docs: update

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

Author: AkihiroSuda

README.md

@@ -52,11 +52,32 @@ See also [`./examples/compose-wordpress`](./examples/compose-wordpress).
 
 ### Debugging Kubernetes
 
-To list Kubernetes containers:
+To list local Kubernetes containers:
 ```console
 # nerdctl --namespace k8s.io ps -a
 ```
 
+To build an image for local Kubernetes without using registry:
+```console
+# nerdctl --namespace k8s.io build -t foo /some-dockerfile-directory
+# kubectl apply -f - <<EOF
+apiVersion: v1
+kind: Pod
+metadata:
+  name: foo
+spec:
+  containers:
+    - name: foo
+      image: foo
+      imagePullPolicy: Never
+EOF
+```
+
+To load an image archive (`docker save` format or OCI format) into local Kubernetes:
+```console
+# nerdctl --namespace k8s.io load < /path/to/image.tar
+```
+
 ### Rootless mode
 
 To launch rootless containerd:
@@ -136,6 +157,7 @@ Major:
 - Recursive read-only (RRO) bind-mount: `nerdctl run -v /mnt:/mnt:rro` (make children such as `/mnt/usb` to be read-only, too).
   Requires kernel >= 5.12, and crun >= 1.4 or runc >= 1.1 (PR [#3272](https://github.com/opencontainers/runc/pull/3272)).
 - [Cosign integration](./docs/cosign.md): `nerdctl pull --verify=cosign` and `nerdctl push --sign=cosign`
+- [Accelerated rootless containers using bypass4netns](./docs/rootless.md): `nerdctl run --label nerdctl/bypass4netns=true`
 
 Minor:
 - Namespacing: `nerdctl --namespace=<NS> ps` .

docs/faq.md

@@ -20,6 +20,7 @@
   - [How to change the CNI binary path?](#how-to-change-the-cni-binary-path)
 - [Kubernetes](#kubernetes)
   - [`nerdctl ps -a` does not show Kubernetes containers](#nerdctl-ps--a-does-not-show-kubernetes-containers)
+  - [How to build an image for Kubernetes?](#how-to-build-an-image-for-kubernetes)
 - [containerd socket (`/run/containerd/containerd.sock`)](#containerd-socket-runcontainerdcontainerdsock)
   - [Does nerdctl have an equivalent of `DOCKER_HOST=ssh://<USER>@<REMOTEHOST>` ?](#does-nerdctl-have-an-equivalent-of-docker_hostsshuserremotehost-)
   - [Does nerdctl have an equivalent of `sudo usermod -aG docker <USER>` ?](#does-nerdctl-have-an-equivalent-of-sudo-usermod--ag-docker-user-)
@@ -243,6 +244,30 @@ Try `sudo nerdctl --namespace=k8s.io ps -a` .
 
 Note: k3s users have to specify `--address` too: `sudo nerdctl --address=/run/k3s/containerd/containerd.sock --namespace=k8s.io ps -a`
 
+### How to build an image for Kubernetes?
+
+For a multi-node cluster:
+```console
+$ nerdctl build -t example.com/foo /some-dockerfile-directory
+$ nerdctl push example.com/foo
+```
+
+For a single-node cluster w/o registry:
+```console
+# nerdctl --namespace k8s.io build -t foo /some-dockerfile-directory
+# kubectl apply -f - <<EOF
+apiVersion: v1
+kind: Pod
+metadata:
+  name: foo
+spec:
+  containers:
+    - name: foo
+      image: foo
+      imagePullPolicy: Never
+EOF
+```
+
 ## containerd socket (`/run/containerd/containerd.sock`)
 
 ### Does nerdctl have an equivalent of `DOCKER_HOST=ssh://<USER>@<REMOTEHOST>` ?