My (python) code runs inside a docker container.
The container is deployed on AWS EC2 for our production and testing purposes, but sometimes on our local machines or other cloud vendors for development and CICD purposes.
For some functionality, I want my python code to be able to distinguish between an EC2 deployment and non-EC2. Is this possible?
I found this answer which uses the EC2 instance metadata endpoint, But I'm wondering:
a) Would this also work from within a docker container?
b) Isn't there a more elegant solution? Issuing an HTTP request and waiting for it seems a bit too much.
(I'm aware that a simple solution is probably to add some proprietary environment variable or flag, trying to find a more native to check this)
I recommend you to go with a custom environment variable. This way you will be able to easily reproduce the required behaviour outside of AWS (on your workstation or using other cloud provider).
Using curl or checking for presence of /etc/cloud would make your application behaviour dependent on third-party services/tools. Beside logic complexity (you'd have to handle possible curl errors, like invalid response codes) that can lead to bugs you surely don't want to meet.
As we move our workloads to AWS I am looking for an ETL tool which is widely used and has the appropriate connectors - Apache Camel appears to fit the bill. However, I am struggling to find information on how Camel can be deployed in AWS - the obvious one is on an EC2 instance, but we would like to avoid the setup and maintenance required by Virtual Machines. I don't see anyone offering it as a managed service, so the option I'd like to explore is running it as a container in ECS, as we will have numerous other containers running.
Containers don't seem to be an installation option on the Apache Camel website - perhaps it is just too limiting for a tool whose purpose is to connect to everything else?
Is it acceptable and practical to run Camel in a container, and where could I find more information about it?
Apache Camel appears to fit the bill.
Indeed the Apache Camel is a great integration framework. And that's the point. It is a framework, not a product. So there are multiple ways to run the Camel flows. As a web app, as a standalone app, as a part if our own code. Camel itself is pretty agnostic to the way you run the flows and that's why you don't have very specific way enforced in the web site.
If you want an out of box product, which can generate containerized deployments with Apache Camel, you could have a look at Apache ServiceMix, Apache Karaf or it's supported RedHat Fuse.
Is it acceptable and practical to run Camel in a container, and where could I find more information about it?
It is perfectly fine.
Question: Can you (are you able) to create a docker container with your (any other) application?. Based on the question this skill is lacking and I really suggest to learn it.
You may check folowing post https://medium.com/#wkrzywiec/how-to-put-your-java-application-into-docker-container-5e0a02acdd6b
FROM java:8-jdk-alpine
COPY ./target/myapp.jar /usr/app/myapp.jar
WORKDIR /usr/app
EXPOSE 8080
ENTRYPOINT ["java", "-jar", "myapp.jar"]
Let's assume you can run your ETL tasks as a standalone application, then just run it in the container as any other standalone application.
it we would like to avoid the setup and maintenance required by Virtual Machines
Question: how do you distribute your camel tasks? I mean - what is result of your build? A war file? A standalone app?
To build a web app you could see https://www.baeldung.com/spring-apache-camel-tutorial
The most convenient way to deploy a war file in AWS is AWS Beanstalk service.
If you build a standalone application (or use servicemix) and you can build a container, then indeed ECS or Fargate seem as natural options.
I want to implement a tool that uses the technologies - Jenkins, Docker, Docker Swarm, and AWS - to achieve a deployment tool that our team of developers can use to manage instances and deploys.
Please recommend what technologies should we (both administrators and developers) be using, what needs to be built and what sorts of machines must be having.
Any help here would be much appreciated.
Your question is too generic to provide a specific answer, as there are different approaches to implement what you are trying to achieve. IMHO the best approach would be to talk with your existing dev team & administrators and come up with a solution which all parties find easy to manage and maintain container based environment rather than specifying several specific technologies.
Each tool you have mentioned has different capabilities and also there are other tools that provide the same features which would be more ideal for your situation. (Thats why proper understanding between Devs and admins are necessary on what you really want to achieve.) .
Since you have asked about what kind of machines you must be having (I suppose this is on AWS env) try Core OS on AWS instances. CoreOS (Container Linux) will be the best option to manage and run your container based environments. [About CoreOS]
Jenkins can run in a docker container and issue docker commands to deploy new docker containers that reside in the same swarm as jenkins. You also need to hook into a software repo like git. Jenkins Blue Ocean is something you could look at for pipe-lining your dev->build->test->deploy->maintain pipes. Also, Travis-ci, github, JIRA, and Dockerhub are useful components to what you are trying to achieve.
I'm new to the configuration management and deployment tools. I have to implement a Continuous Delivery/Continuous Deployment tool for one of the most interesting projects I've ever put my hands on.
First of all, individually, I'm comfortable with AWS, I know what Ansible is, the logic behind it and its purpose. I do not have same level of understanding of Docker but I got the idea. I went through a lot of Internet resources, but I can't get the the big picture.
What I've been struggling is how they fit together. Using Ansible, I can manage my Infrastructure as Code; building EC2 instances, installing packages... I can even deploy a full application by pulling its code, modify config files and start web server. Docker is, itself, a tool that packages an application and ensures that it can be run wherever you deploy it.
My problems are:
How does Docker (or Ansible and Docker) extend the Continuous Integration process!?
Suppose we have a source code repository, the team members finish working on a feature and they push their work. Jenkins detects this, runs all the acceptance/unit/integration test suites and if they all passed, it declares it as a stable build. How Docker fits here? I mean when the team pushes their work, does Jenkins have to pull the Docker file source coded within the app, build the image of the application, start the container and run all the tests against it or it runs the tests the classic way and if all is good then it builds the Docker image from the Docker file and saves it in a private place?
