X-Git-Url: https://zdv2.bktei.com/gitweb/EVA-2020-02.git/blobdiff_plain/f7628e9098c8dd7ac932326967a538b489b81cef..4a6abfedd645d76f7428ef97e8965ca69b78e5c9:/doc/location/README.org?ds=sidebyside diff --git a/doc/location/README.org b/doc/location/README.org index 7158a73..7f13e64 100644 --- a/doc/location/README.org +++ b/doc/location/README.org @@ -1,10 +1,9 @@ * Location Logging This document was created by Steven Baltakatei Sandoval on -<2020-06-29 Mon 12:14> under a [[https://creativecommons.org/licenses/by-sa/4.0/][Creative Commons BY-SA 4.0 license]]. It -was updated by Steven Baltakatei Sandoval on <2020-06-29 Mon 22:06>. +~2020-06-29T12:14Z~ under a [[https://creativecommons.org/licenses/by-sa/4.0/][Creative Commons BY-SA 4.0 license]]. It +was updated by Steven Baltakatei Sandoval on ~2020-07-23T21:49Z~ #+TITLE: Ninfacyzga-01 Manual #+AUTHOR: Steven Baltakatei Sandoval -#+DATE: 2020-06-29T22:16Z #+EMAIL: baltakatei@gmail.com ** Narrative Ninfacyzga-01 records (logs) its position in time and space using a @@ -21,10 +20,13 @@ See the [[https://www.raspberrypi.org/pi-zero-w/][OEM]] webpage for this product **** PiZ UpTime 2.0 See the [[https://alchemy-power.com/piz-uptime-2-0/][OEM]] webpage for this product. *** Software -~bkgpslog~ : The bash script that performs the location data -collection and processing. Is an executable file contained within this -repository at ~exec/bkgpslog~. It should be copied to -~$HOME/.local/bin~. +~bklog~ : A bash script that saves its stdin stream to a tar file. The +file may be compressed by ~gzip~ and encrypted by ~age~. It is an +executable file contained within this repository at ~exec/bklog~. It +should be copied to ~$HOME/.local/bin~. + +~bkgpslog~ : A legacy bash script similar to ~bklog~ but narrower in +scope in that it only records output from ~gpspipe~. ~gpsd~ : A background daemon app capable of interfacing with the Ozzmaker BerryGPS-IMU's GPS submodule. Installed and initialized by @@ -35,7 +37,7 @@ stdout consisting of GPS data lines in NMEA format. Installed via ~apt~. ~gpsbabel~ : A command line app that converts GPS data from one format -into another. ~bkgpslog~ uses it to convert NMEA data into GPX and +into another. ~bklog~ may be used to convert NMEA data into GPX and KML. Installed via ~apt~. ~gzip~ : A simple command line app that compresses stdin into a @@ -47,19 +49,38 @@ executable file contained within this repository at ~exec/age~. It should be copied to ~$HOME/.local/bin~. **** Narrative -~bkgpslog~ populates a 60-second buffer with NMEA data from ~gpsd~ via -~gpspipe~. This buffer is used by ~gpsbabel~ to produce GPX and KML -versions of the buffer. All 3 buffers are then comprssed with ~gzip~, -encrypted with ~age~, and then written to disk. +~bklog~ may be used to log location data by receiving stdout produced +by ~gpspipe~. ~bklog~ contains options that allow file writes to be +performed at adjustable time intervals (default: 300 seconds), +compressed (with ~gzip~), and encrypted (with ~age~). Files are +written in the form of appendages to a ~tar~ archive saved to a +specified location. The NMEA data produced by ~gpspipe~ may be +processed via a ~gpsbabel~ command string specified as an option to +~bklog~, assuming ~gpsbabel~ is installed. *** Output + +Several output file formats have been tested with ~bklog~. + **** File Formats ***** NMEA -See the [[https://en.wikipedia.org/wiki/NMEA_0183][Wikipedia page]] for this. +~NMEA~ is an