systemd-services

# /etc/systemd/system/myapp.service
[Unit]
Description=MyApp Production Server
Documentation=https://docs.example.com/myapp
After=network-online.target postgresql.service
Wants=network-online.target
Requires=postgresql.service

[Service]
Type=notify
User=myapp
Group=myapp
WorkingDirectory=/opt/myapp

# Environment configuration
EnvironmentFile=/etc/myapp/env
Environment=NODE_ENV=production
Environment=PORT=8080

# Execution
ExecStartPre=/opt/myapp/bin/migrate --check
ExecStart=/opt/myapp/bin/server --config /etc/myapp/config.yaml
ExecStartPost=/opt/myapp/bin/healthcheck.sh
ExecReload=/bin/kill -HUP $MAINPID
ExecStop=/opt/myapp/bin/graceful-stop.sh

# Restart behavior
Restart=on-failure
RestartSec=5
StartLimitIntervalSec=300
StartLimitBurst=5

# Timeouts
TimeoutStartSec=30
TimeoutStopSec=30
WatchdogSec=60

# Security hardening
NoNewPrivileges=true
ProtectSystem=strict
ProtectHome=true
PrivateTmp=true
ReadWritePaths=/var/lib/myapp /var/log/myapp
CapabilityBoundingSet=
AmbientCapabilities=

# Logging
StandardOutput=journal
StandardError=journal
SyslogIdentifier=myapp

[Install]
WantedBy=multi-user.target

# Reload systemd after creating or modifying unit files
systemctl daemon-reload

# Start, stop, restart a service
systemctl start myapp
systemctl stop myapp
systemctl restart myapp

# Reload service configuration without restart (if supported)
systemctl reload myapp

# Enable service to start on boot
systemctl enable myapp

# Enable and start in one command
systemctl enable --now myapp

# Disable and stop
systemctl disable --now myapp

# Check service status
systemctl status myapp

# Check if a service is active, enabled, or failed
systemctl is-active myapp
systemctl is-enabled myapp
systemctl is-failed myapp

# List all running services
systemctl list-units --type=service --state=running

# List all failed services
systemctl list-units --type=service --state=failed

# Show all properties of a service
systemctl show myapp

# Show specific property values
systemctl show myapp -p MainPID,MemoryCurrent,CPUUsageNSec

# Mask a service (prevent it from being started at all)
systemctl mask myapp

# Unmask
systemctl unmask myapp

# Reset a failed service state
systemctl reset-failed myapp

# /etc/systemd/system/backup.timer
[Unit]
Description=Daily backup timer

[Timer]
# Run daily at 2:30 AM
OnCalendar=*-*-* 02:30:00
# If the system was off at the scheduled time, run when it boots
Persistent=true
# Add random delay up to 15 minutes to avoid thundering herd
RandomizedDelaySec=900
# Associate with a specific service (defaults to same name .service)
Unit=backup.service

[Install]
WantedBy=timers.target

# /etc/systemd/system/backup.service
[Unit]
Description=Daily backup job
After=network-online.target
Wants=network-online.target

[Service]
Type=oneshot
User=backup
ExecStart=/usr/local/bin/run-backup.sh
StandardOutput=journal
StandardError=journal

# Common OnCalendar expressions: