USB.

 [3077006.701281] usb 1-1.2: new high-speed USB device number 7 using dwc_otg
 [3077006.831891] usb 1-1.2: New USB device found, idVendor=03f0, idProduct=7411 
 [3077006.831908] usb 1-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
 [3077006.831917] usb 1-1.2: Product: Photosmart C4600 series
 [3077006.831925] usb 1-1.2: Manufacturer: HP

If you don’t see it, unplug and plug the device back in.

You can also use usb-devices

 T:  Bus=01 Lev=02 Prnt=02 Port=01 Cnt=02 Dev#=  7 Spd=480 MxCh= 0
 D:  Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1 
 P:  Vendor=03f0 ProdID=7411 Rev=01.00
 S:  Manufacturer=HP
 S:  Product=Photosmart C4600 series
 S:  SerialNumber=<<>><<>>
 C:  #Ifs= 4 Cfg#= 1 Atr=c0 MxPwr=2mA
 I:  If#= 0 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=cc Prot=00 Driver=(none)
 I:  If#= 1 Alt= 0 #EPs= 2 Cls=07(print) Sub=01 Prot=02 Driver=usblp 
 I:  If#= 2 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=ff Driver=(none)
 I:  If#= 3 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50 Driver=usb-storage

Copy the Dockerfile and the cupsd file locally (in the folder etc-cups/cupsd.conf). Cupsd is configured to listen on all interfaces: Listen 0.0.0.0:631

Build the Docker image (based off of this image https://github.com/a0js/rpi-cups and uses a different base image https://hub.docker.com/r/arm32v7/debian/ ) docker build -t cups-pi/cups-pi .

 root@raspberrypi:/data/cups-printer# docker build -t cups-pi/cups-pi . 
 Sending build context to Docker daemon  8.192kB
 Step 1/9 : FROM arm32v7/debian:latest
  ---> 64b4748d266b
 Step 2/9 : ENV DEBIAN_FRONTEND noninteractive
  ---> Using cache
  ---> 38ebdf2f5bb6
 Step 3/9 : RUN apt-get update && apt-get install -y   sudo   locales   whois   cups   cups-client   cups-bsd   printer-driver-all   hpijs-ppds   hp-ppd   hplip
  ---> Using cache
  ---> 0b5b9eac6cef
 Step 4/9 : RUN sed -i "s/^#\ \+\(en_US.UTF-8\)/\1/" /etc/locale.gen && locale-gen en_US en_US.UTF-8
  ---> Using cache
  ---> fd55737901b8
 Step 5/9 : ENV LANG=en_US.UTF-8   LC_ALL=en_US.UTF-8   LANGUAGE=en_US:en
  ---> Using cache
  ---> d6cd104b40ec
 Step 6/9 : RUN useradd   --groups=sudo,lp,lpadmin   --create-home   --home-dir=/home/print   --shell=/bin/bash   --password=$(mkpasswd print)   print   && sed -i '/%sudo[[:space:]]/ s/ALL[[:space:]]*$/NOPASSWD:ALL/' /etc/sudoers   && apt-get clean   && rm -rf /var/lib/apt/lists/*   && mkdir /var/lib/apt/lists/partial
  ---> Using cache
  ---> 156dcd02e397 
 Step 7/9 : COPY etc-cups/cupsd.conf /etc/cups/cupsd.conf
  ---> e1624a96970e
 Step 8/9 : EXPOSE 631
  ---> Running in a16705e0f3d9
 Removing intermediate container a16705e0f3d9
  ---> 60758af63011
 Step 9/9 : ENTRYPOINT ["/usr/sbin/cupsd", "-f"]
  ---> Running in add02d421ea9
 Removing intermediate container add02d421ea9
  ---> 8c6fe42423c8
 Successfully built 8c6fe42423c8
 Successfully tagged cups-pi/cups-pi:ltest

Run the Docker image to start the print server

root@raspberrypi:/data/cups-printer# docker run -d -p 631:631 --privileged -v /var/run/dbus:/var/run/dbus -v /dev/bus/usb:/dev/bus/usb -h myhostm.mydomain.org --name cupsm cups-pi/cups-pi:latest
fe6d9bc34c66911f05b011ef185fce95947efb965e90ef2b4ecdd0f1c3a32d68

It’s important to use the -h if you want to remotely access via hostname.

