I have to create three container and i have to installed package automatically on this container?
How can i do that?
I need save docker file.
Thanks for help by advance.
Basic knowledge
So, read official guideline https://docs.docker.com/reference/builder/ and write your own Dockerfile to automate your installation of your packages in your container.
Reuse existing docker images
docker is built on community as well, before you write your Dockerfile, you may check the http://hub.docker.com to reuse exsiting one or take them as examples
Related
I have Websphere Application Server 8.5.5.14 hosting my ERP. I want to dockerize the application and deploy it into Kubernetes cluster. Can anyone provide me information on how to create image out of my existing WAS 8.5.5.14.
In theory you could do this by creating a tar ball of the filesystem and importing it into docker to make an image via something like:
cat WAS.tar | docker import - appImage
but there's going to be a number of issues you'll need to avoid, for example, if you have resources (jdbc drivers,resource adapters, etc), the tarball will need to have all of those included. You'll also need to expose all of the required ports for your app and its administration. A better way and best practice to solve this would be to start with an IBM supported image of traditional WAS and build your system atop it.
There are detailed instructions to do this at https://github.com/WASdev/ci.docker.websphere-traditional#docker-hub-image
F Rowe's answer is good; if you follow their advice of using the official images you will be using WebSphere v9.0 in the container. You can use this tool that can help figure out if there are any changes you need to make to your application in order to get it working in the container. It also generates some of the wsadmin scripts to configure the server in the image.
I am new to docker and while I was searching for something related to my project, I found a popular container on dockerhub -> https://hub.docker.com/r/augury/haproxy-consul/dockerfile.
This may solve the problem that I was facing before. My question is how do I use it? Do I simply run this container, register my applications on consul and this will handle the rest, or something else.
Is it like npmjs.org, where we simply import libraries and use them?
My idea of docker is that its a replication of images in which you can make modifications,so go ahead and build a container of the said project.Changes or any form of modifications will remain yours(your container) until you push it to a repo(upstream).For how to use it just go to the docker docs for more info on how to use it.Hope this helps.
you can simply pull the image docker pull augury/haproxy-consul and run using docker run augury/haproxy-consul -p 80:80. the container will be running and accessible on 80(2nd port)
And also, You can use the image as a base image in your DockerFile if you want to add something on top of it.
You already have a good idea of how the docker runs.Use the port created to make all your modifications, and yes all the changes are on your local repo.
I am new to Docker. Using Kitematic, how can I setup a Docker container containing the following?
Apache, Memcached, MySQL, Nginx, PHP FPM
Should I find one single image with all these? If so, how do I find that on https://hub.docker.com? It doesn't seem possible to filter by above requirements.
Or should I install these as separate containers?
Bart,
I don't know anything about kitematic but I can give you some general information though to clear things up.
General concensus is to run only a single process per container. There are lot's of discussions and information around why this would be good or bad, one such discussion for example: https://devops.stackexchange.com/questions/447/why-it-is-recommended-to-run-only-one-process-in-a-container.
That said, these are the images I would choose for an environment with the software you described above:
Memcache: https://hub.docker.com/_/memcached
MySql: https://hub.docker.com/_/mysql
Nginx: https://hub.docker.com/_/nginx
PHP FPM: https://hub.docker.com/_/php
How do I get these images? I go to hub.docker.com and search for the software I want, I then start with the official images and see if they suite my needs. If they do, great! Otherwise, I would look for non-official images and eventually if I don't find what I want I will extend the existing images by creating a custom image, based on one from hub.docker.com
Some more explanation about the last one, PHP. PHP is distributed with multiple tags. By going to the docker hub page ('description'-tab) you can see the supported tags. Clicking the tag you are interested in will lead you to a github repo where the Dockerfile is hosted. This file contains the commands, used to construct the image you are researching. You can check all the tags to see which one installs the software you need. For example, there are PHP tags where apache is installed (i.e. 7-apache) and there are tags where FPM is installed (i.e. 7-fpm).
Hope this will help you with the research about what images to use!
You need to run those images within the same docker network, tough a docker-compose (and is associated docker-compose.yml) such as this one.
The docker-compose support in Kinematic UI though... is still an open issue.
you cant find all of these containers as one image.. all you can do is create a docker-compose file and add all those independent images into the compose file.
This way you can handle all your containers as a service in a single with there dependencies too..
For further info refer to https://docs.docker.com/compose/
I'm new to Docker and trying to get my head around extending existing Images.
I understand you can extend an existing Docker image using the FROM command in a Dockerfile (e.g. How to extend an existing docker image?), but my question is -- in general, how can I install additional software / packages without knowing what the base operating system is of the base image or which package manager is available?
Or am I thinking about this the wrong way?
The best practice is to run the base image you want to start FROM (perhaps using docker exec) and see what package managers are available (if any). Then you can write your Dockerfile with the correct software installation procedure.
Think of it the same way you'd add software to any computer: you'd either log into it yourself and poke around, or write an installation program that can handle all of the expected variations.
In most cases, the source Dockerfile is provided and you can walk the chain backwards and gain a better understanding as you do.
For example, if we look at the official Redis image we see the information tab says
Supported tags and respective Dockerfile links
2.6.17, 2.6 (2.6/Dockerfile)
2.8.19, 2.8, 2, latest (2.8/Dockerfile)
So if you're interested in building off redis:latest you'd follow the second link and see that it in turn is built off of debian:wheezy.
Most user-created images will either include their Dockerfile on the hub page or from a link there.
I am new to docker.io and not sure if this is beyond the scope of docker. I have an existing CentOS 6.5 system. I am trying to figure out how to create a docker image from a CentOS Linux system I already have running. I would like to basically clone this existing system; so I can port it to another cloud provider. I was able to create a docker image from a base CentOS image but I want to basically clone my existing system and use docker.io going forward.
Am I stuck with creating a base CentOS from scratch and configure it for docker from there? This might be more of a VirtualBox/Vagrant thing, but am interested in docker.io.
Looks like I need to start with base CentOS and create a Dockerfile with all the addons I need... Think I'm getting there now....
Cloning a system that is up and running is certainly not what Docker is intended for. Instead, Docker is meant to develop your OS and server installation together with the app or service, making DevOps even more DevOpsy. By starting with a clean CentOS image, you will be sure to install only what you need for the service, and have everything under control. You actually don't want all the other stuff that might produce incompatibilities. So, the answer here is that you definitely should approach the problem here the other way around.