Archive for the ‘Technology’ Category

Index Developer Conference

Sunday, February 25th, 2018

IBM launched a new conference in San Francisco under the name Index and I was lucky enough to attend. This wasn’t your usual IBM conference focused on brands and products. Although the tracks were aligned with IBM’s strategic areas (Cloud, Blockchain and AI talks were much in evidence, for example) it really was a developer conference with keynotes and speakers from well-renowned figures across the industry.

You can watch my session covering deploying Jenkins on Kubernetes with Helm and deploying to Kubernetes from Jenkins with Helm below. You can find the deck on SlideShare and the demo material on GitHub. For those who know what I work on, it will be no surprise that this is based on our discoveries when developing Microservice Builder. I highly recommend you also check out some of the other sessions on the conference playlist and watch out for Index 2019!

The timing of the conference meant I had Friday to be a tourist with some colleagues. We headed over to SF MoMA and then made the most of the sunshine with a stroll along the waterfront to see the sea lions and then to have to have lunch overlooking the bay.

Half Term Action

Tuesday, February 20th, 2018

Although we had no particular plans, I had the whole of the February half term off work. We went over to Wales for the first few days. I had a lovely long run in the Forest of Dean on Sunday whilst the others went around the sculpture trail. Christine drew the short straw as she got to run back to Monmouth just as the Arctic conditions arrived.

The next day we had to shovel the snow off the driveway before heading over to Llangorse Activity Centre. Christine wanted to cement the skills she’d learnt on her rope handling course whilst her Dad was around. Sue and I went for a short walk up a snowy hill!

Unfortunately, the weather deteriorated again as we headed back to Southampton. Not surprisingly, therefore, we weren’t the only ones to have the idea of going to the Winchester Science Centre and it was Thursday before I could actually book a ticket. By this time we had blue skies but it made a nice change to actually be able to sit outside and eat our lunch. The children enjoyed the special ‘Secret World of Gases’ show even if only for the loud bangs. I was less sure about the ‘We Are Aliens!‘ film in the planetarium but you could always just lie back and close your eyes… The same was true of our rather belated trip to see Paddington 2 the following day!

Christine took up the reigns again at the weekend with a trip to Mottisfont. I only made it as far as the car park, running back home instead.

Kubernetes arrives in Docker for Mac

Monday, January 8th, 2018

My focus for the last 18 months having been on deployment to Kubernetes, I was excited to hear the news back at DockerCon that Docker Inc were recognising the dominance of Kubernetes. This included adding support to Docker Enterprise Edition (alongside Swarm) and to Docker for Mac/Windows. The latter has now hit beta in the edge channel of Docker for Mac and the following are my first impressions.

Having not had any particular need for the latest and greatest Docker for some time, my first step was to switch from the stable channel back to edge. That’s a pretty painless process. You do lose any of your current containers/images but you’ve got the ones you care about stored away in a registry somewhere haven’t you?! Then open up the preferences, switch to the shiny new Kubernetes tab, check the box to Enable Kubernetes and hit Apply followed by Install. As promised, it took a couple of minutes for the cluster to be created.

The UI leaves you a bit in the dark at this point but thankfully the email that arrived touting the new capability gave you a pointer as to where to go next: the install creates a kubectl context called docker-for-desktop. With this information I could access my new cluster from the command line:

Now to take the cluster for a quick spin. Let’s deploy Open Liberty via the Helm chart:

And, due to the magic of Docker for Mac networking, after a short wait we are treated to the exposed NodePort running on localhost:

Open Liberty on Kubernetes on Docker for Mac

Undoubtedly there will be issues but, at least at first glance, this support would seem to go a long way to answering those who see minikube as an inhibitor to making Kubernetes a part of the developer’s workflow.

Multi-Arch Docker Images

Sunday, October 8th, 2017

Things have been a little hectic recently and a whole month has slipped past without a blog post. The following is old news now but it’s still something that I wanted to call out. As of mid-September, all the official images on Docker Hub have been multi-arch enabled and many of them, including the websphere-liberty image, are now available for multiple platforms.

So what does that mean practically speaking? It means that, whether you are on x, p or z, hardware, you can now use the same docker run websphere-liberty command and have it pull the appropriate image for your architecture. That may seem like a trivial thing: what was so hard about docker run ppc64le/websphere-liberty after all? What it means though is that I can also use the same Dockerfiles, Compose files and Kubernetes configuration, regardless of what platform I’m on.

If you consider WebSphere Liberty, for example, we don’t have any architecture specific code but we are obviously dependent upon Java which has both native code and is dependent on platform specific libraries. That meant that, to build the ppc64le/websphere-liberty image, we had to change the Dockerfile to build from ppc64le/ibmjava. That’s no longer the case.

