Welcome to MultiChain Web Demo

 This software uses PHP to provide a web front-end for a MultiChain blockchain node.

It currently supports the following features:

• Viewing the node's overall status.
• Creating addresses and giving them real names (names are visible to all nodes).
• Changing global permissions for addresses.
• Issuing assets, including custom fields and uploading a file.
• Updating assets, including issuing more units and updating custom fields and file.
• Viewing issued assets, including the full history of fields and files.
• Sending assets from one address to another.
• Creating, decoding and accepting offers for exchanges of assets.
• Creating streams.
• Publishing items to streams, as JSON or text or an uploaded file.
• Viewing stream items, including listing by key or publisher and downloading files.
• Writing, testing and approving Smart Filters (both transaction and stream filters).

The web demo does not yet support the following important functionality in the MultiChain API:

• Managing per-asset and per-stream permissions.
• Multisignature addresses and transactions.
• Adding metadata (or stream items) to permissions or asset transactions.
• Viewing an addresses' transactions.
• Subscribing to assets and viewing their transactions.
• Viewing a list of keys or publishers in a stream.
• Peer-to-peer node management.
• Message signing and verification.
• Blockchain upgrading.
• Working with the binary cache.

The MultiChain Web Demo is still under development, so please contact us if any of these things are crucial for your needs.

System Requirements

• A computer running web server software such as Apache.
• PHP 5.x or later with the curl and JSON extensions.
• MultiChain 1.0 alpha 26 or later, including MultiChain 2.0 alphas and betas.

Create and launch a MultiChain Blockchain

If you do not yet have a chain to work with, Download MultiChain to install MultiChain and create a chain named chain1 as follows:

multichain-util create chain1
multichaind chain1 -daemon

If your web server is running on the same computer as multichaind, you can skip the rest of this section. Otherwise:

multichain-cli chain1 stop

Then add this to ~/.multichain/chain1/multichain.conf:

rpcallowip=[IP address of your web server]

Then start MultiChain again:

multichaind chain1 -daemon

Configure the Web Demo

This section assumes your blockchain is named chain1 and you are running the node and web server on a Unix variant such as Linux. If not, please substitute accordingly.

Make your life easy for the next step by running these on the node's server:

cat ~/.multichain/chain1/multichain.conf
grep rpc-port ~/.multichain/chain1/params.dat

In the web demo directory, copy the config-example.txt file to config.txt:

cp config-example.txt config.txt

In the demo website directory, enter chain details in config.txt e.g.:

default.name=Default                # name to display in the web interface
default.rpchost=127.0.0.1           # IP address of MultiChain node
default.rpcport=12345               # usually default-rpc-port from params.dat
default.rpcuser=multichainrpc       # username for RPC from multichain.conf
default.rpcpassword=mnBh8aHp4mun... # password for RPC from multichain.conf

Multiple chains are supported by the web demo by copying the same section again but with different prefixes before the period, for example:

another.name=...
another.rpchost=...
...

Note that the config.txt file is readable by users of your web demo installation, and contains your MultiChain API password, so you should never use this basic setup for a production system.

How to enable and disable PHP curl module with Apache on Ubuntu Linux and Debian/Ubuntu Linux Specific Commands to Start/Stop/Restart Apache

 

Instructions

Installation of Curl module

Let's install Apache curl module along with Apache 2 webserver and PHP.

# apt install libapache2-mod-php php-curl

Restart the Apache webserver:

# service apache2 restart

Check for curl module state

Insert the following lines into a new PHP script eg. curl-check.php within /var/www/html/ directory:
<?php
echo 'Curl: ', function_exists('curl_version') ? 'Enabled' . "\xA" : 'Disabled' . "\xA";
?>
Make the script executable and use curl command to render the output of curl-check.php php code:
# chmod +x /var/www/html/curl-check.php
# curl localhost/curl-check.php
Curl: Enabled

Disable PHP curl module

To disable curl php module execute:
# phpdismod curl
# service apache2 restart
# curl localhost/curl-check.php
Curl: Disabled

Enable PHP curl module

To enable curl php module execute:
# phpenmod curl
# service apache2 restart
# curl localhost/curl-check.php
Curl: Enabled
source

You can either use service or /etc/init.d/ command as follows on Debian Linux version 7.x or Ubuntu Linux version Ubuntu 14.10 or older:

Restart Apache 2 web server, enter:

# /etc/init.d/apache2 restart
OR
$ sudo /etc/init.d/apache2 restart
OR
$ sudo service apache2 restart

To stop Apache 2 web server, enter:

# /etc/init.d/apache2 stop
OR
$ sudo /etc/init.d/apache2 stop
OR
$ sudo service apache2 stop

To start Apache 2 web server, enter:

# /etc/init.d/apache2 start
OR
$ sudo /etc/init.d/apache2 start
OR
$ sudo service apache2 start

A note about Debian/Ubuntu Linux systemd users

Use the following systemctl command on Debian Linux version 8.x+ or Ubuntu Linux version Ubuntu 15.04+ or above:
## Start command ##
systemctl start apache2.service
## Stop command ##
systemctl stop apache2.service
## Restart command ##
systemctl restart apache2.service
We can view status using the following command:
$ sudo systemctl status apache2.service

● apache2.service - The Apache HTTP Server
     Loaded: loaded (/lib/systemd/system/apache2.service; enabled; vendor preset: enabled)
     Active: active (running) since Wed 2021-02-24 20:39:39 UTC; 5 days ago
       Docs: https://httpd.apache.org/docs/2.4/
    Process: 115 ExecStart=/usr/sbin/apachectl start (code=exited, status=0/SUCCESS)
    Process: 15247 ExecReload=/usr/sbin/apachectl graceful (code=exited, status=0/SUCCESS)
   Main PID: 128 (apache2)
      Tasks: 6 (limit: 4672)
     Memory: 16.4M
     CGroup: /system.slice/apache2.service
             ├─  128 /usr/sbin/apache2 -k start
             ├─15254 /usr/sbin/apache2 -k start
             ├─15255 /usr/sbin/apache2 -k start
             ├─15256 /usr/sbin/apache2 -k start
             ├─15257 /usr/sbin/apache2 -k start
             └─15258 /usr/sbin/apache2 -k start

Feb 27 00:00:23 ubuntu-db-mgmnt systemd[1]: Reloaded The Apache HTTP Server.
Feb 28 00:00:23 ubuntu-db-mgmnt systemd[1]: Reloading The Apache HTTP Server.