Login to the console http://myserver.mydomain.org:631/admin using print:print

Click Add Printer

Select a local printer “HP Photosmart C4600 series (HP Photosmart C4600 series)”

Click Continue

Click Share This Printer

Click Continue

Click Add Printer

Select Media Type – Letter

Click Set Default Options

Click Add

When you find the Printer, you can add the printer

You now have an image ready for use with a CUPS printer. (If you rebuild, you may have to re-setup the default printer…. Just warning you ahead of time). You can always look at http://myhost.mydomain.org:631/printers/HP_Photosmart_C4600_series

If you need to connect to the console, you can look at the docker ps

root@raspberrypi:/data/cups-printer# docker ps
CONTAINER ID        IMAGE                    COMMAND                CREATED             STATUS              PORTS                                    NAMES
fe6d9bc34c66        cups-pi/cups-pi:latest   "/usr/sbin/cupsd -f"   5 minutes ago       Up 5 minutes        0.0.0.0:631->631/tcp                     cups

Extract the CONTAINER ID, and look at the /bin/sh

root@raspberrypi:/data/cups-printer# docker exec
-i -t fe6d9bc34c66 /bin/sh

Then look at the /var/log/cups files, specifically the error_log

	FROM arm32v7/debian:latest

	ENV DEBIAN_FRONTEND noninteractive

	RUN apt-get update && apt-get install -y \
	sudo \
	locales \
	whois \
	cups \
	cups-client \
	cups-bsd \
	printer-driver-all \
	hpijs-ppds \
	hp-ppd \
	hplip

	RUN sed -i "s/^#\ \+$en_US.UTF-8$/\1/" /etc/locale.gen \
	&& locale-gen en_US en_US.UTF-8

	ENV LANG=en_US.UTF-8 \
	LC_ALL=en_US.UTF-8 \
	LANGUAGE=en_US:en

	RUN useradd \
	--groups=sudo,lp,lpadmin \
	--create-home \
	--home-dir=/home/print \
	--shell=/bin/bash \
	--password=$(mkpasswd print) \
	print \
	&& sed -i '/%sudo[[:space:]]/ s/ALL[[:space:]]*$/NOPASSWD:ALL/' /etc/sudoers \
	&& apt-get clean \
	&& rm -rf /var/lib/apt/lists/* \
	&& mkdir /var/lib/apt/lists/partial

	COPY etc-cups/cupsd.conf /etc/cups/cupsd.conf
	EXPOSE 631
	ENTRYPOINT ["/usr/sbin/cupsd", "-f"]

view raw Dockerfile hosted with

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	#
	#
	# Sample configuration file for the CUPS scheduler. See "man cupsd.conf" for a
	# complete description of this file.
	#

	# Log general information in error_log - change "warn" to "debug"
	# for troubleshooting...
	LogLevel warn

	# Deactivate CUPS' internal logrotating, as we provide a better one, especially
	# LogLevel debug2 gets usable now
	MaxLogSize 0

	# Listen to all
	Port 631
	#Listen /var/run/cups/cups.sock
	Listen myhost.mydomain.org:631

	# Show shared printers on the local network.
	Browsing On
	BrowseLocalProtocols dnssd

	# Default authentication type, when authentication is required...
	DefaultAuthType Basic
	DefaultEncryption IfRequested

	# Web interface setting...
	WebInterface Yes

	# Restrict access to the server...
	<Location />
	Order allow,deny
	Allow all
	</Location>

	# Restrict access to the admin pages...
	<Location /admin>
	Order allow,deny
	Allow all
	</Location>

	# Restrict access to configuration files...
	<Location /admin/conf>
	AuthType Default
	Require user @SYSTEM
	Order allow,deny
	Allow all
	</Location>

	# Set the default printer/job policies...
	<Policy default>
	# Job/subscription privacy...
	JobPrivateAccess default
	JobPrivateValues default
	SubscriptionPrivateAccess default
	SubscriptionPrivateValues default

	# Job-related operations must be done by the owner or an administrator...
	<Limit Create-Job Print-Job Print-URI Validate-Job>
	Order deny,allow
	</Limit>

	<Limit Send-Document Send-URI Hold-Job Release-Job Restart-Job Purge-Jobs Set-Job-Attributes Create-Job-Subscription Renew-Subscription Cancel-Subscription Get-Notifications Reprocess-Job Cancel-Current-Job Suspend-Current-Job Resume-Job Cancel-My-Jobs Close-Job CUPS-Move-Job CUPS-Get-Document>
	Require user @OWNER @SYSTEM
	Order deny,allow
	</Limit>

	# All administration operations require an administrator to authenticate...
	<Limit CUPS-Add-Modify-Printer CUPS-Delete-Printer CUPS-Add-Modify-Class CUPS-Delete-Class CUPS-Set-Default CUPS-Get-Devices>
	AuthType Default
	Require user @SYSTEM
	Order deny,allow
	</Limit>

