feat: deprecate embedded postgres ahead of v4

.github/workflows/test.yml

@@ -496,6 +496,68 @@ jobs:
         run: npm run eslint
         working-directory: ./email
 
+  docker-slim-smoke:
+    name: Slim Docker smoke 🐳
+    needs: [backend-build]
+    runs-on: ubuntu-24.04
+    permissions:
+      contents: read
+    services:
+      postgres:
+        image: postgres:17
+        env:
+          POSTGRES_PASSWORD: postgres
+          POSTGRES_DB: postgres
+        ports:
+          - 5432:5432
+        options: >-
+          --health-cmd pg_isready
+          --health-interval 5s
+          --health-timeout 3s
+          --health-retries 10
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup environment
+        uses: ./.github/actions/setup-env
+        with:
+          node: "false"
+
+      - name: Download backend build result
+        uses: ./.github/actions/download-backend-build
+
+      - name: Build slim Docker image
+        run: ./gradlew dockerSlim
+        env:
+          SKIP_SERVER_BUILD: true
+
+      - name: Start slim image
+        run: |
+          docker run -d --name tolgee-slim --network host \
+            -e SPRING_DATASOURCE_URL=jdbc:postgresql://localhost:5432/postgres \
+            -e SPRING_DATASOURCE_USERNAME=postgres \
+            -e SPRING_DATASOURCE_PASSWORD=postgres \
+            tolgee/tolgee:slim
+
+      - name: Wait for app to report healthy
+        run: |
+          for i in $(seq 1 90); do
+            status=$(curl -fsS http://localhost:8080/actuator/health 2>/dev/null \
+              | jq -r '.status // empty')
+            if [ "$status" = "UP" ]; then
+              echo "Slim image healthy after $((i * 2))s"
+              exit 0
+            fi
+            echo "[$i] status=${status:-<unreachable>}; retrying in 2s"
+            sleep 2
+          done
+          echo "❌ Slim image did not report UP within 180s"
+          exit 1
+
+      - name: Dump container logs on failure
+        if: failure()
+        run: docker logs tolgee-slim || true
+
   everything-passed:
     name: Everything passed 🎉
     needs:
@@ -508,6 +570,7 @@ jobs:
       - schema-check
       - migration-check
       - data-cy-check
+      - docker-slim-smoke
       - e2e
       - e2e-code-checks
       - e2e-install-deps
@@ -550,6 +613,10 @@ jobs:
             failed_jobs+=("data-cy-check")
           fi
 
+          if [[ "${{ needs.docker-slim-smoke.result }}" != "success" ]]; then
+            failed_jobs+=("docker-slim-smoke")
+          fi
+
           if [[ "${{ needs.e2e.result }}" != "success" ]]; then
             failed_jobs+=("e2e")
           fi

backend/app/src/main/kotlin/io/tolgee/commandLineRunners/EmbeddedPostgresDeprecationCommandLineRunner.kt

@@ -0,0 +1,27 @@
+package io.tolgee.commandLineRunners
+
+import io.tolgee.configuration.tolgee.PostgresAutostartProperties
+import io.tolgee.configuration.tolgee.PostgresAutostartProperties.PostgresAutostartMode
+import org.slf4j.LoggerFactory
+import org.springframework.boot.CommandLineRunner
+import org.springframework.stereotype.Component
+
+@Component
+class EmbeddedPostgresDeprecationCommandLineRunner(
+  private val postgresAutostartProperties: PostgresAutostartProperties,
+) : CommandLineRunner {
+  private val logger = LoggerFactory.getLogger(this::class.java)
+
+  override fun run(vararg args: String) {
+    if (!postgresAutostartProperties.enabled || postgresAutostartProperties.mode != PostgresAutostartMode.EMBEDDED) {
+      return
+    }
+
+    logger.warn(
+      "The embedded PostgreSQL bundled in the tolgee/tolgee image is deprecated and will be removed in Tolgee v4. " +
+        "Migrate to an external database before upgrading. " +
+        "See https://docs.tolgee.io/platform/self_hosting/running_with_docker" +
+        "#migrate-from-the-bundled-database",
+    )
+  }
+}

backend/data/src/main/kotlin/io/tolgee/configuration/tolgee/PostgresAutostartProperties.kt

