Configuration

There are several entry points available for administrator to manage the configuration of Rdiffweb. This section aims to outline those configurations and explain each option available and what it does.

Since version 2.2, rdiffweb configuration is more flexible. You may configure every option using the configuration file, command line argument or environment variable.

Take note that configuration options are distinct from the runtime setting, available from the web interface. The configuration options here usually meant to be static and set before starting the server. You may get the list of configuration options by calling rdiffweb --help.

Note: If an option is specified in more than one place, the command line arguments override the environment variable, environment variables override config files, and config files override default value.

Configuration file

To use configuration files, you may call rdiffweb with -f or --config to define the configuration file location. When not defined, Rdiffweb loads all configuration files from these locations by default:

• /etc/rdiffweb/rdw.conf

• /etc/rdiffweb/rdw.conf.d/*.conf

Configuration file syntax must define a key and a value. The key is case-sensitive, and you may use underscore (_) or dash (-) seemlessly. All lines beginning with ‘#’ are comments and are intended for you to read. All other lines are configuration for rdiffweb.

E.g.:

# This is a comment
server_port=8081
log_level=DEBUG

Environment variables

In addition to configuration files, you may pass environment variables. The options name must be uppercase and prefixed with RDIFFWEB_. As an example, if you want to change the port used to listen for HTTP request for 8081, you must define server-port option as follow.

RDIFFWEB_SERVER_PORT=8081

Command line arguments

When launching rdiffweb executable, you may pass as many arguments as you want on the command line. The options must be prefixed with double dash (--) and you must single dash (-) to separate words.

E.g. --server-port 8081 or --server-port=8081 are valid

Configure listening port and interface

For security reasons, Rdiffweb listen on port 8080 for HTTP request on loopback interface (127.0.0.1) by default. Consider configuring a reverse proxy like Nginx or Apache2 if you want to make Rdiffweb listen on port 80 for HTTP and port 443 for HTTPS request.

Option	Description	Example
server-host	Define the IP address to listen to. Use 0.0.0.0 to listen on all interfaces. Use 127.0.0.1 to listen on loopback interface.	0.0.0.0
server-port	Define the port to listen for HTTP request. Default to 8080	9090

Configure External URL

To display the correct URL when sending Email Notification to Rdiffweb users, you must provide Rdiffweb with the URL your users use to reach the web application. You can use the IP of your server, but a Fully Qualified Domain Name (FQDN) is preferred.

Option	Description	Example
external-url	Define the base URL used to reach your Rdiffweb application	https://rdiffweb.mycompagny.com

Configure administrator username and password

Using configuration file, you may setup a special administrator which cannot be deleted or renamed from the web interface. You may also configure a specific password for this user that cannot be updated from the web interface either.

In addition, you may also create other administrator users to manage Rdiffweb.

Parameter	Description	Example
admin-user	Define the name of the default admin user to be created	admin
admin-password	administrator encrypted password as SSHA. Read online documentation to know more about how to encrypt your password into SSHA or use http://projects.marsching.org/weave4j/util/genpassword.php When defined, administrator password cannot be updated using the web interface. When undefined, default administrator password is admin123 and it can be updated using the web interface.	modification

Configure logging

Rdiffweb can be configured to send logs to specific location. By default, logs are sent to the console (stdout or stderr). If you have installed Rdiffweb on a server, you should consider enabling the logging to help you keep track of the activities or to help you debug problem.

Option	Description	Example
log-level	Define the log level. ERROR, WARN, INFO, DEBUG	DEBUG
log-file	Define the location of the log file.	/var/log/rdiffweb/server.log
log-access-file	Define the location of the access log file.	/var/log/rdiffweb/access.log

Enable Debugging

A specific option is also available if you want to enable the debugging log. We do not recommend to enable this option in production as it may leak information to the user whenever an exception is raised.

Option	Description	Example
debug	enable rdiffweb debug mode - change the log level to DEBUG, print exception stack trace to the web interface and show SQL query in logs.
environment	Define the type of environment: development or production. This is used to limit the information shown to the user when an error occurs. Default: production	development

Configure database

Rdiffweb use SQL database to store user preferences. The embedded SQLite database is well suited for small deployment (1-100 users). If you intended to have a large deployment, you must consider using a PostgreSQL database instead.

