# Set up your project · Tic Tac Toe on Chromia with Rell and Unity · Learn Chromia

> Complete the following setup steps before you begin:

Source: https://chromia.com/learn/tic-tac-toe/setup/

Tic Tac Toe on Chromia with Rell and UnityLesson 2 of 20

1. [01Tic Tac Toe on Chromia with Rell and Unity](https://chromia.com/learn/tic-tac-toe/introduction/)
2. [02Set up your project](https://chromia.com/learn/tic-tac-toe/setup/)

Module 1: A Rell backend with FT4 accounts

1. [03Overview](https://chromia.com/learn/tic-tac-toe/module-one/)
2. [04Part 1: Database design, operations and queries](https://chromia.com/learn/tic-tac-toe/module-one/data-modeling/)
3. [05Design the data model](https://chromia.com/learn/tic-tac-toe/module-one/data-modeling/tables/)
4. [06Perform basic operations](https://chromia.com/learn/tic-tac-toe/module-one/data-modeling/basic-operations/)
5. [07Write basic queries](https://chromia.com/learn/tic-tac-toe/module-one/data-modeling/write-queries/)
6. [08Part 2: Set up accounts](https://chromia.com/learn/tic-tac-toe/module-one/create-accounts/)
7. [09Configure FT4 accounts](https://chromia.com/learn/tic-tac-toe/module-one/create-accounts/install-configure-ft4/)
8. [10Authentication with FT4 accounts](https://chromia.com/learn/tic-tac-toe/module-one/create-accounts/authentication/)
9. [11Update tests](https://chromia.com/learn/tic-tac-toe/module-one/create-accounts/update-tests/)
10. [12Part 3: How the dapp project is organized](https://chromia.com/learn/tic-tac-toe/module-one/project-structure/)
11. [13Work with Rell modules](https://chromia.com/learn/tic-tac-toe/module-one/project-structure/modules/)
12. [14Add modules to your dapp](https://chromia.com/learn/tic-tac-toe/module-one/project-structure/incorporate-modules/)

Module 2: The Unity project

1. [15Overview](https://chromia.com/learn/tic-tac-toe/module-two/)
2. [16Set up the project](https://chromia.com/learn/tic-tac-toe/module-two/setup/)
3. [17Project scaffold](https://chromia.com/learn/tic-tac-toe/module-two/scaffold/)
4. [18Link the client to the blockchain](https://chromia.com/learn/tic-tac-toe/module-two/connecting-the-client/)
5. [19Summary and manual testing](https://chromia.com/learn/tic-tac-toe/module-two/summary-and-tests/)

1. [20What next?](https://chromia.com/learn/tic-tac-toe/what-next/)

[Learn](https://chromia.com/learn/)[Tic Tac Toe on Chromia with Rell and Unity](https://chromia.com/learn/tic-tac-toe/)

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](https://brew.sh/).
2. Install PostgreSQL with Homebrew:

   shell

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

   plsql

   ```nolines
   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;"
   ```

   note

   A "peer authentication failed" error means you need to switch the authentication method from `peer` to `md5`. Make this change in the `pg_hba.conf` file of your `psql` database.

1. Install PostgreSQL:

   bash

   ```nolines
   sudo apt install postgresql-16
   ```
2. Create and configure the database:

   bash

   ```nolines
   sudo -u postgres psql -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;"
   ```

1. Set up Docker by following the [Docker installation guide](https://docs.docker.com/engine/install/).
2. Create and configure the database:

   dockerfile

   ```nolines
   docker run --name postgres -e POSTGRES_USER=postchain -e POSTGRES_PASSWORD=postchain -p 5432:5432 -d postgres:16.3-alpine3.20
   ```

   note

   The Alpine image of PostgreSQL is used here because its default collation settings are already correct. You can also set the collation explicitly with an environment variable:

   bash

   ```nolines
   POSTGRES_INITDB_ARGS="--lc-collate=C.UTF-8 --lc-ctype=C.UTF-8 --encoding=UTF-8"
   ```

1. Get the PostgreSQL installer from the [PostgreSQL download page](https://www.postgresql.org/download/windows/).
2. Run the installer, then add the PostgreSQL folder that holds the binaries to your environment variables. In the Command Prompt (CMD), run the command below. Check that the path points to your binaries, and substitute the real version number for the `<version>` placeholder:

   shell

   ```nolines
   setx POSTGRESQL "C:\Program Files\PostgreSQL\<version>\bin"
   ```
3. Close and reopen the Command Prompt (CMD) so it picks up the new environment variables. Then run these two commands, one after the other, to create and configure the database:

   plsql

   ```nolines
   psql -U postgres -c "CREATE DATABASE postchain WITH TEMPLATE = template0 LC_COLLATE = 'en_US.UTF-8' LC_CTYPE = 'en_US.UTF-8' ENCODING 'UTF-8';"
   psql -U postgres -c "CREATE ROLE postchain LOGIN ENCRYPTED PASSWORD 'postchain'; GRANT ALL ON DATABASE postchain TO postchain;"
   ```

   note

   Some Windows versions produce permission errors or end up with a broken PostgreSQL installation. If you run into this, install Docker and run PostgreSQL in a container instead.

Install Chromia CLI

## Install Chromia CLI

The steps below cover installing and updating the [Chromia CLI](https://gitlab.com/chromaway/core-tools/chromia-cli).

## Prerequisite

You need the following in place first:

* **PostgreSQL database**: Follow [Set up PostgreSQL database](https://docs.chromia.com/get-started/installation/#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](https://gitlab.com/chromaway/core-tools/chromia-cli/-/packages).

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

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

   bash

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

   bash

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

   bash

   ```nolines
   brew install chromia/core/chr
   ```

   info

   To pin a particular version of Chromia CLI, run:

   shell

   ```
   brew install chromia/core/chr@<version>
   brew unlink chr
   brew link chr@<version>
   ```

   To see which versions are available, run `brew search chr`.
4. Confirm the installation by printing the version:

   bash

   ```nolines
   chr --version
   ```

On Linux or WSL (Windows Subsystem for Linux), install Chromia CLI (`chr`) as follows:

1. Fetch the public key for Chromia's `apt-repo` and add it to your system's trusted keyrings:

   bash

   ```nolines
   curl -fsSL https://apt.chromia.com/chromia.gpg | sudo tee /usr/share/keyrings/chromia.gpg
   ```
2. Add the Chromia repository to your package sources:

   bash

   ```nolines
   echo "deb [arch=amd64 signed-by=/usr/share/keyrings/chromia.gpg] https://apt.chromia.com stable main" | sudo tee /etc/apt/sources.list.d/chromia.list
   ```
3. Refresh your package sources:

   bash

   ```nolines
   sudo apt-get update
   ```

   info

   If you added `apt.chromia.com` before Chromia CLI version `0.16.0`, the repository update will be blocked until you run this command:

   bash

   ```nolines
   sudo apt-get --allow-releaseinfo-change update
   ```
4. After the sources are refreshed, install Chromia CLI:

   bash

   ```nolines
   sudo apt-get install chr
   ```
5. Confirm the installation by printing the version:

   bash

   ```nolines
   chr --version
   ```

On Windows, install Chromia CLI (`chr`) with [Scoop](https://scoop.sh/) as follows:

1. If you don't have Scoop yet, open PowerShell as Administrator and run:

   powershell

   ```nolines
   iwr -useb get.scoop.sh | iex
   ```
2. Add the Chromia bucket to Scoop:

   powershell

   ```nolines
   scoop bucket add chromia https://gitlab.com/chromaway/core-tools/scoop-chromia/
   ```
3. Add the Java bucket to Scoop:

   powershell

   ```nolines
   scoop bucket add java
   ```

   With this bucket in place, Scoop can fetch openjdk21, which chromia-cli needs during installation.
4. Install Chromia CLI:

   powershell

   ```nolines
   scoop install chr
   ```
5. Confirm the installation by printing the version:

   powershell

   ```nolines
   chr --version
   ```

## Updating Chromia CLI

Get the latest Chromia CLI from the [Chromia CLI packages page](https://gitlab.com/chromaway/core-tools/chromia-cli/-/packages). If you installed it with a package manager, update it with the matching command:

shell

```nolines
brew update
brew upgrade chr
```

shell

```nolines
sudo apt-get update
sudo apt-get install chr
```

shell

```nolines
scoop update
scoop update chr
```

## Docker

With Docker, you can run an isolated Linux container that already includes the Chromia CLI. You still need the [PostgreSQL database](https://docs.chromia.com/get-started/installation/#set-up-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](https://docs.docker.com/get-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

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

Windows Command Prompt Users

The `$(pwd)` syntax doesn't work in Windows Command Prompt (cmd). Use the equivalent for your shell instead:

* **PowerShell**: `$(Get-Location)` or `$(pwd)`
* **Command Prompt**: `%CD%`

**Command Prompt example:**

cmd

```nolines
docker run --rm -v %CD%:/usr/app registry.gitlab.com/chromaway/core-tools/chromia-cli/chr:<latest version> chr
```

note

Set up your `chromia.yml` file according to your platform:

* **Mac**: Set `database:host` to `host.docker.internal`.
* **Windows**: Set `database:host` to `host.docker.internal` (Docker Desktop). If the node still cannot reach your database, try `172.17.0.1`, the default Docker bridge address on Linux.
* **Linux**: Pass `--network=host` to your Docker commands.

Without these settings, Chromia CLI can't reach the PostgreSQL instance.

To update or remove the Docker image, consult the [Docker CLI reference](https://docs.docker.com/engine/reference/commandline/docker/).

bash

```
#!/bin/bash

# Allocate a pseudo-TTY one when run in interactive mode
if [ -t 0 ] && [ -t 1 ] ; then TTY="--tty"; else TTY=""; fi

docker 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 "$@"
```

Windows Command Prompt Users

The bash script above relies on `$(pwd)`, which Windows Command Prompt doesn't support. On Windows:

* **PowerShell**: run the command unchanged; PowerShell also understands `$(pwd)`
* **Command Prompt**: Change `$(pwd)` to `%CD%` in the mount command

**Mount line adjusted for Command Prompt:**

cmd

```nolines
--mount type=bind,source="%CD%",target=/usr/app \
```

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

shell

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

Change into the Tic Tac Toe project directory:

shell

```nolines
cd demo-unity/Tic_tac_toe_Rell/
```

Install the required libraries:

text

```nolines
chr install
```

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

[← Previous**Tic Tac Toe on Chromia with Rell and Unity**](https://chromia.com/learn/tic-tac-toe/introduction/)[Next →**Module 1: A Rell backend with FT4 accounts**](https://chromia.com/learn/tic-tac-toe/module-one/)

On this page

* [Install](#install)
* [Prerequisite](#prerequisite)
* [Installation](#installation)
* [Updating Chromia CLI](#updating-chromia-cli)
* [Docker](#docker)