What’s Going On (in my cluster)?

Please note: I am moving this blog.
You can read this article at its new home:
https://haralduebele.github.io/2019/04/08/whats-going-on-in-my-cluster/

Logging and Monitoring have always been important but in a distributed microservices architecture on a Kubernetes cluster it is even more important: watching the ever changing components of a cluster is like “guarding a bag of fleas” as the German proverb says. Even our demo “Cloud Native Starter” has at least 4 or 5 pods running that all create logs that at some point when something doesn’t work you need to look at. There are plenty of articles around logging in a Kubernetes cluster with many different solutions. What is important to me as a developer is that I don’t want to care about maintaining it. I need a logging and monitoring solution but I want somebody else to keep it running for me. Fortunately, IBM Cloud is offering that in the form of “IBM Log Analysis with LogDNA” and “IBM Cloud Monitoring with Sysdig”.

Logging and Monitoring are somewhat hidden in the IBM Cloud dashboard. You find them in the “Observabilty” area of the “Burger” menu where you can create the services, learn how to configure the sources, and access their dashboards.

LogDNA can be used with a Kubernetes Cluster running on the IBM Cloud and it can also be used with a Minikube cluster. It is available in the IBM Cloud Datacenters in Dallas and Frankfurt. There is free (lite) version available but this is limited in its features.

Once a LogDNA instance has been created, the next thing to do is to “Edit log sources”. There are several options, we are only interested in Kubernetes here:

Two kubectl commands need to be executed against the Kubernetes cluster (IBM Kubernetes Service or Minikube work).

The first command creates a Kubernetes secret holding my specific LogDNA ingestion key which is required to write log events into my LogDNA instance. The second command creates a logdna-agent daemon set in the Kubernetes cluster which creates a pod on every Kubernetes worker node. No further installation or configuration is required. If you click on the “View LogDNA” button you’ll see the dashboard:

Notice the filters in the header area. In this screenshot I have filtered on 3 Apps, the listing shows “authors”, “web-api”, and “articles”. I can further filter on showing errors only, save that as a view, and attach an alerting channel to it, for example email or a Slack channel. You can find more infos here.

Sysdig can be used with a Kubernetes Cluster running on the IBM Cloud and it can also be used with a Minikube cluster, too. It is available in the IBM Cloud Datacenters in Dallas, London, and Frankfurt. There is trial version available with limited features which expires after 30 days.

Again, once the Sysdig instance has been created, go to “Edit sources”. There are instructions for Kubernetes, Linux, and Docker. The Kubernetes instructions first explain how to logon to the IBM Cloud and then access the Kubernetes cluster with ibmcloud CLI, this is of course not required for Minikube. Lastly there is a curl command that downloads and install the sysdig agent for Kubernetes. Again, there is no further configuration required. The “View Sysdig” button opens the Sysdig dashboard:

There are several predefined dashboards including 2 predefined Istio dashboards which are not available in the trial version of Sysdig.


Moving from Minikube to IBM Cloud Kubernetes Service

Please note: I am moving this blog.
You can read this article at its new home:
https://haralduebele.github.io/2019/04/04/moving-from-minikube-to-ibm-cloud-kubernetes-service/

In my last blog I have described a project we are working on: Cloud Native Starter. It is a microservices architecture, written mostly in Java with Eclipse MicroProfile, and using many Istio features. We started to deploy on Minikube because that is easy to implement if you have a reasonably powerful notebook. Now that everything works on Minikube, I wanted to deploy it on the IBM Cloud, too, using IBM Cloud Kubernetes Service (IKS).

IKS is a managed Kubernetes offering that provides Kubernetes clusters on either bare metal or virtual servers in many of IBMs Cloud datacenters in Europe, the Americas, and Asia Pacific. One of the latest features (currently beta) are cluster add-ons to automatically install a managed Istio (together with Kiali, Jaeger, Prometheus, etc) onto an IKS cluster. You can even install the Istio Bookinfo sample with a single click, Knative is also available as preview.

There is even a free (lite) Kubernetes cluster available (single node, 2 vCPUs, 4 GB RAM) but you need an IBM Cloud Account with a credit card entered in order to use it, even if it is free of charge. I have heard stories that there was too much Bitcoin mining going on on the lite clusters, go figure! You can also try and get an IBM Cloud promo code, we hand them out at conferences where we are present, your next chances in Germany are JAX in Mainz, WeAreDevelopers and DevOpsCon in Berlin, ContainerDays in Hamburg .

There is also an IBM Cloud Container Registry (ICR) available, this is a container image repository comparable to Dockerhub but private on the IBM Cloud. You can store your own container images there and reference them in Kubernetes deployment files for deployment on the IBM Cloud. You can even use ICR to build your container images.

I have created scripts to deploy Cloud Native Starter onto the IBM Cloud and documented the steps here. Here I want to point out the few things that are different and very specific when deploying to IBM Cloud Kubernetes Service compared to deploying to Minikube

First, you need to be logged on the IBM Cloud of course which you do with the ibmcloud CLI, then you need to set the cloud-based Kubernetes environment configuration, and finally login to the Container Registry, too
$ ibmcloud login
$ ibmcloud region-set us-south
$ ibmcloud ks cluster-config <clustername>
$ ibmcloud cr login

After that, ‘kubectl’ and ‘docker’ commands work with the IBM Cloud and not a local resource. ‘ibmcloud ks cluster-config’ is comparable to the ‘minikube docker-env’ for Minikube.

‘ibmcloud ks cluster-config’ outputs an ‘export KUBECONFIG=/…/… .yaml’. Copy and paste this export statement into your shell and execute it. This statement needs to be executed every time a new shell is opened where a kubectl command should run on your IKS cluster!

This is the command to build the container image for the Authors Service API locally or on Minikube:
$ docker build -f Dockerfile -t authors:1 .
To build the image on the IBM Container Registry requires this command:
$ ibmcloud cr build -f Dockerfile –tag us.icr.io/cloud-native/authors:1 .
‘cr’ is the subcommand for Container Registry, ‘us.icr.io’ is the URL for the Registry hosted in the US, and ‘cloud-native’ is a namespace within this registry. This is the dashboard view of the Registry with all images of Cloud Native Starter:

The deployment YAML files need to be adapted to reference the correct location of the image. This is the spec for Minikube with the image being locally available in Minikube:

spec:
  containers:
  - image: authors:1
    name: authors

This is the spec for IBM Cloud Container Registry:

spec:
  containers:
  - image: us.icr.io/cloud-native/authors:1
    name: authors

Everything else is identical to Minikube in the files. In my deployment scripts, I use ‘sed’ to automatically create new deployment files.

Deploying to IKS is not different to deploying to Minikube, just make sure that the KUBECONFIG environment is setup to use the IKS cluster.

A lite (free) Kubernetes cluster on the IBM Cloud has no Ingress or Loadbalancer available. That is reserved for paid clusters. Istio, however, has its own Ingress (istio-ingressgateway) and this is accessible via a NodePort, http on port 31380, https on port 31390. To determine the public IP address of an IKS worker node, issue the command:
$ ibmcloud ks workers <clustername>
The result looks like this:

To access the Cloud Native Starter webapp, simply point your browser to
http://149.81.xx.x3:31380
In our Github repository is a script iks-scripts/show-urls.sh that will point out all important URLs on the IBM Cloud deployment, including the commands to access Kiali, Jaeger, etc.