Option	Description	Example
database-uri	Location of the database used for persistence. SQLite and PostgreSQL database are supported officially. To use a SQLite database, you may define the location using a file path or a URI. e.g.: /srv/rdiffweb/file.db or sqlite:///srv/rdiffweb/file.db. To use PostgreSQL server, you must provide a URI similar to postgresql://user:pass@10.255.1.34/dbname and you must install required dependencies. By default, Rdiffweb uses a SQLite embedded database located at /etc/rdiffweb/rdw.db.	postgresql://user:pass@10.255.1.34/dbname

SQLite

To use embedded SQLite database, pass the option database-uri with a URI similar to sqlite:///etc/rdiffweb/rdw.db or /etc/rdiffweb/rdw.db.

PostgreSQL

To use an external PostgreSQL database, pass the option database-uri with a URI similar to postgresql://user:pass@10.255.1.34/dbname.

You may need to install additional dependencies to connect to PostgreSQL. Step to install dependencies might differ according to the way you installed Rdiffweb.

Using Debian repository:

apt install python3-psycopg2

Using Pypi repository:

pip install psycopg2-binary

Configure LDAP Authentication

Rdiffweb may integrates with LDAP server to support user authentication.

• Configuring LDAP integration in Rdiffweb

Configure User Session

A user session is a sequence of request and response transactions associated with a single user. The user session is the means to track each authenticated user.

Option	Description	Example
session-idle-timeout	This timeout defines the amount of time a session will remain active in case there is no activity in the session. User Session will be revoke after this period of inactivity, unless the user selected “remember me”. Default 10 minutes.	5
session-absolute-timeout	This timeout defines the maximum amount of time a session can be active. After this period, user is forced to (re)authenticate, unless the user selected “remember me”. Default 20 minutes.	30
session-persistent-timeout	This timeout defines the maximum amount of time to remember and trust a user device. This timeout is used when user select “remember me”. Default 30 days	43200

Configure email notifications

Since Rdiffweb v0.9, you may configure Rdiffweb to send an email notification to the users when their backups did not complete successfully for a period of time. When enabled, Rdiffweb will also send email notification for security reason when user’s password is changed.

Option	Description	Example
email-encryption	Type of encryption to be used when establishing communication with SMTP server. Available values: none, ssl and starttls	starttls
email-host	SMTP server used to send email in the form host:port. If the port is not provided, default to standard port 25 or 465 is used.	smtp.gmail.com:587
email-sender	email addres used for the From: field when sending email.	Rdiffweb example@gmail.com
email-notification-time	time when the email notification should be sent for inactive backups.	22:00
email-username	username used for authentication with the SMTP server.	example@gmail.com
email-password	password used for authentication with the SMTP server.	CHANGEME
email-send-changed-notification	True to send notification when sensitive information get change in user profile. Default: false	True
email-catch-all	When defined, all notification email will be sent to this email address using Blind carbon copy (Bcc)

To configure the notification, you need a valid SMTP server. In this example, you are making use of a Gmail account to send emails.

email-host=smtp.gmail.com:587
email-encryption=starttls
email-sender=example@gmail.com
email-username=example@gmail.com
email-password=CHANGEME
email-send-changed-notification=true

Note: notifications are not sent if the user doesn’t have an email configured in his profile.

Configure user quota

Since v2.1, it’s now possible to customize how user quota is controller for your system without a custom plugin. By defining quota-set-cmd, quota-get-cmd and QuotaUsedCmd configuration options, you have all the flexibility to manage the quota the way you want by providing custom command line to be executed to respectively set the quota, get the quota and get quota usage.

Option	Description	Example
quota-set-cmd	Command line to set the user’s quota.	Yes. If you want to allow administrators to set quota from the web interface.
quota-get-cmd	Command line to get the user’s quota. Should print the size in bytes to console.	No. Default behaviour gets quota using operating system statvfs that should be good if you are using setquota, getquota, etc. For ZFS and other more exotic file system, you may need to define this command.
quota-used-cmd	Command line to get the quota usage. Should print the size in bytes to console.	No.

When Rdiffweb calls the scripts, special environment variables are available. You should make use of this variables in a custom script to get and set the disk quota.

