Simple-Backup-Script

The purpose of this script is to offer a generic way to backup files or databases or whatever and send those backups to remote hosts.

Prerequisites

This script relies on the pysftp and requests modules:

pip3 install pysftp

Sidenote: Please be aware that since we use Python 3, you have to make sure that pip installs the module for Python 3. If your system ships with Python 2 as the default interpreter, pip install pysftp will install pysftp for Python 2. In that case, you might want to install pip3 and run :

pip3 install pysftp
pip3 install requests

Optional: if you want errors to be reported to Sentry, install its SDK:

pip3 install --upgrade sentry-sdk

How does it work?

There are two customizable steps in this process:

Backup

This step copies files or dumps databases and puts everything in a single .tar.gz file. All the logic behind this is contained within a plugin. If you cannot find a suitable plugin (check /plugins dir) for the content you're trying to save, don't hesitate to create a pull request.

A plugin is quite simple: all it does is to run commands to create the single file, and return its complete file path. It also contains a clean function to delete temporary files created during its execution.

Transfer

Once everything is ready, let's upload the files to each remote. We can either upload backup files to remote targets, or copy them in a local directory.

Remote (SFTP) target configuration

Note: SSH Public Key Authentication must be set up or the script won't connect to your remote backup targets:

1. Generate SSH private (~/.ssh/id_rsa) & public (~/.ssh/id_rsa.pub) keys if not already done:

   ssh-keygen -t rsa

2. Copy the public key on the remote server (replace user & 123.45.56.78)

   ssh-copy-id -i ~/.ssh/id_rsa.pub user@123.45.56.78

   If ~/.ssh/id_rsa.pub is your default and only ssh key, you can omit the -i option and simply use

   ssh-copy-id user@123.45.56.78

3. Successfully connect without any password

   ssh user@123.45.56.78

In both remote and target modes, you have to make sure that the user has the right to write in destination directory.

Configuration

Copy or rename config-sample.json to get config.json.

Note: we switched from config.py to config.json. Use backup.py --migrate to create config.json.

Emails

You can receive an e-mail when a backups fails for whatsoever reason. Just customize the alert_emails array with one or more email addresses. A null, empty array ([]) or single empty string array value ([""]) will disable this feature.

"alert_email": ["john@doe.com", "it@doe.com", "accounting@doe.com"],

Once done, run the ./backup.py --test-mails command to check if it works fine.

Sentry reporting

Errors can be reported to Sentry:

"sentry_dsn": "https://123456789abcdef@o1237.ingest.sentry.io/1234567"

Backup profiles

You can add as many backup profiles as you wish.

"my_backup": {              // That's the backup name: no special chars nor spaces please
    "profile": "",          // That's the name of the plugin ("mysql", "filesystem" or whatever)

                            // The whole backup node is sent to the plugin:
    "databases": ["myDb"],  // here are some specific keys
}

Check config-sample.json for some examples: it contains a sample configuration for each plugin.

Targets

Each backup profile will then be sent/copied to every target configured. A target can either be one of the following:

Remote (SFTP)

{
    "type":     "remote",
    "host":     "bkup.domain.com",  // Can either be a local/remote IP address
    "port":     22,                 // Optional, default 22
    "user":     "john",
    "dir":      "/home/john/backups/",
    "days_to_keep": 7               // You can override global DAYS_TO_KEEP for each target
}

Local (simple copy)

{
    "type":     "local",
    "dir":      "/home/john/backups/",
    "days_to_keep": 7               // You can override global DAYS_TO_KEEP for each target
}

FTP

{
    "type":     "ftp",
    "host":     "bkup.domain.com",  // Can either be a local/remote IP address
    "port":     21,                 // Optional, default 21
    "user":     "john",
    "password": "j0hn",
    "dir":      "/home/john/backups/"
}

Note: setting days_to_keep to -1 will disable backups rotation.

Important note: the "dir" directory must only contain backups from this instance. Any other file could be deleted during backups rotation.

Once done, run the ./backup.py --test-config command to check if everything's OK.

Usage

You can either run it in its interactive mode (default), or specify the backup profile you want to run:

# Interactive mode:
./backup.py

# or
./backup.py --backup my_backup

# or all:
./backup.py --all

You can also target a single target by specifying its index in the targets list:

./backup.py --all --target 0

You can configure a daily cron using crontab -e: add the following line to the cron file:

0 0 * * * /home/user/Simple-Backup-Script/backup.py --all

Plugin-specific considerations

PostgreSQL

We have to be careful about authorizations. You'll have to create a .pgpass file in the cron user's home directory with the following syntax: hostname:port:database:username:password, for example:

localhost:5432:db_name:db_user:password

In doubt, you can check postgres's port with sudo netstat -plunt |grep postgres.

Then, chmod 600 /home/cron_user/.pgpass. Running ls -al /home/cron_user/ must look like this afterwards:

-rw-------  1 cron_user cron_user   [...] .pgpass

Permissions

When building your profiles list, please be aware of permissions issues that may arise. Your (unprivileged) backups user should be able to access all the files that are referenced in this script's configuration file. For database dumps, it's recommended to create a specific user with limited roles (SELECT & LOCK should be fine).

For filesystem archives, you can use ACLs to grant permissions: (replace USER="backups" with the name of your Unix user)

function set_acl() {
    # set ACL on var folder if necessary
    USER="backups"
    FOLDER="$1"
    ACL=$(getfacl "$FOLDER" | grep -E "$USER:..x$" -ic)
    if [[ "$ACL" != 4 ]]; then
        echo "setting missing ACLs on $FOLDER"
        setfacl -R -m u:"$USER":rX "$FOLDER" && setfacl -dR -m u:"$USER":rX "$FOLDER"
    fi
}

set_acl "my/path/to/backup"