Installation Guide

Snap is a modern package management system created by Canonical that lets you distribute applications as self‑contained “snaps.” Each snap bundles its own dependencies, runs in a confined environment for strong isolation, and receives automatic updates. This guide walks you through installing snapd on popular Linux distributions, configuring common options, managing snaps, and troubleshooting typical issues—all in a clear, technical yet approachable style.

Prerequisites

• Systemd support – snapd relies on systemd services; older init systems may need manual setup.
• Internet access – snaps are downloaded from the Snap Store.
• Disk space – snaps can be 100 MB–1 GB each, so ensure enough free space.

Installation Steps by Distribution

Distribution	Commands
Ubuntu 18.04+ / Debian 10+	sudo apt update && sudo apt install snapd
Fedora 30+	sudo dnf install snapd sudo systemctl enable --now snapd.socket
CentOS / RHEL 8+	sudo yum install epel-release sudo yum install snapd sudo systemctl enable --now snapd.socket
Arch Linux	sudo pacman -S snapd sudo systemctl enable --now snapd.socket
openSUSE Leap 15.3+	sudo zypper install snapd sudo systemctl enable --now snapd.socket

Post‑Installation Checklist

1. Verify snapd is running – systemctl status snapd.service (the main service) or systemctl status snapd.socket (the socket that activates snapd).
2. Refresh your session – log out and back in or reboot so the snap command appears in your PATH.
3. Test with a simple snap

   sudo snap install hello-world
   hello-world
   

   You should see a greeting message.

Common Configuration Options

Option	Description	How to Set
Auto‑refresh	Snap packages update automatically in the background.	sudo snap set system refresh.retain=2 (keeps the last two revisions).
Disable auto‑refresh	Useful on servers or when bandwidth is limited.	sudo snap set system refresh.timer=00:00 (disables).
Classic confinement	Grants a snap full system access, like traditional packages.	sudo snap install <snap> --classic
Snap store mirror / proxy	Use a different mirror or proxy for faster downloads.	sudo snap set system proxy.http="http://proxy:port" sudo snap set system proxy.https="https://proxy:port"
Snapd debugging	Enables verbose logs for troubleshooting.	sudo snap set system debug=true

Managing Snaps

• snap list – list installed snaps.
• snap remove <snap> – uninstall a snap.
• snap refresh <snap> – manually update a snap.
• snap info <snap> – view detailed information.
• snap find <keyword> – search the Snap Store.

Confinement & Interfaces

• Strict confinement (default) limits a snap’s filesystem access to a predefined set of directories.
• Classic confinement is required for snaps that need full system access (e.g., IDEs, Docker).
• Snap interfaces expose specific capabilities such as network or home.
  • View connections: snap connections <snap>
  • Grant access: snap connect <snap>:<interface>

Troubleshooting Common Issues

Symptom	Likely Cause	Fix
snap command not found	snapd not in PATH or not restarted	Log out/in or sudo systemctl restart snapd
Snap install fails with “cannot connect to snapd”	snapd.socket not active	sudo systemctl enable --now snapd.socket
Snap updates stuck	Disk full or network issue	Free space, check network, sudo snap refresh --list
Snap not launching	Confined app missing interface	sudo snap connect <snap>:<interface>