#Containerization

A few weeks ago I posted an announcement about a JavaScript-based interface for our mg_web WebServer interfacing addon module. mg_web isn't just restricted to use by JavaScript developers though. Many readers will be ObjectScript developers who are more used to using CSP as their web gateway. Some may even have much older legacy WebLink-based applications (and be wondering how to support them given that IRIS does not support WebLink).

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
• Container architecture

In this article, we would talk about building your own container and deploying it.

Imagine you want to see what InterSystems can give you in terms of data analytics. You studied the theory and now you want some practice. Fortunately, InterSystems provides a project that contains some good examples: Samples BI. Start with the README file, skipping anything associated with Docker, and go straight to the step-by-step installation. Launch a virtual instance, install IRIS there, follow the instructions for installing Samples BI, and then impress the boss with beautiful charts and tables. So far so good.

Inevitably, though, you’ll need to make changes.

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:

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.

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
• 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 the fifth article, we talked about containers and how (and why) they can be used.

In this article let's discuss main components you'll need to run a continuous delivery pipeline with containers and how they all work together.

Last time we deployed a simple IRIS application to the Google Cloud. Now we’re going to deploy the same project to Amazon Web Services using its Elastic Kubernetes Service (EKS).

We assume you’ve already forked the IRIS project to your own private repository. It’s called <username>/my-objectscript-rest-docker-template in this article. <root_repo_dir> is its root directory.

Before getting started, install the AWS command-line interface and, for Kubernetes cluster creation, eksctl, a simple CLI utility. For AWS you can try to use aws2, but you’ll need to set aws2 usage in kube config file as described here.

I have Mac OSX and Docker Desktop 2.2 (Engine 19.03).

I have a REST service running on my localhost (Mac) and I was trying to consume it from IRIS running in a Docker container.

If you try something like that don't use localhost as HTTP Server setting (using a Business Operation for example).

You have to use host.docker.internal.

Hi Developers!

Those who use Dockerfile to work with InterSystems IRIS often need to execute several lines of ObjectScript. For me, this was a game of "escaping this and that" every time just to shoot a few commands on ObjectScript to IRIS. Ideally, I'd prefer to code ObjectScript without any quotes and escaping.

Recently I found a nice "hack" on how this could be improved to exactly this state. I got this from @Dmitry.Maslennikov's repo and this lets you use Objectscript in a way as you would type it in IRIS terminal.

Here is what you have in dockerfile:

///
COPY irissession.sh /
SHELL ["/irissession.sh"]
RUN \
  do $SYSTEM.OBJ.Load("Installer.cls", "ck") \
  set sc = ##class(App.Installer).setup()
# bringing the standard shell back
SHELL ["/bin/bash", "-c"]
CMD [ "-l", "/usr/irissys/mgr/messages.log" ]
///

If you're deploying to more than one environment/region/cloud/customer, you will inevitably encounter the issue of configuration management.

While all (or just several) of your deployments can share the same source code, some parts, such as configuration (settings, passwords) differ from deployment to deployment and must be managed somehow.

In this article, I will try to offer several tips on that topic. This article talks mainly about container deployments.

Why SSH ?

If you do not have direct access to the server that runs your IRIS Docker container
you still may require access to the container outside "iris session" or "WebTerminal".
With an SSH terminal (PuTTY, KiTTY,.. ) you get access inside Docker, and then, depending
on your needs you run "iris session iris" or display/manipulate files directly.

Note:

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:

For containers in ECS files are not editable if the file size is larger than ephemeral storage free space. For example if I have 4Gb free I can't edit 8Gb file. But if I start container with 50 Gb of ephemeral storage (24Gb free) I can edit my 8Gb file just fine.

This article is a continuation of Deploying InterSystems IRIS solution on GKE Using GitHub Actions, in which, with the help of GitHub Actions pipeline, our zpm-registry was deployed in a Google Kubernetes cluster created by Terraform. In order not to repeat, we’ll take as a starting point that: