Automate your macOS backup to Backblaze B2 using Restic and launchd.

backup.sh

#!/bin/bash

log () { echo "$(date +"%Y-%m-%d %T") " "$@"; }

home_dir='' # FILL THIS OUT
name='remote'
restic_path='/opt/homebrew/bin' # ADJUST AS NEEDED
pid_file="${home_dir}/.restic/${name}.pid"
timestamp_file="${home_dir}/.restic/${name}.timestamp"
hc_ping="https://hc-ping.com/uuid_here" # REPLACE WITH YOUR UUID
backup_period="+3H"
local_wifi='' # FILL THIS OUT

# Configuration Variables
B2_ACCOUNT_ID=$(/usr/bin/security find-generic-password -s backup-restic-b2-accound-id -w)   || { log "B2 Account ID retrieval failed";  exit 10; }
B2_ACCOUNT_KEY=$(/usr/bin/security find-generic-password -s backup-restic-b2-account-key -w) || { log "B2 Account Key retrieval failed"; exit 10; }
export B2_ACCOUNT_ID
export B2_ACCOUNT_KEY
export RESTIC_REPOSITORY='' # FILL THIS OUT
export RESTIC_PASSWORD_COMMAND='/usr/bin/security find-generic-password -s backup-restic-password-repository -w'

# Checks if a backup is already running.
backup_running () {
    if [ -f "$pid_file" ]; then
        if ps -p "$(cat $pid_file)" > /dev/null; then
            log "File $pid_file exists and $(cat $pid_file) running. Backup is already in progress."
            return 1
        else
            log "File $pid_file exists but process " "$(cat $pid_file)" " not found. Removing PID file."
            rm -f "$pid_file"
            log "Removing restic lock..."
            "${restic_path}/restic" --verbose unlock
        fi
    fi
}

# Checks if its too soon to take a backup.
time_too_soon () {
    if [ -f "$timestamp_file" ]; then
        time_run=$(cat "$timestamp_file")
        current_time=$(date +"%s")

        if [[ $current_time -lt $time_run ]]; then
            return 1
        fi
    fi
}

# Check if you are not on local wifi.
not_local_wifi () {
    if [[ "$(/usr/sbin/networksetup -getairportnetwork en0 | grep -E "$local_wifi")" == "" ]]; then
        log "Unsupported network."
        return 1
    fi
}

# Check if power is not connected.
power_not_connected () {
    if [[ $(pmset -g ps | head -1) =~ "Battery" ]]; then
        log "Computer is not connected to the power source."
        return 1
    fi
}

# Run the backup
run_backup () {
    "${restic_path}/restic" cache --cleanup
    "${restic_path}/restic" backup \
                            --verbose \
                            --files-from   "${home_dir}/.restic/${name}.include" \
                            --exclude-file "${home_dir}/.restic/${name}.exclude"
    backup_success=$?

    if [ $backup_success -ne 0 ]; then
        log "Error running restic backup."
        return 1
    fi
    log "Backup success."
}

# Prune the backup database
prune_backup () {
    ${restic_path}/restic forget \
                          --keep-daily 7 \
                          --keep-weekly 5 \
                          --keep-monthly 12 \
                          --keep-yearly 10 \
                          --prune
    prune_success=$?

    # Exit if pruning is a failure.
    if [ $prune_success -ne 0 ]; then
        log "Pruning failed."
        return 1
    fi
    log "Pruning finished."
}

# Perform Checks
backup_running      || exit 0
time_too_soon       || exit 0
not_local_wifi      || exit 0
power_not_connected || exit 0

echo "$$" > "$pid_file"

# Run backup
log "Backup start"
run_backup || { rm -f "$pid_file"; log "Backup failed."; exit 5; }

# Update backup timestamp
date -v $backup_period +"%s" > "$timestamp_file"
log "Backup finished."

# Prune backup database
prune_backup || { rm -f "$pid_file"; log "Pruning failed."; exit 6; }

curl -fsS -m 10 --retry 5 "$hc_ping" > /dev/null
rm -f "$pid_file"

com.myself.backup_remote.plist

<!-- Edit the paths to point to the correct locations -->
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN"
"http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>Label</key>
    <string>com.myself.backup_remote</string>
    
    <key>Program</key>
    <string>/Users/myself/.local/bin/backup_remote.sh</string>

    <key>ProcessType</key>
    <string>Background</string>

    <key>StartInterval</key>
    <integer>300</integer>
    
    <key>WorkingDirectory</key>
    <string>/Users/myself</string>
    
    <key>EnvironmentVariables</key>
    <dict>
        <key>HOME</key>
        <string>/Users/myself</string>
    </dict>
    
    <key>StandardOutPath</key>
    <string>/Users/myself/Library/Logs/com.myself.backup_remote.out.log</string>

    <key>StandardErrorPath</key>
    <string>/Users/myself/Library/Logs/com.myself.backup_remote.error.log</string>
</dict>
</plist>