HTTP

Configuration for connecting to arbitrary SPARQL HTTP backend

To register a new SPARQL Store you need to make sure the store is available to the DataPlatform. If it is available, use the following set of properties to connect to arbitrary HTTP SPARQL services in your application.yml (conf/dataplatform/application.yml).

Configuration Example

store:
  type: http
  authorization: REWRITE_FROM
  http:
    query-endpoint-url: "http://localhost:7200/repositories/cmem"
    update-endpoint-url: "http://localhost:7200/repositories/cmem/statements"
    graph-store-endpoint-url: "http://localhost:7200/repositories/cmem/rdf-graphs/service"
    username: "user"
    password: "password"

Property: store.type

The type of the store must be set to http.

Category	Value
Default	http
Required	true
Valid values	HTTP
Environment	STORE_TYPE

Property: store.authorization

Category	Value
Default	REWRITE_FROM
Required	false
Valid values	string
Environment	STORE_AUTHORIZATION

Specific settings for HTTP. At least query and update endpoints must be provided.

Property: store.http.query-endpoint-url

Use this property to configure the endpoint to which SPARQL 1.1 queries are sent.

Category	Value
Default	http://localhost:7200/repositories/cmem
Required	true
Valid values	string
Environment	STORE_HTTP_QUERY_ENDPOINT_URL

Property: store.http.update-endpoint-url

Use this property to configure the endpoint to which SPARQL 1.1 updates are sent.

Category	Value
Default	http://localhost:7200/repositories/cmem/statements
Required	true
Valid values	string
Environment	STORE_HTTP_UPDATE_ENDPOINT_URL

Property: store.http.graph-store-endpoint-url

Use this property to configure the endpoint to SPARQL 1.1 Graph Store Protocol requests are sent.

Category	Value
Default	http://localhost:7200/repositories/cmem/rdf-graphs/service
Required	false
Valid values	string
Environment	STORE_HTTP_GRAPH_STORE_ENDPOINT_URL

Property: store.http.username

Basic authentication is used if this parameter is provided.

Category	Value
Default	user
Required	false
Valid values	string
Environment	STORE_HTTP_USERNAME

Property: store.http.password

Basic authentication is used if this parameter is provided.

Category	Value
Default	password
Required	false
Valid values	string
Environment	STORE_HTTP_PASSWORD

Property: store.http.graphListQuery

Defines how the raw list of graphs is retrieved, and therefore which graphs are visible to the system. Graph must be bound to variable ?g !

Category	Value
Default	SELECT distinct ?g {graph ?g {?s ?p ?o}}
Required	false
Valid values	Valid SPARQL query with bound variable “g”
Environment	STORE_HTTP_GRAPHLISTQUERY

Example: Jena Fuseki Store

This section provides an example configuration that uses an Apache Jena Fuseki as store.

Add docker compose File

Add a new docker compose file to configure the execution of the store: compose/docker-compose.store.fuseki.yml. In this case the two environment variables FUSEKI_DOCKER_USER and FUSEKI_ENDPOINT_PORT are introduced.

docker-compose.store.fuseki.yml

# Jena Fuseki
services:
  store_base:
    image: docker.io/secoresearch/fuseki:4.8.0
    user: ${FUSEKI_DOCKER_USER}
    ports:
      - "3030:3030"
    command: /jena-fuseki/fuseki-server --tdb2 --loc /data --update /cmem
    volumes:
      - "store_volume:/data"
    healthcheck:
      test: ["CMD", "echo", "true"]
      interval: 10s
      timeout: 1s
      retries: 5

  dataplatform:
    environment:
      - "FUSEKI_ENDPOINT_PORT=${FUSEKI_ENDPOINT_PORT}"

Configure Variables

Now, the orchestration needs to know that it has to bring up the new store. This happens with the variable DP_STORE. But also the new variables (i.e. FUSEKI_DOCKER_USER, FUSEKI_ENDPOINT_PORT) introduced in the new docker compose file need to be set. This can be done in environments/config.env (see also Docker Orchestration)

environments/config.env (partially)

# DP_STORE=virtuoso-enterprise
# DP_STORE=marklogic
# DP_STORE=neptune
DP_STORE=fuseki

###################
# FUSEKI SETTINGS #
###################
FUSEKI_DOCKER_USER=0:0
FUSEKI_ENDPOINT_PORT=3030

Configure DataPlatform

Finally, the DataPlatform needs to know, how to access the new store. This configuration happens in conf/dataplatform/application.yml.

1. Add the store to the section spring.profiles.group:

conf/dataplaform/application.yml (partially

# Profile groups for the supported stores - these groups are selected by DP_STORE
spring:
  profiles:
    group:
      […]
      fuseki: fuseki-store, auth-graph

2. At the end of the file, add a new section as follows (pay attention to the separator ---):

conf/dataplaform/application.yml (partially

---

###
# Configuration for DP with Fuseki
###
spring:
  config:
    activate:
      on-profile: fuseki-store

## SPARQL Endpoints (Fuseki config)
store:
  type: http
  authorization: REWRITE_FROM
  http:
    query-endpoint-url: "http://store:${FUSEKI_ENDPOINT_PORT}/cmem/query"
    update-endpoint-url: "http://store:${FUSEKI_ENDPOINT_PORT}/cmem/update"

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