make default attachment data source opt-in

Author: J0nasMayr

pom.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
 
     <parent>
@@ -11,7 +12,7 @@
 
     <groupId>it.aboutbits.springboot</groupId>
     <artifactId>emailservice</artifactId>
-    <version>1.2.0</version>
+    <version>BUILD-SNAPSHOT</version>
     <description>Spring Boot Email Service</description>
 
     <properties>

readme.md

@@ -17,13 +17,20 @@ Add the mailer service to the classpath by adding the following maven dependency
 
 ### Attachments
 
-Attachments work out of the box. The library ships a default that stores attachment payloads in the
-lib-owned table `email_service_attachment_payloads`. The table is created automatically the first time the default is
-used, unless `aboutbits.emailservice.migrations.enabled` is set to `false`.
+If you want to use attachments, you will have to define a bean implementing this interface: [AttachmentDataSource.java](src%2Fmain%2Fjava%2Fit%2Faboutbits%2Fspringboot%2Femailservice%2Flib%2FAttachmentDataSource.java)  
+This step is optional. Where the payloads are stored is a decision of the application: you can provide your own
+implementation (e.g. S3), or register the ready-made `JdbcAttachmentDataSource` shipped with the library, which stores
+payloads in the lib-owned table `email_service_attachment_payloads`:
 
-If you want to store payloads somewhere else (e.g. S3), define your own bean implementing this
-interface: [AttachmentDataSource.java](src%2Fmain%2Fjava%2Fit%2Faboutbits%2Fspringboot%2Femailservice%2Flib%2FAttachmentDataSource.java)  
-The default then backs off and its table is never created.
+```java
+
+@Bean
+public AttachmentDataSource attachmentDataSource(JdbcTemplate jdbcTemplate) {
+    return new JdbcAttachmentDataSource(jdbcTemplate);
+}
+```
+
+The `JdbcAttachmentDataSource` creates its table itself on construction, so no further setup is needed.
 
 #### Inline (CID) attachments
 

src/main/java/it/aboutbits/springboot/emailservice/EmailServiceConfiguration.java

@@ -9,15 +9,15 @@
 import it.aboutbits.springboot.emailservice.lib.application.EmailMapper;
 import it.aboutbits.springboot.emailservice.lib.application.EmailMapperImpl;
 import it.aboutbits.springboot.emailservice.lib.application.EmailServiceMigrator;
-import it.aboutbits.springboot.emailservice.lib.application.JdbcAttachmentDataSource;
 import it.aboutbits.springboot.emailservice.lib.application.ManageEmail;
 import it.aboutbits.springboot.emailservice.lib.application.QueryEmail;
 import it.aboutbits.springboot.emailservice.lib.application.SendScheduledEmails;
+import it.aboutbits.springboot.emailservice.lib.application.UnavailableAttachmentDataSource;
 import it.aboutbits.springboot.emailservice.lib.jpa.EmailRepository;
 import org.jspecify.annotations.NullMarked;
+import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.boot.autoconfigure.AutoConfigurationPackage;
-import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.context.annotation.Bean;
 import org.springframework.jdbc.core.JdbcTemplate;
@@ -55,7 +55,7 @@ public QueryEmail queryEmail(EmailRepository emailRepository, EmailMapper emailM
     public ManageEmail manageEmail(
             EmailRepository emailRepository,
             JavaMailSender javaMailSender,
-            AttachmentDataSource attachmentDataSource,
+            ObjectProvider<AttachmentDataSource> attachmentDataSource,
             EmailMapper emailMapper,
             @Value("${aboutbits.emailservice.scheduling.max-attempts:3}") int maxAttempts,
             @Value("${aboutbits.emailservice.scheduling.interval:30000}") long schedulerIntervalMillis,
@@ -64,7 +64,7 @@ public ManageEmail manageEmail(
         return new ManageEmail(
                 emailRepository,
                 javaMailSender,
-                attachmentDataSource,
+                attachmentDataSource.getIfAvailable(UnavailableAttachmentDataSource::new),
                 emailMapper,
                 maxAttempts,
                 Duration.ofMillis(schedulerIntervalMillis),
@@ -93,17 +93,4 @@ public CleanupAttachmentFiles cleanupAttachments(
     ) {
         return new CleanupAttachmentFiles(queryEmail, manageEmail, callbacks, stuckCleanupRecoveryThreshold);
     }
-
-    @Bean
-    @ConditionalOnMissingBean(AttachmentDataSource.class)
-    public JdbcAttachmentDataSource attachmentDataSource(
-            JdbcTemplate jdbcTemplate,
-            @Value("${aboutbits.emailservice.migrations.enabled:true}") boolean migrationsEnabled
-    ) {
-        var dataSource = new JdbcAttachmentDataSource(jdbcTemplate);
-        if (migrationsEnabled) {
-            dataSource.migrate();
-        }
-        return dataSource;
-    }
 }

