## Changelog since v1.18.4

## Changes by Kind

### API Change

- Fixed: log timestamps now include trailing zeros to maintain a fixed width ([#91207](https://github.com/kubernetes/kubernetes/pull/91207), [@iamchuckss](https://github.com/iamchuckss)) [SIG Apps and Node]

### Bug or Regression

- Fixed: log timestamps now include trailing zeros to maintain a fixed width ([#91207](https://github.com/kubernetes/kubernetes/pull/91207), [@iamchuckss](https://github.com/iamchuckss)) [SIG Apps and Node]

- Added warnings to the Services API. Kubernetes now warns for Services in the case of:
  - IPv4 addresses with leading zeros
  - IPv6 address in non-canonical format (RFC 5952) ([#114505](https://github.com/kubernetes/kubernetes/pull/114505), [@aojea](https://github.com/aojea))

    @Test
    @DisplayName("Cache size 0: release zeroes but does not cache; getBuffer allocates new")
    void zeroSizedCacheDoesNotStore() {
        BufferCacheImpl impl = new BufferCacheImpl(0, 8);
        byte[] supplied = new byte[3];
        supplied[0] = 1;
        supplied[1] = 2;

        // Release must not throw and must zero the supplied array

* When HPAScaleToZero feature gate is enabled HPA supports scaling to zero pods based on object or external metrics. HPA remains active as long as at least one metric value available. ([#74526](https://github.com/kubernetes/kubernetes/pull/74526), [@DXist](https://github.com/DXist))
    * To downgrade the cluster to version that does not support scale-to-zero feature:

- Removed leading zeros from the etcd member ID in kubeadm log messages. ([#117919](https://github.com/kubernetes/kubernetes/pull/117919), [@dlipovetsky](https://github.com/dlipovetsky)) [SIG Cluster Lifecycle]

- The apiserver will now return warnings if you create objects with "invalid" IP or
  CIDR values (like "192.168.000.005", which should not have the extra zeros).
  Values with non-standard formats can introduce security problems, and will

   * addresses, the output follows <a href="http://tools.ietf.org/html/rfc5952">RFC 5952</a> section
   * 4. The main difference is that this method uses "::" for zero compression, while Java's version
   * uses the uncompressed form (except on Android, where the zero compression is also done). The
   * other difference is that this method outputs any scope ID in the format that it was provided at

    } finally {
      pool.shutdownNow();
    }

    // Since we have access to the backing map, verify that there are no zeroes in the map
    for (AtomicInteger value : map.values()) {
      assertTrue("map should not contain a zero", value.get() != 0);
    }
  }

  private static class MutateTask implements Callable<int[]> {
    private final ConcurrentHashMultiset<String> multiset;

   * addresses, the output follows <a href="http://tools.ietf.org/html/rfc5952">RFC 5952</a> section
   * 4. The main difference is that this method uses "::" for zero compression, while Java's version
   * uses the uncompressed form (except on Android, where the zero compression is also done). The
   * other difference is that this method outputs any scope ID in the format that it was provided at