I am also happy to announce that I was a tech reviewer on the first study guide for this cert titled “HashiCorp Terraform Certified Associate PreparationGuide“. You can find it here: https://leanpub.com/terraform-certified/. This guide was authored by fellow Microsoft MVP Ned Bellavance and Microsoft CSA Adin Ermie. Huge thanks guys for letting me be a part of this project!
If you work with Terraform I hope you get certified and be sure to use the study guide!
When working with
Containers a common need is to store Container images somewhere. Container
Registries are the go-to for this. Docker hub is an example of a Container
Registry and it is the most well-known Container Registry.
What is a Container Registry?
A Container Registry is a group of repositories used to store container images. A container repository is used to manage, pull or push container images. A Container Registry does more than a repository in that it has API paths, tasks, scanning for vulnerabilities, digital signature of images, access control rules and more.
Container registries can be public or private. For example, a public registry is Docker Hub and anyone can access its container repositories to pull images. A private registry is one that you would host either on-premises or on a cloud provider. All of the major cloud providers including Azure has a Container Registry offering.
Integrate ACR with AKS
With AKS it is a good idea to use a private container registry to host your container images. The process is used Docker to build your image>push the image to your Azure Container Registry>Pull the image from the registry when deploying a Pod to your AKS cluster.
There are 3 ways to
integrate AKS with Azure Container Registry. I typically only use one way and
will focus on that in this blog post.
2 of the ways you can integrate AKS with Azure Container Registry. The first is through an Azure AD service principal name (SPN) that assigns the AcrPull role to the SPN. More on this here. You would use this first way in scenarios where you only have one ACR and this will be the default place to pull images from.
The second is to create a Kubernetes ServiceAccount that would be used to pull images when deploying pods. With this you would add “kind: ServiceAccount” to your Kubernetes cluster and it would use the ACR credentials. Then in your pods yaml files you would need to specify the service account for example “serviceAccountName: ExampleServiceAccountName”.
The way I like to integrate AKS with Azure Container Registry is to use Kubernetes Secret of type docker-registry. With this option basically, you create a secret in the Kubernetes cluster for your Azure Container Registry. You then specify the secret in your pod yaml files. This allows you to have multiple container registries to pull from. This option is also quick and easy to setup. Ok.
To get started you need to build your Docker image and push it up to your Azure Container Registry. In this blog post, I will not cover deploying ACR, or building the Docker image assuming you have already done these things. Now let’s set up the ACR and AKS integration using a docker-registry Kubernetes secret.
1. For the first step, you will need the credentials to your Azure Container Registry. To get this go navigate to:
2. The second step push your Docker image up to your ACR.
# Log into the Azure Container Registry
docker login ACRNAMEHERE.azurecr.io -u ACRUSERNAMEHERE -p PASSWORDHERE
# Tag the docker image with ACR
docker tag DOCKERIMAGENAMEHERE ACRNAMEHERE.azurecr.io/DOCKERIMAGENAMEHERE:v1
# Push the image to ACR
docker push ACRNAMEHERE.azurecr.io/DOCKERIMAGENAMEHERE:v1
3. The third step create the docker-registry Kubernetes secret by running following syntax from Azure Cloud Shell:
In Kubernetes, you have a container or containers running as a pod. In front of the pods, you have something known as a service. Services are simply an abstraction that defines a logical set of pods and how to access them. As pods move around the service that defines the pods it is bound to keeps track of what nodes the pods are running on. For external access to services, there is typically an Ingress controller that allows access from outside of the Kubernetes cluster to a service. An ingress defines the rules for inbound connections.
Microsoft has had an
Application Gateway Ingress Controller for Azure Kubernetes Service AKS in
public preview for some time and recently released for GA. The Application
Gateway Ingress Controller (AGIC) monitors the Kubernetes cluster for ingress
resources and makes changes to the specified Application Gateway to allow
This allows you to leverage the Application Gateway service in Azure as the entry into your AKS cluster. In addition to utilizing the Application Gateway standard set of functionality, the AGIC uses the Application Gateway Web Application Firewall (WAF). In fact, that is the only version of the Application Gateway that is supported by the AGIC. The great thing about this is that you can put Application Gateways WAF protection in front of your applications that are running on AKS.
This blog post is not a detailed deep dive into AGIC. To learn more about AGIC visit this link: https://azure.github.io/application-gateway-kubernetes-ingress. In this blog post, I want to share a script I built that deploys the AGIC. There are many steps to deploying the AGIC and I figured this is something folks will need to deploy over and over so it makes sense to make it a little easier to do. You won’t have to worry about creating a managed identity, getting various id’s, downloading and updating YAML files, or installing helm charts. Also, this script will be useful if you are not familiar with sed and helm commands. It combines PowerShell, AZ CLI, sed, and helm code. I have already used this script about 10 times myself to deploy the AGIC and boy has it saved me time. I thought it would be useful to someone out there and wanted to share it.
