#Containerization

Everybody has a testing environment.

Some people are lucky enough to have a totally separate environment to run production in.

-- Unknown

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In this series of articles, I'd like to present and discuss several possible approaches toward software development with InterSystems technologies and GitLab. I will cover such topics as:

• Git 101
• Git flow (development process)
• GitLab installation
• GitLab WorkFlow
• GitLab CI/CD
• CI/CD with containers

This first part deals with the cornerstone of modern software development - Git version control system and various Git flows.

Hi Developers!

InterSystems Package Manager (ZPM) is a great thing, but it is even better if you don't need to install it but can use immediately.

There are several ways how to do this and here is one approach of having IRIS container with ZPM built with dockerfile.

I've prepared a repository which has a few lines in dockerfile which perform the download and install the latest version of ZPM.

Add these lines to your standard dockerfile for IRIS community edition and you will have ZPM installed and ready to use.

To download the latest ZPM client:

Most of us are more or less familiar with Docker. Those who use it like it for the way it lets us easily deploy almost any application, play with it, break something and then restore the application with a simple restart of the Docker container.

Last time we launched an IRIS application in the Google Cloud using its GKE service.

And, although creating a cluster manually (or through gcloud) is easy, the modern Infrastructure-as-Code (IaC) approach advises that the description of the Kubernetes cluster should be stored in the repository as code as well. How to write this code is determined by the tool that’s used for IaC.

In the case of Google Cloud, there are several options, among them Deployment Manager and Terraform. Opinions are divided as to which is better: if you want to learn more, read this Reddit thread Opinions on Terraform vs. Deployment Manager? and the Medium article Comparing GCP Deployment Manager and Terraform.

This is a continuation of my story about the development of my project isc-tar started in the first part.

Just having tests is not enough, it does not mean that you will run tests after all changes. Running tests should be automated, and when you cover all your functionality with tests, everything should work well after any change in any place. And Continuous Integration (CI) helps to keep the code and deployment procedure with as fewer bugs as possible and automates the routine procedures, like publishing releases.

I use GitHub to store the source code. And some time ago GitHub started to work on its own CI/CD platform and named it GitHub Actions. It is not widely available, yet. You have to be signed as a beta tester for this feature, as I did. GitHub Actions uses quite a different way how to deal with a build workflow. What is important that Github Actions allows to use Docker, and it’s quite easy to customize available actions. And interesting that GitHub Actions is really much bigger than any classic CI like we have in Travis, Circle or Gitlab CI and so on. You can find more in the official documentation.

I have been struggling with a docker run command that kept crashing, the error message was too generic to point me to the right direction.

Since the container is shut down after the failure, I was unable to login to it in order to figure out the problem.

I had to run the container in a way that I'll be able to log into it before it crashed, so I found the adding -u false prevents the docker run command to run the iris session IRIS and the container stayed up and running. then I was able to log into it using:

I want to address the nasty problems about reading a flat text in ASCII, UTF*
explicitly excluding HTML, EBCDIC, and other encoding.
According to Wikipedia there are at least 8 variations of control characters.

• CR+LF is typical for Windows
• LF is typical for the Linux/UNIX world
• CR is Mac's favorite

As you can deduct from the names the inspiration comes from mechanical typewriters.

In this article, we will cover below topics:

• What is Kubernetes?
• Main Kubernetes (K8s) Components

What is Kubernetes?

Kubernetes is an open-source container orchestration framework developed by Google. In essence, it controls container speed and helps you manage applications consisting of multiple containers. Additionally, it allows you to operate them in different environments, e.g., physical machines, virtual machines, Cloud environments, or even hybrid deployment environments.

In this series of articles, I'd like to present and discuss several possible approaches toward software development with InterSystems technologies and GitLab. I will cover such topics as:

• Git 101
• Git flow (development process)
• GitLab installation
• GitLab Workflow
• Continuous Delivery
• GitLab installation and configuration
• GitLab CI/CD
• Why containers?
• GitLab CI/CD using containers

In the first article, we covered Git basics, why a high-level understanding of Git concepts is important for modern software development, and how Git can be used to develop software.

In the second article, we covered GitLab Workflow - a complete software life cycle process and Continuous Delivery.

In the third article, we covered GitLab installation and configuration and connecting your environments to GitLab

In the fourth article, we wrote a CD configuration.

In this article, let's talk about containers and how (and why) they can be used.

If you plan on using the nginx server to front end you IRIS instance (as opposed to the standard apache web gateway install) you will need to add a few configuration options into the CSP.conf file in order for all urls to work. It took me a little bit to figure this out but this seems to be the configuration that works.

Sometimes customers need a small IRIS instance to do something in the cloud and shut it down, or they need hundreds of containers (i.e. one per end user or one per interface) with small workloads. This exercise came about to see how small an IRIS instance could be. For this exercise we focused on what is the smallest amount of memory we can configure for an IRIS instance. Do you know all the parameters that affect the memory allocated by IRIS ?

For those that, at some point, need to test what means that of ECP for horizontal escalability (computing power and/or users and processes concurrency), but they're lazy o have no much time to build the environment, configure the server nodes, etc..., I've just published in Open Exchange the app/sample OPNEx-ECP Deployment .

In this series of articles, I'd like to present and discuss several possible approaches toward software development with InterSystems technologies and GitLab. I will cover such topics as:

• Git 101
• Git flow (development process)
• GitLab installation
• GitLab Workflow
• Continuous Delivery
• GitLab installation and configuration
• GitLab CI/CD
• Why containers?
• Containers infrastructure
• CD using containers
• CD using ICM

In this article, we'll build Continuous Delivery with InterSystems Cloud Manager. ICM is a cloud provisioning and deployment solution for applications based on InterSystems IRIS. It allows you to define the desired deployment configuration and ICM would provision it automatically. For more information take a look at First Look: ICM.