Ubuntu :Installing Geogebra

I tried to install GeoGebra using flatpak.Just for

experiement i installed flatpak using apt

I was greeted with follwoing error when i run command to install geogebra.

Error:

sangram@sangram-Inspiron-14-5430:~$ flatpak install flathub org.geogebra.GeoGebra

Note that the directories

'/var/lib/flatpak/exports/share'

'/home/sangram/.local/share/flatpak/exports/share'

are not in the search path set by the XDG_DATA_DIRS environment variable, so

applications installed by Flatpak may not appear on your desktop until the

session is restarted.

Looking for matches…

error: No remote refs found for ‘flathub’

Solution:

flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo

Open bashrc file:

sudo nano ~/.bashrc

Add following line into it

export XDG_DATA_DIRS=$XDG_DATA_DIRS:/var/lib/flatpak/exports/share:/home/$USER/.local/share/flatpak/exports/share

Reload bashrc

source ~/.bashrc

verify that the Flathub remote was successfully added by listing Flatpak remotes:

flatpak remotes

Output:

Name Options

flathub system

Now I was able to install using following command

flatpak install flathub org.geogebra.GeoGebra

To launch it run

flatpak run org.geogebra.GeoGebra

If you want to remove this app then run

flatpak uninstall flathub org.geogebra.GeoGebra

Confirm it is deleted by seeing list of installed app

flatpak list

Ubuntu:.Recover corrupt bashrc

Somehome you messed with .bashrc file & it

start mulfunctioning then you can just backup

and replace it with its working copy.

Usually .bashrc file located in /home/username (sangram is my username).

cd /home/sangram

Backup

cp .bashrc .bashrc_backup

Delete

rm -rf bashrc

First Way:

Now go for https://gist.github.com/marioBonales/1637696

which has default Ubuntu Bashrc file content.copy its

content and do

nano .bashrc

Then add copied content to it.Then

source .bashrc

Second Way:

copy the content of /etc/skel/.bashrc

and paste it into empty .bashrc

Now

source .bashrc

Ubuntu:Disable Laptop Internal Keyboard

 

I am using Dell Laptop my laptop internal keyboard

acting weird insense it make sound from nowhere &

causing deleteting of folders & files abruptly without

me pressing any keyboard.

Also I observed that when I am typing in some document

it start deleting content,I try to replace it from technician

but still it behaves in same way.

I decided to disable it as I have bluetooth keyboard & mouse that

can do the treak.

Here is How you can disable laptop internal keyboard in Ubuntu,

same method should work whereever their is GRUB.

Edit /etc/default/grub

sudo nano /etc/default/grub

In this opened file look for

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

Now replace this line with following line

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash i8042.nokbd"

We need to regenerate grub.cfg so that our changes will take effect.

Run

update-grub2

Now you can reboot the laptop your Laptop Internal Keyboard will be disabled

You have not worry of your file & folders getting deleted abruptly & nor your

content of opened text in text editor will get deleted nor some weird keyboard

sound which tell some keyboard key is struck.

Ubuntu:Mounting Window 11 partition

Install Packages required to mount window partition in Ubuntu 24

sudo apt install ntfs-3g fuse3

Make Directory to mount Window Partition C

sudo mkdir -p /mnt/windows_c

Find partition to mount:

sudo fdisk -l

 

 Output:

Disk /dev/loop0: 4 KiB, 4096 bytes, 8 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

Disk /dev/loop1: 55.36 MiB, 58052608 bytes, 113384 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

Disk /dev/loop2: 63.7 MiB, 66789376 bytes, 130448 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

Disk /dev/loop3: 74.27 MiB, 77881344 bytes, 152112 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

Disk /dev/loop4: 269.77 MiB, 282873856 bytes, 552488 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

Disk /dev/loop5: 73.88 MiB, 77463552 bytes, 151296 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

Disk /dev/loop6: 10.72 MiB, 11239424 bytes, 21952 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

Disk /dev/loop7: 91.69 MiB, 96141312 bytes, 187776 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

Disk /dev/nvme0n1: 476.94 GiB, 512110190592 bytes, 1000215216 sectors

Disk model: PM9B1 NVMe Samsung 512GB

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: gpt

Disk identifier: D312188E-7631-40DA-9BB4-EB29F963E1A6

Device Start End Sectors Size Type

/dev/nvme0n1p1 2048 411647 409600 200M EFI System

/dev/nvme0n1p2 411648 673791 262144 128M Microsoft reserved

/dev/nvme0n1p3 673792 504090623 503416832 240G Microsoft basic data

/dev/nvme0n1p4 504090624 954650623 450560000 214.8G Linux filesystem

/dev/nvme0n1p5 954650624 956852223 2201600 1G Windows recovery environment

/dev/nvme0n1p6 956852224 997101567 40249344 19.2G Windows recovery environment

/dev/nvme0n1p7 997103616 1000187903 3084288 1.5G Windows recovery environment

Disk /dev/loop8: 505.09 MiB, 529625088 bytes, 1034424 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

Disk /dev/loop9: 11.11 MiB, 11649024 bytes, 22752 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

Disk /dev/loop10: 301.45 MiB, 316096512 bytes, 617376 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

Disk /dev/loop11: 38.83 MiB, 40714240 bytes, 79520 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

Disk /dev/loop12: 10.54 MiB, 11051008 bytes, 21584 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

Disk /dev/loop13: 500 KiB, 512000 bytes, 1000 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

Disk /dev/loop14: 149.63 MiB, 156901376 bytes, 306448 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

Disk /dev/loop16: 568 KiB, 581632 bytes, 1136 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

Disk /dev/loop15: 1.77 MiB, 1855488 bytes, 3624 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

Disk /dev/loop17: 150.29 MiB, 157593600 bytes, 307800 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

We have identified C: as /dev/nvme0n1p3

sudo mount -t ntfs-3g /dev/nvme0n1p3 /mnt/windows_c

As this failed with following error

NTFS signature is missing.

Failed to mount '/dev/nvme0n1p3': Invalid argument

The device '/dev/nvme0n1p3' doesn't seem to have a valid NTFS.

Maybe the wrong device is used? Or the whole disk instead of a

partition (e.g. /dev/sda, not /dev/sda1)? Or the other way around?