To take another example, with my Microservice Builder hat on we are building Helm charts that we want to run on multiple platforms. Previously we’d had to rely on multiple charts or overrides to select the correct image for the platform. That’s also no longer the case.

Now just to be 100% clear, this is not about having a single image that can run on multiple architectures: that would require a hypervisor or emulator. The magic here is purely that websphere-liberty is no longer an image, it is a manifest that points to the layers that make up the images for each architecture, and, when the image is pulled, that indirection is resolved by the client to select the image for the current platform.

If you want to know more of the technical detail and the journey to get this far, I suggest reading the blog posts by my colleagues Phil Estes and Utz Bacher. I also need to call out Tianon Gravi whose tireless work on the official images meant that enabling this support for WebSphere was entirely painless.

Optional Kubernetes resources and PodPresets

Thursday, July 27th, 2017

The sample for Microservice Builder is intended to run on top of the Microservice Builder fabric and also to utilize the ELK sample. As such, the Kubernetes configuration for the microservice pods all bind to a set of resources (secrets and config-maps) created by the Helm charts for the fabric and ELK sample. The slightly annoying thing is that the sample would work perfectly well without these (you just wouldn’t get any logging to the ELK stack) only, as we shall see in a moment, deployment fails if the fabric and ELK sample have not already been deployed. In this post we’ll explore a few possibilities as to how these resources could be made optional.

I’m going to assume a minikube environment here and we’re going to try to deploy just one of the microservices as follows:

If you then perform a kubectl describe  for the pod that is created you’ll see that it fails to start as it can’t bind the volume mounts:

Elsewhere in the output though you’ll see a clue to our first plan of attack:

Doesn’t that optional  flag look promising?! As of Kubernetes 1.7 (and thanks to my one-time colleague Michael Fraenkel) we can mark our usage of secrets and config-maps as optional. Our revised pod spec would now look as follows:

And lo and behold, with that liberal sprinkling of optional attributes we can now successfully deploy the service without either the fabric or ELK sample. Success! But why stop there? All of this is boilerplate that is repeated across all our microservices. Wouldn’t it be better if it simply wasn’t there in the pod spec and we just added it when it was needed? Another new resource type in Kubernetes 1.7 comes to our rescue: the PodPreset. A pod preset allows us to inject just this kind of configuration at deployment time to pods that match a given selector.

We can now slim our deployment down to the bare minimum that we want to have in our basic environment:

Note that we have also added that runtime: liberty  label to the pod which is what we’re going to use to match on. In our advanced environment, we don’t want to be adding the resources to every pod in the environment, in particular,  we don’t want to add it to those that aren’t even running Liberty. This slimmed down deployment works just fine, in the same way that the optional version did.

Now, what do we have to do to get all of that configuration back in an environment where we do have the fabric and ELK sample deployed? Well, we define it in a pod preset as follows:

Note that the selector is matching on the label that we defined in the pod spec earlier. Now, pod presets are currently applied by something in Kubernetes called admission control and, because they are still alpha, minikube doesn’t enable the admission controller for PodPresets by default. We can enable it as follows:

(Note that, prior to minikube v0.21.0 this property was called apiserver.GenericServerRunOptions.AdmissionControl, a change that cost me half an hour of my life I’ll never get back!)

With the fabric, ELK sample and pod preset deployed, we now find that our pod regains its volume mounts when deployed courtesy of the admission controller:

Pod presets are tailor-made for this sort of scenario where we want to inject secrets and config maps but even they don’t go far enough for something like Istio where we want to inject a whole new container into the pod (the Envoy proxy) at deployment time. Admission controllers in general also have their limitations in that they have to be compiled into the API server and, as we’ve seen, they have to be specified when the API server starts up. If you need something a whole lot more dynamic that take a look at the newly introduced initializers.

One last option for those who aren’t yet on Kubernetes 1.7. We’re in the process of moving our generated microservices to use Helm and in a Helm chart template you can make configuration optional. For example, we might define a logging  option in our values.yaml with a default value of disabled , and then we can define constructs along the following lines in our pod spec:

Then all we’ve got to do when we’re deploying to our environment with the fabric and ELK sample in place is to specify an extra --set logging=enabled  on our helm install. Unlike the pod preset, this does mean that the logic is repeated in the Helm chart for every microservice but it certainly wins on the portability stakes.