acronym for National marine Electronics Association. The +NMEA format described in this document follows the NMEA 0183 +standard. It is a newline-delimited streaming text format that encodes +global positioning system (GPS) data such as WGS84 location, time and +date information, satellite count, accuracy, and other +information. Each line is an "NMEA sentence". Descriptions of various +NMEA sentences can be found on [[http://aprs.gids.nl/nmea/][this]] webpage. + +See the [[https://en.wikipedia.org/wiki/NMEA_0183][Wikipedia page for NMEA 0183]] for this. This file format is the +default output of the ~gpspipe -r~ command. ***** GPX -See the [[https://en.wikipedia.org/wiki/GPS_Exchange_Format][Wikipedia page]] for this. [[http://wiki.gis.com/wiki/index.php/WGS84][WGS84]] is the datum used. +See the [[https://en.wikipedia.org/wiki/GPS_Exchange_Format][Wikipedia page]] for this. [[http://wiki.gis.com/wiki/index.php/WGS84][WGS84]] is the datum used. An NMEA file +may be converted to this format using ~gpsbabel~. ***** KML -See the [[https://en.wikipedia.org/wiki/Keyhole_Markup_Language][Wikipedia page]] for this. [[http://wiki.gis.com/wiki/index.php/WGS84][WGS84]] is the datum used. +See the [[https://en.wikipedia.org/wiki/Keyhole_Markup_Language][Wikipedia page]] for this. [[http://wiki.gis.com/wiki/index.php/WGS84][WGS84]] is the datum used. An NMEA file +may be converted to this format using ~gpsbabel~. + **** Encryption Method Files produced by the bkgpslog script are encrypted against a set of public keys using [[https://github.com/FiloSottile/age][~age~]], a simple command line encryption tool @@ -77,18 +98,45 @@ the bech32 public key string produced by ~age-keygen~ for convenience. Help information for ~age~ is available by running ~$ age --help~. ***** Encryption Commands -Files may be encrypted to several recipients using a command similar to: +****** Encryption through ~age~ +In order to illustrate how ~bklog~ encrypts files, below is an example +command illustrating how ~age~ may be used to encrypt a file. + #+BEGIN_EXAMPLE -timeout "60s" gpspipe -r | gpsbabel -i nmea -f - -o gpx -F | age \ +$ echo "asdf" | age -r \ +age1kza7pfshy7xwygf9349zgmk7x53mquvedgw9r98qwyyqhssh830qqjzlsw \ +> "$HOME/secret_file" +#+END_EXAMPLE + +The resulting ~secret-file~ is a binary blob with a plaintext header +indicating how the blob was encrypted (which version of age was used, +which public key was used). + +****** Encryption through ~bklog~ +~bklog~ may instructed to encrypt files via the ~-e~ and ~-r [pubkey +string]~ options. An example is shown below: + +#+BEGIN_EXAMPLE +$ gpspipe -r | bklog -e \ -r age1kza7pfshy7xwygf9349zgmk7x53mquvedgw9r98qwyyqhssh830qqjzlsw \ -r age1ce3pvzrqfcn2pc6zqzglc8ac8yjk3fzukpy08cesqjjwns53xywqmaq7xw \ -r age1pu5usxm743sx7rf22985xv2f4s0luzv6r6yx4fa7p8c2zyvp9fvqus2xr5 \ -> location.gpx.age +-o "$HOME/Location" #+END_EXAMPLE +~bklog~ may be instructed via the ~-e~ and ~-R~ options to watch a +directory in order to locate public key strings in its files. ~bklog~ +reads the first line of each file and interprets it as a public key +string. + In this example, the strings beginning with ~age1...