`app-lblod-harvester`

Mu-semtech stack for harvesting and processing Decisions from external sources. For the harvesting of Worship Decisions with focus on authentication, see app-lblod-harvester-worship.

List of Services

See the docker-compose.yml file.

Setup and startup

To start this stack, clone this repository and start it using docker compose using the following example snippet.

git clone git@github.com:lblod/app-lblod-harvester.git
cd app-lblod-harvester
docker-compose -f docker-compose.yml -f docker-compose.dev.yml up -d

It can take a while before everything is up and running. In case there is an error the first time you launch, just stopping and relaunching docker compose should resolve any issues:

docker-compose -f docker-compose.yml -f docker-compose.dev.yml stop
docker-compose -f docker-compose.yml -f docker-compose.dev.yml up -d

After starting, you might still have to wait for all the services to boot up, and migrations to finish running. You can check this by inspecting the Docker logs and wait for things to settle down. Once the stack is up and running without errors you can visit the frontend in a browser on http://localhost:80.

Setting up the delta-producers

To ensure that the app can share data, it is necessary to set up the producers. We recommend that you first ensure a significant dataset has been harvested. The more data that has been harvested before setting up the producers, the faster the consumers will retrieve their data.

During its initial run, each producer performs a sync operation, which publishes the dataset as a DCAT dataset. This format can easily be ingested by consumers. After this initial sync, the producer switches to 'normal operation' mode, where it publishes delta files whenever new data is ingested.

Please note, for this app, we do not provide live delta-streaming. This means that delta files are not published immediately as new data gets ingested. Instead, delta files are created only during 'healing mode'. This is a background job that runs according to a specific cron pattern to create the delta files. Check ./config/delta-producer/background-job-initiator/config.json for the exact timings of the healing-job.

The reason why we do not provide live streaming is due to performance considerations. It has pushed us towards skipping mu-authorization and updating Virtuoso directly.

Setting up producer besluiten

Only in case you are flushing and restarting from scratch, ensure in ./config/delta-producer/background-job-initiator/config.json
```
    [
      {
        "name": "besluiten",
        # (...) other config

        "startInitialSync": false, # changed from 'true' to 'false'

        # (...) other config

      }
    ]
```
- And also ensure some data has been harvested before starting the initial sync.
Make sure the app is up and running, and the migrations have run.

In ./config/delta-producer/background-job-initiator/config.json file, make sure the following configuration is changed:

    [
      {
        "name": "besluiten",
        # (...) other config

        "startInitialSync": true, # changed from 'false' to 'true'

        # (...) other config

      }
    ]

Restart the services: drc restart delta-producer-background-jobs-initiator
You can follow the status of the job, through the dashboard frontend.

Configuring besluiten dumps

Dumps are used by consumers as a snapshot to start from, this is faster than consuming all delta's. They are generated by the delta-producer-dump-file-publisher which is started by a task created by the delta-producer-background-jobs-initiator. The necessary config is already present in this repository, but you need to enable them by updating the config. It's recommended to set up dumps on a regular interval, preferably at a time slot when no harvesting is happening.

To enable dumps, edit ./config/delta-producer/background-job-initiator/config.json enable creation by setting disableDumpFileCreation to false and set the cron pattern you need:

     "dumpFileCreationJobOperation": "http://redpencil.data.gift/id/jobs/concept/JobOperation/deltas/deltaDumpFileCreation/besluiten",
     "initialPublicationGraphSyncJobOperation": "http://redpencil.data.gift/id/jobs/concept/JobOperation/deltas/initialPublicationGraphSyncing/besluiten",
     "healingJobOperation": "http://redpencil.data.gift/id/jobs/concept/JobOperation/deltas/healingOperation/besluiten",
     "cronPatternDumpJob": "0 10 0 * * 6",
     "cronPatternHealingJob": "0 0 2 * * *",
     "startInitialSync": false,
     "errorCreatorUri": "http://lblod.data.gift/services/delta-producer-background-jobs-initiator-besluiten",
     "disableDumpFileCreation": false
   }

Make sure to restart the background-job-initiator service after changing the config.

Dumps will be generated in data/files/delta-producer-dumps.

docker compose restart delta-producer-background-jobs-initiator

Authentication

By default this application requires authentication. You can generate a migration to add a user account by using mu-cli and running the included project script.

 mu script project-scripts generate-account

This should generate a migration for you to add the user account. Afterwards make sure to restart the migration service to execute the migration

docker compose restart migrations

If you wish to run this application without authentication, this is also possible. You'll need to make the following changes:

#config/authorization/config.ex
       %GroupSpec{
         name: "harvesting",
         useage: [:write, :read_for_write, :read],
-        access: logged_in_user(),
+        access: %AlwaysAccessible{},

#docker-compose.yml
  identifier:
    environment:
-      DEFAULT_MU_AUTH_ALLOWED_GROUPS_HEADER: '[{"variables":[],"name":"public"},{"variables":[],"name":"clean"}]'    
+      DEFAULT_MU_AUTH_ALLOWED_GROUPS_HEADER: '[{"variables":[],"name":"public"},{"variables":[],"name":"harvesting"}, {"variables":[],"name":"clean"}]'
  frontend:
    environment
-     EMBER_AUTHENTICATION_ENABLED: "true"
+     EMBER_AUTHENTICATION_ENABLED: "false"

Triggering the healing-job manually

In some cases, you might want to trigger the healing job manually.

drc exec delta-producer-background-jobs-initiator wget --post-data='' http://localhost/besluiten/healing-jobs

Cleaning up delta related background jobs manually

Trigger the debug endpoints in delta-producer-background-jobs-initiator

Additional notes

Performance

The default Virtuoso settings might be too weak if you need to ingest the production data. There is a better config for this that you can use in your docker-compose.override.yml

virtuoso:
  volumes:
    - ./data/db:/data
    - ./config/virtuoso/virtuoso-production.ini:/data/virtuoso.ini
    - ./config/virtuoso/:/opt/virtuoso-scripts

`delta-producer-report-generator`

Not all required parameters are provided, since these are deploy specific, see the delta-producer-report-generator repository.

`deliver-email-service`

Should have credentials provided, see the deliver-email-service repository.

lblod / app-lblod-harvester

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