Private repositories on Docker Hub

Sunday, July 16th, 2017

Sometimes Docker Hub really is just the quickest and easiest way to share an image from one place to another, particularly when the place I’m trying to share to is expecting to just do a docker pull. It’s not always the case that I want to share those images with the rest of the world though. Docker Hub’s answer to this is the private repository but, on a free plan, you only get one private repository. What you have to remember though is that a repository can contain multiple images: they all share the same name but each has a different tag.

So, a while back I created a repository in my personal namespace called private and made it private using the button on the settings page:

When I then want to push an image up I use the local name as the tag. For example:

Simple as that. There are obviously limitations here in that I lose the ability to have multiple versions of my image with different tags but so far, for my limited use cases, I’ve been able to live with that. In fairness to Docker Inc, I should say that have multiple private repositories is not the only reason to pay for an account on Docker Hub. You also get the ability to run parallel builds on.

Microservice Builder GA Update

Wednesday, July 12th, 2017

As I posted here on the Microservice Builder beta, I thought it only fair that I should offer an update now that it is Generally Available. There is already the official announcement, various coverage in the press including ZDNet and ADT, a post from my new General Manager Denis Kennelly, and, indeed, my own post on the official blog, so I thought I’d focus on what has changed from a technical standpoint since the beta.

If I start with the developer CLI, the most significant change here is that you no longer need a Bluemix login. Indeed, if you aren’t logged in, you’ll no longer be prompted for potentially irrelevant information such as the sub-domain on Bluemix where you want the application to run. Note, however, that the CLI is still using back-end services out in the cloud to generate the projects so you’ll still need internet connectivity when performing a bx dev create.

Moving on to the next part of the end-to-end flow: the Jenkins-based CI/CD pipeline, the Helm chart for this has been modified extensively. It is now based on the community chart which, most significantly, means that it is using the Kubernetes plugin for Jenkins. This results in the use of separate containers for each of the build steps (with Maven for the app build, Docker for the image build, and kubectl for the deploy) and those containers are spun up dynamically as part of a Kubernetes pod representing the Jenkins slave when required.

The Jenkinsfile has also been refactored to make extensive use of a Jenkins library. As you’ll see in the sample projects, this means that the generated Jenkinsfile is now very sparse:

I could say much more about the work we’ve done with the pipeline but to do so would be stealing the thunder from one of my colleagues who I know is penning an article on this subject.

Looking at the runtime portion, what we deploy for the Microservice Builder fabric has changed significantly. We had a fair amount of heartache as we considered security concerns in the inter-component communication. This led us to move the ELK stack and configuration for the Liberty logstash feature out into a sample. This capability will return although likely in a slightly different form. The fabric did gain a Zipkin server for collation and display of Open Tracing data. Again, the security concerns hit home here and, for now, the server is not persisting data and the dashboard is only accessible via kubectl port-forward.

Another significant change, and one of the reasons I didn’t post this immediately, was that a week after we GA’d, IBM Spectrum Conductor for Containers morphed into IBM Cloud private. In the 1.2 release, this is largely a rebranding exercise but there’s certainly a lot more to come in this space. Most immediately for Microservice Builder, it means that you no longer need to add our Helm repository as it will be there in the App Center out of the box. It also meant a lot of search and replace for me in our Knowledge Center!

You may be wondering where we are heading next with Microservice Builder. As always, unfortunately I can’t disclose future product plans. What I can do is highlight existing activity that is happening externally. For example, if you look at the Google Group for the MicroProfile community, you will see activity ramping up there and proposals for a number of new components. Several of the Microservice Builder announcements also refer to the Istio service mesh project on which IBM is collaborating with Google. It’s still early days there but the project is moving fast and you can take a look at some of the exciting features on the roadmap.

Multi-Stage Docker Build

Friday, May 5th, 2017

Docker 17.05 enabled the ability to perform multiple build stages in a single Dockerfile, copying files between them. This brings to regular Docker build a capability that I’ve previously talked about in the context of Rocker, and something that’s of particular use in a compiled language like Java. Let’s see what it would look like in the context of the WebSphere Liberty ferret sample.

The original Dockerfile looks as follows:

We can see that it assumes that the application has already been built and just pulls in the WAR file, in this case from Maven Central. With a multi-stage build we can perform the build of the application and the build of the image in a single Dockerfile:

The first line uses the Maven on-build image to build the application using the source in the same directory as the Dockerfile. Although the stages are given an index by default, naming them using the AS keyword makes the file much more readable. Further down in the Dockerfile we can see that the COPY command takes the built WAR file from the first stage and copies it into the Liberty dropins directory as before. The important thing about all of this is that the final image doesn’t end up with the application source in it, or Maven, or an SDK – just the artifacts that are needed at runtime – thereby keeping down the final image size.