Defaults System

Configure and save installation settings for reusable container deployments

The defaults system provides a three-tier configuration hierarchy that allows you to save and reuse installation settings across container deployments. This eliminates repetitive configuration and ensures consistency across your infrastructure.

Understanding the System

Three-Tier Configuration Hierarchy

Settings are applied in the following priority order:

1. Environment Variables (Highest Priority)

   Variables set in your shell environment before running a script

   export var_cpu=8
   export var_ram=4096
   
2. App Defaults

   Application-specific saved settings stored in:

   /usr/local/community-scripts/defaults/<appname>.vars
   
3. User Defaults

   Your global defaults applied to all containers stored in:

   /usr/local/community-scripts/default.vars
   
4. Built-in Defaults (Lowest Priority)

   Hardcoded defaults within each script, providing sensible fallback values

Installation Modes

When you run any installation script, you’ll be presented with several options:

Default Settings

Quick installation using built-in defaults with no configuration prompts.

Best For

First-time users and quick deployments where default settings are acceptable

Advanced Settings

Full customization with 19 configuration steps covering every aspect of the container.

Available Settings:

• CPU cores, RAM amount, disk size
• Container name and network configuration
• SSH access, API access, features
• Password, SSH keys, tags
• Security options

After completing advanced setup, you’ll be prompted to save these settings as App Defaults for future deployments

User Defaults

Use your saved global defaults that apply to all container installations.

# Run any script and select option 3
bash pihole-install.sh
# Select: 3) User Defaults

App Defaults

Use previously saved application-specific defaults for identical deployments.

This option only appears if you’ve previously saved App Defaults for the specific application

Saving Defaults

During Installation

The easiest way to create defaults:

App Defaults

# Run installation with Advanced Settings
bash pihole-install.sh

# Select: 2) Advanced Settings
# Configure all options
# At the end, when prompted:
# "Save as App Defaults for PiHole?" → Yes

# Settings saved to:
# /usr/local/community-scripts/defaults/pihole.vars

Manual File Creation

For advanced users who want to create defaults without running installation:

User Defaults

sudo tee /usr/local/community-scripts/default.vars > /dev/null << 'EOF'
# Global User Defaults
var_cpu=4
var_ram=2048
var_disk=20
var_unprivileged=1
var_brg=vmbr0
var_gateway=192.168.1.1
var_timezone=Europe/Berlin
var_ssh=yes
var_container_storage=local
var_template_storage=local
EOF

App Defaults

sudo tee /usr/local/community-scripts/defaults/pihole.vars > /dev/null << 'EOF'
# App-specific defaults for PiHole
var_unprivileged=1
var_cpu=2
var_ram=1024
var_disk=10
var_brg=vmbr0
var_gateway=192.168.1.1
var_hostname=pihole
var_container_storage=local
var_template_storage=local
EOF

Managing Defaults

View Settings

User Defaults

cat /usr/local/community-scripts/default.vars

Edit Settings

# Edit User Defaults
sudo nano /usr/local/community-scripts/default.vars

# Edit App Defaults
sudo nano /usr/local/community-scripts/defaults/pihole.vars

Update Existing Defaults

Re-run the installation with Advanced Settings:

bash pihole-install.sh
# Select: Advanced Settings
# Make desired changes
# When asked to save: "Defaults already exist, Update?" → Yes

Delete Defaults

Deleting defaults cannot be undone. You’ll need to recreate them manually or through Advanced Settings.

# Delete User Defaults
sudo rm /usr/local/community-scripts/default.vars

# Delete specific App Defaults
sudo rm /usr/local/community-scripts/defaults/pihole.vars

# Delete all App Defaults
sudo rm /usr/local/community-scripts/defaults/*

Example Configurations

High-Performance Gaming Server

# /usr/local/community-scripts/defaults/gaming.vars
var_cpu=8
var_ram=8192
var_disk=100
var_unprivileged=0
var_fuse=1
var_nesting=1
var_tags=gaming;performance

Development Environment

# /usr/local/community-scripts/defaults/development.vars
var_cpu=4
var_ram=4096
var_disk=50
var_unprivileged=1
var_nesting=1
var_ssh=yes
var_tags=development;docker

Low-Resource IoT Container

# /usr/local/community-scripts/defaults/iot.vars
var_cpu=1
var_ram=512
var_disk=8
var_unprivileged=1
var_nesting=0
var_fuse=0
var_tun=0
var_tags=iot;monitoring

Troubleshooting

App Defaults not available

You haven’t created App Defaults yet for this application.

Solution:

1. Run the app with “Advanced Settings”
2. Configure your preferences
3. When finished, save as App Defaults
4. Next time, App Defaults will be available

Settings not being applied

Check the following:

# Verify files exist
ls -la /usr/local/community-scripts/default.vars
ls -la /usr/local/community-scripts/defaults/<app>.vars

# Check file permissions
stat /usr/local/community-scripts/default.vars

# Check for environment variable override
env | grep var_
# If you have var_* set, those override saved defaults

Cannot write to defaults location

Permission denied when saving defaults.

Solution:

# Create the defaults directory if missing
sudo mkdir -p /usr/local/community-scripts/defaults

# Fix permissions
sudo chmod 755 /usr/local/community-scripts
sudo chmod 755 /usr/local/community-scripts/defaults

# Make sure you're running as root
sudo bash pihole-install.sh

File Format

Defaults files use a simple key=value format with specific syntax rules

# Comments start with #
var_name=value

# No spaces around =
var_cpu=4              # ✓ Correct
var_cpu = 4            # ✗ Wrong

# String values don't need quotes
var_hostname=mycontainer           # ✓ Correct
var_hostname='mycontainer'         # ✓ Also correct

# Values with spaces or special chars need quotes
var_tags="docker,production,testing"  # ✓ Correct

Best Practices

Do

• Use App Defaults for app-specific settings
• Use User Defaults for global preferences
• Edit defaults files directly with nano
• Keep separate App Defaults for each app
• Back up your defaults regularly
• Use environment variables for temporary overrides

Don't

• Don’t use source on defaults files (security risk)
• Don’t put sensitive passwords in defaults
• Don’t modify defaults during installation
• Don’t delete defaults directory while creating containers
• Don’t use special characters without escaping

Related Resources

Environment Variables

Complete list of available configuration variables

Unattended Deployment

Automate deployments with defaults and environment variables