docs: fix minor issues in docker readme

deploy/docker/README.md

@@ -30,11 +30,15 @@ Starting from 3.0 release, *EMQX* broker fully supports MQTT V5.0 protocol speci
 
 Execute some command under this docker image
 
-``docker run -d --name emqx emqx/emqx:$(tag)``
+```console
+$ docker run -d --name emqx emqx/emqx:${tag}
+```
 
 For example
 
-``docker run -d --name emqx -p 18083:18083 -p 1883:1883 emqx/emqx:latest``
+```console
+$ docker run -d --name emqx -p 18083:18083 -p 1883:1883 emqx/emqx:latest
+```
 
 The EMQX broker runs as Linux user `emqx` in the docker container.
 
@@ -42,7 +46,7 @@ The EMQX broker runs as Linux user `emqx` in the docker container.
 
 Use the environment variable to configure the EMQX docker container.
 
-By default, the environment variables with ``EMQX_`` prefix are mapped to key-value pairs in configuration files.
+By default, the environment variables with `EMQX_` prefix are mapped to key-value pairs in configuration files.
 
 You can change the prefix by overriding `HOCON_ENV_OVERRIDE_PREFIX`.
 
@@ -53,9 +57,9 @@ EMQX_LISTENERS__SSL__DEFAULT__ACCEPTORS <--> listeners.ssl.default.acceptors
 EMQX_ZONES__DEFAULT__MQTT__MAX_PACKET_SIZE <--> zones.default.mqtt.max_packet_size
 ```
 
-+ Prefix ``EMQX_`` is removed
++ Prefix `EMQX_` is removed
 + All upper case letters is replaced with lower case letters
-+ ``__`` is replaced with ``.``
++ `__` is replaced with `.`
 
 If `HOCON_ENV_OVERRIDE_PREFIX=DEV_` is set:
 
@@ -75,41 +79,43 @@ These environment variables will ignore for configuration file.
 
 #### EMQX Configuration
 
-> NOTE: All EMQX Configuration in [`etc/emqx.conf`](https://github.com/emqx/emqx/blob/master/etc/emqx.conf) can be configured via environment variables. The following list is just an example, not a complete configuration.
+> NOTE: All EMQX Configuration in [`etc/emqx.conf`](https://github.com/emqx/emqx/blob/master/apps/emqx/etc/emqx.conf) can be configured via environment variables. The following list is just an example, not a complete configuration.
 
 | Options                    | Default            | Mapped                    | Description                           |
 | ---------------------------| ------------------ | ------------------------- | ------------------------------------- |
 | `EMQX_NAME`                | container name     | none                      | EMQX node short name                  |
 | `EMQX_HOST`                | container IP       | none                      | EMQX node host, IP or FQDN            |
 
-The list is incomplete and may changed with [`etc/emqx.conf`](https://github.com/emqx/emqx/blob/master/etc/emqx.conf) and plugin configuration files. But the mapping rule is similar.
+The list is incomplete and may be changed with [`etc/emqx.conf`](https://github.com/emqx/emqx/blob/master/apps/emqx/etc/emqx.conf) and plugin configuration files. But the mapping rule is similar.
 
-If set ``EMQX_NAME`` and ``EMQX_HOST``, and unset ``EMQX_NODE_NAME``, ``EMQX_NODE_NAME=$EMQX_NAME@$EMQX_HOST``.
+If set `EMQX_NAME` and `EMQX_HOST`, and unset `EMQX_NODE_NAME`, `EMQX_NODE_NAME=$EMQX_NAME@$EMQX_HOST`.
 
 For example, set MQTT TCP port to 1883
 
-``docker run -d --name emqx -e EMQX__LISTENERS__TCP__DEFAULT__BIND=1883 -p 18083:18083 -p 1883:1883 emqx/emqx:latest``
+```console
+$ docker run -d --name emqx -e EMQX__LISTENERS__TCP__DEFAULT__BIND=1883 -p 18083:18083 -p 1883:1883 emqx/emqx:latest
+```
 
 #### EMQX Loaded Modules Configuration
 
-| Oprtions                 | Default            | Description                           |
-| ------------------------ | ------------------ | ------------------------------------- |
-| `EMQX_LOADED_MODULES`    | see content below  | default EMQX loaded modules           |
+| Options                 | Default            | Description                           |
+| ----------------------- | ------------------ | ------------------------------------- |
+| `EMQX_LOADED_MODULES`   | see content below  | default EMQX loaded modules           |
 
-Default environment variable ``EMQX_LOADED_MODULES``, including
+Default environment variable `EMQX_LOADED_MODULES`, including
 
-+ ``emqx_mod_presence``
++ `emqx_mod_presence`
 
