Configuring Apache Maven to build an integrated .jar file took a little research, especially when building with NetBeans.. but it can be done with a little hand editing.
NOTE: Project using this example can be forked/pulled from: IngeniiCode/AvMet
Setting up the basic POM
My project originated as a NetBeans nbproject, but I wanted to convert it over to Maven for a variety of reasons, not the least of which was standardization. To do this I created a dummy Maven project, copied the pom.xml and reconfigured my project. There are many tutorials on that, so I won’t cover that here; but I will cover the pom.xml itself for reference to others, as well as myself.
This block defines the most basic properties of the application. I’m including the bounding block here one more time just for continuity / reference; even though all blocks are within this bounding block. The ellipsis ( […] ) is not part of the package.. it’s only denoting that there is more of pom than just this section.
For the current iteration of this project, I am importing the JDBC library for accessing SQLite database. This is a fairly heavy-weight chunk of code (resulting jar is over 6 MB). Before using the Maven configuration, project simply included the current copy of the jar. That was OK for a Proof of Concept but, bad for security patching, and keeping updates integrated when they are released. Your own Maven version handling scheme will of course dictate when/if you define later updates.. but this will get you started.
This configuration is latest as of time time of this was originally published (2-NOV-2017).
Finally, the build block will determine how your jar(s) are built.
This configuration will end up generating two Jars (as of original publishing date, the version number was 0.1.0). AvMet-0.1.0.jar is the stripped Jar, and to execute will require the other supporting jars to be available in a ‘lib/’ sub directory. The other jar, AvMet.jar is the integrated (fat) executable jar.
74382 Nov 2 10:57 target/AvMet-0.1.0.jar
6708128 Nov 2 10:57 target/AvMet.jar
This build block will create those two executables. To prevent Maven from appending the string ‘jar-with-dependencies’ to your combined executable, the option ‘<appendAssemblyId>false</appendAssemblyId>’ must be defined in your build configuration.
To create an integrated (single) jar, this ‘<goals>’ block must be defined:
<goals>
<goal>single</goal>
</goals>
In addition, to generate a specific final jar name (such as not without the version number), the ‘<finalName>${project.name}</finalName>’ tag will enable that action.
This is what my Maven build block looks like:
<build>
<plugins>
<plugin>
<!-- Build an executable JAR -->
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>3.0.2</version>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<classpathPrefix>lib/</classpathPrefix>
<mainClass>com.ingeniigroup.stratux.AvMet.AvMet</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
<plugin>
<!-- Build a *fat* executable JAR -->
<artifactId>maven-assembly-plugin</artifactId>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
<configuration>
<!-- tell plugin to NO addpend the descriptionRef into target filename -->
<appendAssemblyId>false</appendAssemblyId>
<!-- define the final assembly name -->
<finalName>${project.name}</finalName>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<mainClass>com.ingeniigroup.stratux.AvMet.AvMet</mainClass>
</manifest>
</archive>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
</plugin>
</plugins>
</build>
Conclusion
One you have a good pom.xml setup, you can build run within NetBeans and end up with an integrated executable that will run with this simple command path:
Following my initial vanilla setup of STRATUX, I decided to make some networking and file system modifications to turn it into a fix (ground) monitoring station.
The initial effort was quite successful; that is until I ran out of disk space and during my cleanup effort accidentally wrecked the source tree, rendering it mostly inoperable. So, I’m taking that opportunity to re-document the setup process I used to accomplish the following:
The first step was performing a default STRATUX install to a micro SD card. I selected a 16GB card for this project, but Stratux will run on anything down to 4 GB, based on what I observed with the default file system (default size is under 2GB).
I won’t repeat the installation instruction here, since they might have changed since this article was written. The instructions I used, and link to the latest Pi Image are located here: [ STRATUX.me ]
Preliminary Work
Once the card was imaged, I plugged in an HDMI cable, keyboard, mouse and Ethernet cable to start work.
Once powered up and the boot sequence completes, your are challenged with a simple login prompt. The initial login is: pi and the password is raspberry.
Once you login, you’ll see this welcome screen (sorry for the crappy photo.. if I can figure out how to PiP the HDMI output to my Mac to snap a good screen shot, I’ll re-do this!
You will WANT to change that default password first!