Cara Instal Windows Subsystem For Linux 2 di Windows 10

 

Windows 10 – Lengkap Dengan Gambar

Windows Subsystem For Linux telah diperbarui, awalnya WSL 2 ini dirumorkan akan hadir mulai dari Windows 10 1909 tapi nyatanya mulai dirilis Microsoft pada Windows 10 May 2020 Update yang dikirim beberapa hari lalu, ada beberapa peningkatan yang ditambahkan termasuk peningkatan performa yang kini lebih cepat dibandingkan sebelumnya.

 Bedah Fitur Windows 10 ep.1: File Explorer!

Dan pada artikel kali ini, WinPoin akan menunjukan langkah Instalasi Windows Subsystem For Linux 2 di Windows 10. Sebenarnya langkahnya bisa dibilang mirip dengan instalasi WSL 1 hanya saja ada langkah tambahan yang perlu dilakukan. Langsung saja, berikut adalah langkah langkahnya.

Langkah 1. Pastikan kamu sudah menggunakan Windows 10 May 2020 Update.

Langkah 2. Silahkan kamu tambahkan ‘Windows Subsystem For Linux’ di Turn Windows Features.

Atau cara cepatnya, kamu juga bisa memasukan perintah berikut dalam Windows Powershell Run As Administrator.

dism.exe /online /enable-feature /featurename:Microsoft-Windows-Subsystem-Linux /all /norestart

Catatan : Jika hanya instalasi Windows Subsystem For Linux Generasi pertama, setelah langkah ini kamu hanya perlu restart dan download distro linux dari Microsoft Store.

Langkah 3. Untuk melanjutkan instalasi WSL 2, selanjutnya kamu harus mengaktifkan ‘Virtual Machine Platform’ masih dari Turn Windows Features.

Atau langkah cepatnya kamu bisa mengetikan perintah berikut dalam Windows Powershell Run As Administrator.

dism.exe /online /enable-feature /featurename:VirtualMachinePlatform /all /norestart

Untuk menyelesaikan perubahan, silahkan Restart perangkat yang kamu gunakan.

Langkah 4. Untuk menjadikan WSL 2 sebagai Versi WSL Default, kamu bisa mengetikan perintah berikut masih dalam Windows Powershell Run As Administrator.

wsl --set-default-version 2

Jika kamu mendapati pesan “WSL 2 requires an update to its kernel component. For information please visit https://aka.ms/wsl2kernel” seperti pada gambar diatas, kamu harus mendownload dan menginstal file WSL Update yang dapat kamu download pada halaman Microsoft berikut.

Selanjutnya silahkan install file tersebut seperti biasa.

Panduan Instalasi Windows Server - Enable the Windows Subsystem for Linux

 

Windows Server Installation Guide

• The Windows Subsystem for Linux is available for installation on Windows Server 2019 (version 1709) and later. This guide will walk through the steps of enabling WSL on your machine.

Enable the Windows Subsystem for Linux

Before you can run Linux distros on Windows, you must enable the "Windows Subsystem for Linux" optional feature and reboot.

Open PowerShell as Administrator and run:

PowerShell

    Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Windows-Subsystem-Linux

Download a Linux distribution

Follow these instructions to download your favorite Linux distribution.

Extract and install a Linux distribution

Now that you've downloaded a Linux distribution, in order to extract its contents and manually install, follow these steps:

1. Extract the <distro>.appx package's contents, using PowerShell:

   PowerShell

   Rename-Item .\Ubuntu.appx .\Ubuntu.zip
   Expand-Archive .\Ubuntu.zip .\Ubuntu
   

2. Run the distribution launcher application in the target folder. The launcher is typically named <distro>.exe (for example, ubuntu.exe).

   

 Caution

Installation failed with error 0x8007007e: If you receive this error, then your system doesn't support WSL. Ensure that you're running Windows build 16215 or later. Check your build. Also check to confirm that WSL is enabled and your computer was restarted after the feature was enabled.

3.Add your distro path to the Windows environment PATH (C:\Users\Administrator\Ubuntu in this example), using PowerShell:

PowerShell

$userenv = [System.Environment]::GetEnvironmentVariable("Path", "User")
[System.Environment]::SetEnvironmentVariable("PATH", $userenv + ";C:\Users\Administrator\Ubuntu", "User")

You can now launch your distribution from any path by typing <distro>.exe. For example: ubuntu.exe.

Now that it is installed, you must initialize your new distribution instance before using it.

source : https://docs.microsoft.com/en-us/windows/wsl/install-on-server

Maintance iptables kernel module missing after upgrade from Ubuntu 18.04 -> 20.04

 Salah satu cara untuk melakukan maintance dari iptables

sudo apt-get install --reinstall iptables

sudo apt-get install --reinstall linux-headers-$(uname -r)

sudo dpkg-reconfigure iptables

dkms autoinstall

To get the same error by typing:

iptables -L

I've already upgrade my kernel with:

sudo apt-get update
sudo apt-get full-upgrade

I've tried to reboot the system but it didn't work.