Lets use other method:

sudo blkid

Output:

/dev/nvme0n1p4: UUID="2be2c7c1-62de-4734-8373-48e0fc083321" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="d2d1f772-7ad2-44b8-b4a6-c3651ff97179"

/dev/loop1: BLOCK_SIZE="131072" TYPE="squashfs"

/dev/nvme0n1p7: LABEL="DELLSUPPORT" BLOCK_SIZE="512" UUID="AA46EDC646ED92FD" TYPE="ntfs" PARTUUID="56b859e8-8a4f-43f1-8673-39f46dc6ac4b"

/dev/nvme0n1p5: LABEL="WINRETOOLS" BLOCK_SIZE="512" UUID="AED6479BD64762A7" TYPE="ntfs" PARTUUID="d0944af5-6b66-4830-a766-71376d7b791b"

/dev/nvme0n1p3: TYPE="BitLocker" PARTLABEL="Basic data partition" PARTUUID="9838e955-a1ed-4bb2-b548-ff0bbfee5dea"

/dev/nvme0n1p1: LABEL_FATBOOT="ESP" LABEL="ESP" UUID="9280-D831" BLOCK_SIZE="512" TYPE="vfat" PARTLABEL="EFI system partition" PARTUUID="5c9392f9-e8a7-4bda-a20a-9cbbc370888e"

/dev/nvme0n1p6: LABEL="Image" BLOCK_SIZE="512" UUID="CEF647B2F647999B" TYPE="ntfs" PARTUUID="401fff82-a681-4e84-b2a7-617f3215afd4"

/dev/loop17: BLOCK_SIZE="131072" TYPE="squashfs"

/dev/loop8: BLOCK_SIZE="131072" TYPE="squashfs"

/dev/loop15: BLOCK_SIZE="131072" TYPE="squashfs"

/dev/loop6: BLOCK_SIZE="131072" TYPE="squashfs"

/dev/loop13: BLOCK_SIZE="131072" TYPE="squashfs"

/dev/loop4: BLOCK_SIZE="131072" TYPE="squashfs"

/dev/loop11: BLOCK_SIZE="131072" TYPE="squashfs"

/dev/loop2: BLOCK_SIZE="131072" TYPE="squashfs"

/dev/loop0: BLOCK_SIZE="131072" TYPE="squashfs"

/dev/loop9: BLOCK_SIZE="131072" TYPE="squashfs"

/dev/loop16: BLOCK_SIZE="131072" TYPE="squashfs"

/dev/loop7: BLOCK_SIZE="131072" TYPE="squashfs"

/dev/loop14: BLOCK_SIZE="131072" TYPE="squashfs"

/dev/loop5: BLOCK_SIZE="131072" TYPE="squashfs"

/dev/loop12: BLOCK_SIZE="131072" TYPE="squashfs"

/dev/loop3: BLOCK_SIZE="131072" TYPE="squashfs"

/dev/loop10: BLOCK_SIZE="131072" TYPE="squashfs"

/dev/nvme0n1p2: PARTLABEL="Microsoft reserved partition" PARTUUID="b10249a2-2134-4fc3-ab2b-46a1239d75b8"

Install

sudo apt install dislocker

sudo mkdir /mnt/bitlocker

sudo dislocker -r -V /dev/nvme0n1p3 -- /mnt/bitlocker

The unlocked data will be accessible in the dislocker-file within /mnt/bitlocker:

sudo mount -o loop /mnt/bitlocker/dislocker-file /mnt/windows_c

Automounting Partitions at Boot:

we need to find the UUID of window partition.

Hence

sudo blkid /dev/nvme0n1p3

Output:

/dev/nvme0n1p3: TYPE="BitLocker" PARTLABEL="Basic data partition" PARTUUID="9838e955-a1ed-4bb2-b548-ff0bbfee5dea"

Edit fstab file:

sudo nano /etc/fstab

Add following at end of file:

# Mount the BitLocker partition using dislocker

UUID=9838e955-a1ed-4bb2-b548-ff0bbfee5dea /mnt/bitlocker dislocker defaults 0 0

# Mount the unlocked data

/mnt/bitlocker/dislocker-file /mnt/windows_c ntfs-3g defaults,windows_names,locale=en_US.utf8 0 0

If we prefer that partition is not mounted automatically then we need to update above to following

# Mount the BitLocker partition using dislocker, do not auto-mount

UUID=9838e955-a1ed-4bb2-b548-ff0bbfee5dea /mnt/bitlocker dislocker noauto 0 0

# Mount the unlocked data, do not auto-mount

/mnt/bitlocker/dislocker-file /mnt/windows_c ntfs-3g noauto,defaults,windows_names,locale=en_US.utf8 0 0

But then you have to manually mount & unmount it.

Manually Mounting whenever needed:

sudo dislocker -r -V /dev/nvme0n1p3 -- /mnt/bitlocker

sudo mount -o loop /mnt/bitlocker/dislocker-file /mnt/windows_c

Manually Unmounting at shutdown:

sudo umount /mnt/windows_c

sudo umount /mnt/bitlocker

I will prefer automated mounting approach.

Now I need to gracefully unmount it before shutdown automatically.

So lets have Script to Unmount Partitions

sudo nano /usr/local/bin/unmount_bitlocker.sh

Add following code into it

#!/bin/bash

# Unmount the unlocked data

umount /mnt/windows_c 2>/dev/null

# Unmount the dislocker mount

umount /mnt/bitlocker 2>/dev/null

save & exit.

Make script executable

sudo chmod +x /usr/local/bin/unmount_bitlocker.sh

Create a service to call this script

sudo nano /etc/systemd/system/unmount-bitlocker.service

Add following content to it

[Unit]

Description=Unmount BitLocker Partitions

DefaultDependencies=no

Before=shutdown.target reboot.target halt.target

[Service]

Type=oneshot

ExecStart=/usr/local/bin/unmount_bitlocker.sh

RemainAfterExit=yes

[Install]

WantedBy=halt.target reboot.target shutdown.target

Lets enable the service so it runs at shutdown.

sudo systemctl enable unmount-bitlocker.service

Now suppose you modified this service then to make it

work do following

sudo systemctl daemon-reload

sudo systemctl enable unmount-bitlocker.service

Test the Configuration: After making changes, you can test it by running:

sudo mount -a

Now, every time the system is shutting down, your script will

run and unmount the BitLocker partitions automatically & boot

time it will mount the system.

We need to test this setup by shutting down your system and

ensuring the partitions are unmounted as expected.

