Then, near the end of the `Dockerfile`, we copy all the code. As this is what **changes most frequently**, we put it near the end, because almost always, anything after this step will not be able to use the cache.

```Dockerfile
COPY ./app /code/app
```

### Build the Docker Image

 * need to be on the same host. This operation does not copy extended
 * file attibutes such as ACLs but it does copy regular attributes as
 * well as create and last write times. This method is almost twice as
 * efficient as manually copying as it employs an additional write
 * thread to read and write data concurrently.
 * <p/>
 * It is not possible (nor meaningful) to copy entire workgroups or
 * servers.

- No-op and GC related updates to cluster trust bundles no longer require attest authorization when the `ClusterTrustBundleAttest` plugin is enabled. ([#120779](https://github.com/kubernetes/kubernetes/pull/120779), [@enj](https://github.com/enj))

- bump master cidr range from /30 to /29 ([#32886](https://github.com/kubernetes/kubernetes/issues/32886))
- non-hostNetwork daemonsets will almost always have a pod that fails to schedule ([#32900](https://github.com/kubernetes/kubernetes/issues/32900))
- Service loadBalancerSourceRanges doesn't respect updates ([#33033](https://github.com/kubernetes/kubernetes/issues/33033))

        canned Estimators`.
    *   `Estimator.export_savedmodel` has been renamed to `export_saved_model`.
    *   When saving to SavedModel, Estimators will strip default op attributes.
        This is almost always the correct behavior, as it is more forwards
        compatible, but if you require that default attributes to be saved with
        the model, please use `tf.compat.v1.Estimator`.

    <sub-class-of type="application/x-msdownload"/>
    <magic priority="55">
      <!-- Technically the header offset is stored at 0x3c, and isn't a -->
      <!-- constant, but it's almost always set to start at 0x80, 0xb0, -->
      <!-- 0xd0 or 0xf0. Will always have the MZ msdoc header too. -->
      <match value="MZ" type="string" offset="0">
         <match value="PE\000\000" type="string" offset="128"/>

- Added a alpha feature, behind the `RelaxedEnvironmentVariableValidation` feature gate.
  When that gate is enabled, Kubernetes allows almost all printable ASCII characters to be used in the names
  of environment variables for containers in Pods. ([#123385](https://github.com/kubernetes/kubernetes/pull/123385), [@HirazawaUi](https://github.com/HirazawaUi))

  Server-side apply now considers `.spec.defaultBackend` to be an atomic struct.  This means that any field-owner who sets values in that struct (they are mutually exclusive) owns the whole struct. For almost all users this change has no impact; for controllers that want to change the default backend port from number to name (or vice-versa), this makes it easier. ([#126207](https://github.com/kubernetes/kubernetes/pull/126207), [@thockin](https://github.com/thockin))...

* Change `kubeadm create token` to default to the group that almost everyone will want to use.  The group is system:bootstrappers:kubeadm:default-node-token and is the group that kubeadm sets up, via an RBAC binding, for auto-approval (system:certificates.k8s.io:certificatesigningrequests:nodeclient). ([#53512](h...

* Add API version apps/v1, and bump DaemonSet to apps/v1 ([#53278](https://github.com/kubernetes/kubernetes/pull/53278), [@janetkuo](https://github.com/janetkuo))