Changing Default Password
Switch user to root and change the pi user’s password. You do not NEED to be root to change your own password, but we’ll need to be root from here on out.. and why not just do it that way?
pi@raspberrypi: sudo su -
root@raspberrypi: passwd pi
Enter new UNIX password: enter your password here
Retype new UNIX password: re-enter your password here
Enable eth0 for wired LAN
Next step involves enabling eth0 and turning on it’s DHCP setting. Once this is complete, it should be possible to SSH into the pi and continue the modifications from your ‘master’ computer.
root@raspberrypi:~# cd /etc/network
root@raspberrypi:~# vi interfaces
At the top of the file you will see the line auto lo, below that add the following ‘auto eth0’. Then below the line iface lo inet loopback, add the line ‘iface eth0 inet dhcp’
auto lo auto eth0
iface lo inet loopback iface eth0 inet dhcp
...
At this point I do not plan to try enable the WiFi, first want to verify that eth0 will come up with a LAN address.
Close the edited file, and then restart networking, then run ifconfig to verify that eth0 is up with and assigned IP address (my local DHCP range is 10.10.1.10 – 1.50).
At this point you should be able to ssh into the machine directly and continue the work. From your main computer (hopefully a *NIX variant), open up a shell and ssh to the Pi. You will receive a password challenge:
IngeniiGroup:STRATUX$ ssh pi@10.10.0.11
pi@10.10.0.11's password: _enter your password_
If the login was successful, you will see this welcome banner:
Next, will be the modifications to disable the adhoc network and enable local WiFi connectivity.
Disable adhoc ‘stratux’ WiFi
Now that you are logged into the Stratux via ssh, assume root user and then cd to the networking directory again:
pi@raspberrypi:~ $ sudo su -
root@raspberrypi:~# cd /etc/network
root@raspberrypi:~# vi interfaces
Now, this time the interfaces file will be heavily modified to configure the eth0 and wlan0, along with some rational routing, using the ‘metric’ setting to prioritize route assignments.
Once again, at the top of the file another new line will be added:
auto lo auto wlan0
auto eth0
iface lo inet loopback
Then replacing the entire eth0 and wlan0 entries with the following block of text. NOTE: The line `wireless-power off` will disable the power management for WiFi. If this is not done, I have found that the chip will shut down after a couple of hours and the device will become unreachable via wifi, until it’s rebooted. This discovery took no short amount of time to discovery and remedy.
Restart networking and verify everything is working by logging back in.
root@raspberrypi:~# service networking restart
IngeniiGroup:STRATUX$ ssh pi@10.10.0.11
pi@10.10.0.11's password: _enter your password_
pi@raspberrypi:~ $ sudo su -
If you were able to log in again, using the fixed IP address, then the first part of the static IP configurations are completed.
Configure the wlan0 WiFi
NOTE!: As of 14-MAY-2017 and Raspberry Pi 3b; 5.0GHz Wifi IS NOT SUPPORTED.
Now.. the really fun part.. connecting the Pi to your WiFi network. Obviously I will not be displaying my own real WiFi access credentials, so you will need to find the SSID you want to connect to and the password for that network before starting.
The networking configuration that you setup in the previous step contains this setting: ‘wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf‘. The next step is to create/configure that file.
The file is fairly simple, and with the SSID and Password you already obtained for your network (you did that already.. right?). You’ll simple fill that information into the blanks named _SSID_ and _NETWORK_PASS_.
Open the file and edit:
root@raspberrypi:~# vi /etc/wpa_supplicant/wpa_supplicant.conf
Add this block below the original lines, using your settings:
network={
ssid="_SSID_"
psk="_NETWORK_PASS_"
}
Save this file, restart networking, signal a daemon reload, and then, reboot of the device. While it is rebooting, unplug the Ethernet cable (from eth0). Once the networking is back up, check to make sure you are able to contact the machine via it’s WiFi connection.
root@raspberrypi:~# service networking restart
root@raspberrypi:~# ystemctl daemon-reload
root@raspberrypi:~# reboot
After 2-3 Min. the Pi should have completed restarting and you should be able to verify a successful WiFi login.
IngeniiGroup:STRATUX$ ssh pi@10.100.0.21
Increasing Root Filesystem Space
By default, the size of the disk partitions on the image is VERY small; less than 2GB. Most of that space is used by by the base Stratux install, leaving about 400MB of space to save logs (and your replay database if you turn it on). You can see this with the ‘df’ command:
This just isn’t enough space, especially for the ‘/var/log’ directory where a lot of transient/logging data is written. My solution is to create a disk partition and mount it to `/var/log`.
Locate the disk device
Instructions on the web are not exactly correct, some suggest /dev/sda as the main device, however my testing shows it’s actually this named ‘/dev/mmcblk0’.
root@raspberrypi:~# fdisk -l | grep Disk
[...]
Disk /dev/mmcblk0: 14.5 GiB, 15523119104 bytes, 30318592 sectors
… with the following partitions:
Device Boot Start End Sectors Size Id Type
/dev/mmcblk0p1 8192 131071 122880 60M c W95 FAT32 (LBA)
/dev/mmcblk0p2 131072 3887103 3756032 1.8G 83 Linux
Running fdisk
With the physical partition located.. start fdisk:
fdisk -u /dev/mmcblk0
Welcome to fdisk (util-linux 2.25.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
First, order of business is to increase the size of the main partition, to give it a big more room than just 1.8GB. I like to bump it up to around 4GB to leave room for installing more system updates and tools. To do this you will need to know the starting and ending blocks of the partition. That is available with the ‘print’ command:
Command (m for help): p
Disk /dev/mmcblk0: 14.5 GiB, 15523119104 bytes, 30318592 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xe6a544c8
Device Boot Start End Sectors Size Id Type
/dev/mmcblk0p1 8192 131071 122880 60M c W95 FAT32 (LBA) /dev/mmcblk0p2 131072 3887103 3756032 1.8G 83 Linux
Now delete the partition. Yes.. feels VERY dangerous.. and it is.. but as long as the starting block is maintained, and the end block number is increased.. this will end up being a safe operation. Verify that you targeted the correct partition by using ‘p’ again:
Command (m for help): d
Partition number (1,2, default 2): 2
Partition 2 has been deleted.
Command (m for help): p
Disk /dev/mmcblk0: 14.5 GiB, 15523119104 bytes, 30318592 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xe6a544c8
Device Boot Start End Sectors Size Id Type
/dev/mmcblk0p1 8192 131071 122880 60M c W95 FAT32 (LBA)
If this is correct, now recreate it with same number (2), start and type but with a bigger end (taking care not to overlap with other partitions). Try to align things on a megabyte boundary that is for end, make it a multiple of 2048 minus 1. Change the type if needed with t (for partitions holding an extX or btrfs filesystem, the default of 83 is fine). Then `w` to write and `q` to quit.
Command (m for help): n
Partition type
p primary (1 primary, 0 extended, 3 free)
e extended (container for logical partitions)
Select (default p): p
Partition number (2-4, default 2): 2
First sector (2048-30318591, default 2048): 131072
Last sector, +sectors or +size{K,M,G,T,P} (131072-30318591, default 30318591): 8451072
Created a new partition 2 of type 'Linux' and of size 4 GiB.
Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table. Re-reading the partition table failed.: Device or resource busy
The kernel still uses the old table. The new table will be used at the next reboot or after you run partprobe(8) or kpartx(8).
root@raspberrypi:~#
The partition table will have been modified but the kernel will not be able to take that into account as some partitions are mounted.
However, if in-use partitions were only enlarged, you should be able to force the kernel to take the new layout with:
root@raspberrypi:~# partx /dev/mmcblk0
NR START END SECTORS SIZE NAME UUID
1 8192 131071 122880 60M e6a544c8-01 2 131072 8451072 8320001 4G e6a544c8-02
If the command works the next step is to expand the filesystem. In my case I needed to reboot before the kernel picked up the new partition size, despite running partx to fill up this new space.
root@raspberrypi:~# init 6
Following the restart, execute `resize2fs` and run an on-line expansion of the filesystem, and finally verify it again with ‘df -h’
root@raspberrypi:~# resize2fs /dev/mmcblk0p2
resize2fs 1.42.12 (29-Aug-2014)
Filesystem at /dev/mmcblk0p2 is mounted on /; on-line resizing required
old_desc_blocks = 1, new_desc_blocks = 1
The filesystem on /dev/mmcblk0p2 is now 1040000 (4k) blocks long.
