From 74484b36e3a3fd0dc124d1a10e7f45b43e6b3442 Mon Sep 17 00:00:00 2001
From: Andrei Gherzan <andrei.gherzan@huawei.com>
Date: Tue, 19 Jul 2022 12:49:03 +0200
Subject: [PATCH] docs: Add documentation on containers topic
Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>
---
docs/index.rst | 1 +
docs/supported-technologies/containers.rst | 102 +++++++++++++++++++++
2 files changed, 103 insertions(+)
create mode 100644 docs/supported-technologies/containers.rst
diff --git a/docs/index.rst b/docs/index.rst
index 802a2d7a..4f7bc2c7 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -35,6 +35,7 @@ Build System Guide
:maxdepth: 2
supported-technologies/openthread
+ supported-technologies/containers
.. toctree::
:caption: Troubleshoot
diff --git a/docs/supported-technologies/containers.rst b/docs/supported-technologies/containers.rst
new file mode 100644
index 00000000..1af3cc39
--- /dev/null
+++ b/docs/supported-technologies/containers.rst
@@ -0,0 +1,102 @@
+.. SPDX-FileCopyrightText: Huawei Inc.
+..
+.. SPDX-License-Identifier: CC-BY-4.0
+
+.. include:: ../definitions.rst
+
+Containers
+##########
+
+|main_project_name| maintains support for a container-based architecture
+included as part of the OS when using the reference images (or images derived
+from them). This OS functionality aims at facilitating the deployment of
+container-based applications. This feature plays a part in the wider
+|main_project_name| update software stack for managing deployments and updates
+from the host operating system to the container-based applications.
+
+.. note::
+
+ The current support is aiming at the Linux-based |main_project_name| images.
+
+As part of this architecture, |main_project_name| currently provides the
+integration and support for the following container management engines:
+
+Podman
+********
+
+`Podman <https://podman.io/>`_ is a daemonless container engine that can run
+both in root and rootless mode. |main_project_name| supports both of these
+modes while keeping the read-only root filesystem assumption valid by taking
+advantage of the application partition for storing persistent data.
+
+The OS integration provides seamless integration with `docker` CLI so that
+`docker` commands are handled transparently by `podman`.
+
+When using `podman` alone, deploying a service is as simple as running the
+associated CLI command for spawning a container of a specific image. For
+example, running a `busybox` container using an image from `dockerhub`
+container registry is achieved by running the following when logged in as the
+`oniro` user:
+
+.. code-block:: console
+
+ $ podman run -ti --rm docker.io/library/busybox:latest ls
+
+This will spawn, run and remove a `busybox` rootless container. You can run the
+same example in root mode:
+
+
+.. code-block:: console
+
+ $ sudo podman run -ti --rm docker.io/library/busybox:latest ls
+
+Updating a containerised application, when using `podman` alone follows the
+classic container flow:
+
+ * stop container
+ * update/pull image
+ * start a new container
+
+As an example, we use the same container image above running a tool in
+background mode:
+
+.. code-block:: console
+
+ # run a container in background
+ $ podman run -d --name busybox_top docker.io/library/busybox:latest top
+ 8fcc484d8a905a9e6cb24e1eac87782970f91951ab1cb0d1b0ec64729e0ffb01
+
+ # the container is running
+ $ podman ps
+ CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
+ 8fcc484d8a90 docker.io/library/busybox:latest top 6 seconds ago Up 4 seconds ago busybox_top
+
+ # stop the container
+ $ podman stop busybox_top
+ busybox_top
+
+ # pull an updated container image
+ $ podman pull docker.io/library/busybox:latest
+ Trying to pull docker.io/library/busybox:latest...
+ Getting image source signatures
+ Copying blob 19d511225f94 skipped: already exists
+ Copying config 62aedd01bd done
+ Writing manifest to image destination
+ Storing signatures
+ 62aedd01bd8520c43d06b09f7a0f67ba9720bdc04631a8242c65ea995f3ecac8
+
+ # run the updated container
+ $ podman run -d --name busybox_top_update docker.io/library/busybox:latest top
+ 1a3a7383a111e79b702fd081d4204a5827698b252d2d00ee9ae818306dbbef87
+
+ # check that the updated container is running
+ $ podman ps
+ CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
+ 1a3a7383a111 docker.io/library/busybox:latest top 8 seconds ago Up 5 seconds ago busybox_top_update
+
+ # cleanup
+ $ podman stop busybox_top_update
+ $ podman rm busybox_top busybox_top_update
+
+The output above may be slightly different due to variations in your local
+setup. That is expected.
--
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