Querying the blockchain

To start an instance of cardano-db-sync we are going to use Docker as manager and deployment of this instance. Before continuing make sure you have Docker installed.

First we uninstall possible old versions of Docker:

sudo apt-get remove docker docker-engine docker.io containerd runc

Update the package repository:

sudo apt-get update

Install the necessary packages for the repositories over https:

sudo apt-get install \
    apt-transport-https \
    ca-certificates \
    curl \
    gnupg-agent \
    software-properties-common

Add the official Docker GPG key:

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -

Verify the key:

sudo apt-key fingerprint 0EBFCD88

Set up the stable Docker repository.

sudo add-apt-repository \
   "deb [arch=amd64] https://download.docker.com/linux/ubuntu \
   $(lsb_release -cs) \
   stable"

Finally we update the repo (to get the most recent version) and install it.

sudo apt-get update
sudo apt-get install docker-ce docker-ce-cli containerd.io docker-compose

Install cardano-db-sync

Download the source code of cardano-db-sync project:

git clone https://github.com/input-output-hk/cardano-db-sync.git
cd cardano-db-sync

Lets check the configuration with which the new environment will be launch:

docker-compose config

My personal configuration is as follows:

version: "3.5"

services:
  postgres:
    image: postgres:11.5-alpine
    shm_size: 1g
    environment:
      - POSTGRES_LOGGING=true
      - POSTGRES_DB_FILE=/run/secrets/postgres_db
      - POSTGRES_PASSWORD_FILE=/run/secrets/postgres_password
      - POSTGRES_USER_FILE=/run/secrets/postgres_user
    secrets:
      - postgres_password
      - postgres_user
      - postgres_db
    volumes:
      - postgres:/var/lib/postgresql/data
    ports:
      - 5432:5432
    restart: on-failure
    logging:
      driver: "json-file"
      options:
        max-size: "200k"
        max-file: "10"

  cardano-node:
    image: inputoutput/cardano-node:1.19.0
    environment:
      - NETWORK=${NETWORK:-mainnet}
    volumes:
      - node-db:/data/db
      - node-ipc:/ipc
    restart: on-failure
    logging:
      driver: "json-file"
      options:
        max-size: "200k"
        max-file: "10"

  cardano-db-sync:
    image: inputoutput/cardano-db-sync:4.0.0
    environment:
      - NETWORK=${NETWORK:-mainnet}
      - POSTGRES_HOST=postgres
      - POSTGRES_PORT=5432
    depends_on:
      - cardano-node
      - postgres
    secrets:
      - postgres_password
      - postgres_user
      - postgres_db
    volumes:
      - node-ipc:/node-ipc
    restart: on-failure
    logging:
      driver: "json-file"
      options:
        max-size: "200k"
        max-file: "10"

secrets:
  postgres_db:
    file: ./config/secrets/postgres_db
  postgres_password:
    file: ./config/secrets/postgres_password
  postgres_user:
    file: ./config/secrets/postgres_user

volumes:
  postgres:
  node-db:
  node-ipc:

If we look at the configuration we see that Docker is going to use the postgres_db, postgres_password and postgres_user credentials. It will look for them in the /home/cardano/cardano-db-sync/config/secrets folder. The default repository brings these files under the suffix * _example, we just have to replace or duplicate the examples.

cp ~/home/cardano/cardano-db-sync/config/secrets/postgres_db_example \
    ~/home/cardano/cardano-db-sync/config/secrets/postgres_db

cp ~/home/cardano/cardano-db-sync/config/secrets/postgres_password_example \
    ~/home/cardano/cardano-db-sync/config/secrets/postgres_password

Remember change the password.

cp ~/home/cardano/cardano-db-sync/config/secrets/postgres_user_example \
    ~/home/cardano/cardano-db-sync/config/secrets/postgres_user

Before running Docker we need to add our user to the docker group:

sudo usermod -aG docker $USER

Start the instance with the log messages activated:

docker-compose up -d && docker-compose logs -f

With this we have started a cardano-node services, the postgresql database, and the cardano-db-sync tool. We can access these services through the default port: 5432.

A more optimal execution

We are going to use tmux to run docker in the background and show the machine status live.

start.sh

Create the script that starts the service in the background:

cd /home/cardano/cardano-db-sync
vim start.sh

#!/bin/bash
session="cardano-db-sync"
# Check if the session exists, discarding output
# We can check $? for the exit status (zero for success, non-zero for failure)
tmux has-session -t $session 2>/dev/null
if [ $? != 0 ]; then
 tmux attach-session -t $session
 tmux new -s "cardano-db-sync" -n "node" -d
 tmux split-window -v
 tmux select-pane -t 'cardano-db-sync:node.0'
 tmux split-window -h
 tmux send-keys -t 'cardano-db-sync:node.0' './init-cardano-db.sh' Enter
 tmux send-keys -t 'cardano-db-sync:node.1' 'htop' Enter
 tmux send-keys -t 'cardano-db-sync.2' 'nload' Enter
fi

tmux attach-session -t $session

init-cardano-db.sh

Create the script that executes docker:

cd /home/cardano/cardano-db-sync
vim init-cardano-db.sh

#!/bin/bash
docker-compose up -d && docker-compose logs -f

stop.sh

Create the script that ends the service associated with the "cardano-db-sync" session.

cardano-db-sync

vim stop.sh

#!/bin/bash
# Check if the session exists, discarding output
# We can check $? for the exit status (zero for success, non-zero for failure)
session="cardano-db-sync"
# Check if the session exists, discarding output
# We can check $? for the exit status (zero for success, non-zero for failure)

tmux has-session -t $session 2>/dev/null
if [ $? != 0 ]; then
        echo "Session not found."
else
        echo "Killing session"
        tmux kill-session -t cardano-db-sync
fi

Add execution permissions to the scripts:

chmod +x start.sh stop.sh init-cardano-db.sh

Finally, start the service:

./start.sh

Once started we can launch queries to the address localhost: 5432.

List all the containers:

docker container ls -a

Delete a specific container by its ID:

docker container rm 661525b875a1

Terminate all instances:

docker-compose down -v

Relaunch the instances:

docker-compose up --remove-orphans --force-recreate

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