added expiry date in license

x-pack/plugin/core/src/main/java/org/elasticsearch/license/License.java

@@ -15,6 +15,7 @@
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.LoggingDeprecationHandler;
 import org.elasticsearch.common.xcontent.XContentHelper;
+import org.elasticsearch.xcontent.ToXContent;
 import org.elasticsearch.xcontent.ToXContentObject;
 import org.elasticsearch.xcontent.XContentBuilder;
 import org.elasticsearch.xcontent.XContentParser;
@@ -518,6 +519,8 @@ public XContentBuilder toInnerXContent(XContentBuilder builder, Params params) t
 
         if (expiryDate != LicenseSettings.BASIC_SELF_GENERATED_LICENSE_EXPIRATION_MILLIS) {
             builder.timestampFieldsFromUnixEpochMillis(Fields.EXPIRY_DATE_IN_MILLIS, Fields.EXPIRY_DATE, expiryDate);
+            double daysUntilExpiry = LicenseUtils.getDaysUntilExpiry(this, System.currentTimeMillis());
+            builder.field(Fields.EXPIRY_IN_DAYS, String.format(Locale.ROOT, "%.1f", daysUntilExpiry));
         }
 
         if (licenseVersion >= VERSION_ENTERPRISE) {
@@ -740,6 +743,7 @@ public static final class Fields {
         public static final String FEATURE = "feature";
         public static final String EXPIRY_DATE_IN_MILLIS = "expiry_date_in_millis";
         public static final String EXPIRY_DATE = "expiry_date";
+        public static final String EXPIRY_IN_DAYS = "expiry_in_days";
         public static final String START_DATE_IN_MILLIS = "start_date_in_millis";
         public static final String START_DATE = "start_date";
         public static final String MAX_NODES = "max_nodes";

x-pack/plugin/core/src/main/java/org/elasticsearch/license/LicenseUtils.java

@@ -171,4 +171,21 @@ public static String getExpiryWarning(long licenseExpiryDate, long currentTime)
         }
         return null;
     }
+
+    /**
+     * Calculate the number of days until license expiry
+     * @param license The license to check
+     * @param now Current time in milliseconds
+     * @return Number of days until expiry (can be negative if expired)
+     */
+    public static double getDaysUntilExpiry(License license, long now) {
+        if (license == null) {
+            return 0.0;
+        }
+        final long expiryDate = getExpiryDate(license);
+        if (expiryDate == LicenseSettings.BASIC_SELF_GENERATED_LICENSE_EXPIRATION_MILLIS) {
+            return Double.POSITIVE_INFINITY;
+        }
+        return (expiryDate - now) / (24.0 * 60 * 60 * 1000);
+    }
 }

x-pack/plugin/core/src/test/java/org/elasticsearch/license/LicenseUtilsTests.java

@@ -77,6 +77,49 @@ public void testGetXPackLicenseStatus() {
         assertThat(status.expiryWarning(), containsStringIgnoringCase("license expired"));
     }
 
+    public void testGetDaysUntilExpiry() {
+        // Test null license
+        assertEquals(0.0, LicenseUtils.getDaysUntilExpiry(null, 0), 0.01);
+
+        // Test basic license (should return infinity)
+        License basicLicense = License.builder()
+            .uid("test")
+            .type(License.LicenseType.BASIC)
+            .issueDate(System.currentTimeMillis())
+            .expiryDate(LicenseSettings.BASIC_SELF_GENERATED_LICENSE_EXPIRATION_MILLIS)
+            .issuedTo("test")
+            .issuer("test")
+            .maxNodes(1000)
+            .build();
+        assertEquals(Double.POSITIVE_INFINITY, LicenseUtils.getDaysUntilExpiry(basicLicense, System.currentTimeMillis()), 0.01);
+
+        // Test regular license with 30 days remaining
+        long now = System.currentTimeMillis();
+        long thirtyDaysInMillis = TimeUnit.DAYS.toMillis(30);
+        License trialLicense = License.builder()
+            .uid("test")
+            .type(License.LicenseType.TRIAL)
+            .issueDate(now)
+            .expiryDate(now + thirtyDaysInMillis)
+            .issuedTo("test")
+            .issuer("test")
+            .maxNodes(1000)
+            .build();
+        assertEquals(30.0, LicenseUtils.getDaysUntilExpiry(trialLicense, now), 0.01);
+
+        // Test expired license (should return negative days)
+        License expiredLicense = License.builder()
+            .uid("test")
+            .type(License.LicenseType.TRIAL)
+            .issueDate(now - thirtyDaysInMillis)
+            .expiryDate(now - thirtyDaysInMillis)
+            .issuedTo("test")
+            .issuer("test")
+            .maxNodes(1000)
+            .build();
+        assertEquals(-30.0, LicenseUtils.getDaysUntilExpiry(expiredLicense, now), 0.01);
+    }
+
     private License getLicense(License.LicenseType type, long issueDate, long expiryDate) {
         License.Builder builder = License.builder()
             .uid(UUIDs.randomBase64UUID(random()))