@@ -21,7 +21,13 @@ class PostgresAutostartProperties {
         "This is default option when running Tolgee using Java. " +
         "See [Running with Java](/self_hosting/running_with_java.mdx).\n" +
         "- `EMBEDDED` - Tolgee tries to run it's embedded PostgreSQL " +
-        "which is bundled in the `tolgee/tolgee` Docker image.",
+        "which is bundled in the `tolgee/tolgee` Docker image.\n" +
+        "\n" +
+        "`EMBEDDED` is deprecated. Tolgee v4 removes the bundled PostgreSQL from the " +
+        "`tolgee/tolgee` image, so setups using it have to move to an external database " +
+        "before upgrading. See " +
+        "[Migrate from the bundled database](/self_hosting/running_with_docker" +
+        "#migrate-from-the-bundled-database).",
   )
   var mode: PostgresAutostartMode = PostgresAutostartMode.DOCKER
 

docker/app/Dockerfile.slim

@@ -0,0 +1,47 @@
+FROM eclipse-temurin:21-jre-alpine
+
+RUN apk --no-cache add bash
+
+#############
+### Tolgee  #
+#############
+
+# Expose application port
+EXPOSE 8080
+
+# Define persistent volume for data storage
+VOLUME /data
+
+# Environment variables for configuration
+# Postgres autostart is disabled — the slim image doesn't bundle the postgres
+# server, so it must be run against an external database.
+ENV HEALTHCHECK_PORT=8080 \
+    spring_profiles_active=docker \
+    TOLGEE_POSTGRES_AUTOSTART_ENABLED=false
+
+# Copy necessary application files
+COPY BOOT-INF/lib /app/lib
+COPY META-INF /app/META-INF
+COPY BOOT-INF/classes /app
+COPY --chmod=755 cmd.sh /app
+
+# Download OpenTelemetry Java agent for distributed tracing
+# When OTEL_JAVAAGENT_ENABLED=true, cmd.sh will use this agent
+# See: docs/observability/
+# Version is passed from gradle.properties via --build-arg (see gradle/docker.gradle)
+ARG OTEL_AGENT_VERSION
+RUN test -n "$OTEL_AGENT_VERSION" || (echo "OTEL_AGENT_VERSION build arg is required" && exit 1)
+RUN wget -O /app/opentelemetry-javaagent.jar \
+    "https://github.com/open-telemetry/opentelemetry-java-instrumentation/releases/download/v${OTEL_AGENT_VERSION}/opentelemetry-javaagent.jar"
+
+#################
+### Let's go   ##
+#################
+
+# Define the startup command
+ENTRYPOINT ["/app/cmd.sh"]
+
+
+# Health check to ensure the app is up and running
+HEALTHCHECK --interval=10s --timeout=3s --retries=20 \
+    CMD wget --spider -q "http://127.0.0.1:$HEALTHCHECK_PORT/actuator/health" || exit 1

gradle/docker.gradle

@@ -33,6 +33,23 @@ tasks.register('docker') {
     dependsOn("dockerPrepare")
 }
 
+// Builds the slim Docker image, tagged as tolgee/tolgee:slim.
+// Uses Dockerfile.slim - JRE-only base, no embedded postgres.
+// The slim image is not published; it is built on demand by the EE image
+// build in the billing repo and by the slim smoke test.
+tasks.register('dockerSlim') {
+    doLast {
+        exec {
+            workingDir dockerPath
+            commandLine "docker", "build", ".",
+                "-f", "Dockerfile.slim",
+                "-t", "tolgee/tolgee:slim",
+                "--build-arg", "OTEL_AGENT_VERSION=${opentelemetryJavaagentVersion}"
+        }
+    }
+    dependsOn("dockerPrepare")
+}
+
 // Builds and pushes multi-platform Docker image for CI.
 // Reads configuration from environment variables:
 //   - VERSION: image tag version (default: 'latest')