diff --git a/MAINTAINING.md b/MAINTAINING.md
index ce5cc370..f21533ef 100644
--- a/MAINTAINING.md
+++ b/MAINTAINING.md
@@ -2,4 +2,4 @@
 
 To make and publish new docker images on docker hub, maintainers should create branch under `apisix-docker` repo with specific name.
 
-For apisix new version, the branch name should use prefix `release/apisix` and `release/dashboard` separately (e.g. `release/apisix-2.6`). Remember to delete the release branch after the new images published, since the branch would got no use afterwards.
+For apisix new version, the branch name should use prefix `release/apisix` (e.g. `release/apisix-2.6`). Remember to delete the release branch after the new images published, since the branch would got no use afterwards.
diff --git a/example/dashboard_conf/conf.yaml b/example/dashboard_conf/conf.yaml
deleted file mode 100644
index ea0b15de..00000000
--- a/example/dashboard_conf/conf.yaml
+++ /dev/null
@@ -1,112 +0,0 @@
-#
-# 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
-# (the "License"); you may not use this file except in compliance with
-# the License.  You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# 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.
-#
-
-conf:
-  listen:
-    host: 0.0.0.0     # `manager api` listening ip or host name
-    port: 9000          # `manager api` listening port
-  allow_list:           # If we don't set any IP list, then any IP access is allowed by default.
-    - 0.0.0.0/0
-  etcd:
-    endpoints:          # supports defining multiple etcd host addresses for an etcd cluster
-      - "http://etcd:2379"
-                          # yamllint disable rule:comments-indentation
-                          # etcd basic auth info
-    # username: "root"    # ignore etcd username if not enable etcd auth
-    # password: "123456"  # ignore etcd password if not enable etcd auth
-    mtls:
-      key_file: ""          # Path of your self-signed client side key
-      cert_file: ""         # Path of your self-signed client side cert
-      ca_file: ""           # Path of your self-signed ca cert, the CA is used to sign callers' certificates
-    # prefix: /apisix     # apisix config's prefix in etcd, /apisix by default
-  log:
-    error_log:
-      level: warn       # supports levels, lower to higher: debug, info, warn, error, panic, fatal
-      file_path:
-        logs/error.log  # supports relative path, absolute path, standard output
-                        # such as: logs/error.log, /tmp/logs/error.log, /dev/stdout, /dev/stderr
-    access_log:
-      file_path:
-        logs/access.log  # supports relative path, absolute path, standard output
-                         # such as: logs/access.log, /tmp/logs/access.log, /dev/stdout, /dev/stderr
-                         # log example: 2020-12-09T16:38:09.039+0800	INFO	filter/logging.go:46	/apisix/admin/routes/r1	{"status": 401, "host": "127.0.0.1:9000", "query": "asdfsafd=adf&a=a", "requestId": "3d50ecb8-758c-46d1-af5b-cd9d1c820156", "latency": 0, "remoteIP": "127.0.0.1", "method": "PUT", "errs": []}
-  security:
-      # access_control_allow_origin: "http://httpbin.org"
-      # access_control_allow_credentials: true          # support using custom cors configration
-      # access_control_allow_headers: "Authorization"
-      # access_control-allow_methods: "*"
-      # x_frame_options: "deny"
-      content_security_policy: "default-src 'self'; script-src 'self' 'unsafe-eval' 'unsafe-inline'; style-src 'self' 'unsafe-inline'; frame-src *"  # You can set frame-src to provide content for your grafana panel.
-
-authentication:
-  secret:
-    secret              # secret for jwt token generation.
-                        # NOTE: Highly recommended to modify this value to protect `manager api`.
-                        # if it's default value, when `manager api` start, it will generate a random string to replace it.
-  expire_time: 3600     # jwt token expire time, in second
-  users:                # yamllint enable rule:comments-indentation
-    - username: admin   # username and password for login `manager api`
-      password: admin
-    - username: user
-      password: user
-
-plugins:                          # plugin list (sorted in alphabetical order)
-  - api-breaker
-  - authz-keycloak
-  - basic-auth
-  - batch-requests
-  - consumer-restriction
-  - cors
-  # - dubbo-proxy
-  - echo
-  # - error-log-logger
-  # - example-plugin
-  - fault-injection
-  - grpc-transcode
-  - hmac-auth
-  - http-logger
-  - ip-restriction
-  - jwt-auth
-  - kafka-logger
-  - key-auth
-  - limit-conn
-  - limit-count
-  - limit-req
-  # - log-rotate
-  # - node-status
-  - openid-connect
-  - prometheus
-  - proxy-cache
-  - proxy-mirror
-  - proxy-rewrite
-  - redirect
-  - referer-restriction
-  - request-id
-  - request-validation
-  - response-rewrite
-  - serverless-post-function
-  - serverless-pre-function
-  # - skywalking
-  - sls-logger
-  - syslog
-  - tcp-logger
-  - udp-logger
-  - uri-blocker
-  - wolf-rbac
-  - zipkin
-  - server-info
-  - traffic-split