Chromia
Start Building

02 / 20

Set up your project

Complete the following setup steps before you begin:

Set up PostgreSQL database

Set up PostgreSQL database

Rell needs PostgreSQL 16.3. You can use the IDE without a database, but you won't be able to run a node. Neither a console nor a remote postchain app needs a database.

By default, Rell expects these database settings:

  • database: postchain
  • user: postchain
  • password: postchain

Install

  1. Set up Homebrew by following the Homebrew installation guide.

  2. Install PostgreSQL with Homebrew:

    shell
    brew install postgresql@16brew services start postgresql@16createuser -s postgres
  3. Create and configure the database:

    plsql
    psql -U postgres -c "CREATE DATABASE postchain WITH TEMPLATE = template0 LC_COLLATE = 'C.UTF-8' LC_CTYPE = 'C.UTF-8' ENCODING 'UTF-8';" -c "CREATE ROLE postchain LOGIN ENCRYPTED PASSWORD 'postchain'; GRANT ALL ON DATABASE postchain TO postchain;"
Install Chromia CLI

Install Chromia CLI

The steps below cover installing and updating the Chromia CLI.

Prerequisite

You need the following in place first:

  • PostgreSQL database: Follow Set up PostgreSQL database.
  • RELL_JAVA environment: Chromia CLI runs on a Java runtime, version 21 or later. The package managers handle this dependency for you, so no manual setup is needed. To choose which Java runtime runs Chromia CLI, set the RELL_JAVA environment variable to the path of a valid Java installation.

Installation

Install Chromia CLI through a package manager, or download it directly from Chromia CLI Packages.

On macOS, install Chromia CLI (chr) as follows:

  1. If you don't have Homebrew yet, install it:

    bash
    /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
  2. Register the Chromia repository with Homebrew:

    bash
    brew tap chromia/core https://gitlab.com/chromaway/core-tools/homebrew-chromia.git
  3. Install Chromia CLI:

    bash
    brew install chromia/core/chr
  4. Confirm the installation by printing the version:

    bash
    chr --version

Updating Chromia CLI

Get the latest Chromia CLI from the Chromia CLI packages page. If you installed it with a package manager, update it with the matching command:

shell
brew updatebrew upgrade chr

Docker

With Docker, you can run an isolated Linux container that already includes the Chromia CLI. You still need the PostgreSQL database set up.

The published images require Docker to be installed and configured on your host. For Windows, Mac, and Linux instructions, see install Docker in the Docker documentation.

Start the Docker container with Chromia CLI pre-installed

To run the newest Chromia CLI, pass the CLI image name and chr to docker run:

shell
docker run --rm -v $(pwd):/usr/app registry.gitlab.com/chromaway/core-tools/chromia-cli/chr:<latest version> chr

To update or remove the Docker image, consult the Docker CLI reference.

bash
#!/bin/bash# Allocate a pseudo-TTY one when run in interactive modeif [ -t 0 ] && [ -t 1 ] ; then TTY="--tty"; else TTY=""; fidocker run \  # Sets the network to host to not need to change the database hostname (linux only)  --network=host \  # Set timezone based on system settings (linux only)  -e TZ=$(cat /etc/timezone) \  # Sets process ownership to current user  --user $(id -u):$(id -g) \  --mount type=bind,source="/etc/passwd",target=/etc/passwd,readonly \  --mount type=bind,source="/etc/group",target=/etc/group,readonly \  # Configures ssh-agent (only needed if chr install is called on non-public repositores)  -e SSH_AUTH_SOCK=$SSH_AUTH_SOCK \  --volume "$SSH_AUTH_SOCK:$SSH_AUTH_SOCK" \  --mount type=bind,source="${HOME}/.ssh",target=${HOME}/.ssh,readonly \  --mount type=bind,source="${HOME}/.config/jgit",target=${HOME}/.config/jgit \  # Mounts current folder into the container (Use `Get-Location` on PowerShell)  --mount type=bind,source="$(pwd)",target=/usr/app \  --interactive ${TTY} \  --rm \  registry.gitlab.com/chromaway/core-tools/chromia-cli/chr:${CHR_VERSION:-latest} chr "$@"

Start by setting up the project for your blockchain app. Clone the Tic Tac Toe game repository:

shell
git clone git@bitbucket.org:chromawallet/demo-unity.git

Change into the Tic Tac Toe project directory:

shell
cd demo-unity/Tic_tac_toe_Rell/

Install the required libraries:

text
chr install
Written for this site from Chromia’s public course. Code samples are the course’s own.