~ are -bech32-formatted public key strings. +bech32-formatted public key strings. Please see the [[*Key Generation][Key Generation]] +section for an explanation. + +Since ~age~ also accepts ~ssh~ public key strings, these may also be +used if they are of the following form (no comment). +: ssh-rsa AAAAB3NzaC1yc2EAAAADAQABA…AACAQDLnJbPs7CjwPT+OxXd ***** Decryption Commands Files may be decrypted using a command similar to: @@ -98,6 +146,7 @@ cat location.gpx.age | age -d -i key.txt > location.gpx #+END_EXAMPLE The version of ~age~ used to perform the encryption + ** Operating Procedures *** Initial Startup See OEM (Ozzmaker) [[https://ozzmaker.com/berrygps-berrygps-imu-quick-start-guide/][quickstart guide for the BerryGPS-IMU]]. @@ -112,7 +161,6 @@ conflict so a simple stacking and soldering with long header pins is possible. **** Software Setup - ***** Install Executables Install Raspbian 10 Buster onto an SD card image. See the Raspberry Pi @@ -132,44 +180,109 @@ Install ~syncthing~ for log file transfer capability. Place ~age~ binary (the one compiled for ARM CPU architecture for Linux) in ~$HOME/.local/bin~. -***** Automatic Start Configuration +***** Disable Swap File +Since standard Raspbian 10 (Buster) install involves copying +unencrypted file system image to SD card which is mounted by the +Raspberry Pi, system memory may be written to disk in the form of a +Swap file as described [[https://ideaheap.com/2013/07/stopping-sd-card-corruption-on-a-raspberry-pi/][here]]. In order to reduce the chance that +location log data is ever written to disk, swap file functionality +must be disabled[fn:ideaheap_20130731_disableswap]. + +Raspbian 10 uses dphys-swapfile to manage a swap file. It may be +disabled persistently[fn:rpf_20190702_disableswappersist] by running +the following command: -Edit the user cron job list with ~$ crontab -e~ to add the following -lines: +: sudo systemctl disable dphys-swapfile.service + +To view the status of the swap file in Raspbian 10, run ~free -m~: #+BEGIN_EXAMPLE -0 * * * * /bin/bash ~/bkgpslog --output ~/dir +pi@ninfacyzga-01:~$ free -m + total used free shared buff/cache available +Mem: 432 86 36 21 309 268 +Swap: 99 0 99 +#+END_EXAMPLE + +After disabling the swap file and rebooting: -@reboot /bin/bash ~/bkgpslog --output ~/dir +#+BEGIN_EXAMPLE +pi@ninfacyzga-01:~$ free -m + total used free shared buff/cache available +Mem: 432 89 214 3 128 289 +Swap: 0 0 0 #+END_EXAMPLE -The first line will run ~bkgpslog~ at the start of every hour and save -output files to the ~dir~ directory in your home folder. +[fn:ideaheap_20130731_disableswap] Explanation: +https://ideaheap.com/2013/07/stopping-sd-card-corruption-on-a-raspberry-pi/ -The second line will run ~bkgpslog~ when the system starts up. +[fn:rpf_20190702_disableswappersist] Persistant disabling of swap in +Raspbian 10 Buster: +https://www.raspberrypi.org/forums/viewtopic.php?p=1490692&sid=5c596a124b7805d6b10dab8d3d7caf16#p1490692 -~/bin/bash~ tells ~cron~ to run ~bkgpslog~ with Bash. +***** Automatic Start Configuration -If encryption and compression are required, then the appropriate -options must be added. The lines that must be added via ~$ crontab -e~ -may resemble: +It is recommended to create a daily ~cron~ job that executes a bash +script that starts ~bklog~ jobs to record location along with other +types of data recording. An example of such a script is below: #+BEGIN_EXAMPLE -0 * * * * /bin/bash ~/bkgpslog -c -e -r age1z2...qkv6p -o ~/dir - -@reboot /bin/bash ~/bkgpslog -c -e -r age1z2...qkv6p -o ~/dir +#!