src/main/java/it/aboutbits/springboot/emailservice/lib/application/JdbcAttachmentDataSource.java

@@ -19,9 +19,10 @@ public class JdbcAttachmentDataSource implements AttachmentDataSource {
 
     public JdbcAttachmentDataSource(JdbcTemplate jdbcTemplate) {
         this.jdbcTemplate = jdbcTemplate;
+        migrate();
     }
 
-    public void migrate() {
+    private void migrate() {
         log.info("EmailService: running attachment payload DB migrations...");
 
         jdbcTemplate.execute(

src/main/java/it/aboutbits/springboot/emailservice/lib/application/UnavailableAttachmentDataSource.java

@@ -0,0 +1,25 @@
+package it.aboutbits.springboot.emailservice.lib.application;
+
+import it.aboutbits.springboot.emailservice.lib.AttachmentDataSource;
+import it.aboutbits.springboot.emailservice.lib.exception.AttachmentException;
+import org.jspecify.annotations.NullMarked;
+
+import java.io.InputStream;
+
+@NullMarked
+public final class UnavailableAttachmentDataSource implements AttachmentDataSource {
+    @Override
+    public InputStream getAttachmentPayload(long fileReference) throws AttachmentException {
+        throw new AttachmentException("attachments not available");
+    }
+
+    @Override
+    public long storeAttachmentPayload(InputStream payload) throws AttachmentException {
+        throw new AttachmentException("attachments not available");
+    }
+
+    @Override
+    public void releaseAttachment(long fileReference) throws AttachmentException {
+        throw new AttachmentException("attachments not available");
+    }
+}

src/test/java/it/aboutbits/springboot/emailservice/lib/application/JdbcAttachmentDataSourceTest.java

@@ -1,12 +1,13 @@
 package it.aboutbits.springboot.emailservice.lib.application;
 
-import it.aboutbits.springboot.emailservice.lib.AttachmentDataSource;
 import it.aboutbits.springboot.emailservice.lib.exception.AttachmentException;
 import it.aboutbits.springboot.emailservice.support.database.WithPostgres;
 import org.jspecify.annotations.NullMarked;
+import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.jdbc.core.JdbcTemplate;
 
 import java.io.ByteArrayInputStream;
 
@@ -19,11 +20,13 @@
 @NullMarked
 class JdbcAttachmentDataSourceTest {
     @Autowired
-    AttachmentDataSource attachmentDataSource;
+    JdbcTemplate jdbcTemplate;
 
-    @Test
-    void defaultAttachmentDataSource_shouldBeJdbcBased() {
-        assertThat(attachmentDataSource).isInstanceOf(JdbcAttachmentDataSource.class);
+    JdbcAttachmentDataSource attachmentDataSource;
+
+    @BeforeEach
+    void setup() {
+        attachmentDataSource = new JdbcAttachmentDataSource(jdbcTemplate);
     }
 
     @Test