LinkedDataHub (LDH) is an open source software you can use to manage data, create visualizations and build apps on RDF Knowledge Graphs.
Welcome to LinkedDataHub. We started the project with the intention to use it for Linked Data publishing, but gradually realized that we've built a multi-purpose data-driven platform.
We are building LinkedDataHub for:
- domain experts who work with RDF data and need an accessible low-code publishing, exploration and management tool
- developers who are looking for a declarative full stack framework for web application and API development
- data engineers who need an open-source RDF platform that can be customized for a variety of use cases
What makes LinkedDataHub unique is its completely data-driven architecture: applications and documents are defined as data, managed using a single generic HTTP API and presented using declarative technologies. The default application structure and user interface are provided, but they can be completely overridden and customized. Unless a custom server-side processing is required, no imperative code such as Java or JavaScript needs to be involved at all.
Follow the Get started guide to build your first application on LinkedDataHub. The setup and basic configuration sections are provided below and should get you running.
Click to expand
- Install Docker
- Install Docker Compose, if it is not already included in the Docker installation
- Fork this repository and clone the fork into a folder
- In the folder, create an
.envfile and fill out the missing values (you can use.env_sampleas a template). For example:
COMPOSE_CONVERT_WINDOWS_PATHS=1
COMPOSE_PROJECT_NAME=linkeddatahub
PROTOCOL=https
PROXY_HTTP_PORT=81
PROXY_HTTPS_PORT=4443
HOST=localhost
ABS_PATH=/
[email protected]
OWNER_GIVEN_NAME=John
OWNER_FAMILY_NAME=Doe
OWNER_ORG_UNIT=My unit
OWNER_ORGANIZATION=My org
OWNER_LOCALITY=Copenhagen
OWNER_STATE_OR_PROVINCE=Denmark
OWNER_COUNTRY_NAME=DK
OWNER_KEY_PASSWORD=changeit
- Run this from command line:
docker-compose up
- LinkedDataHub will start and create the following sub-folders:
certswhere your WebID certificates are storeddatawhere the triplestore(s) will persist RDF datauploadswhere LDH stores content-hashed file uploads
- Install
certs/owner.p12into a web browser of your choice (password is theOWNER_KEY_PASSWORDvalue)- Google Chrome:
Settings > Advanced > Manage Certificates > Import... - Mozilla Firefox:
Options > Privacy > Security > View Certificates... > Import... - Apple Safari: The file is installed directly into the operating system. Open the file and import it using the Keychain Access tool.
- Microsoft Edge: Does not support certificate management, you need to install the file into Windows. Read more here.
- Google Chrome:
- Open https://localhost:4443/ in that web browser
After a successful startup, the last line of the Docker log should read:
linkeddatahub_1 | 02-Feb-2020 02:02:20.200 INFO [main] org.apache.catalina.startup.Catalina.start Server startup in 3420 ms
- You will likely get a browser warning such as
Your connection is not privatein Chrome orWarning: Potential Security Risk Aheadin Firefox due to the self-signed server certificate. Ignore it: clickAdvancedandProceedorAccept the riskto proceed.- If this option does not appear in Chrome (as observed on some MacOS), you can open
chrome://flags/#allow-insecure-localhost, switchAllow invalid certificates for resources loaded from localhosttoEnabledand restart Chrome
- If this option does not appear in Chrome (as observed on some MacOS), you can open
.env_sampleand.envfiles might be invisible in MacOS Finder which hides filenames starting with a dot. You should be able to create it using Terminal however.- On Linux your user may need to be a member of the
dockergroup. Add it using
sudo usermod -aG docker ${USER}
and re-login with your user. An alternative, but not recommended, is to run
sudo docker-compose up
Click to expand
Besides owner WebID configuration, the most common case is changing the base URI from the default https://localhost:4443/ to your own.
Lets use https://ec2-54-235-229-141.compute-1.amazonaws.com/linkeddatahub/ as an example. We need to split the URI into components and set them in the .env file using the following parameters:
PROTOCOL=https
HTTP_PORT=80
HTTPS_PORT=443
HOST=ec2-54-235-229-141.compute-1.amazonaws.com
ABS_PATH=/linkeddatahub/
ABS_PATH is required, even if it's just /.
Dataspaces are configured in config/system.trig. Relative URIs will be resolved against the base URI configured in the .env file.
urn: URI scheme, since LinkedDataHub application resources are not accessible under their own dataspace.
If you need to start fresh and wipe the existing setup (e.g. after configuring a new base URI), you can do that using
sudo rm -rf certs data && docker-compose down -v
LinkedDataHub CLI wraps the HTTP API into a set of shell scripts with convenient parameters. The scripts can be used for testing, automation, scheduled execution and such. It is usually much quicker to perform actions using CLI rather than the user interface, as well as easier to reproduce.
The scripts can be found in the scripts subfolder.
An environment variable JENA_HOME is used by all the command line tools to configure the class path automatically for you. You can set this up as follows:
On Linux / Mac
export JENA_HOME=the directory you downloaded Jena to
export PATH="$PATH:$JENA_HOME/bin"
Get the source code
SCRIPT_ROOT environmental variable to the scripts subfolder of your LinkedDataHub fork or clone. For example:
export SCRIPT_ROOT="/c/Users/namedgraph/WebRoot/AtomGraph/LinkedDataHub/scripts"
- contribute a new LDH application or modify one of ours
- work on good first issues
- work on the features in our Roadmap
- join our community
LinkedDataHub includes an HTTP test suite. The server implementation is also covered by the Processor test suite.
Please report issues if you've encountered a bug or have a feature request.
Commercial consulting, development, and support are available from AtomGraph.
- [email protected] (mailing list)
- @atomgraphhq on Twitter
- AtomGraph on LinkedIn
- W3C Declarative Linked Data Apps Community Group