The next step is to add a 3rd partition which will then be mounted to `/var/log`
Creating a dedicated filesystem for logging / database
I ended up creating 3 primary partitions, the largest of which will be mounted to `/var/log`.
fdisk /dev/mmcblk0
Command (m for help): n
Partition type
p primary (2 primary, 0 extended, 2 free)
e extended (container for logical partitions)
Select (default p): p
Partition number (3,4, default 3): 3
First sector (2048-30318591, default 2048): 8451073
Last sector, +sectors or +size{K,M,G,T,P} (8451073-30318591, default 30318591): 30318591
Created a new partition 3 of type 'Linux' and of size 10.4 GiB.
Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
Re-reading the partition table failed.: Device or resource busy
The kernel still uses the old table. The new table will be used at the next reboot or after you run partprobe(8) or kpartx(8).
root@raspberrypi:~# partprobe
Checked to make sure the device was crated by checking the `/dev` directory:
root@raspberrypi:~# ls -l /dev/mmcblk0*
brw-rw---- 1 root disk 179, 0 May 15 15:11 /dev/mmcblk0
brw-rw---- 1 root disk 179, 1 May 15 15:11 /dev/mmcblk0p1
brw-rw---- 1 root disk 179, 2 May 15 15:11 /dev/mmcblk0p2 brw-rw---- 1 root disk 179, 3 May 15 15:11 /dev/mmcblk0p3
Next, put a filesystem on this new partition. Using df to determine the type of filesystem currently in use; I recommend that you stick with it for this most basic of operations:
Creating filesystem with 2733439 4k blocks and 684096 inodes
Filesystem UUID: 94f004af-7008-4dbe-8805-3eb2d739436b
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208
Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information:... this might go on for a bit..
Once completed.. mount this where the logs and databases live. To do this the first thing that needs to happen is to check your current fstab:
cat /etc/fstab
proc /proc proc defaults 0 0
/dev/mmcblk0p1 /boot vfat defaults 0 2
/dev/mmcblk0p2 / ext4 defaults,noatime 0 1
# a swapfile is not a swap partition, no line here
# use dphys-swapfile swap[on|off] for that
My first order of business was to copy the current `/var/log` to a new location, create a new clean mount point for `/var/log` and then mount the new filesystem, and then verify it’s mounted using `df -h`
Edit the fstab file to create a mount point for the new partition where the logs used to be written (added the orange line), and ran mount to verify that it will automount on a restart.
root@raspberrypi:~# vi /etc/fstab
proc /proc proc defaults 0 0
/dev/mmcblk0p1 /boot vfat defaults 0 2
/dev/mmcblk0p2 / ext4 defaults,noatime 0 1 /dev/mmcblk0p3 /var/log ext4 defaults,noatime 0 0
# a swapfile is not a swap partition, no line here
# use dphys-swapfile swap[on|off] for that
root@raspberrypi:~# mount -a
Restart and verify
Restart the little box and verify that the mount was preserved.
init 6
Log back in, and run df to check the filesystem health. It should now has the the main filesystem has some breathing room again:
If you do not have a GPS receiver attached to your Stratux, then it might not be able to determine proper system time. When this is the case, enabling ntpd will be your solution. Using national time sync services, it will keep your system clock correct. If you have your GPS plugged in, it’s getting really good timing signals already.. or the location function would not work at all! For the non GPS users:
Install ndptdate:
root@raspberrypi:~# apt-get install ntpdate
Reading package lists... Done
Building dependency tree
Reading state information... Done
[...]
Do you want to continue? [Y/n] Y
Get:1 http://mirrordirector.raspbian.org/raspbian/ jessie/main liblockfile-bin armhf 1.09-6 [18.2 kB]
Get:2 http://mirrordirector.raspbian.org/raspbian/ jessie/main liblockfile1 armhf 1.09-6 [14.7 kB]
Get:3 http://mirrordirector.raspbian.org/raspbian/ jessie/main ntpdate armhf 1:4.2.6.p5+dfsg-7+deb8u2 [69.0 kB]
[...]
Setting up ntpdate (1:4.2.6.p5+dfsg-7+deb8u2) ...
Processing triggers for libc-bin (2.19-18+deb8u3) ...
It should now start at bootup and resolve any timing issues you might have.
Update your Pi with the latest updates and security patches
Some might remember “Black Friday” when a worm created some serious disruption in the tech world.. including at hospitals in the UK. And it happened primarily because people are not applying their security patches! Although the risk of your Pi being botified and ransomed my not be high.. you should be updating it regardless! So, let’s do that now.
Finish up with this command to clean up some of the used disk space. Since you’ve already bumped the numbers on your partitions in the previous steps.. this is not nearly as necessary, but why leave unused stuff lying around? Your mother taught you to clean up afteryourself, right?
