Installation

You should have received access to the Debian package (for example linkahead-0.9.0.deb) via your subscription or as a trial version. For easier maintenance, LinkAhead uses Docker for deployment. The Debian package does however not contain the Docker image (since the image is quite large) and the image will be downloaded during the installation process from a docker registry. You will need to provide the credentials to the docker registry during the installation process (except for the trial version).

On a Debian or Ubuntu system, install the package with: sudo apt install ./linkahead-0.9.0.deb (replace the file name with your exact version).

Warning

apt may inform you about packages that can be removed now. Note that there is a bug in Ubuntu which may lead to inadvertently removing your graphics drivers when you follow that suggestion.

The installation procedure may ask for your LinkAhead subscription credentials (user name and token). It will automatically install, enable and start LinkAhead as a systemd service, so that LinkAhead will be started automatically on reboot in the future. You can also start the service manually using

$ systemctl start linkahead.service

Shutting down LinkAhead is done analogously with systemctl stop linkahead.service.

Note

Instead of a systemd service, LinkAhead can also be started completely manually. In that case, the path to the profile (see Configuration) and further options have to be given manually. The command to start LinkAhead then is linkahead -p path/to/profile.yml start --no-health --no-build (diagnostic health checks and building the image locally have to be disabled); it is stopped with linkahead -p path/to/profile.yml stop.

Typically, the required docker image will be downloaded on first startup, if it does not yet exist on the system. This may take a while. You can monitor the progress of the download and the subsequent start with:

$ journalctl -u linkahead -f

Once the log output says Starting org.caosdb.server.CaosDBServer application the installation is done and LinkAhead is running with the default configuration. You can check whether the LinkAhead server can be accessed by sending a curl request on the same machine:

$ curl -k https://localhost:10443
<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="https://localhost:10443/webinterface/1614339482/webcaosdb.xsl" ?>
<Response srid="11883904-301d-4bd9-8f74-86d95837239b" timestamp="1614339817505" baseuri="https://localhost:10443">
  <UserInfo>
    <Roles>
      <Role>anonymous</Role>
    </Roles>
  </UserInfo>
</Response>

If the command shows a similar empty reply to the one above, the installation was successful and you can continue with the configuration.

Requirements

Requirements are installed automatically. You can list them via apt-cache depends linkahead

Configuration

The path to the profile with which LinkAhead is started can be set in /etc/linkahead/linkahead.conf. The default profile is located at /usr/share/linkahead/profiles/default/profile.yml. See Configuration for more details on how to configure your profile.

Troubleshooting

Unable to fetch some archives

If apt finishes with this error, run apt update and try the installation again.

Old data still exists

Data is kept in persistent docker volumes. You can remove existing data the following way:

Warning

This cannot be undone. Make sure you have backups.

Have a look at the docker volumes: docker volume ls. The name depends on your profile, but typically you want to remove the following two: docker volume rm default_caosdb-sqldata default_caosdb-caosroot

docker-compose is not recent enough

You can install an up-to-date version with:

$ pip install --user docker-compose

The screen is black after the next reboot

This is not a bug in LinkAhead, but may be because you followed apt’s recommendation to automatically remove all packages which are deemed unnecessary by the system. This may remove your graphics drivers. It is a known issue in Ubuntu and will hopefully be fixed soon. In the meantime you may want to manually reinstall your graphics driver.