Automated mounting approach fails so /etc/fstab is modified as

# Mount the BitLocker partition using dislocker, do not auto-mount

UUID=9838e955-a1ed-4bb2-b548-ff0bbfee5dea /mnt/bitlocker dislocker noauto 0 0

# Mount the unlocked data, do not auto-mount

/mnt/bitlocker/dislocker-file /mnt/windows_c ntfs-3g noauto,defaults,windows_names,locale=en_US.utf8 0 0

I am creating script to run after boot:

sudo nano /usr/local/bin/mount_bitlocker.sh

Add following content to it

#!/bin/bash

# Mounting BitLocker-encrypted drive

sudo dislocker -r -V /dev/nvme0n1p3 -- /mnt/bitlocker

# Mount the dislocker file

sudo mount -o loop /mnt/bitlocker/dislocker-file /mnt/windows_c

save & exit.

Make script executable

sudo chmod +x /usr/local/bin/mount_bitlocker.sh

create a service

sudo nano /etc/systemd/system/mount_bitlocker.service

Add Following content to service

[Unit]

Description=Mount BitLocker Encrypted Drive

After=local-fs.target

[Service]

Type=oneshot

User=root

ExecStart=/usr/local/bin/mount_bitlocker.sh

RemainAfterExit=yes

[Install]

WantedBy=multi-user.target

Save & Exit.

Enable service:

sudo systemctl enable mount_bitlocker.service

Test Script Manually

sudo /usr/local/bin/mount_bitlocker.sh

I checked this approach now its working.

Ubuntu : How to clean up space from logs ?

Clean accumulated .deb files from /var/cache/apt/archives

Move .deb files to external drive

cd /var/cache/apt/archives

sudo mv *.deb /media/sangram/Elements/Ubuntu22.4LTSAPTArchieve/

ls -lh .

Run autoclean

sudo apt-get autoclean

Truncate System,Kernel & Auth Logs:

sudo truncate -s 0 /var/log/syslog

sudo truncate -s 0 /var/log/auth.log

sudo truncate -s 0 /var/log/kern.log

Remove Apt Cache:

sudo truncate -s 0 /var/log/apt/history.log

sudo truncate -s 0 /var/log/apt/term.log

cd /var/log/apt

sudo rm -rf *.gz

ls -lh /var/log/apt/

Restart rsynclog servicea

sudo systemctl restart rsyslog

Ubuntu : How to Upgrade from Ubuntu 22.04 LTS to Ubuntu 24.04 LTS ?

Make sure your current system is fully up-to-date:

sudo apt update && sudo apt upgrade

sudo apt dist-upgrade

sudo apt autoremove

Run the following command to make sure your upgrade tool is up-to-date:

sudo apt install update-manager-core

Begin the upgrade process by running:

sudo do-release-upgrade

Check for Available Upgrades:

sudo do-release-upgrade -d

Ubuntu:add-apt-repoitory error - "could not find a distribution template"

Error on adding apt repository

sudo add-apt-repository ppa:forkotov02/ppa

Error :

Traceback (most recent call last): File "/usr/bin/add-apt-repository", line 363, in <module> addaptrepo = AddAptRepository() File "/usr/bin/add-apt-repository", line 41, in __init__

self.distro.get_sources(self.sourceslist) File "/usr/lib/python3/dist-packages/aptsources/distro.py", line 91, in get_sources raise

NoDistroTemplateException( aptsources.distro.NoDistroTemplateException: Error: could not find a distribution template for Neon/jammy

Actually some files in /etc/*-release got modified when you

tried to install some package in my case i try to add Kde-Neon

repository but not installed Kde Neon.

To rectify this we need to set these two files (lsb-release

& os-release) to Ubuntu default.

For that follow following instructions.

Run

sudo nano /etc/*-release

First File:(lsb-release)

    DISTRIB_ID=ubuntu     DISTRIB_RELEASE=22.04     DISTRIB_CODENAME=jammy     DISTRIB_DESCRIPTION="Ubuntu 22.04 LTS"

Second File:(os-release)

PRETTY_NAME="Ubuntu 22.4 LTS"

NAME="Ubuntu"

VERSION_ID="22.04"

VERSION="22.4 LTS (Jammy Jellyfish)"

VERSION_CODENAME=jammy

ID=ubuntu

ID_LIKE=debian

HOME_URL="https://www.ubuntu.com/"

SUPPORT_URL="https://help.ubuntu.com/"

BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"

PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"

UBUNTU_CODENAME=jammy

LOGO=start-here

Reboot The Computer

After Reboot try

sudo add-apt-repository ppa:forkotov02/ppa

sudo apt update

sudo apt install qmmp-qt6 qmmp-plugin-pack-

In my case i was able to add apt repository without any

problem after doing above procedure.

Ubuntu/Apt:Trying to overwrite file which is also in package

While doing routine apt upgrade you encountered error

similar to below

dpkg: error processing archive /var/cache/apt/archives/qt6-base_6.7.2-0zneon+22.04+jammy+release+build2_amd64.deb (--unpack):

trying to overwrite '/usr/lib/x86_64-linux-gnu/libQt6Core.so.6', which is also in package libqt6core6:amd64 6.2.4+dfsg-2ubuntu1.1

Complete Error:

Preparing to unpack .../qt6-base_6.7.2-0zneon+22.04+jammy+release+build2_amd64.deb ...

Unpacking qt6-base (6.7.2-0zneon+22.04+jammy+release+build2) ...

dpkg: error processing archive /var/cache/apt/archives/qt6-base_6.7.2-0zneon+22.04+jammy+release+build2_amd64.deb (--unpack):

trying to overwrite '/usr/lib/x86_64-linux-gnu/libQt6Core.so.6', which is also in package libqt6core6:amd64 6.2.4+dfsg-2ubuntu1.1

Preparing to unpack .../qt6-declarative_6.7.2-0zneon+22.04+jammy+release+build3_amd64.deb ...

Unpacking qt6-declarative (6.7.2-0zneon+22.04+jammy+release+build3) ...

