From 4a8060f08bd5b472eddb1ee52d5339fc014dd5a0 Mon Sep 17 00:00:00 2001
From: Yanqiang Miao <miao.yanqiang@zte.com.cn>
Date: Wed, 7 Mar 2018 17:00:32 +0800
Subject: [PATCH] Add document about registry configuration

Signed-off-by: Yanqiang Miao <miao.yanqiang@zte.com.cn>
---
 docs/registry.md | 56 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 docs/registry.md

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+# Configure Image Registry for CRI-containerd
+This document describes the methods to configure the image registry for `cri-containerd`.
+
+In `cri-containerd`, `docker.io` is the default image registry. You can also set up other image registries similar to docker. `cri-containerd` provides two ways to set up the image registry.
+
+<!-- TODO: will remove the document for standalone mode, ref `containerd/containerd#2120` -->
+
+## Configure Image Registry with `--registry` Option
+
+Start `cri-containerd` with `--registry` option like:
+```bash
+$ cri-containerd \
+    --registry=test.secure-registry.io=https://HostIP1:Port1 \
+    --registry=test.insecure-registry.io=http://HostIP2:Port2
+```
+
+If you want configure a insecure registry, you need set the endpoint with `http://` prefix. If you want to configure a secure registry, you need set the endpoint with `https://` prefix.
+
+This method is only suitable for standalone mode.
+
+
+## Configure Image Registry with Config File in Standalone Mode
+In standalone mode, `cri-containerd` also specifies registris using the configuration file located in `/etc/cri-containerd/config.toml`. You can set registries in the configuration file as follows:
+```toml
+[registry.mirrors]
+  [registry.mirrors."docker.io"]
+    endpoint = ["https://registry-1.docker.io"]
+  [registry.mirrors."test.secure-registry.io"]
+    endpoint = ["https://HostIP1:Port1"]
+  [registry.mirrors."test.insecure-registry.io"]
+    endpoint = ["http://HostIP2:Port2"]
+```
+
+In the same way, the default configuration also can be generated by `cri-containerd default-config > /etc/cri-containerd/config.toml`. 
+
+The endpoint is a list that can contain multiple image registry URLs splited by commas.
+
+After modify the config file, you need restart the `cri-containerd` service.
+
+## Configure Image Registry with Config File in CRI Plugin Mode
+Today, `cri-containerd` can also be used as a native plugin of `containerd`. In this mode, you should set registries in `/etc/containerd/config.toml` as follows:
+```toml
+[plugins.cri.registry.mirrors]
+  [plugins.cri.registry.mirrors."docker.io"]
+    endpoint = ["https://registry-1.docker.io"]
+  [plugins.cri.registry.mirrors."test.secure-registry.io"]
+    endpoint = ["https://HostIP1:Port1"]
+  [plugins.cri.registry.mirrors."test.insecure-registry.io"]
+    endpoint = ["http://HostIP2:Port2"]
+```
+
+The default configuration can be generated by `containerd config default > /etc/containerd/config.toml`.
+
+The endpoint is a list that can contain multiple image registry URLs splited by commas.
+
+After modify the config file, you need restart the `containerd` service.