I typically deploy RBAC enabled AKS clusters so this script is set up to work with an RBAC enabled AKS cluster. If you are deploying AGIC for a non-RBAC AKS cluster be sure to view the notes in the script and adjust a couple of lines of code to make it non-RBAC ready. Also note this AGIC script is focused on brownfield deployments so before running the script there are some components you should already have deployed. These components are:
VNet and 2 Subnets (one for your AKS cluster and one for the App Gateway)
The script will
deploy and do the following:
Deploys the AAD Pod Identity.
Creates the Managed Identity used by the AAD Pod Identity.
Gives the Managed Identity Contributor access to Application Gateway.
Gives the Managed Identity Reader access to the resource group that hosts the Application Gateway.
Downloads and renames the sample-helm-config.yaml file to helm-agic-config.yaml.
Updates the helm-agic-config.yaml with environment variables and sets RBAC enabled to true using Sed.
Adds the Application Gateway ingress helm chart repo and updates the repo on your AKS cluster.
Installs the AGIC pod using a helm chart and environment variables in the helm-agic-config.yaml file.
Now let’s take a look at running the script. It is recommended to upload to and run this script from Azure Cloud shell (PowerShell). Run:
You will be prompted
for the following as shown in the screenshot:
Enter the name of the Azure Subscription you want to use.:
Enter the name of the Resource Group that contains the AKS Cluster.:
Enter the name of the AKS Cluster you want to use.:
Enter the name of the new Managed Identity.:
Here is a screenshot
of what you will see while the script runs.
That’s it. You don’t have to do anything else except entering values at the beginning of running the script. To verify your new AGIC pod is running you can check a couple of things. First, run:
kubectl get pods
Note the name of my
AGIC pod is appgw-ingress-azure-6cc9846c47-f7tqn.
Your pod name will be different.
Now you can check
the logs of the AGIC pod by running:
kubectl logs appgw-ingress-azure-6cc9846c47-f7tqn
You should not have
any errors but if you do they will show in the log. If everything ran fine the
output log should look similar to:
After its all said and done you will have a running Application Gateway Ingress Controller that is connected to the Application Gateway and ready for new ingresses.
This script does not deploy any ingress into your AKS cluster. That will need to be done in addition to this script as you need. The following is an example YAML code for an ingress. You can use this to create an ingress for a pod running in your AKS cluster.
When working in my Azure labs I tend to end up with a lot of Azure App Registrations. Recently I had hundreds and hundreds of them in the directory. Its been a while since I cleaned this up. I needed to clean this out and did not want to do this manually through the portal. PowerShell to the rescue.
I pulled together a script that will place your app registrations in a variable. It will then loop through the app registrations to remove them. Note you will be prompted with a confirmation to remove each one.
This is a great service if you just need to run a single container or even a couple of containers that you have in Docker Compose. This service is PaaS and abstracts away an orchestration system like Kubernetes. If you need insight into the Azure App Service Web App for Containers service check out the blog post on 4sysops.
In this long blog post I am going to take things a step further and walk-through the build & release of a Container from Azure DevOps to Azure Web App for Containers. The overall goal of this post is to help someone else out if they want to setup a build and release pipeline for building and deploying a container to Azure App Service. We will use a very simple PHP web app I built that will run in the container.
Here are the components that are involved in this scenario:
Azure Container Registry (ACR): We will use this to store our container image. We will be pushing up the container image and pull it back down from the registry as a part of the build and release process.
Azure DevOps (ADO): This is the DevOps tooling we will use to build our container, push it up to ACR, pull it down into our release pipeline and then deploy to our Azure App Service.
App Service Web App for Containers: This is the web server service on Azure that will be used to host our container. Under the hood this will be a container that is running Linux and Apache to host the PHP web app.
Here is the data Flow for our containerized web app:
Deploy the Azure App Service Web App for Containers instance
Deploy the Azure Container Registry
Deploy the Azure DevOps organization and project, create repository to host the code, clone repository in VS Code (Not shown in this blog post. Assume you know how to this up.)
Update the application code (PHP code and Docker image) in Visual Studio code
Commit application code from Visual Studio code to the Azure DevOps repo (Not shown in this blog post. Assume you know how to this up.)
Setup build and then run container build and push the container image to ACR
Setup release pipeline and then kick off the release pipeline pulling down the container image from ACR and deploys the container to the App Service Web App for Containers instance.
Here is a diagram detailing out the build and release process we will be using:
Ok. Let’s get into the setup of core components of the solution and the various parts of the build and release pipeline.
For starters this solution will need a project in Azure DevOps with a repo. Create a project in Azure DevOps and a repo based on Git. Name the repo exerciseoftheday. Next up let’s create the core framework we need in Azure.
Deploy Azure App Service Web App for Containers
Let’s create the Azure App Service Web App for Containers that will be needed. We will need a resource group, an app service plan and then we can setup the app service. The PHP app we will be running is named Exercise Of The Day (EOTD) for short so our resources will use EOTD. Use the following steps to set all of this up.