Errors were encountered while processing:

/var/cache/apt/archives/qt6-base_6.7.2-0zneon+22.04+jammy+release+build2_amd64.deb

E: Sub-process /usr/bin/dpkg returned an error code (1)

Then identify the file & do force overwrite for it like below

sudo dpkg -i --force-overwrite /var/cache/apt/archives/qt6-base_6.7.2-0zneon+22.04+jammy+release+build2_amd64.deb

Then

sudo apt-get -f install

WSL : Install Linux GUI App on Windows 11

If wsl is not installed  then run    

    wsl --install

If already installed then run

    wsl --update

Need restart of WSL for the update to take effect

    wsl --shutdown

Install Linux GUI App

    sudo apt update

    sudo apt install gnome-text-editor

    sudo apt install gimp

    sudo apt install nautilus

    sudo apt install vlc

    sudo apt install x11-apps

    Install Google Chrome

        cd /tmp

        wget https://dl.google.com/linux/direct/google-chrome-stable_current_amd64.deb

        sudo apt install --fix-missing ./google-chrome-stable_current_amd64.deb

    Install Microsoft Edge

        sudo apt install software-properties-common apt-transport-https wget

        wget -q https://packages.microsoft.com/keys/microsoft.asc -O- | sudo apt-key add -

        sudo add-apt-repository "deb [arch=amd64] https://packages.microsoft.com/repos/edge stable main"

        sudo apt install microsoft-edge-dev

    Install Node.js

        curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/master/install.sh | bash

        nvm ls

        nvm install --lts

    Suppose You installed VLC as mentioned above,then you can search in normal

    window start menu it has mentioned that "VLC Media Player(Ubuntu)"

    Now open the VLC & download sample mp3 fileto download folder of Windows.

    You can access the Downloaded File from Launched VLC Player in

        /mnt/c/Users/sangram

    How to access WSL File in Window App Like Explorer ?    

       In Explorer below This PC & Network there is Icon

       on Linux from here you can navigate further

       Path can be

            \\wsl.localhost\Ubuntu\home\sangram

Ubuntu:Key is stored in legacy trusted.gpg keyring

First run

sudo apt update

If you get message saying "Key is stored in legacy

trusted.gpg keyring like below"

Fetched 1,701 kB in 4s (422 kB/s)

Reading package lists... Done

Building dependency tree... Done

Reading state information... Done

28 packages can be upgraded. Run 'apt list --upgradable'

to see them.

W: http://archive.neon.kde.org/user/dists/bionic/InRelease:

Key is

stored in legacy trusted.gpg keyring

(/etc/apt/trusted.gpg), see the DEPRECATION

                section in apt-key(8) for details.

Then you can get rid of this message using following

procedure

cd /etc/apt

sudo cp trusted.gpg trusted.gpg.d

Now run

sudo apt update

You will not get "Key is stored in legacy trusted.gpg

keyring like below" message

Ubuntu :How to install Arduino IDE ?

Download the Installable AppImage file

cd /home/sangram/Applications

wget https://downloads.arduino.cc/arduino-ide/arduino-ide_2.3.3_Linux_64bit.AppImage

Make AppImage Executable

chmod +x arduino-ide_2.3.3_Linux_64bit.AppImage

In Ubuntu 22.04 or higher

sudo add-apt-repository universe

sudo apt install libfuse2

Create /etc/udev/rules.d/99-arduino.rules file

and add following content to it

SUBSYSTEMS=="usb", ATTRS{idVendor}=="2341", GROUP="plugdev", MODE="0666"

Add Launcher

nano ~/.local/share/applications/arduino-ide.desktop

Add Following Content to it

[Desktop Entry]

Version=1.0

Name=Arduino IDE

Exec=/home/sangram/Applications/arduino-ide_2.3.3_Linux_64bit.AppImage

Terminal=false

Icon=/home/sangram/Applications/arduino-ide.png

Type=Application

Categories=Utility;Development;

Clear Icon Cache

gtk-update-icon-cache ~/.icons

gtk-update-icon-cache /usr/share/icons/hicolor

For Gnome:

gsettings reset org.gnome.shell app-picker-layout

Ubuntu: Troubleshooting Installation of dotnet-sdk-8.0

If you try to install Dotnet 8.0 in Ubuntu you get following

error

The following packages have unmet dependencies: dotnet-host-7.0 :

Conflicts: dotnet-host E: Error, pkgProblemResolver::Resolve generated breaks,

this may be caused by held packages.

Lets Troubleshoot it

Remove all repositaries related to microsoft most of the time you added for mssql & vscode

sudo rm -f /etc/apt/sources.list.d/mssql-release.list

sudo rm /etc/apt/sources.list.d/microsoft-prod.list.save

Now remove all dotnet related installed packages

sudo apt purge dotnet-sdk* dotnet-host* dotnet* aspnetcore* netstandard*

Try installing again

sudo apt update

sudo apt install dotnet-sdk-8.0

You can remove this package as

sudo apt-get remove dotnet-sdk-6.0

You cam upgrade from this package by

sudo apt upgrade dotnet-sdk-8.0

Confirm installed packages

dotnet --info

You can confirm list of SDK

dotnet --list-sdk

List runtimes

dotnet --list-runtimes

Ubuntu : Disable Pro Upgrade Messages

Whenever you try to upgrade ubuntu through command line using

sudo apt upgrade

you see message regarding Ubuntu Pro

e.g.

sangram@sangram-Inspiron-14-5430:/etc/apt/sources.list.d$ sudo apt upgrade

Reading package lists... Done

Building dependency tree... Done

Reading state information... Done

Calculating upgrade... Done

Get more security updates through Ubuntu Pro with 'esm-apps' enabled:

You dont want to see this message then

1) Activate the Pro repository.

This repository is not public and is free for up to five machines.

You'll need to create an account (email, username, password) to access it,

which provides additional security updates. To proceed,

register at https://ubuntu.com/pro to obtain your personal token,

then execute the following command:

sudo pro attach your-personal-token

This is the recommended approach by Ubuntu.

2) Remove the advertisement.

Run this command to disable the advertisement:

sudo dpkg-divert --divert /etc/apt/apt.conf.d/20apt-esm-hook.conf.bak

--rename --local /etc/apt/apt.conf.d/20apt-esm-hook.conf

This will create a .bak suffix for the configuration file,

effectively disabling it. This method will remain effective

even after future apt upgrades.

To verify that the changes have taken effect, run apt upgrade. If successful,

the additional text should no longer appear.

Let me know if you need any further adjustments!