Stratux has a rich community of forums, and a lot of information about debugging Strtux, but so far good hacking information is really hard to find. One of the things of most interest to me was “What is severing up this webpage?”
Every search was a dead end, so I went back to my *NIX system administration roots and thought.. “Well, if someone wont admit what’s serving up the stream.. I’ll find out for myself.
Who’s Your Server? — gen_gdl90
A couple of quick commands told me which PID was hanging onto Port 80 and from there which process was associated with the PID:
Once I had an idea of who’m I was looking for, running lsof with the port number gave me 60 entries… and bingo.. there was the nugget of gold I was looking for:
Once onto the trail of the web path, I see that this is an Angular based application (ugh.. I really despise Angular.. I just do.), and all based on some JS stuffs. I get it. for an app like this the two-way data binding of Angular is probably the right too; but I still do not (no do I have to) like it.
root@raspberrypi:~# cd /var/www/maui/
root@raspberrypi:/var/www/maui# ls -l
total 12
drwxr-xr-x 2 root root 4096 Mar 15 2016 css
drwxr-xr-x 2 root root 4096 Mar 15 2016 fonts
drwxr-xr-x 2 root root 4096 Mar 15 2016 js
root@raspberrypi:/var/www/maui#
What I was hoping to find was the location of the that status page.. but.. I believe that what I’m looking for now is the .JS file that manages that label. Initially this looked like a dead end…
Realiazing this was some templating sub-directory, and the root was likely at /var/www, I ran another search that found the location of the desired string, and likely the location of the parts I’m looking for:
Checking in with my Starux project this morning, I found it unresponsive. A physical check shows a flashing red light on the Pi… something has gone haywire, and I couldn’t SSH into the little thing, so a really hard cold restart was in order.
Following the restart I quickly shut Stratux back down to start performing diagnostics:
pi@raspberrypi:~ $ sudo su -
root@raspberrypi:~# service stratux stop
Diagnostics 101
Check Filesystem Health
The last time the little Stratux suddenly had problems it was a filesystem space issue ( previous article ). It turns out the boot drive space was OK but the new Logging partition was again, completely consumed:
There are a number of ways to locate large file on a *NIX system. My favorite tool is find. First thing I want to do is locate any file that is larger than 1 Gigabyte, and sure enough it located a massive sqlite database file. The same one that ate up all the space on the boot drive. So.. this is going to require some more extrodinary measures to maintain 100% 24×7 operational status.
First order of business is to move aside the massive database, but try to preserve the data for examination. Since the filesystem is full, I can’t zip this thing in place, so first some space needs to cleared on the device. The things I’m least interested in go first.. like the zipped syslogs and any other ‘archived’ file (those with a .# suffix).
But.. that’s not going to doe the complete trick, especially if after deleting files df still shows 100% utilization. You need to figure out what is holding which deleted file(s).
Normallyh, the best way to do that on *NIX is with lsof. Much to my chagrin, it was not available on the OS… so I had to go grab it. Thankfully I had the main filesystem on a different partition that still had enough space to install more tools! Once lsof was installed, grep through the list of open file handles and find those marked for delete.. and those are the processes that have handles pointing to those files. However, this didn’t help me with Rasperian Jessie. I know that a reboot will recover the space so.. that was the next step.. a brutal warm-boot.
root@raspberrypi:/var/log# lsof
-su: lsof: command not found
root@raspberrypi:/# apt-get install lsof
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following extra packages will be installed:
libperl4-corelibs-perl
The following NEW packages will be installed:
libperl4-corelibs-perl lsof
...
The first thing was to move aside the current database, and then restart stratux to verify it can created a new empty database for it’s purposes.. then shut it right back down again.
root@raspberrypi:/var/log# mv stratux.sqlite stratux.sqlite.1
root@raspberrypi:/var/log# service stratux start
root@raspberrypi:/var/log# ls -l
total 7291480
[...]
-rw-r--r-- 1 root root 4096 Apr 30 14:27 stratux.sqlite
-rw-r--r-- 1 root root 7466160128 Apr 30 14:24 stratux.sqlite.1
[...]
root@raspberrypi:/var/log# service stratux stop
A new empty database file has been created [ 4096 Apr 30 14:27 stratux.sqlite ]. This tells me that moving aside the current database file on a periodic basis, compressing and then archiving it should be sufficient to maintain operational status.