Note the loginServer from the output. This is the FQDN of the registry. Normally we would need this, admin enabled, and the password to log into the registry. In this scenario we won’t need admin enabled or the password because we will be adding a connection to Azure DevOps and the pipelines will handle pushing to and pulling the image from the registry.
When it’s all done you should see the following resources in the new resource group:
Next, we will need to build an application and a container image.
In that blog post, I called out an Azure Policy on-demand evaluation PowerShell script I wrote. This PowerShell script will trigger Azure Policy to run the evaluation right away so you don’t have to wait for the next time Azure Policy will run the evaluation.
This is especially helpful when you are developing Azure Policies and you want to see if they are working properly or not. You can run the on-demand evaluation PowerShell script in Azure Cloud Shell at https://shell.azure.com/.
Well, that brings us to the end of this blog post. I wanted to make a short blog post for this script so that it would be easier to find.
Today I passed the Docker Certified Associate exam! In this post, I will share some details about the exam and the resources I used to study for it.
The certification is good for 2 years after passing the exam. It demonstrates that you have foundational real-world Docker skills. It is multiple choice with 55 questions, you have 1.5 hours to finish it and costs $195 USD. It is recommended that you have 6 to 12 months of hands-on experience with Docker before taking the exam. You can read about and sign up for the exam here: https://success.docker.com/certification.
I have had some folks ask me why I would waste my time taking the Docker exam. They say to focus on Kubernetes and Open Shift instead of Docker. Lets talk about why I chose to pursue the Docker certification. First off you have to run containers on those orchestration platforms mentioned before and chances are you will run Docker containers on them. Therefore before diving into an orchestration platform it is important to be knowledgable on containers. Also, I have seen many scenarios in the cloud where it makes sense to run containers directly on the cloud platform itself and again chances are those will be Docker containers. Docker is still a leader in the container space. There are several reports and articles that point to this. Here are some of the reports and articles backing this up:
Docker listed as the leader in the “Container Tools Used” section of the RightScale 2019 State of the Cloud Report” here:
Docker is listed as #2 with 31.35% market share on Datanyze 2020 “Containerization Market Share Competitor Analysis Report” here:
I will call out that the Docker exam covers Swarm mode orchestration platform that is included with Docker. Swarm mode is a lot easier to learn and use compared to Kubernetes however, Kubernetes has won the orchestration platform war. It would be nice if Docker would revamp the exam reducing or removing Swarm and replace with some Kubernetes objectives. This would make more sense because there is a strong chance Swarm will not be used in the real world.
The Docker exam was not an easy exam and you definitely want to have some hands-on with Docker before taking it. There are a ton of resources out there that you can leverage beyond hands-on to assist in your study for this certification. There are many books available. You can do a quick search on Amazon and check the reviews for one that would be a good fit for you. I have read a couple of books on Docker and have co-authored a book on AKS with a chapter dedicated to Docker in it.
Here is the list of what I used to study.
Free Hands on Docker labs (This resource was huge for me. It gave me environments to use and scenarios for training with Docker and Docker Swarm mode.):
I attended a “Docker JumpStart Virtual Workshop” by Microsoft MVP Mike Pfeiffer and Microsoft MVP/Docker Captain Dan Wahlin (This workshop ocurred in the past but I beleive you can sign up and watch the recordings from the workshop.):
Spent time working with Docker on some projects (self explanatory).
Overall the Docker certification is a good move for your career as an IT Pro, developer, if you work in DevOps, and with cloud. I definitely recommend getting this certification. If you decide to go after it good luck!
Stay tuned for more blog posts with insights on certifications in the future.
Towards the end of 2019, I had the opportunity to be the sole Tech Reviewer on an Azure Azure Strategy and Implementation Guide. This is the third edition of this guide so it has really current Azure information. It was authored by former MVP and now Microsoft trainer Peter De Tender (@pdtit) and others.
This guide gives a step by step introduction to using Azure
for your cloud infrastructure. The guide also covers an overview of Azure
benefits and best practices for planning your migration, assistance with cloud
architecture and design choices, and insight on how to manage and optimize your
new cloud environment.
The best part is that this guide is free! Get your copy
This will be a short
post and this one is mostly for me so I can easily find this information in the
future when I need it again. 🙂
Recently I was
containerizing some PHP websites that use Composer. If you are not familiar
with Composer but you are working with PHP, you will run across it at some
point. Composer is a dependency package manager for PHP. Composer manages
(install/update) any required libraries and dependencies needed for your PHP
To use Composer you must first declare the libraries and dependencies in a composer.json file in your site directory and then you would run Composer and it will do its magic. For more information on Composer visit: https://getcomposer.org/doc/00-intro.md
Back to my task, I
needed to install Composer in the containers I was building and run it to
install all the dependencies. I needed these actions in the Dockerfile so it
would all happen during the container build. After some research on Composer I
was able to pull something together. Here is the syntax that I ended up putting
in the Dockerfile:
# Install Composer
RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer
# Set working directory for composer (Contains the composer.json file)
# Run Composer
RUN composer install
Note: I placed the above code at the end of the
Dockerfile ensuring Apache, PHP etc was all in place first.