最新在学习Docker,想搭建一个java tomcat环境，有知道的么？越详细越好，先谢了。
大家讲道理2017-04-21 10:58:11
I think this blog explains your problem very clearly, you can read it carefully,
http://www.blogjava.net/yongboy/archive/2013/12/12/407498.html
Docker aims to provide an automated deployment solution for applications. It can quickly create a container (lightweight virtual machine) on a Linux system and deploy and run applications. It can also easily realize automated installation of applications through configuration files. Deployment and upgrade are very convenient. Because of the use of containers, the production environment and development environment can be easily separated without affecting each other. This is the most common method of docker. More ways to play include large-scale web applications, database deployment, continuous deployment, clusters, test environments, service-oriented cloud computing, virtual desktop VDI, etc.
Subjective impression: Docker is written in Go language, uses cgroups to achieve resource isolation, and the container technology uses LXC. It provides a lightweight virtualization solution that can run Unix processes independently. It provides a way to automate the deployment of software in a secure, repeatable environment. LXC commands are a bit complicated. If you are interested, here is an article I wrote before based on LXC (building a simple version of JAVA PAAS cloud platform from scratch). You can review it in advance.
Relevant implementation principles, related theories, application scenarios, etc. will be written later in this series. Here is a brief taste of it, completely manual, building a Tomcat running environment based on Docker. First come out a decent Demo, we can see the effect, which may help us go further.
Environment
In all environments of this article, ubuntu-13.10-server-amd64 is running on VMware WorkStation. Note that it is a 64-bit system. In theory, other virtual machines are also completely feasible.
Install Docker
Docker version 0.7 requires Linux kernel 3.8 support and the AUFS file system.
sudo apt-get update
sudo apt-get install linux-image-extra-uname -r
sudo sh -c "wget -qO- https://get.docker.io/gpg | apt-key add -"
sudo sh -c "echo deb http://get.docker.io/ubuntu docker main > /etc/apt/sources.list.d/docker.list"
sudo apt-get update
sudo apt-get install lxc-docker
sudo docker version
Go version (client): go1.2
Git commit (client): 88df052
Server version: 0.7.1
Git commit (server): 88df052
Go version (server): go1.2
Last stable version: 0.7.1
Remove sudo
Under Ubuntu, when executing Docker, you have to enter sudo and password every time, which is very tiring. Let’s fine-tune it here and add the current user’s execution permissions to the corresponding docker user group.
sudo groupadd docker
sudo gpasswd -a yongboy docker
sudo service docker restart
docker version
sudo reboot
Install a Docker running instance-ubuntu virtual machine
After Docker is installed, the background process is automatically started, and you can install a virtual machine instance (here, take the learn/tutorial image used in the official demonstration as an example):
docker pull learn/tutorial
After the installation is complete, take a look at the effect
docker run learn/tutorial /bin/echo hello world
Interactively enter the newly installed virtual machine
docker run -i -t learn/tutorial /bin/bash
You will see:
root@51774a81beb3:/#
Indicates that the interactive environment has been entered.
Install SSH terminal server to facilitate our external use of SSH client to log in and access
apt-get update
apt-get install openssh-server
which sshd
/usr/sbin/sshd
mkdir /var/run/sshd
passwd #Enter the user password, I set it to 123456 here to facilitate SSH client login
exit #Exit
Get the instance container ID of the instance you just operated
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
51774a81beb3 learn/tutorial:latest /bin/bash 3 minutes ago Exit 0 thirsty_pasteur
You can see that the container ID of the current operation is: 51774a81beb3. Note that once all operations are performed, they need to be submitted and saved for easy SSH login:
docker commit 51774a81beb3 learn/tutorial
Run this image instance as a background process for a long time:
docker run -d -p 22 -p 80:8080 learn/tutorial /usr/sbin/sshd -D
The SSH Server running in the ubuntu container occupies port 22, and -p 22 is specified. -p 80:8080 means that our ubuntu will run tomcat on port 8080, but the port mapped externally (outside the container) is 80.
At this time, check whether it runs successfully.
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
871769a4f5ea learn/tutorial:latest /usr/sbin/sshd -D About a minute ago Up About a minute 0.0.0.0:49154->22/tcp, 0.0.0.0:80->8080/tcp focused_poincare
Note that the randomly assigned SSH connection port number is 49154:
ssh root@127.0.0.1 -p 49154
After entering the password, can I enter? Once you control SSH, the rest is very simple, install JDK, install tomcat, etc., it's up to you. The following is the installation script:
apt-get install python-software-properties
add-apt-repository ppa:webupd8team/java
apt-get update
apt-get install -y wget
apt-get install oracle-java7-installer
java -version
wget http://mirror.bit.edu.cn/apache/tomcat/tomcat-7/v7.0.47/bin/apache-tomcat-7.0.47.tar.gz
tar xvf apache-tomcat-7.0.47.tar.gz
cd apache-tomcat-7.0.47
bin/startup.sh
By default, tomcat will occupy port 8080. When starting the mirror instance, -p 80:8080 was specified. The ubuntu mirror instance/container opens port 8080, which is mapped to the host port 80. If you know the host IP address, you can access it freely. On the host machine, just test it through curl:
curl http://192.168.190.131
Of course, you can also use a browser to access it.
In real situations, Tomcat may not be allowed to directly open port 80 to the outside world. It is usually located behind nginx/apache or a firewall. The above is just a demonstration.
Summary
Building a Tomcat runtime environment with the help of Docker is very simple overall and allows us to see the presence of PAAS. Yes, using Docker as the underlying service of PAAS is not complicated in itself. If we have time, we will talk about how to use a script file to build an image instance. We will also talk about the implementation principles and mechanisms of Docker.