Logging Insanity
Before restarting Stratux, I zerod out these log files. Running for first a few moments these files were already reading up a lot of space. Tailing one of them I see that Stratux, with my current settings is logging A LOT of data to these log files. I feel this was my first error.. enabling too much logging. My settings look like this:
With those settings enabled, there are a lot of GPS and other events that I don’t really have a use for, being dumped into the Statux log.
Turning OFF ‘Verbose Message Log’ made that insanity stop.
Replay logging is what is writing to the SQLite database. So the question is. how much of that data do I want to keep, and how much will I lose if I turn off the replay logs. I think that will be research for another day… right now the goal is to recover disk space by compressing the massive database file that was moved aside, and get Stratux stabilized again. Once compressed, check filesystem and file size!
Running .schema will show you a ‘CREATE’ statement that can be used to build the database table. The issues I have with using this are that the command only shows the original CREATE, not any subsequent changes such as indexes, are worse yet, new fields! Regardless, here is an example: .schema traffic
CREATE TABLE traffic (id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, Icao_addr INTEGER, Reg TEXT, Tail TEXT, Emitter_category INTEGER, OnGround INTEGER, Addr_type INTEGER, TargetType INTEGER, SignalLevel REAL, Squawk INTEGER, Position_valid INTEGER, Lat REAL, Lng REAL, Alt INTEGER, GnssDiffFromBaroAlt INTEGER, AltIsGNSS INTEGER, NIC INTEGER, NACp INTEGER, Track INTEGER, Speed INTEGER, Speed_valid INTEGER, Vvel INTEGER, Timestamp STRING, PriorityStatus INTEGER, Age REAL, AgeLastAlt REAL, Last_seen STRING, Last_alt STRING, Last_GnssDiff STRING, Last_GnssDiffAlt INTEGER, Last_speed STRING, Last_source INTEGER, ExtrapolatedPosition INTEGER, Bearing REAL, Distance REAL, timestamp_id INTEGER);
This is my favored by far. Format can actually be taken and dropped int a Wiki page, or JIRA case or any other similar document system.. but it’s still not the most ideal, as you can see:
By turning headers ‘on’ you will now get a tabular list of what each of these fields mean. Note that the first operator command does not use a terminating semi-colon. .headers on PRAGMA table_info(traffic);
cid|name|type|notnull|dflt_value|pk
0|id|INTEGER|1||1
1|Icao_addr|INTEGER|0||0
2|Reg|TEXT|0||0
3|Tail|TEXT|0||0
[... you get the idea ...]
35|timestamp_id|INTEGER|0||0
There you go.. three (OK two) ways to list a table schema in SQLite.
If you’re a hacker, and you’re a data geek.. you probably want to know what’s in that Stratus SQLite database!
Get a SQLite client
I wasn’t able to find a SQLite client on the Straux image, so I installed one with apt-get:
sudo apt-get install sqlite3
Next, run a basic function test to see if it installed and will run:
sqlite3
SQLite version 3.8.7.1 2014-10-29 13:59:56
Enter ".help" for usage hints.
Connected to a transient in-memory database.
Use ".open FILENAME" to reopen on a persistent database.
Cracking open the data file
The sqlist logging / database file is in /var/log, and is named stratux.sqlite.
Cracking open the database and checking the schema I found:
sqlite3 stratux.sqlite
SQLite version 3.8.7.1 2014-10-29 13:59:56
Enter ".help" for usage hints.
sqlite>
sqlite> .tables
dump1090_terminal messages startup traffic
es_messages mySituation status
gps_attitude settings timestamp
Stratux SQLite Tables
Some of these tables contain alot of data:
Table Name
Record Count
dump1090_terminal
313290
messages
307
startup
29
traffic
47038
mySituation
0
status
5350
timestamp
252097
settings
0
es_messages
463973
gps_attitude
0
es_messages table
This contains some interesting things. Here are the last 5 records from the database:
select * from es_messages order by timestamp_id desc limit 5;
These seems to be the 1090 ‘es’ messages, however (at least this example) is missing tail number and squawk information. It’s interesting.., but not very actionable.
The next table I looked at was a completely different story!
traffic table
This looks like a good dataset to mine. With about 47,000 contacts int it.. this might be the basic dataset I’m looking for to use for some visualization.
Question.. what are the top 10 traffic events by Tail number?
