Element Web Updater

A simple Bash script for installing and updating Element Web from GitHub releases.

Warning

Back up your config.json before using this script.

The script is designed to preserve config.json during updates, but you should always keep a separate backup copy in a safe location. Use this script at your own risk.

Features

• Automatically detects the latest Element Web release.
• Checks the currently installed version and skips the update if it is already up to date.
• Supports both fresh installations and updates.
• Preserves the existing config.json.
• Downloads and verifies the release archive (SHA-256) before touching the current installation.
• Removes files from previous releases that are no longer present in the new release.
• Shows a download progress bar when run interactively and stays quiet under systemd, cron, or another non-interactive environment.

Requirements

• Bash
• curl
• sha256sum
• tar
• find
• sed and awk (POSIX, normally preinstalled)

No additional packages or runtime environments are required.

Configuration

The script is configured using variables at the very top of the script. All of them can also be overridden using an optional .env file.

DESTINATION

The directory where Element Web is installed.

There is no default: DESTINATION must always be provided, either in the .env file or at the top of the script.

Example:

DESTINATION="/var/www/element"

TMP_DIR

The directory used for downloading the release archive and temporarily extracting it before installation.

It must be different from DESTINATION.

Default:

TMP_DIR="/tmp"

Example:

TMP_DIR="/var/tmp/element"

REPO

The GitHub repository from which the Element Web releases are downloaded.

Default:

REPO="element-hq/element-web"

Example:

REPO="element-hq/element-web"

.env

The .env file is optional. If present in the current working directory, it overrides the default values.

Only the DESTINATION, TMP_DIR and REPO keys are read; everything else is ignored. Values may be quoted, comments and empty lines are allowed. The file is parsed, not executed.

Example:

DESTINATION="/var/www/element"
TMP_DIR="/var/tmp/element"
REPO="element-hq/element-web"

If no .env file is provided, the default values defined in the script are used.

Because the file is looked up in the current working directory, when running the script from cron or a systemd timer make sure the working directory (the WorkingDirectory= option in systemd, or a cd in cron) points to the directory that contains .env.

How it works

The installed version is read from $DESTINATION/version. This file is shipped inside the release archive itself (its value includes a v prefix, e.g. v1.12.25, which the script normalizes), so the script does not maintain its own version file.

For a fresh install, $DESTINATION must be empty except for config.json. This prevents the script from accidentally overwriting unrelated files.

For an existing installation, the script:

1. Checks the latest Element Web release on GitHub.
2. Downloads the release archive to $TMP_DIR and verifies its SHA-256 digest.
3. Extracts the archive to a temporary directory.
4. Verifies the archive looks like Element Web (contains index.html and version).
5. Removes the old installation files (keeping config.json) and copies the new release into place.
6. The version file is copied together with the other files, so the installed version is always tracked.

If downloading, verifying or extracting fails, the current installation is left untouched.

Note: step 5 is not atomic — the old files are deleted before the new ones are copied. A failure during the copy (for example a full disk) can leave a partial installation. Keep a backup.

Usage

Make the script executable and run it:

chmod +x element-web-updater.sh
./element-web-updater.sh

or run it directly with Bash:

bash element-web-updater.sh

Files are copied with the permissions and ownership of the user running the script. If your web server runs under a different user (for example www-data), make sure the installation directory is writable by the script's user, or run the script as the web server user and adjust ownership afterwards.

The script can also be executed periodically using systemd timers. See Scheduled updates (systemd timer).

Releases

Release archives are published on the Releases page and contain:

• element-web-updater-<version>.tar.gz — the script, the README.md and the LICENSE (MIT);
• SHA256SUMS — checksums of the archive for integrity verification.

Verify the archive before using it:

sha256sum -c SHA256SUMS

The project is licensed under the MIT license.

Scheduled updates (systemd timer)

The updater can be run on a schedule with a systemd timer. The service should run as the user that runs the web server (for example www-data), so that the installed files get the correct ownership and permissions.

Service unit

Create /etc/systemd/system/element-web-updater.service:

[Unit]
Description=Update Element Web
After=network-online.target
Wants=network-online.target

[Service]
Type=oneshot
User=www-data
Group=www-data
WorkingDirectory=/srv/element-web-updater
ExecStart=/srv/element-web-updater/element-web-updater.sh
NoNewPrivileges=true
PrivateTmp=true
ProtectSystem=full

[Install]
WantedBy=multi-user.target

Notes on the service unit:

• User= and Group= must be set to the user that runs the web server (here www-data). That user must be able to read and execute the updater script and to write to DESTINATION.
• WorkingDirectory= must point to the directory that contains the updater's .env file — the script looks it up in the current working directory. If you do not use a .env file, point it to any directory and configure DESTINATION, TMP_DIR and REPO at the top of the script instead.
• PrivateTmp=true gives the service an isolated temporary directory. With the default TMP_DIR=/tmp the download and extraction happen inside that private directory and are cleaned up automatically.
• When run by systemd, stdout is not a terminal, so the script stays quiet and does not show a progress bar.

Timer unit

Create /etc/systemd/system/element-web-updater.timer:

[Unit]
Description=Run the Element Web updater daily

[Timer]
OnCalendar=daily
RandomizedDelaySec=15min
Persistent=true

[Install]
WantedBy=timers.target

• OnCalendar=daily runs the update once a day; other schedules are possible, for example OnCalendar=*-*-* 03:00:00 for a fixed time.
• RandomizedDelaySec spreads the run over up to 15 minutes to avoid load spikes.
• Persistent=true runs a missed update right after boot if the machine was off at the scheduled time.

Enabling the timer

Make sure the installation directory is writable by the web server user, and that the updater script and its .env file are readable by it:

sudo chown -R www-data:www-data /var/www/element

Then enable and start the timer:

sudo systemctl daemon-reload
sudo systemctl enable --now element-web-updater.timer

Check the schedule and the results of the last run:

systemctl list-timers element-web-updater.timer
systemctl status element-web-updater.service
journalctl -u element-web-updater.service

To trigger an update manually under the same conditions as the timer:

sudo systemctl start element-web-updater.service

Notes

• If DESTINATION is not writable by the user set with User=, the update will fail. Either run the service as the owner of the installation directory, or change its ownership with chown.
• With ProtectSystem=full, the directories /usr, /boot and /etc are read-only. DESTINATION and TMP_DIR must live outside of them; if that does not fit your setup, drop or adjust the hardening options.
• The examples assume the web server runs under www-data and that .env contains DESTINATION="/var/www/element". Adjust User=, Group=, WorkingDirectory= and the chown target to your environment.

Configuration file

The config.json file is considered user-managed and is never overwritten by the script.

The release archive ships a config.sample.json instead of a config.json. As a safety measure the script also removes any config.json from the extracted archive before copying, so a preserved user configuration always survives an update.

Important

The script preserves the existing config.json during installation and updates. However, you should always keep a backup copy of your config.json in a safe location before using the script.

The author is not responsible for any data loss, configuration loss, service interruption, or other damage resulting from the use of this script.

Use the script at your own risk and make sure you have a working backup before performing an update.