Full Arch Linux Installation STEP by STEP In a Virtual Machine : Complete walk through

Sharing PDF document among multichain blockchain nodes with exclusive permissions

MULTICHAIN : Sharing encrypted data among nodes with Stream Confidentiality

Multichain : Appending Data to Blockchain with BINARYCACHE

 

Multichain : Appending Data to Blockchain with DATA STREAMS

 

MultiChain streams enable a blockchain to be used as a general purpose append-only database, with the blockchain providing time stamping, notarization and immutability. This video continues from the earlier video post in playlist and now focuses on populating data in the "nutsbolts" blockchain created earlier. 

 

Erstwhile seen node "A" creates a data stream data1, populates some sample data, which is immediately visible in the other node "B". Node A further grants exclusive permissions to Node "B" for send and writing to data stream data1. The complete demonstration is shown on two separate Linux machines as introduced in M-1 and M-2 videos in Multichain playlist i.e. Node A and Node B. data stream created name: "data1" 

 

 Commands used

 

create stream data1 '{"restrict":"write"}' 

 

listpermissions data1.* publish data1 key1 '{"json":{"name":"kabali","city":"chennai"}}' 

 

liststreams 

 

subscribe data1 

 

liststreamitems data1 

 

grant 1...send 

 

grant 1...data1.write 

 

publish data1 key2 '{"json":{"name":"baasha","city":"mumbai"}}' 

 

subscribe data1 

 

liststreamitems data1 

 

liststreamkeys data1 

 

liststreamkeyitems data1 key1 

 

liststreampublishers data1 

 

liststreampublisheritems data1 1...

Multichain : How to Connect-Receive-Send to a Blockchain node?

Continuing from the first video that was peculiar to basic instruction and installation of Multichain blockchain platform on Node A, this video moves further by connecting another node B. Node B is a independent node on the network in which the Multichain blockchain application is already installed exactly with the steps seen in the first video of Multichain playlist . The set of commands used in this videos are available as below:

Node A 

First command onwards 

multichain-util create nutsbolts 

multichaind nutsbolts -daemon 

 

 Node B multichaind nutsbolts@192.168.10.19:4265 (IP is as I have configured and you are free to choose ur configuration as u wish) and you will get a unique address starting with 1...... 

 

Node A multichain-cli nutsbolts grant 1... connect send receive (Here with you grant exclusive permission to Node B from Node A Node B 

 

multichaind nutsbolts -daemon (Now the blockchain network will be seen connected to) 

 

To get into interactive shell mode simply type this command at both the node terminals 

 

multichain-cli nutsbolts 

and then on either terminal use the following commands to get useful info of the created blockchain and network peers 

 

getinfo : See a list of all available commands: 

help : Show all permissions currently assigned: 

listpermissions : List the addresses in the wallet: 

listaddresses : For each node, get a list of connected peers: 

getpeerinfo: Get peer info of connected nodes

 

 

Multichain Blockchain Platform: Brief Introduction & Installation

This video gives a minimal few minutes introduction to the Multichain blockchain platform followed by quick installation on an Ubuntu 20.04 OS terminal. This is one of the easiest platforms to play with and understand in much better way the mechanics of blockchain. Primarily CLI based, this video installs the multichain with few commands.

 

MERGING PDF: UBUNTU 20.04 LTS

This small post shares a one line command in Ubuntu terminal to merge to PDFs. While for the regulars,merging the same online would seem to be the quickest and the best but there are times when you wish your PDFs are not compromised by third party websites offering these mergers for free...so why not use a one line command with the help of a tool pdftk.

The command to install the same is 

sudo apt-get install pdftk

and the command thereafter to merger the PDFs like three files 1.pdf, 2.pdf and 3.pdf is as seen below:

 pdftk 1.pdf 2.pdf 3.pdf cat output 4.pdf

where 4.pdf is the merged final output file.

That's all...no third party website reliance for private files.

REMOVE METADATA FROM IMAGES: UBUNTU with exiftool utility

Just few commands in Ubuntu to check the meta data and thereafter remove the same.I am using a utility exiftool which does not come inbuilt to most of the Linux systems,but we need to install them.

INSTALL COMMAND

sudo apt-get install libimage-exiftool-perl

USAGE COMMAND

exiftool -all= IMG_20200504_215424.jpg

(The above command creates a separate copy of the original file and the new file which is created with removed metadata)

or

exiftool -overwrite_original -all= IMG_20200504_215424.jpg 

(The above command overwrites the original file with the new file created with removed metadata)

Showing you output of one file prior to removal of meta data and thereafter removing the meta data

ORIGINAL FILE

kabali@Kabali:~/Desktop/ddd$ jhead IMG_20200504_215424.jpg
File name    : IMG_20200504_215424.jpg
File size    : 3588382 bytes
File date    : 2021:01:31 14:10:13
Camera make  : Xiaomi
Camera model : Mi A2
Date/Time    : 2020:05:04 21:54:24
Resolution   : 4000 x 3000
Orientation  : rotate 90
Flash used   : No
Focal length :  4.1mm  (35mm equivalent: 4mm)
Exposure time: 0.050 s  (1/20)
Aperture     : f/1.8
ISO equiv.   : 1000
Whitebalance : Auto
Metering Mode: center weight
GPS Latitude : ? ?
GPS Longitude: ? ?
JPEG Quality : 98

REMOVED METADATA FILE

kabali@Kabali:~/Desktop/ddd$ jhead IMG_20200504_215424.jpg

File name    : IMG_20200504_215424.jpg
File size    : 3556853 bytes
File date    : 2021:01:31 14:30:08
Resolution   : 4000 x 3000
JPEG Quality : 98

 

REMOVING META DATA FROM VIDEO FILES : UBUNTU TERMINAL COMMANDS

Hello everyone, this post focuses on removing metadata from a video file using ffmpeg inbuilt utility in Ubuntu OS. The following command includes the original file MAH08207.mp4 being stripped of metadata and being output into a new file as output.mp4.

ffmpeg -i MAH08207.mp4 -map 0 -map_metadata -1 -c copy output.mp4

The output of the command is as below:

ffmpeg version 4.2.4-1ubuntu0.1 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 9 (Ubuntu 9.3.0-10ubuntu2)
  configuration: --prefix=/usr --extra-version=1ubuntu0.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-nvenc --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'MAH08207.mp4':
  Metadata:
    major_brand     : MSNV
    minor_version   : 22675568
    compatible_brands: MSNVmp42isom
    creation_time   : 2020-11-09T00:48:18.000000Z
  Duration: 00:00:44.16, start: 0.000000, bitrate: 12146 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709/bt709/iec61966-2-4), 1440x1080 [SAR 4:3 DAR 16:9], 12016 kb/s, 25 fps, 25 tbr, 25k tbn, 50 tbc (default)
    Metadata:
      creation_time   : 2020-11-09T00:48:18.000000Z
      handler_name    : Video Media Handler
      encoder         : AVC Coding
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 127 kb/s (default)
    Metadata:
      creation_time   : 2020-11-09T00:48:18.000000Z
      handler_name    : Sound Media Handler
Output #0, mp4, to 'output.mp4':
  Metadata:
    encoder         : Lavf58.29.100
    Stream #0:0: Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709/bt709/iec61966-2-4), 1440x1080 [SAR 4:3 DAR 16:9], q=2-31, 12016 kb/s, 25 fps, 25 tbr, 25k tbn, 25k tbc (default)
    Stream #0:1: Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 127 kb/s (default)
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (copy)
Press [q] to stop, [?] for help
frame= 1104 fps=0.0 q=-1.0 Lsize=   65489kB time=00:00:44.13 bitrate=12154.5kbits/s speed= 540x    
video:64774kB audio:688kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.039428%

The size of the original file and the stripped of file is

-rw-r--r-- 1 kabali kabali 67050400 Nov  9 06:19 MAH08207.mp4
-rw-rw-r-- 1 kabali kabali 67060450 Jan 29 20:23 output.mp4 

Thus difference between the files is the meta data removed.

I am also showing the output of ffprobe utility run on the two files to show you the difference of meta data removed too.

ffprobe MAH08207.mp4

 ffprobe version 4.2.4-1ubuntu0.1 Copyright (c) 2007-2020 the FFmpeg developers
  built with gcc 9 (Ubuntu 9.3.0-10ubuntu2)
  configuration: --prefix=/usr --extra-version=1ubuntu0.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-nvenc --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'MAH08207.mp4':
  Metadata:
    major_brand     : MSNV
    minor_version   : 22675568
    compatible_brands: MSNVmp42isom
    creation_time   : 2020-11-09T00:48:18.000000Z
  Duration: 00:00:44.16, start: 0.000000, bitrate: 12146 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709/bt709/iec61966-2-4), 1440x1080 [SAR 4:3 DAR 16:9], 12016 kb/s, 25 fps, 25 tbr, 25k tbn, 50 tbc (default)
    Metadata:
      creation_time   : 2020-11-09T00:48:18.000000Z
      handler_name    : Video Media Handler
      encoder         : AVC Coding
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 127 kb/s (default)
    Metadata:
      creation_time   : 2020-11-09T00:48:18.000000Z
      handler_name    : Sound Media Handler

ffprobe output.mp4 

 ffprobe version 4.2.4-1ubuntu0.1 Copyright (c) 2007-2020 the FFmpeg developers
  built with gcc 9 (Ubuntu 9.3.0-10ubuntu2)
  configuration: --prefix=/usr --extra-version=1ubuntu0.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-nvenc --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'output.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf58.29.100
  Duration: 00:00:44.16, start: 0.000000, bitrate: 12148 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709/bt709/iec61966-2-4), 1440x1080 [SAR 4:3 DAR 16:9], 12016 kb/s, 25 fps, 25 tbr, 25k tbn, 50 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 127 kb/s (default)
    Metadata:
      handler_name    : SoundHandler

SPLIT VIDEOS IN UBUNTU: SINGLE LINE COMMAND{ffmpeg utility}

Sharing here just a single line command of ffmpeg utility which can split a video with time duration's specified.So if your video is suppose 05:03(min:sec) long and you wanna split it into two sizes with part 1 as 00:00 to 02:28 and the other part 2 as 02:28 to 05:03,the commands to be executed will be

ffmpeg -i VID_20210129_115611.mp4 -ss 00:00:00 -t 00:02:28 part1.mp4

ffmpeg -i VID_20210129_115611.mp4 -ss 00:02:28 -t 00:05:03 part2.mp4

where VID_20210129_115611.mp4 is the main file and part1.mp4/part2.mp4 are the respective output files.

MERGE VIDEOs IN UBUNTU: TWO TERMINAL COMMANDS

Hi guys...no time waste here...I m mentioning two commands to simply merge your multiple videos quickly in an Ubuntu OS.No GUI or other applications to download or use. The ffmpeg command inbuilt to Ubuntu easily merges without hassles.

So,the first command is 

find "$(pwd)" -type f -name '*.mp4' -printf "file '%p'\n" | tee mp4_compile.txt

The above command will simply find your all mp4 files in the directory wherein you run this command in the terminal directory and compile them into one text file. This text file is named here as mp4_compile.txt. You can name it any thing.

The second command is as given below:

ffmpeg -f concat -safe 0 -i mp4_compile.txt -c copy merged.mp4

This command will merge all the files compiled in the txt file and merge into one output file names as merged.mp4

Thats all...I actually went through a lot of softwares and applications...tried online merge too but all had some kind of limitation in size...till I found these commands.So happy sharing and happy merging.

NOTHING BLOCKCHAIN ABOUT IT :-)

Ubuntu 20.04 LTS brightness control with command line[SOLVED]

While I moved my kernel face from 18.04  to 20.04 LTS,there were few irritants while I got adapted to new interface and features…and one of them was the missing brightness tab in Ubuntu 20.04 LTS. Don’t know why it was removed,but then may be a small community used it and so was discontinued. So I tried third party plugins, few new brightness apps also tried brightness controller but somehow was not happy with the desired screen brightness control.Though Ubuntu 20.04 has night light feature wherein you can tweak with color temperatures from  less warm to more warm but that too fall short of my requirement. So I just wanted a clean hassle free solution. So I got to know about the xrandr command. Xrandr is used to set the size, orientation and/or  reflection  of  the outputs for a screen. It can also set the screen size. 

The good thing is that this utility comes pre-installed with the OS. You just need to use it vide few command line inputs and these are as below:

The first command is

xrandr | grep " connected" | cut -f1 -d " "

This command basically gives you an output of the name of your monitor. In my case it gives HDMI-0.

 

After this command you need to use the same command with different switch and adjusting the brightness to suit your eyes. While 1 refers to highest brightness 0.1 refers to the lowest.So in bright rooms if you wish to set like me,I generally prefer 0.7.The command line goes like this:

 xrandr --output HDMI-0 --brightness 0.7

Other functions that this utility can assist you are with setting resolution and refresh rates. The command lines are mentioned below:

 

SETTING RESOLUTION

xrandr --output HDMI-0--mode 1680x1050

SCREEN REFRESH RATE

xrandr --output HDMI-0--mode 1680x1050 --rate 60.00

Another switch –q will query your monitors and give details as seen below

 Just remember to change your screen name as per your monitor name...in my case like I said...it is HDMI-0.