Let’s find out! The simplest way I know of to do this.. and it offers the advantage that the select query against the large dataset with aggregation only runs ONCE.. is to get the parts you want, and the summary count and jam them into a temporary table. With SQLite, you can do it like this:
CREATE TABLE traffic_summary AS select Reg,Tail,count(*) as hits from traffic group by Tail;
That produced a summary table with 423 records in it:
select count(*) from traffic_summary;
423
Now.. who’s the nosiest one of them all?
select * from traffic_summary WHERE Tail>'' order by hits DESC limit 10;
Running a Stratux in test-bench mode (not in an aircraft, and for days at a time), you’ll likely run into an issue with disk space. The ISO image I acquired from Stratux only provided a 1.8 BG partition for things to live in, and it’s quickly exhausted.
Here is the status of my system after running for about 36 hours… it’s full.
Now to get about the business of increasing the partition and filesystem size without destroying it. First
Locate the disk device
Instructions on the web are not exactly correct, some suggest /dev/sda as the main device, however my testing shows it’s actually this named ‘/dev/mmcblk0’.
root@raspberrypi:~# fdisk -l | grep Disk
[...]
Disk /dev/mmcblk0: 14.5 GiB, 15523119104 bytes, 30318592 sectors
… with the following partitions:
Device Boot Start End Sectors Size Id Type
/dev/mmcblk0p1 8192 131071 122880 60M c W95 FAT32 (LBA)
/dev/mmcblk0p2 131072 3887103 3756032 1.8G 83 Linux
Running fdisk
With the physical partition located.. start fdisk:
fdisk /dev/mmcblk0
Welcome to fdisk (util-linux 2.25.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
I ended up creating 3 primary partitions. The plan is to delete partition 3 and then re-size the main partition to use up remaining space:
Device Boot Start End Sectors Size Id Type
/dev/mmcblk0p1 8192 131071 122880 60M c W95 FAT32 (LBA)
/dev/mmcblk0p2 131072 3887103 3756032 1.8G 83 Linux /dev/mmcblk0p3 2048 8191 6144 3M 5 Extended
/dev/mmcblk0p4 3887104 20664319 16777216 8G 83 Linux
Command (m for help): d
Partition number (1-5, default 5): 3
Partition 3 has been deleted.
Device Boot Start End Sectors Size Id Type
/dev/mmcblk0p1 8192 131071 122880 60M c W95 FAT32 (LBA)
/dev/mmcblk0p2 131072 3887103 3756032 1.8G 83 Linux
/dev/mmcblk0p4 3887104 20664319 16777216 8G 83 Linux
Write out the partition and… then run to enable it:
Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
partprobe
Next, put a filesystem on this new partition. Using df to determine the type of filesystem currently in use; I recommend that you stick with it for this most basic of operations:
df -T
Filesystem Type 1K-blocks Used Available Use% Mounted on
/dev/root ext4 1815440 1799056 0 100% /
Run mkfs
/sbin/mkfs -t ext4 /dev/mmcblk0p4
Creating filesystem with 2097152 4k blocks and 524288 inodes
Filesystem UUID: e36a8f6c-a457-4531-b67d-bea4885a9583
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632
Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information:... this might go on for a bit..
Once completed.. mount this where the logs and databases live. To do this the first thing that needs to happen is to check your current fstab:
cat /etc/fstab
proc /proc proc defaults 0 0
/dev/mmcblk0p1 /boot vfat defaults 0 2
/dev/mmcblk0p2 / ext4 defaults,noatime 0 1
# a swapfile is not a swap partition, no line here
# use dphys-swapfile swap[on|off] for that
My first order of business was to mount the new filesystem to a temporary location (/var/log2) and then copy the contents of /var/log to that location, then delete everything in the log directory, and then unmount log2.
/var/log2
mount -t ext4 /dev/mmcblk0p4 /var/logs
cp -R log/* log2/.
cd log
rm -rf *
umount /dev/mmcblk0p4
Edit the fstab file to create a mount point for the new partition where the logs used to be written (added the orange line), and ran mount to verify that it will automount on a restart.
NOTE TO DEVELOPERS: Make sure that your system has an acceptable clock source, i.e., a GPS
with sufficient signal or enable ntpd (internet connection required).
Everything here comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
Type 'stratux-help' (as root) for a few debugging commands.
pi@raspberrypi:~ $ df