fix(bug): ImageName should respect project.build.outputTimestamp when present (3780)

fix(bug): ImageName should respect project.build.outputTimestamp when present
---
fix(bug): Add PR to changelog
---
fix(bug): replace with parameterized test

Author: ash-thakur-rh

CHANGELOG.md

@@ -24,6 +24,7 @@ Usage:
 * Fix #3750: Remove unneeded XMLUtil.createNewDocument method
 * Fix #3740: Add verbose extension prop as per the gradle plugin docs
 * Fix #3779: Compatibility with gradle 9
+* Fix #3780: ImageName should respect project.build.outputTimestamp when present
 
 ### 1.18.1 (2025-02-11)
 * Fix #3642: Config properties resolved for generated images

jkube-kit/build/api/src/main/java/org/eclipse/jkube/kit/build/api/helper/ImageNameFormatter.java

@@ -14,9 +14,12 @@
 package org.eclipse.jkube.kit.build.api.helper;
 
 import java.text.SimpleDateFormat;
+import java.time.Instant;
+import java.time.format.DateTimeParseException;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.TimeZone;
 
 import static org.eclipse.jkube.kit.common.JKubeFileInterpolator.DEFAULT_FILTER;
 import static org.eclipse.jkube.kit.common.JKubeFileInterpolator.interpolate;
@@ -150,6 +153,12 @@ private static class DefaultTagLookup extends AbstractLookup {
          */
         private static final String DOCKER_IMAGE_TAG = "jkube.image.tag";
 
+        /**
+         * Maven property for reproducible builds timestamp.
+         * See <a href="https://maven.apache.org/guides/mini/guide-reproducible-builds.html">...</a>
+         */
+        private static final String OUTPUT_TIMESTAMP = "project.build.outputTimestamp";
+
         // how to resolve the version
         private final Mode mode;
 
@@ -207,14 +216,45 @@ private String generateTag(String plusSubstitute) {
 
             switch (mode) {
             case SNAPSHOT_WITH_TIMESTAMP:
-                return "snapshot-" + new SimpleDateFormat("yyMMdd-HHmmss-SSSS").format(now) + buildmetadata;
+                Date timestamp = getTimestamp();
+                SimpleDateFormat dateFormat = new SimpleDateFormat("yyMMdd-HHmmss-SSSS");
+                dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
+                return "snapshot-" + dateFormat.format(timestamp) + buildmetadata;
             case SNAPSHOT_LATEST:
                 return "latest" + buildmetadata;
             default:
                 throw new IllegalStateException("mode is '" + mode.name() + "', which is not implemented.");
             }
         }
 
+        /**
+         * Gets the timestamp to use for image tagging.
+         * First checks for project.build.outputTimestamp property (for reproducible builds),
+         * then falls back to the current time.
+         *
+         * @return the timestamp to use for tagging
+         */
+        private Date getTimestamp() {
+            final String outputTimestamp = getProperty(OUTPUT_TIMESTAMP);
+            if (StringUtils.isBlank(outputTimestamp)) {
+                return now;
+            }
+
+            try {
+                // Try parsing as a number (seconds since epoch)
+                long epochSeconds = Long.parseLong(outputTimestamp);
+                return Date.from(Instant.ofEpochSecond(epochSeconds));
+            } catch (NumberFormatException e) {
+                // Not a number, try parsing as ISO 8601 timestamp
+                try {
+                    return Date.from(Instant.parse(outputTimestamp));
+                } catch (DateTimeParseException ex) {
+                    // Invalid format, fall back to now
+                    return now;
+                }
+            }
+        }
+
         private static String sanitizeTag(String tagName, String plusSubstitute) {
             StringBuilder ret = new StringBuilder(tagName.length());
 

jkube-kit/build/api/src/test/java/org/eclipse/jkube/kit/build/api/helper/ImageNameFormatterTest.java

@@ -12,7 +12,6 @@
  *   Red Hat, Inc. - initial API and implementation
  */
 package org.eclipse.jkube.kit.build.api.helper;
-import org.eclipse.jkube.kit.build.api.helper.ImageNameFormatter;
 import org.eclipse.jkube.kit.common.JavaProject;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
@@ -179,4 +178,54 @@ void format_whenPropertyInImageName_thenResolveProperty() {
         // Then
         assertThat(result).isEqualTo("registry.gitlab.com/myproject/myrepo/mycontainer:der12");
     }
+
+    @ParameterizedTest(name = "version = {0}, outputTimestamp = {1} should generate {2}")
+    @MethodSource("outputTimestampReproducibleData")
+    void format_whenOutputTimestampSet_thenUsesReproducibleTimestamp(String version, String outputTimestamp, String expectedTag) {
+        // Given
+        project.setVersion(version);
+        project.getProperties().put("project.build.outputTimestamp", outputTimestamp);
+        formatter = new ImageNameFormatter(project, new Date());
+        // When
+        final String result = formatter.format("%g/%a:%t");
+        // Then
+        assertThat(result)
+            .isEqualTo(expectedTag)
+            .satisfies(i -> assertThat(new ImageName(i)).isNotNull());
+    }
+
+    static Stream<Arguments> outputTimestampReproducibleData() {
+        return Stream.of(
+            arguments("1.2.3-SNAPSHOT", "1672531200", "jkube/kubernetes-maven-plugin:snapshot-230101-000000-0000"),
+            arguments("1.2.3-SNAPSHOT", "2023-01-01T00:00:00Z", "jkube/kubernetes-maven-plugin:snapshot-230101-000000-0000"),
+            arguments("1.2.3-SNAPSHOT+semver.build_meta-data", "1672531200", "jkube/kubernetes-maven-plugin:snapshot-230101-000000-0000-semver.build_meta-data")
+        );
+    }
+
+    @Test
+    void format_whenOutputTimestampNotSet_thenUsesCurrentTime() {
+        // Given
+        project.setVersion("1.2.3-SNAPSHOT");
+        formatter = new ImageNameFormatter(project, new Date());
+        // When
+        final String result = formatter.format("%g/%a:%t");
+        // Then
+        assertThat(result)
+            .matches("^jkube/kubernetes-maven-plugin:snapshot-\\d{6}-\\d{6}-\\d{4}$")
+            .satisfies(i -> assertThat(new ImageName(i)).isNotNull());
+    }
+
+    @Test
+    void format_whenOutputTimestampInvalid_thenFallsBackToCurrentTime() {
+        // Given
+        project.setVersion("1.2.3-SNAPSHOT");
+        project.getProperties().put("project.build.outputTimestamp", "invalid-timestamp");
+        formatter = new ImageNameFormatter(project, new Date());
+        // When
+        final String result = formatter.format("%g/%a:%t");
+        // Then
+        assertThat(result)
+            .matches("^jkube/kubernetes-maven-plugin:snapshot-\\d{6}-\\d{6}-\\d{4}$")
+            .satisfies(i -> assertThat(new ImageName(i)).isNotNull());
+    }
 }