 ```bash
 # The default EMQX_LOADED_MODULES env
 EMQX_LOADED_MODULES="emqx_mod_presence"
 ```
 
-For example, set ``EMQX_LOADED_MODULES=emqx_mod_delayed,emqx_mod_rewrite`` to load these two modules.
+For example, set `EMQX_LOADED_MODULES=emqx_mod_delayed,emqx_mod_rewrite` to load these two modules.
 
 You can use comma, space or other separator that you want.
 
-All the modules defined in env ``EMQX_LOADED_MODULES`` will be loaded.
+All the modules defined in env `EMQX_LOADED_MODULES` will be loaded.
 
 ```bash
 EMQX_LOADED_MODULES="emqx_mod_delayed,emqx_mod_rewrite"
@@ -119,28 +125,28 @@ EMQX_LOADED_MODULES="emqx_mod_delayed | emqx_mod_rewrite"
 
 #### EMQX Loaded Plugins Configuration
 
-| Oprtions                 | Default            | Description                           |
-| ------------------------ | ------------------ | ------------------------------------- |
-| `EMQX_LOADED_PLUGINS`    | see content below  | default EMQX loaded plugins           |
+| Options                 | Default            | Description                           |
+| ----------------------- | ------------------ | ------------------------------------- |
+| `EMQX_LOADED_PLUGINS`   | see content below  | default EMQX loaded plugins           |
 
-Default environment variable ``EMQX_LOADED_PLUGINS``, including
+Default environment variable `EMQX_LOADED_PLUGINS`, including
 
-+ ``emqx_recon``
-+ ``emqx_retainer``
-+ ``emqx_rule_engine``
-+ ``emqx_management``
-+ ``emqx_dashboard``
++ `emqx_recon`
++ `emqx_retainer`
++ `emqx_rule_engine`
++ `emqx_management`
++ `emqx_dashboard`
 
 ```bash
 # The default EMQX_LOADED_PLUGINS env
 EMQX_LOADED_PLUGINS="emqx_recon,emqx_retainer,emqx_management,emqx_dashboard"
 ```
 
-For example, set ``EMQX_LOADED_PLUGINS= emqx_retainer,emqx_rule_engine`` to load these two plugins.
+For example, set `EMQX_LOADED_PLUGINS= emqx_retainer,emqx_rule_engine` to load these two plugins.
 
 You can use comma, space or other separator that you want.
 
-All the plugins defined in ``EMQX_LOADED_PLUGINS`` will be loaded.
+All the plugins defined in `EMQX_LOADED_PLUGINS` will be loaded.
 
 ```bash
 EMQX_LOADED_PLUGINS="emqx_retainer,emqx_rule_engine"
@@ -150,7 +156,7 @@ EMQX_LOADED_PLUGINS="emqx_retainer | emqx_rule_engine"
 
 #### EMQX Plugins Configuration
 
-The environment variables which with ``EMQX_`` prefix are mapped to all EMQX plugins' configuration file, ``.`` get replaced by ``__``.
+The environment variables which with `EMQX_` prefix are mapped to all EMQX plugins' configuration file, `.` get replaced by `__`.
 
 Example:
 
@@ -177,7 +183,7 @@ docker run -d --name emqx -p 18083:18083 -p 1883:1883 \
     emqx/emqx:latest
 ```
 
-For numbered configuration options where the number is next to a ``.`` such as:
+For numbered configuration options where the number is next to a `.` such as:
 
