Add mergepdf microservice [minor]

[joecorall]

This PR does two things:

1. Builds the alpaca JAR instead of downloading it from maven. Mainly to test Add full event as base 64 encoded X-Islandora-Event header Islandora/Alpaca#94 easily
2. Adds a new mergepdf microservice to aggregate all children images of a paged content item into a single PDF

How to test

1. Ensure your Drupal site is based on Islandora starter site OR has the two Drupal Views mentioned in the mergepdf dependencies. Also ensure the term by name view allows for JWT auth i.e. Add JWT authentication to term_from_term_name view islandora-starter-site#221
2. Add the mergepdf service from this PR to your docker compose project

services:
  mergepdf:
    image: islandora/mergepdf:alpaca-94
    secrets: *secrets-jwt-public

3. Update your alpaca service's tag to use this PR alpaca-94

services:
  alpaca:
    image: islandora/alpaca:alpaca-94

4. On your Drupal site create an action to generate a PDF for paged content items. i.e. go to /admin/config/development/configuration/single/import, select Configuration type > Action, paste:

langcode: en
status: true
dependencies:
  module:
    - islandora
id: paged_content_created_aggregated_pdf
label: 'Paged Content - Created Aggregated PDF'
type: node
plugin: emit_node_event
configuration:
  queue: islandora-connector-mergepdf
  event: 'Generate Derivative'

And import it
5. At /admin/content select a paged content item that has a valid IIIF manifest at /node/{node}/book-manifest and apply the Paged Content - Created Aggregated PDF action to the node
6. Your paged content item should have a PDF attached as an original file after a few seconds/minutes

Links

Islandora-Labs/rfds#1

Interested parties

@aOelschlager @seth-shaw-asu

[aOelschlager]

I've been trying to test this today but it hasn't created a pdf yet. All of the containers were up including the new mergepdf service. I imported the action config on my site. I added jwt to the term from term name view. I checked the activemq gui and the number of consumers is 0 for the islandora-connector-mergepdf queue. I thought it should be at least 1.

[joecorall]

@aOelschlager I checked the activemq gui and the number of consumers is 0 for the islandora-connector-mergepdf queue. I thought it should be at least 1.

Are you overriding the ALPACA_DERIVATIVE_SYSTEMS environment variable or the alpaca properties file in your alpaca service definition in docker-compose.yaml?

[aOelschlager]

It ended up being that the environment variable ALPACA_DERIVATIVE_MERGEPDF_ENABLE was set to false by default. I switch it to true and I have a consumer now for mergepdf queue.

I'm still debugging this since I'm getting errors in the logs but now it is new errors.

[aOelschlager]

Tested and it works! Thanks Joe and Seth!