Ubuntu: Using Samba to share Apt Cache archives across local network

We will copy apt cache archive and create a folder

that can accessed over network using samba.

create directory inside /home/sangram my username

mkdir -p /home/sangram/cache/apt/archives

Copy all deb files from archive

sudo mv /var/cache/apt/archives/*.deb /home/sangram/cache/apt/archives

Create a user sadmin for purpose of software installtion

Create a New User

sudo adduser --no-create-home sadmin

sudo adduser sadmin

I kept password say "sangram" for user sadmin

You can delete sadmin user by following command

sudo deluser --remove-home sadmin

groupdel sadmin

you can switch user to samin as follows

su sadmin

Add the User to the sudo Group

sudo usermod -aG sudo sadmin

List groups to which sadmin belongs

groups sadmin

Then add sadmin to samba group & set samba password

sudo smbpasswd -a sadmin

Add user sadmin to groups

sudo usermod -aG sambashare sadmin

Change Ownership of /home/sangram/cache/apt/archives folder to sadmin

sudo chown -R sangram:sambashare /home/sangram/cache/

sudo chmod 775 /home/sangram/cache/apt/archives

List users added to samba group

sudo pdbedit -L

Edit smb.conf to make folder /home/sangram/cache/apt/archives

available over network.

sudo nano /etc/samba/smb.conf

Add following to end of file

[SharedAptCacheArchives]

path = /home/sangram/cache/apt/archives

browsable = yes

writable = yes

guest ok = no

read only = no

create mask = 0755

directory mask = 0755

force create mode = 0755

Add following to global section

usershare owner only = false

how to test smb.conf configuration is correct

testparm

Restart samba service:

sudo systemctl restart smbd nmbd

If My Machine Ip Address is 192.168.0.122 then smb://192.168.0.122/SharedAptCacheArchives

will be network url

Mount Shared SharedAptCacheArchives folder

cd /mnt

sudo mkdir SharedAptCacheArchives

sudo chmod 750 /home/sangram

sudo chown sangram:sambashare /home/sangram

sudo chmod -R 755 /mnt/SharedAptCacheArchives

sudo chown -R sangram:sambashare /mnt/SharedAptCacheArchives

sudo mount -t cifs //192.168.0.122/SharedAptCacheArchives /mnt/SharedAptCacheArchives -o sec=ntlmv2,username=sadmin,password=sangram,vers=3.0,uid=$(id -u sadmin),gid=$(id -g sadmin)

If mounted successfully then /mnt/SharedAptCacheArchives will acts as if

this folder contain all debian files in it from /home/sangram/cache/apt/archives

Enable Required Services (troubleshooting):

sudo systemctl enable systemd-networkd-wait-online

sudo systemctl enable networkd-dispatcher.service

sudo systemctl enable systemd-networkd.service

sudo systemctl enable NetworkManager-wait-online.service

systemctl status networkd-dispatcher.service systemd-networkd.service

View Logs of error in mounting at

sudo dmesg | tail -n 20

You can also view mounted filesystems by checking the /proc/mounts file

cat /proc/mounts

Check Folder Permission

cd /home/sangram/cache/apt/archives/

ls *.deb -ld .

To test our setting we will use smbclient as follows

List all shared folderson the ip address (Machine)

smbclient -L //192.168.0.122 -U sadmin

You can check if our setup worked or not by using smbclient.

After login run "ls"command to verify files are there.

smbclient //192.168.0.122/SharedAptCacheArchives -U sadmin

smbclient //192.168.0.122/SharedAptCacheArchives -U sangram

Logs of error while mounting can be viewed by following query:

sudo dmesg | tail -n 20

Ubuntu : How to use ftp package repositary

In soucres.list mostly all package repositoies are https or

http but we can also use ftp package repositary.

Lets first edit our sources.list

sudo nano /etc/apt/sources.list

add following to it

deb ftp://ftp.ubuntu.com/ubuntu/ focal main universe

save & exit.

But By Default in ubuntu repository need to be https or http

to use ftp with it run following command

echo 'Dir::Bin::Methods::ftp "ftp";' | sudo tee -a /etc/apt/apt.conf.d/99local-ftp

Now run

sudo apt-get update

Now it will use ftp url also.

MATLAB - Adding missing launcher in UBUNTU

Add Missing Launcher for MatLab in Ubuntu

Launch Terminal

1.download your own icon-

sudo wget

http://upload.wikimedia.org/wikipedia/commons/2/21/

Matlab_Logo.png -O /usr/share/icons/matlab.png

2.create launcher file

sudo touch /usr/share/applications/matlab.desktop

3.edit launcher file

sudo nano /usr/share/applications/matlab.desktop

4.add following into the launcher file.

#!/usr/bin/env xdg-open

[Desktop Entry]

Type=Application

Icon=/usr/share/icons/matlab.png

Name=MATLAB R2014a

Comment=Start MATLAB - The Language of Technical Computing

Exec=/usr/local/MATLAB/R2024b/bin/matlab -desktop

Categories=Development;

Save & lauch matlab from icon.

Lets write simple script to display triangle as follows

Create Following Script in MatLab& Run.

clc

clear all

close all

x=[0,1,2]

y=[0,1,0]

plot(x,y,'Color','blue','LineWidth',1);

area(x,y,'FaceColor','green');

Now save it & run,IF you got low level graphic error then

cd /usr/local/MATLAB/R2024b/bin

now launch matlab as

./matlab -softwareopengl

Now Try to run script if this time script render

triangle then

In Matlab terminal

opengl('save','software')

This will add prefernces to matlab wrt opengl

Exit & launch Matlab from Launcher instead of command line &

recheck if it is rendering Triangle as previously.

Running Javascript function from Angular component

 

we can run javascript from angular code on certain event.

For that first create a javascript file inside asset folder.

Mine is located at src/assets/js/selectPickerTrigger.js

Inside this js file add following code

function reRenderSelect(){

alert("I M IN")

}

Go to angular.json file search for script tag & add path to your js file here.

"scripts": [

"src/assets/js/selectPickerTrigger.js"

]

Now go to your name.component.ts file

add following to list of import statements.

import { Component, OnInit, ViewChild, ElementRef } from '@angular/core';

declare function reRenderSelect(): any;

Now you can call our reRenderSelect() function from anywhere in component.ts

code as

onCountrySelected(value: string) {

reRenderSelect()

}

Here I am running reRenderSelect() function from a event handler for select

change,you can run it from anywhere in name.component.ts

Node.js:Getting latitude & longitude based on address.

Recently I was got into situation where I have tables of country,state,

city with

proper foreign key and referenced in other data but I need latitude &

longitude for city.I does not wanted to create new table so I altered City

Table.

