diff --git a/Dockerfile b/Dockerfile
index c2012b2450287d3d54be186d230e4efcf98f3f73..589aa2191b965f1038f0bd7d5d2e323c3ff0b172 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,12 +1,14 @@
-FROM nginx
+FROM nginx:latest
 
 MAINTAINER Edward Lee <freesky.edward@gmail.com>
 
-RUN apt-get update && \
-    apt install curl -y && \
-    apt-get install git -y
-
 ENV HUGO_VERSION=0.68.1
+ENV RUN_USER nginx
+ENV RUN_GROUP nginx
+
+RUN apt-get update && apt-get install -y \
+    git curl && \
+    rm -rf /var/lib/apt/lists/*
 
 RUN mkdir -p /usr/local/src && \
     cd /usr/local/src && \
@@ -18,7 +20,5 @@ RUN cd /src/ && /usr/local/bin/hugo -b / && \
     cp -rf /src/public/* /usr/share/nginx/html/ && \
     chmod -R 755 /usr/share/nginx/html
 
-ENV RUN_USER nginx
-ENV RUN_GROUP nginx
 EXPOSE 80
 ENTRYPOINT nginx -g "daemon off;"
diff --git a/README.md b/README.md
index 25e77c9a1c7ed7431dbcf42e05b2cbe8c8af3205..087c562ac6f15ac20519ff5ff8d40d0e98f535c0 100644
--- a/README.md
+++ b/README.md
@@ -7,7 +7,7 @@ you are welcome to join us.
 
 ### Installation
 
-1. Build Image
+1. Build an image
 
 ```
 docker build -t docs:v0.0.1 .
@@ -23,18 +23,19 @@ note: here ```docs``` is the image name, you can change it as you need.
 >
 > `--build-arg` can be specified many times, like `http_proxy`, `https_proxy`, `HTTP_PROXY`, `HTTPS_PROXY` and so on.
 
-2. Running in container
+2. Run a container
 
 ```
-docker run -p 80:80 -d docs:v0.0.1 > docs.pid
+# YOUR_PORT could be 80 or any other free port on host system
+docker run -p ${YOUR_PORT}:80 -d docs:v0.0.1 > docs.pid
 ```
 
-The website will serving on http://your-server-ip:80
+The website will serving on http://your-server-ip:${YOUR_PORT}
 
 The defalut language(en) will serving on http://your-server-ip/
 Other language(zh) will serving on http://your-server-ip/zh
 
-3. Stopping the container
+3. Stop the container
 
 ```
 docker rm -f `cat docs.pid` && rm -f docs.pid