Add microservice to add OCR to PDF

.github/workflows/lint-test-build.yml

@@ -71,7 +71,7 @@ jobs:
       - name: Find docker files
         id: images
         run: |
-          dockerFiles=$(find examples -name Dockerfile | grep -v -E '(mergepdf|coverpage)' | jq -c --raw-input --slurp 'split("\n")| .[0:-1]')
+          dockerFiles=$(find examples -name Dockerfile | grep -v -E '(mergepdf|coverpage|ocrpdf)' | jq -c --raw-input --slurp 'split("\n")| .[0:-1]')
           echo "dockerFiles=$dockerFiles" >> $GITHUB_OUTPUT
         env:
           GITHUB_REF: ${{ github.ref }}
@@ -93,7 +93,7 @@ jobs:
     needs: [build-push]
     strategy:
       matrix:
-        dockerFile: ["examples/coverpage/Dockerfile", "examples/mergepdf/Dockerfile"]
+        dockerFile: ["examples/coverpage/Dockerfile", "examples/mergepdf/Dockerfile", "examples/ocrpdf/Dockerfile",]
     uses: ./.github/workflows/build-push.yml
     with:
       dockerFile: ${{ matrix.dockerFile }}

ci/k8s/ingress.yaml

@@ -81,3 +81,10 @@ spec:
                 name: islandora-mergepdf
                 port:
                   number: 8080
+          - path: /ocrpdf(/|$)(.*)
+            pathType: Prefix
+            backend:
+              service:
+                name: islandora-ocrpdf
+                port:
+                  number: 8080

ci/k8s/ocrpdf.yaml

@@ -0,0 +1,46 @@
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: islandora-ocrpdf
+spec:
+  selector:
+    app: islandora-ocrpdf
+  ports:
+    - protocol: TCP
+      port: 8886
+      targetPort: 8080
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: islandora-ocrpdf
+spec:
+  replicas: 3
+  selector:
+    matchLabels:
+      app: islandora-ocrpdf
+  template:
+    metadata:
+      labels:
+        app: islandora-ocrpdf
+    spec:
+      containers:
+        - name: scyllaridae-ocrpdf
+          image: lehighlts/scyllaridae-ocrpdf:main
+          imagePullPolicy: IfNotPresent
+          resources:
+            requests:
+              memory: "128Mi"
+              cpu: "500m"
+            limits:
+              memory: "1Gi"
+          ports:
+            - containerPort: 8080
+              hostPort: 8886
+          readinessProbe:
+            httpGet:
+              path: /healthcheck
+              port: 8080
+            initialDelaySeconds: 5
+            periodSeconds: 10

examples/ocrpdf/Dockerfile

@@ -0,0 +1,24 @@
+ARG TAG=main
+ARG DOCKER_REPOSITORY=local
+FROM ${DOCKER_REPOSITORY}/scyllaridae-imagemagick:${TAG} AS scyllaridae
+
+RUN apk update && \
+  apk add --no-cache \
+    ghostscript==10.04.0-r0 \
+    jq==1.7.1-r0 \
+    leptonica-dev==1.84.1-r0 \
+    tesseract-ocr==5.3.4-r0 \
+    tesseract-ocr-data-eng==5.3.4-r0 \
+    tesseract-ocr-data-fra==5.3.4-r0 \
+    tesseract-ocr-data-spa==5.3.4-r0 \
+    tesseract-ocr-data-ita==5.3.4-r0 \
+    tesseract-ocr-data-por==5.3.4-r0 \
+    tesseract-ocr-data-hin==5.3.4-r0 \
+    tesseract-ocr-data-deu==5.3.4-r0 \
+    tesseract-ocr-data-jpn==5.3.4-r0 \
+    tesseract-ocr-data-rus==5.3.4-r0 \
+    poppler-utils==24.02.0-r1
+
+COPY . /app
+
+ENTRYPOINT ["/app/docker-entrypoint.sh"]

examples/ocrpdf/README.md

@@ -0,0 +1,49 @@
+# ocrpdf
+
+Add OCR to PDF with no OCR
+
+## Install
+
+### Deploy microservice
+
+
+#### docker-compose
+
+Add the microservice to your docker compose
+
+```
+    ocrpdf-dev: &ocrpdf
+        <<: [*dev, *common]
+        image: lehighlts/scyllaridae-ocrpdf:main
+        networks:
+            default:
+                aliases:
+                    - ocrpdf
+    ocrpdf-prod:
+        <<: [*prod, *ocrpdf]
+```
+
+#### kubernetes
+
+See [service/deployment manifest in scyllaridae repo](https://github.com/lehigh-university-libraries/scyllaridae/blob/main/ci/k8s/ocrpdf.yaml)
+
+
+### Configure alpaca
+
+You'll also need to add `ocrpdf` to `derivative.systems.installed` in your `alpaca.properties` by adding that string to the `ALPACA_DERIVATIVE_SYSTEMS` environment variable in your alpaca service.
+
+```
+ALPACA_DERIVATIVE_SYSTEMS=ocrpdf
+```
+
+You'll also need to define the service in alpaca.properties.tmpl
+
+```
+derivative.whisper.enabled=true
+derivative.whisper.in.stream=queue:islandora-connector-ocrpdf
+# this url may be different if deploying via kubernetes
+derivative.whisper.service.url=http://ocrpdf:8080
+derivative.whisper.concurrent-consumers=1
+derivative.whisper.max-concurrent-consumers=-1
+derivative.whisper.async-consumer=true
+```

examples/ocrpdf/cmd.sh

@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+
+set -eou pipefail
+
+TMP_DIR=$(mktemp -d)
+
+cd "$TMP_DIR"
+
+# split pdf into PNG files
+pdftoppm -r 300 - page -png
+
+# add OCR to each PNG
+for i in page-*.png; do
+  tesseract "$i" "${i%.png}" --dpi 300 pdf
+done
+
+# put the PDF back together
+pdfunite page-*.pdf output.pdf
+
+# make sure the PDF is legit
+pdfinfo output.pdf > /dev/null || exit 1
+
+# print the results to stdout
+cat output.pdf
+
+# cleanup
+cd /app
+rm -rf "$TMP_DIR"

examples/ocrpdf/scyllaridae.yml

@@ -0,0 +1,5 @@
+allowedMimeTypes:
+  - "application/pdf"
+cmdByMimeType:
+  default:
+    cmd: /app/cmd.sh