My City Altered Table schema in MySQL after modification look like below

CREATE TABLE `City` (

`id` int unsigned NOT NULL AUTO_INCREMENT,

`name` varchar(255) NOT NULL,

`countryId` int unsigned NOT NULL,

`stateId` int unsigned NOT NULL,

`createdAt` datetime NOT NULL,

`updatedAt` datetime NOT NULL,

`deletedAt` datetime DEFAULT NULL,

`latitude` float DEFAULT NULL,

`longitude` float DEFAULT NULL,

PRIMARY KEY (`id`),

KEY `countryId` (`countryId`),

KEY `stateId` (`stateId`),

CONSTRAINT `City_ibfk_5` FOREIGN KEY (`countryId`) REFERENCES `Country` (`id`),

CONSTRAINT `City_ibfk_6` FOREIGN KEY (`stateId`) REFERENCES `State` (`id`)

) ENGINE=InnoDB

Now I left with way to find latitude & longitude for each city ,some data is

available freely online but it is needed to inserted into new table then extract

latitude & longitude for my table.

I came across a API provider by geocode.maps.co that lets you get latitude &

longitude from address. I registered for API Key ,its free plan lets us make

100,000 api calls per month with limit 1 request per second.

Below is code in Node.js to accomplish same.

What I am doing in code.

1) Getting City which does not have latitude & longitude in City table along

with country & state names

2) Making API call to get latitude & longitude based on city name, state

name,country name.

3) Update the City record with its latitude & longitude.

NPM dependencies used in code:

npm i mysql2

Node.js Code:

const mysql = require('mysql2/promise');

const apiKey = '{Your API Key}';

// Function to create a delay

function delay(ms) {

return new Promise(resolve => setTimeout(resolve, ms));

}

async function getCityWithoutLatLong() {

let connection;

try {

connection = await getConnection();

const query = 'SELECT country.id as countryId, country.name

                countryName, state.id as stateId, state.name stateName,

                city.id as cityId, city.name cityName FROM City city

                INNER JOIN Country country ON city.countryId = country.id

                INNER JOIN State state ON city.stateId = state.id

                WHERE city.countryId = 101;';

const [results] = await connection.query(query);

// Process each city sequentially with a delay

for (const element of results) {

const address = `${element.countryName},${element.stateName},

${element.cityName}`;

const apiEndpoint = `https://geocode.maps.co/search?

q=${address}&api_key=${apiKey}`;

console.log(`Calling API with cityId=${element.cityId}`);

await callAPI(element.cityId, apiEndpoint);

await delay(1000); // Wait for 1 second before the next API call

}

} catch (err) {

console.error('Error in getCityWithoutLatLong:', err);

} finally {

if (connection && connection.end) await connection.end();

console.log("Exited Process in function getCityWithoutLatLong");

process.exit();

}

}

// Function to call an API and process the response

async function callAPI(cityId, apiEndpoint) {

try {

const requestOptions = {

method: "GET",

redirect: "follow"

};

const response = await fetch(apiEndpoint, requestOptions);

if (!response.ok) {

throw new Error(`HTTP error! Status: ${response.status}`);

}

const data = await response.json();

const lat = data[0].lat;

const long = data[0].lon;

console.log(`lat=${lat}, long=${long}`);

const updateResult = await updateCityWithLatLong(cityId, lat, long);

console.log("City updated:", updateResult);

} catch (error) {

console.error('Fetch error:', error);

}

}

// Function to update the city with latitude and longitude in the database

async function updateCityWithLatLong(cityId, lat, long) {

let connection;

try {

connection = await getConnection();

const query = `UPDATE City SET latitude = ?, longitude = ? WHERE id = ?`;

const [results] = await connection.query(query, [lat, long, cityId]);

return results;

} catch (err) {

console.error('Database query error:', err);

} finally {

if (connection && connection.end) await connection.end();

}

}

// Function to get a connection to the database

async function getConnection() {

const connection = await mysql.createConnection({

host: 'localhost',

user: 'root',

password: 'sangram#81',

database: 'MatrimonyDb'

});

return connection;

}

getCityWithoutLatLong();

In My Code I Hardcoded Id of Country India i.e. 101.Modify My Code as per your

table structure,You need to replace API KEY in above code.

Dynamoose & Express.js :CRUD Operations

Today we explore dynamoose a ODM or dynamodb.I am using local dynamodb

instead of cloud instance.

As usual I am creating by base express template using generator.

express --view=ejs dynamoose-express

Now i will create a demo.js in route & mount it in app.js at mountpoint 'demo'

Content of demo.js

var express = require("express");

var router = express.Router();

var User = require("../models/userModel");

/* GET home page. */

router.post("/createUser", async function (req, res, next) {

try {

// Use the model

const user = new User({

name: req.body.name,

email: req.body.email,

age: req.body.age,

});

// Save the user to DynamoDB

let savedUser = await user.save({ overwrite: false });

savedUser.createdAt = new Date(savedUser.createdAt)

res.json({

success: true,

message: "User created Successully",

data: savedUser,

});

} catch (exp) {

res.json({ success: false, message: exp.message });

}

});

//get record by email

router.get("/getByEmail/:email", async function (req, res, next) {

try {

let user = await User.query("email").eq(req.params.email).exec();

res.json({ success: true, message: "User found", data: user });

} catch (exp) {

res.json({ success: false, message: exp.message });

}

});

//get record by user id

router.get("/getByUserId/:userId", async function (req, res, next) {

try {

let user = await User.query("userId").eq(req.params.userId).exec();

res.json({ success: true, message: "User found", data: user });

} catch (exp) {

res.json({ success: false, message: exp.message });

}

});

//get all records

router.get("/getAll", async function (req, res, next) {

try {

const users = await User.scan().exec();

res.json({ success: true, message: "User found", data: users });

} catch (exp) {

res.json({ success: false, message: exp.message });

}

});

//greater than

router.get("/youngerThan/:age", async function (req, res, next) {

try {

const users = await User.scan()

.filter("age")

.gt(parseInt(req.params.age))

.exec();

res.json({ success: true, message: "User found Successully", data: users });

} catch (exp) {

res.json({ success: false, message: exp.message });

}

});

//delete

router.delete("/:userId", async (req, res, next) => {

try {

let myUser = await User.query("userId").eq(req.params.userId).exec();

if (myUser.length) {

await myUser[0].delete(); // Delete the user with the specified userId

res.json({ success: true, message: "User deleted successfully" });

} else {

res.json({ success: false, message: "User not found" });

}

} catch (exp) {

res.json({ success: false, message: exp.message });

}

});

//update

router.put("/:userId", async (req, res, next) => {

try {

let myUser = new User({

name: req.body.name,

email: req.body.email,

age: req.body.age,

userId: req.params.userId,

updatedAt: Date.now(),

});

myUser = await myUser.save({ overwrite: true });

myUser.updatedAt = new Date(myUser.updatedAt)

myUser.createdAt = new Date(myUser.createdAt)

res.json({

success: true,

message: "User saved successfully",

data: myUser,

});

