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Setup a (Local) Block Explorer

What is a Block Explorer?​

A block explorer is a web-based tool that allows users to search and view information about blocks, transactions, and other data on a blockchain. This information can include details about the transaction history of a particular address, the number of confirmations a transaction has received, and the current status of a transaction.

Block explorers are useful for a number of reasons. For users of a blockchain network, block explorers can provide useful information about their own transactions and the state of the network. For example, a user can use a block explorer to view the current status of a transaction they have made, or to check the balance of their wallet.

Additionally, block explorers can be useful for developers working on applications or other projects that make use of a blockchain. By providing access to detailed information about transactions and blocks, block explorers can help developers to understand how the blockchain is being used and to identify potential issues or problems.

In general, block explorers are an important resource for anyone interested in learning more about a particular blockchain or in using a blockchain for their own projects.

Running Blockscout locally (MacOS)​

BlockScout provides a comprehensive, easy-to-use interface for users to view, confirm, and inspect transactions on EVM (Ethereum Virtual Machine) blockchains.

Cloning the Repository​

We have our own deltaDAO fork of blockscout which includes our specific branding.

git clone git@github.com:deltaDAO/blockscout.git

External: 
git clone https://github.com/blockscout/blockscout.git

docker-compose - Easiest way to run a local instance (not for development)​

The easiest way to run Blockscout on you mac is via the docker-compose. Make sure docker is already set up. 

cd docker-compose/

Adjust environment variables in blockscout/docker-compose/envs/common-blockscout.env

After adjusting the .env file run docker-compose. This may take a few minutes. Find further information in the blockscout/docker-compose/README.md.

docker-compose up --build

Setting up a local Blockscout dev environment​

Official Blockscout Documentation on manual deployment: https://docs.blockscout.com/for-developers/manual-deployment

Step 1: Clone the repository​

See above.

Step 2: Setup dependencies​

Install dependencies from https://docs.blockscout.com/for-developers/information-and-settings/requirements.

Erlang & Elixir

It's recommended to use asdf for Erlang and Elixir installation.

brew install asdf

The docs state Erlang 24 and Elixir 1.13.4, but use the versions specified in this file instead: blockscout/.tool-versions

Example:

elixir 1.14.1
erlang 25.1.1
nodejs 16.16.0

Postgres

Docker is recommended for setting up a local Postgres instance: 

docker pull postgres

You have to set POSTGRES_PASSWORD=mysecretpassword env variable (choosing your own password) for the postgres docker container. Don't forget to expose a port on your host machine, 5432 is recommended.

You can use the Docker Desktop UI or run this command:

docker run --name postgres-db -e POSTGRES_PASSWORD=mysecretpassword -p 5432:5432 -d postgres

You have to create a database called blockscout. You can do it easily using the UI of pgAdmin 4 (brew install --cask pgadmin4) or via the psql console. pgAdmin 4 is highly recommended.

Node.js

Install version 16.x.x.

Alternatively: Install nvm to easily manage node versions. (https://github.com/nvm-sh/nvm)

brew install node@16

Xcode Command Line Tools

Install the Xcode Command Line Tools.

xcode-select --install

Automake, Libtool, GCC Compiler, GMP

brew install automake
brew install libtool
brew install gcc
brew install gmp

Make, G++ Compiler

Nothing to do, included in the Xcode Command Line Tools.

Rust & Cargo

brew install rust

Step 3: Setup environment variables​

Create an .env file within project root blockscout/ with the following values (make sure to adjust database password and port for the DATABASE_URL):

DATABASE_URL structure:

export DATABASE_URL="postgresql://<user>:<password>@<host>:<port>/<database_name>"

blockscout/.env

Make sure to replace <RPC_NODE_ADDRESS> with the IP of your node. There is no need to adjust SECRET_KEY_BASE for local development, it's needed for production.

export ETHEREUM_JSONRPC_HTTP_URL="http://<RPC_NODE_ADDRESS>:8545"
export ETHEREUM_JSONRPC_TRACE_URL="http://<RPC_NODE_ADDRESS>:8545"
export DATABASE_URL="postgresql://postgres:mysecretpassword@127.0.0.1:5432/blockscout"
export ETHEREUM_JSONRPC_WS_URL="ws://<RPC_NODE_ADDRESS>:8545/ws"
export SECRET_KEY_BASE="wCLrUwfKFpPF0MBlZw7CPyKWVSCTH4istk1qlDk/jvklO6S/Frw4ucfuS1ezpo+G"
export CHAIN_ID=100
export SUBNETWORK="GEN-X"
export LOGO="/images/blockscout_logo.svg"
export LOGO_FOOTER="/images/blockscout_logo.svg"
export COIN="GX"
export COIN_NAME="GX"
export INDEXER_DISABLE_BLOCK_REWARD_FETCHER="true"
export INDEXER_DISABLE_PENDING_TRANSACTIONS_FETCHER="true"
export INDEXER_DISABLE_INTERNAL_TRANSACTIONS_FETCHER="true"
export MIX_ENV="dev"
export BLOCKSCOUT_PROTOCOL="http"
export PORT=4000
export DISABLE_EXCHANGE_RATES="true"
export POOL_SIZE=40
export POOL_SIZE_API=40
export ACCOUNT_POOL_SIZE=5
export ECTO_USE_SSL="false"
export HEART_BEAT_TIMEOUT=60
export INDEXER_MEMORY_LIMIT="3Gb"
export FETCH_REWARDS_WAY="manual"
export INDEXER_EMPTY_BLOCKS_SANITIZER_BATCH_SIZE=1000

Now apply these variables to your zsh:

source .env

echo $DATABASE_URL # should give the variable as output if successful

You will have to run the source .env command before every start

Step 4: Installing code dependencies​

For detailed information check the README.md files in the different projects in /apps.

$ cd ../.. # go to project root /blockscout
$ mix local.hex --force
$ mix do deps.get, local.rebar, deps.compile, compile

Step 5: Migrate database​

Make sure that the database blockscout is already created and running before you continue

If you are in dev environment and have run the application previously with a different blockchain, drop the previous database mix do ecto.drop, ecto.create, ecto.migrate Be careful since it will delete all data from the DB. Don't execute it on production if you don't want to lose all the data!

mix do ecto.create, ecto.migrate

Step 6: Enable HTTPS in development (will result in build error if skipped)​

The Phoenix server only runs with HTTPS. https://github.com/blockscout/blockscout/issues/1373

cd apps/block_scout_web
mix phx.gen.cert blockscout blockscout.local

Optional: Add blockscout and blockscout.local to your /etc/hosts for convenience 

127.0.0.1       localhost blockscout blockscout.local
255.255.255.255 broadcasthost
::1             localhost blockscout blockscout.local

Step 7: Install Node.js dependencies​

$ cd assets # blockscout/apps/block_scout_web/assets
$ npm install

Step 8: Start the Phoenix Server (Interactive Elixir)​

$ cd ../../.. # go to project root /blockscout
$ iex -S mix phx.server # run IEx (Interactive Elixir)