X-Git-Url: https://zdv2.bktei.com/gitweb/EVA-2020-02.git/blobdiff_plain/170f63baf5a56d9ece11b31924a9f4a81cd92812..d50056c252de758c21e28606056de58d64b55950:/doc/location/README.org?ds=inline diff --git a/doc/location/README.org b/doc/location/README.org index d626dd0..7f13e64 100644 --- a/doc/location/README.org +++ b/doc/location/README.org @@ -1,7 +1,10 @@ * 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 16:05>. +~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 +#+EMAIL: baltakatei@gmail.com ** Narrative Ninfacyzga-01 records (logs) its position in time and space using a [[https://en.wikipedia.org/wiki/Satellite_navigation_device][GPS receiver]]. The NMEA location data produced by the receiver is @@ -17,10 +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 @@ -31,7 +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 @@ -43,27 +49,312 @@ 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. +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. +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]]. The public keys are bech32 strings supplied as -options to bkgpslog when called. +public keys using [[https://github.com/FiloSottile/age][~age~]], a simple command line encryption tool +selected over ~gpg~ because of ~age~'s deliberate lack of +configurability. + +The public keys are bech32 strings supplied as options to bkgpslog +when called. The secret key should *NOT* be stored in Ninfacyzga-01. + +If a key pair was generated using ~age-keygen~, then it is an [[https://en.wikipedia.org/wiki/Curve25519][~X25519~]] +key pair. See the [[https://age-encryption.org/v1][~age~ Version 1 specification]]. + +An ~ssh-rsa~ or ~ssh-ed25519~ SSH public key string may be used instead of +the bech32 public key string produced by ~age-keygen~ for convenience. + +Help information for ~age~ is available by running ~$ age --help~. +***** Encryption Commands +****** 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 +$ 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 \ +-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. 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: + +#+BEGIN_EXAMPLE +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]]. + +**** Physical Setup + +BerryGPS-IMU must be electrically connected to the correct pins on the +GPIO header of a Raspberry Pi Zero W. + +*Optional*: stack together with PiZ Uptime 2.0 module. No GPIO pins +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 +Foundation [[https://www.raspberrypi.org/documentation/installation/installing-images/README.md][installation instructions]]. Configure WiFi to permit log +file transfer. Configure SSH to permit remote administration via the +command line interface. + +Make sure to install the ~unattended-upgrades~ package to make sure +the latest security patches for packages are installed. See [[https://linux-audit.com/using-unattended-upgrades-on-debian-and-ubuntu/][this page]] +for a description of how ~unattended-upgrades~ works. + +Install ~gpsd~, ~gpspipe~, ~git~, and this repository for location +logging capability. + +Install ~syncthing~ for log file transfer capability. + +Place ~age~ binary (the one compiled for ARM CPU architecture for +Linux) in ~$HOME/.local/bin~. + +***** 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: + +: sudo systemctl disable dphys-swapfile.service + +To view the status of the swap file in Raspbian 10, run ~free -m~: + +#+BEGIN_EXAMPLE +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: + +#+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 + +[fn:ideaheap_20130731_disableswap] Explanation: +https://ideaheap.com/2013/07/stopping-sd-card-corruption-on-a-raspberry-pi/ + +[fn:rpf_20190702_disableswappersist] Persistant disabling of swap in +Raspbian 10 Buster: +https://www.raspberrypi.org/forums/viewtopic.php?p=1490692&sid=5c596a124b7805d6b10dab8d3d7caf16#p1490692 + +***** Automatic Start Configuration + +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 +#!/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 + +This script, if it were saved at +~"$HOME/.local/bin/cron/dailylog.sh"~ would then be added as a +line in the ~crontab~ file as shown below: + +#+BEGIN_EXAMPLE +$ crontab -e +0 0 * * * /bin/bash ~/.local/bin/cron/dailylog.sh +@reboot /bin/bash ~/.local/bin/cron/dailylog.sh +#+END_EXAMPLE + +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]] +manual for how to set up a shared folder and add Ninfacyzga-01 as a +device. Syncthing's directory synchronization capability allows a +remote machine to delete files from Ninfacyzga-01 by deleting from the +shared folder that they both share. + +When log files are removed from Ninfacyzga-01 is not within the scope +of this document. + +***** Key Generation +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 # So key.txt will have no perms except for owner (you) +$ umask # Confirm umask set to 066 +0066 +$ age-keygen > key.txt +Public key: age1pu5usxm743sx7rf22985xv2f4s0luzv6r6yx4fa7p8c2zyvp9fvqus2xr5 +$ ls -al key.txt +-rw------- 1 baltakatei baltakatei 184 Jun 29 18:28 key.txt +$ umask 0022 # Return umask to default value +$ umask +0022 +#+END_EXAMPLE + +The resulting public/private keypair data looks like: +#+BEGIN_EXAMPLE +$ cat key.txt +# created: 2020-06-29T18:01:56Z +# public key: age1pu5usxm743sx7rf22985xv2f4s0luzv6r6yx4fa7p8c2zyvp9fvqus2xr5 +AGE-SECRET-KEY-1NEUU5U2XGZGL9UYWNPU5DL99TGJJHFSN4F2E2WCCSDJJ6L5ZMLESNTVTU0 +#+END_EXAMPLE + +The file ~key.txt~ is not password-protected by default and should be +secured like an SSH public key should. The ~$ umask 066~ command run +before the ~$ age-keygen > key.txt~ command ensures ~key.txt~ will not +be readable, writeable, or executable to anyone except the owner +(you). + *** Normal Startup +Turn on Ninfacyzga-01 by supplying 5VDC power to the Raspberry Pi. No +further interaction should be required. +*** Normal Operation +No interaction beyond continually supplying approximately 100mA of +5VDC power and occasionally removing log files to conserve disk space +is required. +**** Log Transfer +Log files may be transferred by use of ~syncthing~ shared folders. +**** Automatic Updates +The ~automatic-upgrades~ package, if installed, should automatically +install security patches to packages installed via ~apt~. *** Normal Shutdown +The system may be shutdown via SSH by running: + +: $ sudo shutdown -r 0 + *** Unscheduled Shutdown +Ninfacyzga-01 as described and setup should tolerate unscheduled power +loss. Log files being written every 60 seconds means, at most, 60 +seconds worth of location data may be lost. *** End of Life Disposal +LiPo batteries used by the PiZ Uptime 2.0 module should be disposed of +properly with their potential ignitability in mind, especially if they +are not fully discharged. + +Consult your local municipality for its "E-Waste Disposal" (or +equivalent) policy. Metals used in the Raspberry Pi and related +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.