/bin/bash + +# Log location +gpspipe -r | /bin/bash "$HOME/.local/bin/bklog" -c -e -z "UTC" -t "/dev/shm" \ + -r age1kza7pfshy7xwygf9349zgmk7x53mquvedgw9r98qwyyqhssh830qqjzlsw \ + -r age1ce3pvzrqfcn2pc6zqzglc8ac8yjk3fzukpy08cesqjjwns53xywqmaq7xw \ + -R "$HOME/.config/bklog/recipients" -w ".nmea" -b "300" -B "day" \ + -o "$HOME/Sync/Evanescent_Location" -l "location" \ + -p "gpsbabel -i nmea -f - -o gpx -F - " ".gpx" \ + -p "gpsbabel -i nmea -f - -o kml -F - " ".kml" & +# Log pressure +python ~/.local/bin/bmp388.py | /bin/bash "$HOME/git-OC/ninfacyzga-01/exec/bklog" \ + -c -e -z "UTC" -t "/dev/shm" \ + -r age1kza7pfshy7xwygf9349zgmk7x53mquvedgw9r98qwyyqhssh830qqjzlsw \ + -r age1ce3pvzrqfcn2pc6zqzglc8ac8yjk3fzukpy08cesqjjwns53xywqmaq7xw \ + -R "$HOME/.config/bklog/recipients" -w ".txt" -b "300" -B "day" \ + -o "$HOME/Sync/Evanescent_Location" -l "pressure" & #+END_EXAMPLE -The ~age1z2...qkv6p~ is an ~age~ public key string. Please see the -[[*Key Generation][Key Generation]] section for an explanation. +This script, if it were saved at +~"$HOME/.local/bin/cron/dailylog.sh"~ would then be added as a +line in the ~crontab~ file as shown below: -The options are: +#+BEGIN_EXAMPLE +$ crontab -e +0 0 * * * /bin/bash ~/.local/bin/cron/dailylog.sh +@reboot /bin/bash ~/.local/bin/cron/dailylog.sh +#+END_EXAMPLE -: -c : tells bkgpslog to compress output -: -e : tells bkgpslog log to encrypt output -: -r : tells bkgpslog to interpret the next argument as a pubkey string -: -o : tells bkgpslog to write output files to the directory represented +In the example script, the options are: + +: -c : tells bklog to compress output +: -e : tells bklog log to encrypt output +: -r : tells bklog to interpret the next argument as a pubkey string +: -R : tells bklog to interpret the next argument as a directory +: where public keys may be found (first line of each file is +: read). +: -o : tells bklog to write output files to the directory represented +: -t : tells bklog to interpret the next argument as a directory +: for storing temporary files : by the next argument +: -p : tells bklog a command string through which output is piped +: before being compressed and encrypted. Also expected is a +: file extension to be appended before the compression and +: encryption file extensions. +: -w : tells bklog to save the unprocessed stdin with a specified +: file extension (instead of the default '.stdin'). +: -b : tells bklog how long each buffer round (time between file +: writes) lasts in seconds. +: -B : specifies the time-to-live for the bklog script. A valid value may +: one of the time elements such as "day" or "hour". +: -l : specfies a custom string to be used in output file names to +: help differentiate tar files produced via bklog from different +: sources of data. +: -z : specifies a time zone to be used to determine the script time-to-live. +: By default, bklog uses whatever time is specified by the TZ +: environment variable. ***** Log Transfer Configuration Log files may be shared to other machines via ~syncthing~. See [[https://docs.syncthing.net/][this]] @@ -186,7 +299,7 @@ An ~age~ encryption key may be generated like so: #+BEGIN_EXAMPLE $ umask # Gets current umask 0022 # Note: This is the default umask for Raspbian 10 -$ umask 066 # Sets umask so key.txt will have no permissions except for owner (you) +$ umask 066 # So key.txt will have no perms except for owner (you) $ umask # Confirm umask set to 066 0066 $ age-keygen > key.txt @@ -245,4 +358,3 @@ components may be recycled. Take extra precuation if lead solder was used in assembling the electronics. Consumer electronics in early 21st century should use lead-free solder. -