	# All printer operations require a printer operator to authenticate...
	<Limit Pause-Printer Resume-Printer Enable-Printer Disable-Printer Pause-Printer-After-Current-Job Hold-New-Jobs Release-Held-New-Jobs Deactivate-Printer Activate-Printer Restart-Printer Shutdown-Printer Startup-Printer Promote-Job Schedule-Job-After Cancel-Jobs CUPS-Accept-Jobs CUPS-Reject-Jobs>
	AuthType Default
	Require user @SYSTEM
	Order deny,allow
	</Limit>

	# Only the owner or an administrator can cancel or authenticate a job...
	<Limit Cancel-Job CUPS-Authenticate-Job>
	Require user @OWNER @SYSTEM
	Order deny,allow
	</Limit>

	<Limit All>
	Order deny,allow
	</Limit>
	</Policy>

	# Set the authenticated printer/job policies...
	<Policy authenticated>
	# Job/subscription privacy...
	JobPrivateAccess default
	JobPrivateValues default
	SubscriptionPrivateAccess default
	SubscriptionPrivateValues default

	# Job-related operations must be done by the owner or an administrator...
	<Limit Create-Job Print-Job Print-URI Validate-Job>
	AuthType Default
	Order deny,allow
	</Limit>

	<Limit Send-Document Send-URI Hold-Job Release-Job Restart-Job Purge-Jobs Set-Job-Attributes Create-Job-Subscription Renew-Subscription Cancel-Subscription Get-Notifications Reprocess-Job Cancel-Current-Job Suspend-Current-Job Resume-Job Cancel-My-Jobs Close-Job CUPS-Move-Job CUPS-Get-Document>
	AuthType Default
	Require user @OWNER @SYSTEM
	Order deny,allow
	</Limit>

	# All administration operations require an administrator to authenticate...
	<Limit CUPS-Add-Modify-Printer CUPS-Delete-Printer CUPS-Add-Modify-Class CUPS-Delete-Class CUPS-Set-Default>
	AuthType Default
	Require user @SYSTEM
	Order deny,allow
	</Limit>

	# All printer operations require a printer operator to authenticate...
	<Limit Pause-Printer Resume-Printer Enable-Printer Disable-Printer Pause-Printer-After-Current-Job Hold-New-Jobs Release-Held-New-Jobs Deactivate-Printer Activate-Printer Restart-Printer Shutdown-Printer Startup-Printer Promote-Job Schedule-Job-After Cancel-Jobs CUPS-Accept-Jobs CUPS-Reject-Jobs>
	AuthType Default
	Require user @SYSTEM
	Order deny,allow
	</Limit>

	# Only the owner or an administrator can cancel or authenticate a job...
	<Limit Cancel-Job CUPS-Authenticate-Job>
	AuthType Default
	Require user @OWNER @SYSTEM
	Order deny,allow
	</Limit>

	<Limit All>
	Order deny,allow
	</Limit>
	</Policy>

	#
	#

view raw etc-cups---cupsd.conf hosted with

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Reference

List USB Devices Linux https://linuxhint.com/list-usb-devices-linux/

Dockerfile https://github.com/a0js/rpi-cups https://github.com/ryansch/docker-cups-rpi https://github.com/aadl/docker-cups/blob/master/2.2.1/Dockerfile

Arm 7 https://hub.docker.com/r/arm32v7/debian/

Cupsd.conf https://raw.githubusercontent.com/a0js/rpi-cups/master/etc-cups/cupsd.conf https://wiki.archlinux.org/index.php/CUPS/Printer_sharing

SSL / Advanced Configuration http://chschneider.eu/linux/server/cups.shtml http://192.168.86.176:631/admin (use IP if receiving a bad request indicator to the admin interface)

Advanced Ubuntu Configuration https://help.ubuntu.com/lts/serverguide/cups.html.en

2019-04-21

Raspberry Pi – Part IV – Simple Wiring Test

I am plugging away working with my Pi. I went back to the Ada Fruit Site, and started working on one of the tutorials from the part I purchased – https://www.adafruit.com/products/2125 I want to be able to demonstrate a simple wiring with my Pi works.

I selected Email Notifier. I read through it, and realized I needed to convert it to work for the B+ model. The pi4j website has a nice diagram for the pins http://pi4j.com/images/j8header-b-plus-large.png and I simplified the test a bit.

