C 313: Multichain Explorer (10 pts.)

What you need:

Purpose

Blockchain explorers allow people to examine the blockchain with a Web browser. Here are some public blockchain explorers: In this project, you'll add an explorer to your Samchain node.]\

Installing Prerequisites

In a Terminal, execute these commands, one at a time: 
sudo apt update
sudo apt install sqlite3 libsqlite3-dev python-dev python-pip -y
pip install pycrypto
pip install py-ubjson

Installing Multichain Explorer

On your Ubuntu server, in a Terminal, execute these commands: 
cd
git clone https://github.com/MultiChain/multichain-explorer.git
cd multichain-explorer
python setup.py install --user
A long series of "copying" messages scrolls by, as shown below.

Finding the RPC Port

In a Terminal, execute this command: 
grep rpc ~/.multichain/samchain/params.dat
The default-rpc-port should be 4415, as shown below.

Execute this command to add the port number to the configuration file: 

echo "rpcport=4415" >> ~/.multichain/samchain/multichain.conf

Configuring the Web Server

In a Terminal, execute these commands: 
cd
cd multichain-explorer
cp chain1.example.conf samchain.conf
nano samchain.conf

Make these changes, as shown below:

Save the file with Ctrl+X, Y, Enter.

Load Data

To load existing data into the explorer, execute this command: 
python -m Mce.abe --config samchain.conf --commit-bytes 100000 --no-serve
A series of blocks load, as shown below.

Start the Web Server

To serve the Multichain Explorer page, execute this command: 
python -m Mce.abe --config samchain.conf
The server starts listening, as shown below.

Allowing port 2750 Traffic

In the Google Cloud Platform page, in the line for one of your Debian servers, on the right side, click the three-dot icon, and click "View network details", as shown below.

On the "Firewall rules" page, click "CREATE FIREWALL RULE", as shown below.

On the 'Create a firewall fule" page, make these entries, as shown below:

At the bottom of the page, click the Create button.

Viewing Multichain Explorer

In your browser, go to this URL, replacing the IP address with the correct address of your server:

http://172.16.1.132:2750

Multichain Explorer appears, as shown below.

Viewing the Genesis Block

Near the top of the Multichain Explorer window, the number of Blocks appears. When I did it, there were 152 blocks; it will be larger when you do it.

To see the first block, also known as the "Genesis" block, in the Search field, enter 0, as shown in the image above.

Click the Search button.

In the "Search Results" page, click "MultiChain samchain 0".

C 313.1: Nonce (10 pts)

The flag is the Nonce value for block 0, covered by a green box in the image below.

Sources

Welcome to MultiChain Explorer
Errors after pip upgrade
Posted 6-18-18 by Sam Bowne
Revised for Google cloud and the new scoring engine 7-7-19