Introduction
Duplicacy is state-of-the-art backup tool that has extensive cloud support. It also supports local disks and your own SFTP servers. Duplicacy is available as a web-based GUI or as a commmand line tool. The software does require a license but the command-line interface (CLI) version is free for personal use. That is the version we’ll be using for this tutorial.
Installation
STEP 1:
Pre-compiled binaries are availble for Linux, macOS, and Windows directly from the Duplicacy GitHub repository.
Download the latest version for your system.
$ wget https://github.com/gilbertchen/duplicacy/releases/download/v2.7.2/duplicacy_linux_x64_2.7.2
STEP 2:
Make the file execuable.
$ chmod +x duplicacy_linux_x64_2.7.2
STEP 3:
Rename the file to duplicacy.
$ mv duplicacy_linux_x64_2.7.2 duplicacy
STEP 4:
Change the file permissions.
$ chmod 755 duplicacy
STEP 5:
Move duplicacy to the /usr/bin directory.
$ sudo mv duplicacy /usr/bin/
Initialize the remote storage and repository
The duplicacy init command is used to initialize the remote storage and the backup directory.
duplicacy init [command options] <snapshot id> <storage url>
The <snapshot id> refers to the name you want to give to your backup job.
The <storage url> refers to the remote server and directory path for your backups.
We will only use the following options:
-encrypt, -e encrypt the storage with a password
-storage-name <name> assign a name to the storage
Example scenario:
You have an sftp server named nacho.local that you want to use to backup your Photos directory.
You have a directory named remotePhotos on the nacho.local sftp server. This is the directory to be used for the backups.
You can connect to the nacho.local sftp server using ssh keys.
You want to name the backup job photoBackup. This refers to the <snapshot id> option.
You want to name the remote storage nachoStorage. This refers to the -storage-name <name> option.
For me, I would use sftp://[email protected]/remotePhotos for the
<storage url>.
STEP 1:
Initialize the remote storage and repository.
$ duplicacy init -e -storage-name nachoStorage photoBackup sftp://[email protected]/remotePhotos
You will see the following prompts:
Enter SSH password:
Enter the path of the private key file:
Enter storage password for sftp://[email protected]/remotePhotos:
Re-enter storage password:
Enter SSH password: Hit the enter key on your keybord to leave the password blank if you use ssh keys.
Enter the path of the private key file: Type in the full path to your private ssh key.
For me, I would enter /home/curt/.ssh/id_rsa for the path.
Enter storage password: Type in the storage password you wish to use.
STEP 2:
Duplicacy creates a configuration folder named .duplicacy after the initialization is completed.
Copy your private ssh key to this directory. Here is how I would copy it on my system:
$ cp /home/curt/.ssh/id_rsa /home/curt/Photos/.duplicacy/
STEP 3:
Edit the .duplicacy/preferences file to change the "keys": line. Use a plan text editor such as vim or nano.
$ vim .duplicacy/preferences
Default setting:
"keys": null,
Change "keys": null, to this:
"keys": {
"ssh_key_file": ".duplicacy/id_rsa"
},
Use a text editor such as
vimornanoto edit the file because spacing is important.
Running the backup command
STEP 1:
Run the duplicacy backup command from the backup directory.
$ duplicacy backup -stats
You will be prompted to enter the storage password. Enter the storage password you created when you initialized the repostiory.
If you do not want to enter the storage password every time you run the backup, you can use the DUPLICACY_<STORAGENAME>_PASSWORD environment variable. If you want to automate your backups by running them from a bash script via cron, you will need to also use this variable.
If your storage password is ThisIsNotAVerySecurePassword, the command would like this in our example scenario:
export DUPLICACY_NACHOSTORAGE_PASSWORD="ThisIsNotAVerySecurePassword"
NOTE: You need to use capitalization for the remote storage name regardless of the actual name of the storage. This means that nachoStorage needs to be written as NACHOSTORAGE.
You can run this shell command before you run the duplicacy backup command or add it to a bash script.