METAHASH WALLET INSTALLATION : UBUNTU 18.04 LTS

The following blog post shares few screen shots to installation of metahash wallet.The first step needs to go to https://metahash.org/ and then click the appro download as per the OS of the user.In my case I have a Ubuntu 18.04 LTS,so I download the bin file and the rest action follows as per the screen shots below which are all self explanatory.

 this is followed by simply executing the file on the terminal with sudo rights ie sudo ./Meta*.bin

SUBLIME editor installation in UBUNTU 18.04 LTS

1. Sublime Text is a proprietary cross-platform source code editor with a Python application programming interface. It natively supports many programming languages and markup languages, and functions can be added by users with plugins, typically community-built and maintained under free-software licenses.The installation part of the same on Ubuntu will just take few commands as seen below and the sublime editor will be ready to go.The commands are listed below : 

First step

wget -qO - https://download.sublimetext.com/sublimehq-pub.gpg | sudo apt-key add -

(click on image to enlarge)

 Second step

echo "deb https://download.sublimetext.com/ apt/stable/" | sudo tee /etc/apt/sources.list.d/sublime-text.list

(click on image to enlarge)

Third step

sudo apt update 

(click on image to enlarge)

Fourth step

sudo apt install sublime-text

(click on image to enlarge)

and you are ready to work on sublime

(click on image to enlarge)

SPLIT LARGE FILES INTO SMALLER PARTS & MERGE : FOR EASY MIGRATION in LINUX SYSTEMS

1.    Routine troubleshooting in system handling gives us a way to explore and try new options.Recently tried a new way to migrate large files(around ~17 GB in my case here ). Although there are easier options available by simply copying in a external device,but in my case external devices were not allowed so attempted to split the large file into 3 GB size files and then finally could merge them....and could also verify the hash....and it was absolutely right...sharing few screen shots :

2.    The entire thing of splitting and merging gets over in simple two commands of SPLIT & CAT

 > split -b file.name
 > cat x* > file.name

3.   I have a .vdi virtual image file which is approx 16 GB in size.The file details are seen in the screen shot below :

Here ..before I go for the split...I have taken the hash of the same to compare it later after i merge the split parts...to check the originality of files and I get the hash of the file as bb867749cf4c0325abe145a0998e3b04

 

In the screen shot below I use the split command,which is inbuilt to UBUNTU and typically all Linux systems....I split the file in 3GB parts...

 

This screen shot shows the watch screen shot of the populating split parts...

 This screen shot shows the watch screen shot of the populating split parts...

 and here i get the final .vdi file as well m able to match the hash as same ie bb867749cf4c0325abe145a0998e3b04

How to install Graylog on Ubuntu 18.04.1 LTS ?

1.    Graylog2 is a powerful log management and analysis tool that has many use cases, from monitoring SSH logins and unusual activity to debugging applications. It is based on Elasticsearch, Java, MongoDB, and Scala.The installation is not exactly to say simple since a lot of integration goes behind involving different applications including Elasticsearch, Java, MongoDB, and Scala. But in few steps and little modifications in default configuration files,the same can be run with ease.

2.   Below are terminal commands with screen shots to achieve the same running

Firstly,the system that I m installing the GRAYLOG on ..the specs are as below

 Then coming to the root terminal...from where all the commands will be executed for installation.

$ apt update && apt upgrade

 Next we install the JDK module

$ apt install apt-transport-https uuid-runtime pwgen openjdk-8-jre-headless

 This is followed by installing ELASTICSEARCH

$ wget -qO - https://artifacts.elastic.co/GPG-KEY-elasticsearch | apt-key add -

 $ echo "deb https://artifacts.elastic.co/packages/5.x/apt stable main" | sudo tee -a /etc/apt/sources.list.d/elastic-5.x.list

Next we install
 $ apt update && apt install elasticsearch

This is followed by enabling the service and starting

$   systemctl enable elasticsearch $   systemctl start elasticsearch

Amend cluster.name as graylog

 Followed by these lines at the EOF

script.inline: false

script.indexed: false

script.file: false

 

This is followed by

$ systemctl restart elasticsearch

 

Now install the key

$ apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 2930ADAE8CAF5059EE73BB4B58712A2291FA4AD5 

 Then MANGODB repository

$ echo "deb [ arch=amd64,arm64 ] https://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.6 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-3.6.list

 Install mongodb

$ apt update && apt install mongodb-org

$   systemctl start mongod

$    systemctl enable mongod

$ wget https://packages.graylog2.org/repo/packages/graylog-2.5-repository_latest.deb
$ dpkg -i graylog-2.5-repository_latest.deb
$ apt-get update
$ apt-get install graylog-server

After installation of the Graylog package is finished, we need to edit the configuration file to set our password in it and we do it using pwgen command 

$ pwgen -N 1 -s 96

 $ echo -n your_password | sha256sum

 

We place the above generated output in the conf file as seen below : 

Assistance reference from https://www.osradar.com/how-to-install-graylog-on-ubuntu-18-04/ - Thanks