} catch (exp) {

res.json({ success: false, message: exp.message });

}

});

module.exports = router;

Changes required in app.js

var demoRouter = require('./routes/demo');

&

app.use('/demo', demoRouter);

Now lets install required npm packages

Please check the packages to install from package.json below

{

"name": "dynamoose-express",

"version": "0.0.0",

"private": true,

"scripts": {

"start": "node ./bin/www"

},

"dependencies": {

"cookie-parser": "~1.4.4",

"debug": "~2.6.9",

"dotenv": "^16.4.5",

"dynamoose": "^4.0.1",

"ejs": "~2.6.1",

"express": "^4.19.2",

"http-errors": "~1.6.3",

"morgan": "~1.9.1",

"uuid": "^9.0.1"

}

}

Now add connection.js at root

const dynamoose = require('dynamoose');

dynamoose.aws.ddb.local("http://localhost:8000")

module.exports = dynamoose

create a models folder and add userModel.js into it as

const dynamoose = require("../connection");

const { v4: uuidv4 } = require('uuid');

const UserSchema = new dynamoose.Schema(

{

userId: {

type: String,

hashKey: true,

default:uuidv4()

},

email: {

type: String,

index: {

name: "EmailIndex",

global: true,

rangeKey: "userId",

},

},

name: {

type: String,

},

age: Number,

createdAt: {

type: Date,

default: Date.now,

},

updatedAt: {

type: Date,

default: null,

},

},

{

throughput: "ON_DEMAND", // or { read: 5, write: 5 }

}

);

const User = dynamoose.model("User", UserSchema);

module.exports = User;

My .env file is as below

AWS_ACCESS_KEY_ID = "fakeMyKeyId"

AWS_SECRET_ACCESS_KEY = "fakeSecretAccessKey"

AWS_REGION = "fakeRegion"

You can run npm install meanwhile if npm packages not yet installed.

Now to check & rest endpoint created run npm start.

Endpoint:

For creation of User:

curl --location 'http://localhost:3000/demo/createUser' \

--header 'Content-Type: application/json' \

--data-raw '{

"name":"Vijay Desai",

"email":"Vijay@gmail.com",

"age":24

}'

Output:

{

"success": true,

"message": "User created Successully",

"data": {

"name": "Vijay Desai",

"email": "Vijay@gmail.com",

"age": 24,

"userId": "fda3f7e2-c835-45ff-853c-b93f8b26cb93",

"createdAt": "2024-05-04T13:28:45.554Z"

}

}

For Updation of Existing User.

curl --location --request PUT 'http://localhost:3000/demo/2' \

--header 'Content-Type: application/json' \

--data-raw '{

"name": "Sangram Desai",

"email": "sangram@gmail.com",

"age": 43

}'

Output:

{

"success": true,

"message": "User saved successfully",

"data": {

"name": "Sangram Desai",

"email": "sangram@gmail.com",

"age": 43,

"userId": "2",

"updatedAt": "2024-05-04T13:31:30.480Z",

"createdAt": "2024-05-04T13:31:30.483Z"

}

}

For viewing list o all users:

curl --location 'http://localhost:3000/demo/getAll'

For getting user by its userId:

curl --location 'http://localhost:3000/demo/getByUserId/fda3f7e2-c835-45ff-853c-b93f8b26cb93'

There are some other endpoint that you can explore.

The complete code of this project is available at

https://github.com/gitsangramdesai/dynamoose-express.

In DynamoDb there is no inbuild functionlity that is similar to auto-increment id in mysql,

people usually use uuid's for primary key.primary key in Dynamodb is made up of partition key

& sort key.Records with same partition key will be saved in one partition & sorted by

sort key(range key).You can also define primary key without sort key(range key)

AWS DynamoDB: How to install locally in Ubuntu?

It is possible to install dynamodb locally,lets explore how.

First Download jar file

wget https://d1ni2b6xgvw0s0.cloudfront.net/v2.x/dynamodb_local_latest.tar.gz

Now extract the the archieve.

Rename extracted folder as dynamodb

Copy it to location where you want to install binary

mv dynamodb /usr/share/

Now on command line go to folder in which dynamodb is copied,

in this case /usr/share/dynamodb.

cd /usr/share/dynamodb

Test i it runs from terminal by running this

sudo java -Djava.library.path=./DynamoDBLocal_lib -jar DynamoDBLocal.jar -sharedDb

Now if you want to test the server each time you would have to run this command

To keep it running each time without running manually we need a service.

To create a service

sudo nano /etc/systemd/system/dynamodb.service

add ollowing to it

[Unit]

Description=DynamoDB Service

[Service]

User=root

WorkingDirectory=/usr/share/dynamodb

ExecStart=/usr/share/dynamodb/dynamodb.sh

SuccessExitStatus=143

TimeoutStopSec=10

Restart=on-failure

RestartSec=5

[Install]

WantedBy=multi-user.target

save & exit

Now we will create a shell script file referred in service above.

cd /usr/share/dynamodb

nano dynamodb.sh

add

#!/bin/sh

sudo java -Djava.library.path=./DynamoDBLocal_lib -jar DynamoDBLocal.jar -sharedDb

save and exit.

Make shell script executable file

chmod u+x dynamodb.sh

Now let system know that we have created a new service

sudo systemctl daemon-reload

sudo systemctl enable dynamodb

sudo systemctl start dynamodb

sudo systemctl status dynamodb

output of last command in my case is like below

● dynamodb.service - Dynamo DB Local Service

Loaded: loaded (/etc/systemd/system/dynamodb.service; enabled; vendor preset: enabled)

Active: active (running) since Sat 2024-05-04 11:13:52 IST; 11min ago

Main PID: 33499 (dynamodb.sh)

Tasks: 41 (limit: 18708)

Memory: 150.8M

CPU: 4.333s

CGroup: /system.slice/dynamodb.service

├─33499 /bin/sh /usr/share/dynamodb/dynamodb.sh

├─33500 sudo java -Djava.library.path=./DynamoDBLocal_lib -jar DynamoDBLocal.jar -sharedDb

└─33501 java -Djava.library.path=./DynamoDBLocal_lib -jar DynamoDBLocal.jar -sharedDb

May 04 11:13:52 sangram-Inspiron-14-5430 sudo[33500]: root : PWD=/usr/share/dynamodb ; USER=root ; COMMAND=/usr/bin/java -Djava.library.path=./DynamoDBLocal_lib -jar DynamoDBLocal.jar -sharedDb

