docs(deployment): sync design to online docs (apache#7256)

* docs(deployment): sync design to online docs

Signed-off-by: spacewander <spacewanderlzx@gmail.com>

* Apply suggestions from code review

Co-authored-by: Sylvia <39793568+SylviaBABY@users.noreply.github.com>

* change image

Thanks for @SylviaBABY

Signed-off-by: spacewander <spacewanderlzx@gmail.com>

* change

Signed-off-by: spacewander <spacewanderlzx@gmail.com>

Co-authored-by: Sylvia <39793568+SylviaBABY@users.noreply.github.com>

docs/en/latest/architecture-design/deployment-role.md

@@ -0,0 +1,137 @@
+---
+title: Deployment Role
+---
+
+<!--
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
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+#     http://www.apache.org/licenses/LICENSE-2.0
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+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+-->
+
+## Concept
+
+Previously, the DP (Data Plane) and the CP (Control Plane) are not separate explicitly.
+
+Although we clearly distinguish the different responsibilities of DP and CP in the documentation, not everyone has correctly deployed APISIX in the production environment.
+
+Therefore, we introduce new concepts called deployment modes/roles, to help users deploy APISIX easily and safely.
+
+APISIX under different deployment modes will act differently.
+
+The table below shows the relationship among deployment modes and roles:
+
+| Deployment Modes | Role                       | Description                                                                              |
+|------------------|----------------------------|------------------------------------------------------------------------------------------|
+| traditional      | traditional                | DP + CP are deployed together by default. People need to disable `enable_admin` manually |
+| decoupled        | data_plane / control_plane | DP and CP are deployed independently.                                                    |
+| standalone       | data_plane                 | Only DP, load the all configurations from local yaml file                                |
+
+## Deployment Modes
+
+### Traditional
+
+![traditional](../../../assets/images/deployment-traditional.png)
+
+In the traditional deployment mode, one instance can be both DP & CP.
+
+There will be a `conf server` listens on UNIX socket and acts as a proxy between APISIX and etcd.
+
+Both the DP part and CP part of the instance will connect to the `conf server` via HTTP protocol.
+
+Here is the example of configuration:
+
+```yaml title="conf/config.yaml"
+deployment:
+    role: traditional
+    role_traditional:
+        config_provider: etcd
+    etcd:
+       host:
+           - http://xxxx
+       prefix: /apisix
+       timeout: 30
+```
+
+### Decoupled
+
+![decoupled](../../../assets/images/deployment-cp_and_dp.png)
+
+The instance deployed as data_plane will:
+
+1. Fetch configurations from the CP, the default port is 9280
+2. Before the DP service starts, it will perform a health check on all CP addresses
+    - If all CP addresses are unavailable, the startup fails and an exception message is output to the screen.
+    - If at least one CP address is available, print the unhealthy CP check result log, and then start the APISIX service.
+    - If all CP addresses are normal, start the APISIX service normally.
+3. Handle user requests.
+
+Here is the example of configuration:
+
+```yaml title="conf/config.yaml"
+deployment:
+    role: data_plane
+    role_data_plane:
+       config_provider: control_plane
+       control_plane:
+           host:
+               - xxxx:9280
+           timeout: 30
+    certs:
+        cert: /path/to/ca-cert
+        cert_key: /path/to/ca-cert
+        trusted_ca_cert: /path/to/ca-cert
+```
+
+The instance deployed as control_plane will:
+
+1. Listen on 9180 by default, and provide Admin API for Admin user
+2. Provide `conf server` which listens on port 9280 by default. Both the DP instances and this CP instance will connect to the `conf server` via HTTPS enforced by mTLS.
+
+Here is the example of configuration:
+
+```yaml title="conf/config.yaml"
+deployment:
+    role: control_plane
+    role_control_plan:
+        config_provider: etcd
+        conf_server:
+            listen: 0.0.0.0:9280
+            cert: /path/to/ca-cert
+            cert_key: /path/to/ca-cert
+            client_ca_cert: /path/to/ca-cert
+    etcd:
+       host:
+           - https://xxxx
+       prefix: /apisix
+       timeout: 30
+    certs:
+        cert: /path/to/ca-cert
+        cert_key: /path/to/ca-cert
+        trusted_ca_cert: /path/to/ca-cert
+```
+
+### Standalone
+
+In this mode, APISIX is deployed as DP and reads configurations from yaml file in the local file system.
+
+Here is the example of configuration:
+
+```yaml title="conf/config.yaml"
+deployment:
+    role: data_plane
+    role_data_plane:
+       config_provider: yaml
+```

docs/en/latest/config.json

@@ -7,7 +7,8 @@
       "items": [
         "architecture-design/apisix",
         "architecture-design/plugin-config",
-        "architecture-design/debug-mode"
+        "architecture-design/debug-mode",
+        "architecture-design/deployment-role"
       ]
     },
     {