	#!/usr/bin/env python

	#REF https://learn.adafruit.com/raspberry-pi-e-mail-notifier-using-leds/python-script
	import RPi.GPIO as GPIO
	import time

	GPIO.setwarnings(True)
	GPIO.setmode(GPIO.BCM)
	GREEN_LED = 23
	GPIO.setup(GREEN_LED, GPIO.OUT)

	def loop():
	GPIO.output(GREEN_LED, True)
	time.sleep(100)

	if __name__ == '__main__':
	try:
	print 'Press Ctrl-C to quit.'
	while True:
	loop()

	finally:
	GPIO.cleanup()

view raw testPi.py hosted with

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I launched the simple python file

pi@seconds ~ $ sudo python testPi.py

Pi with a Green Light - Using Python — Pi with a Green Light – Using Python

I added the pi4j dependency to my maven pom

<dependency>
    <groupId>com.pi4j</groupId>
    <artifactId>pi4j-core</artifactId>
   <version>1.0</version>
</dependency>

I create a servlet which replicated the same code from before (GPIO).

	package bastide.pi.bbq;

	import java.io.IOException;

	import javax.servlet.ServletException;
	import javax.servlet.annotation.WebServlet;
	import javax.servlet.http.HttpServlet;
	import javax.servlet.http.HttpServletRequest;
	import javax.servlet.http.HttpServletResponse;

	import com.pi4j.io.gpio.GpioController;
	import com.pi4j.io.gpio.GpioFactory;
	import com.pi4j.io.gpio.GpioPinDigitalOutput;
	import com.pi4j.io.gpio.PinMode;
	import com.pi4j.io.gpio.PinState;
	import com.pi4j.io.gpio.RaspiPin;

	/**
	* Servlet implementation class Control
	*/
	@WebServlet("/Control")
	public class Control extends HttpServlet {
	private static final long serialVersionUID = 1L;

	/**
	* @see HttpServlet#HttpServlet()
	*/
	public Control() {
	super();
	// TODO Auto-generated constructor stub
	}

	/**
	* simple processing of the status flag for the servlet
	* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	*/
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
	String param = request.getParameter("status");

	if(param!=null && !param.isEmpty()){
	boolean status = Boolean.parseBoolean(param);

	final GpioController gpio = GpioFactory.getInstance();
	// RaspiPin.GPIO_23);

	final GpioPinDigitalOutput pin = gpio.provisionDigitalOutputPin(RaspiPin.GPIO_23, "MyLED", PinState.HIGH);

	gpio.setMode(PinMode.DIGITAL_OUTPUT, pin);

	System.out.println("--> GPIO state should be: " + status);
	}
	}

	}

view raw Control.java hosted with

by GitHub

I copied the war file to the local webapp directory, and restarted jetty

pi@seconds /opt/jetty/web/bbq/webapps $ sudo cp ~/pi.webapp.war ./
pi@seconds /opt/jetty/web/bbq/webapps $ sudo chown jetty:jetty pi.webapp.war
pi@seconds /opt/jetty/web/bbq/webapps $ sudo /etc/init.d/jetty restart

Refer to https://wiki.eclipse.org/Jetty/Howto/Deploy_Web_Applications and I did have to add –module=jsp to the start.ini for my web configuration.

I hit the servlet – http://192.168.1.200/pi.webapp/Control?status=true

Which makes sense, since “Software using the Pi4J library must be run with ROOT level permissions.” (actually it doesn’t since I am running as root)…

Issues remain. I’ll tackle them on a different day … Part 5 …

2015-04-23

Raspberry Pi – Part III – Setting up Jetty

The Raspberry Pi is a device that has so many options open: You can extend the hardware. You can extend the software. I choose to tackle extending the software to start, so I can get the experience that I want setup, and running on the device. The experience I am after is the web interface to control my Raspberry Pi.

For a Java developer, I conclude that a lightweight interface hosted on a Jetty server is probably easiest. The Jetty server is a 12.9M download and 30M expanded. It’s also used frequently in devices, and why reinvent the wheel, use the approach that Industry is using. Jetty is designed for a small memory footprint. (I did consider using Tomcat Embedded, and came to the conclusion I’d probably want to many features.)