• RDIFFWEB_USERID: rdiffweb user id. e.g.: 34

• RDIFFWEB_USERNAME: rdiffweb username. e.g.: patrik

• RDIFFWEB_USERROOT: user’s root directory. e.g.: /backups/patrik/

• RDIFFWEB_ROLE: user’s role e.g.: 10 1:Admin, 5:Maintainer, 10:User

• RDIFFWEB_QUOTA: only available for quota-set-cmd. Define the new quota value in bytes. e.g.: 549755813888 (0.5 TiB)

Continue reading about how to configure quotas for EXT4. We generally recommend making use of project quotas with Rdiffweb to simplify the management of permission and avoid running Rdiffweb with root privileges. The next section presents how to configure project quota. Keep in mind it’s also possible to configure quota using either user’s quota or project quota.

Configure prjquota

For EXT4

This section is not a full documentation about how to configure ext4 project quota, but provide enough guidance to help you.

1. Enabled project quota feature
   You must enable project quota feature for the EXT4 partition where your backup resides using:
   tune2fs -O project -Q prjquota /dev/sdaX
   The file system must be unmounted to change this setting and may require you to boot your system with a live-cd if your backups reside on root file system (/).
   Also, add prjquota options to your mount point configuration /etc/fstab. Something like /dev/sdaX   /   ext4    errors=remount-ro,prjquota     0    1

2. Turn on the project quota after reboot
   quotaon -Pv -F vfsv1 /

3. Check if the quota is working
   repquota -Ps /

4. Add +P attribute on directories to enabled project quotas
   chattr -R +P /backups/admin

5. Then set the project id on directories
   chattr -R -p 1 /backups/admin where 1 is the rdiffweb user’s id

Next, you may configure Rdiffweb quota command line for your need. For EXT4 project quotas, you only need to define quota-set-cmd with something similar to the following. quota-get-cmd and quota-used-cmd should not be required with EXT4 quota management.

quota-set-cmd=setquota -P $RDIFFWEB_USERID $((RDIFFWEB_QUOTA / 1024)) $((RDIFFWEB_QUOTA / 1024)) 0 0 /

This effectively, makes use of Rdiffweb user’s id as project id.

ZFS

This section is not a full documentation about how to configure ZFS project quotas, but provide enough guidance to help you. This documentation uses tank/backups as the dataset to store rdiffweb backups.

1. Quota feature is a relatively new feature for ZFS On Linux. Check your operating system to verify if your ZFS version support it. You may need to upgrade your pool and dataset using:

   zpool upgrade tank zfs upgrade tank/backups

2. Add +P attribute on directories to enabled project quotas
   chattr -R +P /backups/admin chattr -R -p 1 /backups/admin OR zfs project -p 1 -rs /backups/admin Where 1 is the rdiffweb user’s id

Take note, it’s better to enable project quota attributes when the repositories are empty.

Configure usrquota

This section is not a full documentation about how to enabled and configure ext4 quota, but provide enough guidance to help you in this configuration for you own need.

NOTE: When using this mode of operation, each rdiffweb username should match a linux user.

This documentation assume you have a separate partition for your storage /dev/sdb1 mounted on /backups.

1. First, you may need to install some dependencies required to enable the quota management:

   apt update apt install quota e2fsprogs

2. First, you need to unmount the partition to apply modifications:

   umount -l /dev/sdb1

3. Once unmounted, you may enabled the quota feature on the partition:

   tune2fs -O quota /dev/sdb1

4. You may then re-mount the partition:

   mount /dev/sdb1

5. Verify if it’s working by settings a quota:

   setquota -u $(id -u) 524288000 524288000 0 0 -a repquota

6. Finally, you must configure rdiffweb by editing it’s configuration file /etc/rdiffweb/rdw.conf.

   quota-set-cmd=setquota -u $RDIFFWEB_USERNAME $((RDIFFWEB_QUOTA / 1024)) $((RDIFFWEB_QUOTA / 1024)) 0 0 -a quota-get-cmd=quota -u $RDIFFWEB_USERNAME | tail -n 1 | awk '{ print $3 * 1024; }' quota-used-cmd=quota -u $RDIFFWEB_USERNAME | tail -n 1 | awk '{ print $2 * 1024; }'

Configure Rate-Limit

Rdiffweb could be configured to rate-limit access to anonymous to avoid bruteforce attacks and authenticated users to avoid Denial Of Service attack.

Option	Description	Example
rate-limit	maximum number of requests per hour that can be made on sensitive endpoints. When this limit is reached, an HTTP 429 message is returned to the user or the user is logged out. This security measure is used to limit brute force attacks on the login page and the RESTful API.	20
rate-limit-dir	location where to store rate-limit information. When undefined, data is kept in memory.	/var/lib/rdiffweb/session

Custom user’s password length limits

By default, Rdiffweb supports passwords with the following lengths:

• Minimum: 8 characters

• Maximum: 128 characters

Changing the minimum or maximum length does not affect existing users’ passwords. Existing users are not prompted to reset their passwords to meet the new limits. The new limit only applies when an existing user changes their password.

Option	Description	Example
password-min-length	Minimum length of the user’s password	8
password-max-length	Maximum length of the user’s password	128
password-score	Minimum zxcvbn’s score for password. Value from 0 to 4. Default value 1.	4

You may want to read more about zxcvbn score value.

Configure Rdiffweb Branding

A number of options are available to customize the appearance of Rdiffweb to your need. Most likely, you will want to make it closer to your business brand.

Option	Description	Example
welcome-msg	Replace the headline displayed in the login page. It may contains HTML.	Custom message displayed on login page.
brand-header-name	Define the application name displayed in the title bar and header menu.	My Backup
brand-default-theme	Define the theme. Either: default, blue or orange. Define the css file to be loaded in the web interface.	orange
brand-favicon	Define the FavIcon to be displayed in the browser title	/etc/rdiffweb/my-fav.ico
brand-logo	location of an image (preferably a .png) to be used as a replacement for the rdiffweb logo displayed in Login page.	/etc/rdiffweb/logo2.png
brand-header-logo	location of an image (preferably a .png) to be used as a replacement for the rdiffweb header logo displayed in navigation bar.	/etc/rdiffweb/logo1.png
brand-link-color	define a CSS color to be used for link.	#eeffee
brand-btn-fg-color	define a CSS color to use for the button text. Default to white if undefined	#ffffff
brand-btn-bg-color	define a CSS color to use for the background of the button. Default to link-color if undefined	#eeeeff
brand-btn-radius	activate or deactivate the rounded corners of the buttons	0

Configure SSH Key management

Rdiffweb allows users to manage their SSH Keys by adding and removing them using the web interface. This feature may be disabled with disable-ssh-keys.

When this feature is enabled, adding or removing an SSH Key from the web interface. Updates, the ${user_root}/.ssh/authorized_keys file if the file already exists.

Configure repositories clean-up job

Using the web interface, users may configure a retention period on individual repository to keep only a fixed number of days in backup. This is useful to control the growth of a repository disk usage.

To support this feature, Rdiffweb schedule a job to clean-up the repositories in backup. This job is ran once a day. You may change the default time when this schedule job is running by defining another value for option remove-older-time.

Parameter	Description	Example
remove-older-time	Time when to execute the remove older task	22:00

Configure temporary folder location

To restore file or folder, Rdiffweb needs a temporary directory to create the file to be downloaded. By default, Rdiffweb will use your default temporary folder defined using environment variable TMPDIR, TEMP or TMP. If none of these environment variables are defined, Rdiffweb fallback to use /tmp.

If you want to enforce a different location for the temporary directory, you may define the option tempdir with a different value. Take note, this directory must be created with the right ownership and permissions to allow Rdiffweb to use it. Also make sure enough disk space is available. Usually, a 32GiB is enough.

Parameter	Description	Example
tempdir	alternate temporary folder to be used when restoring files. Might be useful if the default location has limited disk space	/tmp/rdiffweb/

Configure repository lookup depthness

When defining the UserRoot value for a user, Rdiffweb will scan the content of this directory recursively to lookups for rdiff-backup repositories. For performance reason, Rdiffweb limits the recursiveness to 3 subdirectories. This default value should suit most use cases. If you have a particular use case, it’s possible to allow Rdiffweb to scan for more subdirectories by defining a greater value for the option max-depth. Make sure to pick a reasonable value for your use case as it may impact the performance.

Parameter	Description	Example
–max-depth	Define the maximum folder depthness to search into the user’s root directory to find repositories. This is commonly used if your repositories are organised with multiple sub-folders. Default: 3	No

Configure default language

By default, the web application uses the HTTP Accept-Language headers to determine the best language to use for display. Users can also manually select a preferred language to use for all communication. The default-language setting is used when the user has not selected a preferred language and none of the Accept-Language headers match a translation.

Parameter	Description	Example
–default-lang	default application locale. e.g.: fr	es

Configure Version Check

Rdiffweb include a feature to check version and notify administrator if an upgrade is available.

• Rdiffweb Version Check