Should Jenkins tag the final image using x.y.z for example!?
Docker containers configuration :
Suppose we have an image built by Jenkins stored somewhere, how to handle deploying the same image into different environments, and even, different configurations parameters ( Vhosts config, DB hosts, Queues URLs, S3 endpoints, etc...) What is the most flexible way to deal with this issue without breaking Docker principles? Are these configurations backed in the image when it gets build or when the container based on it is started, if so how are they injected?
Ansible and Docker:
Ansible provides a Docker module to manage Docker containers. Assuming I solved the problems mentioned above, when I want to deploy a new version x.t.z of my app, I tell Ansible to pull that image from where it was stored on, start the app container, so how to inject the configuration settings!? Does Ansible have to log in the Docker image, before it's running ( this sounds insane to me ) and use its Jinja2 templates the same way with a classic host!? If not, how is this handled?!
Excuse me if it was a long question or if I misspelled something, but this is my thinking out loud. I'm blocked for the past two weeks and I can't figure out the correct workflow. I want this to be a reference for future readers.
Please, it would very helpful to read your experiences and solutions because this looks like a common workflow.
I would like to answer in parts
How does Docker (or Ansible and Docker) extend the Continuous Integration process!?
Since docker images same everywhere, you use your docker images as if they are production images. Therefore, when somebody committed a code, you build your docker image. You run tests against it. When all tests pass, you tag that image accordingly. Since docker is fast, this is a feasible workflow.
Also docker changes are incremental; therefore, your images will have minimal impact on storage. Also when your tests fail, you may also choose to save that image too. In this way, developer will pull that image and investigate easily why your tests failed. Developer may choose to run tests in their machine too since docker images in jenkins and their machine are not different.
What this brings that all developers will have same environment, same version of all software since you decide which one will be used in docker images. I have come across to bugs that are due to differences between developer machines. For example in the same operating system, unicode settings may affect your code. But in docker images all developers will test against same settings, same version software.
Docker containers configuration :
If you are using a private repository, and you should use one, then configuration changes will not affect hard disk space much. Therefore except security configurations, such as db passwords, you can apply configuration changes to docker images(Baking the Configuration into the Container). Then you can use ansible to apply not-stored configurations to deployed images before/after startup using environment variables or Docker Volumes.
https://dantehranian.wordpress.com/2015/03/25/how-should-i-get-application-configuration-into-my-docker-containers/
Does Ansible have to log in the Docker image, before it's running (
this sounds insane to me ) and use its Jinja2 templates the same way
with a classic host!? If not, how is this handled?!
No, ansible will not log in the Docker image, but ansible with Jinja2 templates can be used to change dockerfile. You can change dockerfile with templates and can inject your configuration to different files. Tag your files accordingly and you have configured images to spin up.
Regarding your question about handling multiple environment configurations using the same Docker image, I have been planning on using a Service Discovery tool like Consul as a centralized config/property management tool. So, when you start your container up, you set an ENV var that tells it what application it is (appID), and what environment config it should use (ex: MyApplication:Dev) and it will pull its config from Consul at startup. I still have to investigate the security around Consul (as if we are storing DB connection credentials in there for example, how do we restrict who can query/update those values). I don't want to just use this for containers, but all apps in general. Another cool capability is to change the config value in Consul and have a hook back into your app to apply the changes immediately (maybe like a REST endpoint on your app to push changes down to and dynamically apply it). Of course your app has to be written to support this!
You might be interested in checking out Martin Fowler's blog articles on immutable infrastructure and on Phoenix servers.
Although not a complete solution, I have suggestions for two of your issues. Although they might not be perfect, these are the practices we are using in our workflow, and prove themselves so far.
Defining different environments - supposing you've written a different Ansible role for each environment you launch, we define an environment variable setting the environment we wish the container to belong to. We then download the suitable configuration file from an S3 bucket using the env variable set before into the container (which should be possible if you supply AWS creds or give your server an IAM role) and inject these parameters into the code when building it.
Ansible doesn't need to log into the docker app, but the solution is a bit tricky. I've tried two ways of tackling this problem, and both aren't ideal. The first one is to download the configuration file as part of the docker image command line, and build the app on container startup. While this solution works - it breaches the Docker philosophy and makes the image highly prone to build errors.
Another solution is pushing several images to your docker hub repo, and then pulling the appropriate image according to the environment at hand.
In a broader stroke, I've tried launching our app completely with Ansible and it was hell, many configuration steps are tricky and get trickier when you try to implement them as a playbook. When I switched to maintaining the severs alone with Ansible, and deploying the app itself with Docker things got a lot easier.
I am searching for a solution to do continuous deployment in a cloud environment, more specific, in an Amazon AWS environment.
The code to be deployed are mainly Microsoft's ASP and PHP, so this framework should work on both platforms. As I have an auto-scale environment, this framework will work if it pulls the new code, like Puppet does.
My first thought was to deploy direct from the VCS, but I ended in a problem where all repository information was mirrored to the servers, as GIT, for instance, works. This is a problem because the repository keeps growing and the servers will demand more and more space.
I found Ansible, that works the way I need, but does not work on Windows environment. It only sends to the servers the production code, not the VCS repository, and keeps track which servers are updated.
Without using an easy-to-setup framework like this, I will need to create a Puppet + Jenkins + a VCS framework, where Jenkins creates the package from a VCS source code and Puppet delivers it.
Does anybody know any small framework for my needs or the Puppet + Jenkins + VCS is the way to go?
Consider CloudMunch (www.cloudmunch.com) for this. The platform is built exactly to solve this kind of polyglot requirements.
Disclaimer: I work for CloudMunch