03 / 16Module 1: Initialize the full-stack applicationIntermediate

Prepare the full-stack application

Make sure the following prerequisites are in place before you begin:

Set up PostgreSQL database

Rell needs PostgreSQL 16.3. You can use the IDE without it, but you can't run a node. A console or a remote postchain app runs without a database.

By default, Rell expects these database settings:

database: postchain
user: postchain
password: postchain

Install

Install Homebrew by following the Homebrew installation guide.

Install PostgreSQL:

shell

brew install postgresql@16brew services start postgresql@16createuser -s postgres

Set up the PostgreSQL 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 PostgreSQL:
bash
```
sudo apt install postgresql-16
```

Set up the PostgreSQL database:

bash

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;"

Install Docker by following the Docker installation guide.
Set up the PostgreSQL database:
dockerfile
```
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 correct. You can also set the collation explicitly with this environment variable:
bash
```
POSTGRES_INITDB_ARGS="--lc-collate=C.UTF-8 --lc-ctype=C.UTF-8 --encoding=UTF-8"
```

Get the PostgreSQL installer from the PostgreSQL download page.
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 swap the <version> placeholder for your installed version number:
shell
```
setx POSTGRESQL "C:\Program Files\PostgreSQL\<version>\bin"
```
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 set up the PostgreSQL database:
plsql
```
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 as a container instead.

Install Chromia CLI

Follow these steps to install and update the Chromia CLI.

Prerequisite

Check that you have the following before you continue:

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 for you, so no manual setup is needed. To choose which Java runtime runs Chromia CLI, set the RELL_JAVA environment variable to 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:

Install Homebrew if you don't already have it:

bash

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

bash

brew tap chromia/core https://gitlab.com/chromaway/core-tools/homebrew-chromia.git

Install Chromia CLI:
bash
```
brew install chromia/core/chr
```
info
To pin a specific Chromia CLI version, run:
shell
```
brew install chromia/core/chr@<version>brew unlink chrbrew link chr@<version>
```
Run brew search chr to see which versions are available.
Confirm the installation by printing the version:
bash
```
chr --version
```

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

Download the public key for Chromia's apt-repo and add it to your system's trusted keyrings:
bash
```
curl -fsSL https://apt.chromia.com/chromia.gpg | sudo tee /usr/share/keyrings/chromia.gpg
```

Add the Chromia repository to your package sources:

bash

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

Refresh your package sources:
bash
```
sudo apt-get update
```
info
If you added apt.chromia.com before Chromia CLI version 0.16.0, run this command so the repository can be updated:
bash
```
sudo apt-get --allow-releaseinfo-change update
```
After the repository update finishes, install Chromia CLI:
bash
```
sudo apt-get install chr
```
Confirm the installation by printing the version:
bash
```
chr --version
```

On Windows, install Chromia CLI (chr) with Scoop as follows:

Install Scoop if you don't already have it. Run this in PowerShell as Administrator:
powershell
```
iwr -useb get.scoop.sh | iex
```

Add the Chromia bucket to Scoop:

powershell

scoop bucket add chromia https://gitlab.com/chromaway/core-tools/scoop-chromia/

Add the Java bucket to Scoop:
powershell
```
scoop bucket add java
```
With this bucket, Scoop can fetch openjdk21, which chromia-cli needs during installation.
Install Chromia CLI:
powershell
```
scoop install chr
```
Confirm the installation by printing the version:
powershell
```
chr --version
```

Updating Chromia CLI

Grab the newest Chromia CLI from the Chromia CLI package registry. If you installed it with a package manager, update it with:

shell

brew updatebrew upgrade chr

shell

sudo apt-get updatesudo apt-get install chr

shell

scoop updatescoop update 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. See the Docker guide to install Docker on Windows, Mac, or Linux.

Start the Docker container with Chromia CLI pre-installed

To run the latest Chromia CLI, call docker run with the CLI image name followed by chr.

shell

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 one of these instead:

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

Command Prompt example:

cmd

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

For updating or removing the Docker image, see the Docker command line 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 "$@"

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: In the mount command, swap $(pwd) for %CD%

Mount line adjusted for Command Prompt:

cmd

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

Start by creating your blockchain app project with the Chromia CLI.

Make a new directory for the project and switch into it:

shell

chr create-rell-dapp asset_management --template=asset-management

shell

cd asset_management

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