 + backend.redis.pool1.server
 + backend.redis.hook.message.publish.1
@@ -186,20 +192,20 @@ You can configure an arbitrary number of them as long as each has a unique numbe
 
 ```bash
 docker run -d --name emqx -p 18083:18083 -p 1883:1883 \
-    -e EMQX_BACKEND_REDIS_POOL1__SERVER=127.0.0.1:6379
+    -e EMQX_BACKEND_REDIS_POOL1__SERVER=127.0.0.1:6379 \
     [...]
-    -e EMQX_BACKEND__REDIS__POOL5__SERVER=127.0.0.5:6379
-    -e EMQX_BACKEND__REDIS__HOOK_MESSAGE__PUBLISH__1='{"topic": "persistent/topic1", "action": {"function": "on_message_publish"}, "pool": "pool1"}'
-    -e EMQX_BACKEND__REDIS__HOOK_MESSAGE__PUBLISH__2='{"topic": "persistent/topic2", "action": {"function": "on_message_publish"}, "pool": "pool1"}'
-    -e EMQX_BACKEND__REDIS__HOOK_MESSAGE__PUBLISH__3='{"topic": "persistent/topic3", "action": {"function": "on_message_publish"}, "pool": "pool1"}'
+    -e EMQX_BACKEND__REDIS__POOL5__SERVER=127.0.0.5:6379 \
+    -e EMQX_BACKEND__REDIS__HOOK_MESSAGE__PUBLISH__1='{"topic": "persistent/topic1", "action": {"function": "on_message_publish"}, "pool": "pool1"}' \
+    -e EMQX_BACKEND__REDIS__HOOK_MESSAGE__PUBLISH__2='{"topic": "persistent/topic2", "action": {"function": "on_message_publish"}, "pool": "pool1"}' \
+    -e EMQX_BACKEND__REDIS__HOOK_MESSAGE__PUBLISH__3='{"topic": "persistent/topic3", "action": {"function": "on_message_publish"}, "pool": "pool1"}' \
     [...]
-    -e EMQX_BACKEND__REDIS__HOOK_MESSAGE__PUBLISH__13='{"topic": "persistent/topic13", "action": {"function": "on_message_publish"}, "pool": "pool1"}'
+    -e EMQX_BACKEND__REDIS__HOOK_MESSAGE__PUBLISH__13='{"topic": "persistent/topic13", "action": {"function": "on_message_publish"}, "pool": "pool1"}' \
     emqx/emqx:latest
 ```
 
 ### Cluster
 
-EMQX supports a variety of clustering methods, see our [documentation](https://www.emqx.io/docs/en/latest/advanced/cluster.html) for details.
+EMQX supports a variety of clustering methods, see our [documentation](https://www.emqx.io/docs/en/latest/deploy/cluster/intro.html) for details.
 
 Let's create a static node list cluster from docker-compose.
 
@@ -236,7 +242,6 @@ Let's create a static node list cluster from docker-compose.
   networks:
     emqx-bridge:
       driver: bridge
-
   ```
 
 + Start the docker-compose cluster
@@ -276,7 +281,7 @@ volumes:
 
 services:
   emqx:
-    image: emqx/emqx:v4.0.0
+    image: emqx/emqx:latest
     restart: always
     environment:
       EMQX_NAME: foo_emqx
@@ -289,12 +294,11 @@ services:
 
 ### Kernel Tuning
 
-Under Linux host machine, the easiest way is [Tuning guide](https://www.emqx.io/docs/en/latest/tutorial/tune.html).
+Under Linux host machine, the easiest way is [Tuning guide](https://www.emqx.io/docs/en/latest/deploy/tune.html).
 
 If you want tune Linux kernel by docker, you must ensure your docker is latest version (>=1.12).
 
 ```bash
-
 docker run -d --name emqx -p 18083:18083 -p 1883:1883 \
     --sysctl fs.file-max=2097152 \
     --sysctl fs.nr_open=2097152 \
@@ -312,7 +316,6 @@ docker run -d --name emqx -p 18083:18083 -p 1883:1883 \
     --sysctl net.ipv4.tcp_max_tw_buckets=1048576 \
     --sysctl net.ipv4.tcp_fin_timeout=15 \
     emqx/emqx:latest
-
 ```
 
 > REMEMBER: DO NOT RUN EMQX DOCKER PRIVILEGED OR MOUNT SYSTEM PROC IN CONTAINER TO TUNE LINUX KERNEL, IT IS UNSAFE.