I downloaded the Jetty archive to my local user’s directory. Note, since I want to just use jetty.zip I’m renaming the output file with wget -O.

wget -O jetty.zip http://download.eclipse.org/jetty/stable-9/dist/jetty-distribution-9.2.10.v20150310.zip

I make a directory for the application server, and move over jetty.zip to that directory.

sudo mkdir -p /opt/jetty
sudo mv jetty.zip /opt/jetty

Next I launched into the sudoers root shell, and extract the Jetty archive. I decided to move it into the runtime folder, so I can have an easy place to backup from. (Remove the extra space from the .zip)

sudo -s 
cd /opt/jetty
unzip jetty.zip
mv jetty-distribution-9.2.10.v20150310/ runtime
rm jetty.zip

Next, I wanted to setup Jetty as a service, and check that Jetty starts

cp runtime/bin/jetty.sh /etc/init.d/jetty
echo JETTY_HOME=`pwd`/runtime > /etc/default/jetty
service jetty start
Starting Jetty: . . . OK Sun Apr 12 15:38:40 UTC 2015
service jetty stop
Stopping Jetty: OK

Next, I want to automatically start Jetty with the right runlevels

update-rc.d jetty defaults

I want to configure Jetty to run with a set user jetty.

mkdir -p /opt/jetty/web/bbq
mkdir -p /opt/jetty/temp
useradd --user-group --shell /bin/false --home-dir /opt/jetty/temp jetty

There is a base configuration that needs to be setup the base site.

cd /opt/jetty/web/bbq
java -jar /opt/jetty/runtime/start.jar --add-to-start=deploy,http,logging

Next, edit the default port value.

vi start.ini

## HTTP port to listen on
jetty.port=80

Finally, I wrap the configuration of the jetty service and app.

chown -R jetty:jetty /opt/jetty
echo "JETTY_HOME=/opt/jetty/runtime" > /etc/default/jetty
echo "JETTY_BASE=/opt/jetty/web/bbq" >> /etc/default/jetty
echo "TMPDIR=/opt/jetty/temp" >> /etc/default/jetty

A good check is to look at service jetty status, and confirm the settings, and then restart your Raspberry Pi. I did find that the startup time was significantly effected by the additional service. ( +25 seconds from the original 15)

Navigate to http://192.168.1.200/ (or whatever IP you have used) and confirm the page loads Jetty. If you see a 404, you’re off and ready for the next phase. (as am I)

2015-04-12

Raspberry Pi – Part II – Get Up and Going with Java

In recent weeks, I haven’t revisited the Raspberry Pi – Running, Vacation, Work have conspired to keep me away from hobby project.

I’ve stared at the parts long enough, and decide to plug the Raspberry Pi base into the wired network. I plugged in the Raspberry Pi into the Power outlet, and I got the Red Light. I logged into my router to see if the Pi picked up the Raspberry Pi, and I found the IP from my routers IP reservations table. I was able to SSH into the Pi and quickly check the release version ( cat issue ) – Raspbian GNU/Linux 7 \n \l.

I turned on the SSH server using sudo raspi-config and the advanced options.

The first thing I thought – Upgrade / Update to get the latest environment for the Raspberry Pi. It’s a good start – always good to be up-to-date. Per the documentation, it may be necessary to run – sudo apt-get clean.

sudo apt-get upgrade
sudo apt-get update

The raspi-config is another item that may need to be updated. The update goes out and queries for the latest raspi-config, installs and relaunches the raspi-config.

sudo raspi-config
Select Option 8 - Advanced Options
Selection Option A0 - Update 
Select Yes

Next, I looked updated the Java version. From reading the documentation, the next versions of the Pi are going to automatically include the Java installs.

sudo apt-get update && sudo apt-get install oracle-java7-jdk

I grabbed the Pi4J project jar files. The Pi4J is an opensource project which has some great details on PINOUT and boilerplate java code to access the underlying pin readouts. I ran some quick code to get the latest snapshot installed.

wget http://get.pi4j.com/download/pi4j-1.1-SNAPSHOT.deb
sudo dpkg -i pi4j-1.1-SNAPSHOT.deb

Pi4J is also installed on the Sonatype repositories and developed on GitHub. Pi4J includes a script for managing updates. It’s very convenient with the Apache 2.0 License.

I was ready run a sample program – Get Sample, Compile and Run.

wget https://raw.githubusercontent.com/Pi4J/pi4j/master/pi4j-example/src/main/java/ListenGpioExample.java
pi4j ListenGpioExample.java
pi4j -run ListenGpioExample

Eventually, I am going to get to the point where I use the diagram from Pi4j. The future efforts are going to take some time to get to – This step was the right step in the direction I want to go. BBQ Champion.

2015-04-05

Tag: raspberry pi

Raspberry Pi: Setting up backup

Cups and Raspberry Pi – How to setup your print server

Raspberry Pi – Part IV – Simple Wiring Test

Raspberry Pi – Part III – Setting up Jetty

Raspberry Pi – Part II – Get Up and Going with Java