May 04 11:13:52 sangram-Inspiron-14-5430 sudo[33500]: pam_unix(sudo:session): session opened for user root(uid=0) by (uid=0)

May 04 11:13:53 sangram-Inspiron-14-5430 dynamodb.sh[33501]: Initializing DynamoDB Local with the following configuration:

May 04 11:13:53 sangram-Inspiron-14-5430 dynamodb.sh[33501]: Port: 8000

May 04 11:13:53 sangram-Inspiron-14-5430 dynamodb.sh[33501]: InMemory: false

May 04 11:13:53 sangram-Inspiron-14-5430 dynamodb.sh[33501]: Version: 2.4.0

May 04 11:13:53 sangram-Inspiron-14-5430 dynamodb.sh[33501]: DbPath: null

May 04 11:13:53 sangram-Inspiron-14-5430 dynamodb.sh[33501]: SharedDb: true

May 04 11:13:53 sangram-Inspiron-14-5430 dynamodb.sh[33501]: shouldDelayTransientStatuses: false

May 04 11:13:53 sangram-Inspiron-14-5430 dynamodb.sh[33501]: CorsParams: null

Now we need to install awscli on ubuntu as ollows

curl "https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip"

-o "awscliv2.zip"

unzip awscliv2.zip

sudo ./aws/install

Now run aws configure

and give below response to when prompted.

AWS Access Key ID [****************yId"]: fakeMyKeyId

AWS Secret Access Key [****************Key"]: fakeSecretAccessKey

Default region name ["fakeRegion"]: fakeRegion

Default output format [None]:

The response need to be given as given above.

Now you can check lists o tables in dynamodb by running follwoing command

aws dynamodb list-tables --endpoint-url http://localhost:8000

You may also like to check how to do CRUD oprtion in dynamoDb using exprress

https://msdotnetbuddy.blogspot.com/2023/05/working-with-dynamo-db.html.

References:

https://medium.com/aws-lambda-serverless-developer-guide-with-hands/

amazon-dynamodb-primary-key-partition-key-and-sort-key-how-to-choose-right-

key-for-dynamodb-ea5673cb87c0

Sequelize-Postgres-Express:Upload file to database

Today we will explore how to upload an file (image) into

mysql database using sequelize.

Lets first create a express application using express generator.

express --view=ejs express-postgres-upload-file

Here is my package.json whivh you can check to install required npm

packages,

{

"name": "express-mysql-upload-file",

"version": "0.0.0",

"private": true,

"scripts": {

"start": "node ./bin/www"

},

"dependencies": {

"cookie-parser": "~1.4.4",

"debug": "~2.6.9",

"dotenv": "^16.4.5",

"ejs": "~2.6.1",

"express": "~4.16.1",

"http-errors": "~1.6.3",

"morgan": "~1.9.1",

"multer": "^1.4.5-lts.1",

"pg": "^8.11.5",

"sequelize": "^6.37.3"

}

}

Here we are installing multer,dotenv,sequelize,mysql2 packages.

Run npm i.

create .env file in root folder with content

PG_USER=sangram

PG_PASSWORD="sangram#81"

PG_PORT=5432

PG_DATABASE=playground

PG_SERVER=localhost

Now add upload.js in root folder with ollowing content.

var multer = require("multer");

var storage = multer.diskStorage({

destination: (req, file, cb) => {

cb(null, "./public/uploads/profile_pic/");

},

filename: function (req, file, cb) {

var fileparts = file.originalname.split(".");

var ext = fileparts[fileparts.length - 1];

cb(null, file.fieldname + "-" + Date.now() + "." + ext);

},

});

var upload = multer({ storage: storage });

module.exports = upload;

create models folder in root location & add image.js in it.

module.exports = function (sequelize, DataTypes) {

const Image = sequelize.define('image', {

imageId: {

type: DataTypes.INTEGER,

autoIncrement: true,

primaryKey: true

},

mimeType: {

type: DataTypes.STRING,

},

fileName: {

type: DataTypes.STRING,

field: 'name'

},

data: {

type: DataTypes.BLOB("long"),

}

}, {

freezeTableName: true

});

return Image;

}

Now create index.js inside model folder with following content

let { sequelize, Sequelize } = require("../connection.js");

let db = {};

db.Images = require("./image.js")(Sequelize,sequelize);

db.Sequelize = Sequelize;

db.sequelize = sequelize;

module.exports = db;

Now add uploads folder in public folder & inside uploads folder

add profile_pic folder.

Now create demo.js inside rotes folder with following content.

var express = require("express");

var router = express.Router();

var db = require("../models");

var upload = require("../uploads");

var fs = require("fs");

var path = require("path");

router.post("/", upload.single("image"), async (req, res, next) => {

try {

let imageCreated = await db.Images.create({

mimeType: req.file.mimetype,

fileName: req.file.filename,

data: fs.readFileSync(

path.join("./public/uploads/profile_pic/" + req.file.filename)

),

});

res.json({

success: true,

message: "File Uploaded to Mysql Successfully",

data: imageCreated,

});

} catch (exp) {

res.json({ success: false, message: exp.message.toString() });

}

});

router.get("/:fileId", async (req, res) => {

try {

var imageFound = await db.Images.findOne({

where: { imageId: req.params.fileId },

});

var buffer = imageFound.data;

var mimeType = imageFound.mimeType;

res.contentType(mimeType);

res.send(buffer);

} catch (exp) {

res.json({ success: false, message: exp.message.toString() });

}

});

module.exports = router;

Inside app.js add

var demoRouter = require('./routes/demo');

and

app.use('/demo', demoRouter);

in suitable location.

Now we are ready to run our application.Usually testing can be done using

postman.

For uploading image

curl --location 'http://localhost:3000/demo' \

--form 'image=@"/home/sangram/Pictures/Photo.jpg"'

Output:

{

"success": true,

"message": "File Uploaded to Mysql Successfully",

"data": {

"imageId": 1,

"mimeType": "image/jpeg",

"fileName": "image-1714485923005.jpg",

"data":{contain binary data},

"updatedAt": "2024-04-30T13:07:35.512Z",

"createdAt": "2024-04-30T13:07:35.512Z"

}

}

Please notice imageId that we are going to use in next api call.

curl --location 'http://localhost:3000/demo/1'

This will output image uploaded in previous step.

The complete code of this application can be found at

https://github.com/gitsangramdesai/express-sequelize-pg-upload-file