Monthly notes 49

Working From Home edition.

Issue 49, 27.3.2020


Now that COVID-19 has all of us in corontine and working from home, also the technology conferences have been moved to online and free. Here's some.

Working From Home Conf with talks from technology to projects, best practices, lessons learned and about working from home. Agenda and recorded videos: part 1, part 2, part 3.

DEVOPS 2020, April 21 to 22
The Next Decade. The first day (main conference) has interesting talks from use cases and lessons learned, scaling devsecops, transformation journey and more.

MagnoliaJS, April 15-17
JavaScript heavy talks like component reusability, modern JavaScript for modern browsers, JavaScript’s exciting new features, how to supercharge teams and much more.

Red Hat Summit 2020, April 28-29

Tips and tricks

How to do effective video calls
tl;dr; TL;DR "Get good audio, use gallery view, mute if not talking, and welcome the cat."


Work together like you’re in the same room. Fast screen sharing with multiplayer control, drawing & video. (from @use_screen)

An open-source screen recorder built with web technology.

The paramount collection of productive Mac apps.

Using NGINX Ingress Controller on Google Kubernetes Engine

If you've used Kubernetes you might have come across Ingress which manages external access to services in a cluster, typically HTTP. When running with GKE the "default" is GLBC which is a "load balancer controller that manages external loadbalancers configured through the Kubernetes Ingress API". It's easy to use but doesn't let you to to customize it much. The alternative is to use for example NGINX Ingress Controller which is more down to earth. Here are my notes of configuring ingress-nginx with cert manager on Google Cloud Kubernetes Engine.

This article takes much of it's content from the great tutorial at Digital Ocean.

Deploying ingress-nginx to GKE

Provider specific steps for installing ingress-nginx to GKE are quite simple.

First you need to initialize your user as a cluster-admin with the following command:

kubectl create clusterrolebinding cluster-admin-binding \
   --clusterrole cluster-admin \
   --user $(gcloud config get-value account)

Then if you are using a Kubernetes version previous to 1.14, you need to change to at line 217 of mandatory.yaml.

Now you're ready to create mandatory resources, use kubectl apply and the -f flag to specify the manifest file hosted on GitHub:

kubectl apply -f

$ kubectl apply -f ingress-nginx_mandatory.yaml
namespace/ingress-nginx created
configmap/nginx-configuration created
configmap/tcp-services created
configmap/udp-services created
serviceaccount/nginx-ingress-serviceaccount created created created created created
deployment.apps/nginx-ingress-controller created
limitrange/ingress-nginx created

Create the LoadBalancer Service:

$ kubectl apply -f
service/ingress-nginx created

Verify installation:

$ kubectl get svc --namespace=ingress-nginx
NAME            TYPE           CLUSTER-IP      EXTERNAL-IP      PORT(S)                      AGE
ingress-nginx   LoadBalancer   80:30598/TCP,443:31334/TCP   40s

$ kubectl get pods --all-namespaces -l --watch
NAMESPACE       NAME                                        READY   STATUS    RESTARTS   AGE
ingress-nginx   nginx-ingress-controller-6cb75cf6dd-f4cx7   1/1     Running   0          2m17s

Configure proxy settings

In some situations the payload for ingress-nginx might be too large and you have to increase it. Add the "" annotation to your ingress metadata with value you need. 0 to not limit the body size.

kind: Ingress
  name: ingress
  annotations: nginx "letsencrypt-prod" "0" "600" "600"


Check the Ingress Resource Events:

$ kubectl get ing ingress-nginx

Check the Ingress Controller Logs:

$ kubectl get pods -n ingress-nginx
NAME                                        READY   STATUS    RESTARTS   AGE
nginx-ingress-controller-6cb75cf6dd-f4cx7   1/1     Running   0          149m

$ kubectl logs -n ingress-nginx nginx-ingress-controller-6cb75cf6dd-f4cx7

Check the Nginx Configuration:

kubectl exec -it -n ingress-nginx nginx-ingress-controller-6cb75cf6dd-f4cx7  cat /etc/nginx/nginx.conf

Check if used Services Exist:

kubectl get svc --all-namespaces

Promote ephemeral to static IP

If you want to keep the IP you got for the ingress-nginx then promote it to static. As we bound our ingress-nginx IP to a subdomain we want to retain that IP.

To promote the allocated IP to static, you can update the Service manifest:

kubectl --namespace=ingress-nginx patch svc ingress-nginx -p '{"spec": {"loadBalancerIP": ""}}'

And promote the IP to static in GKE/GCE:

gcloud compute addresses create ingress-nginx --addresses --region europe-north1

Creating the Ingress Resource

Creating your Ingress Resource to route traffic directed at a given subdomain to a corresponding backend Service and apply it to Kubernetes cluster.

$ kubectl apply -f ingress.yaml
ingress.extensions/ingress created

Verify installation:

kubectl get pods --all-namespaces -l --watch

Installing and Configuring Cert-Manager

Next we'll install cert-manager into our cluster. It's a Kubernetes service that provisions TLS certificates from Let’s Encrypt and other certificate authorities and manages their lifecycles.

Create namespace:

kubectl create namespace cert-manager

install cert-manager and its Custom Resource Definitions (CRDs) like Issuers and ClusterIssuers.

kubectl apply --validate=false -f

Verify installation:

kubectl get pods --namespace cert-manager

Rolling Out Production Issuer

Create a production certificate ClusterIssuer, prod_issuer.yaml:

kind: ClusterIssuer
  name: letsencrypt-prod
  namespace: cert-manager
    # The ACME server URL
    # Email address used for ACME registration
    # Name of a secret used to store the ACME account private key
      name: letsencrypt-prod
    # Enable the HTTP-01 challenge provider
    - http01:
          class: nginx

Apply production issuer using kubectl:

kubectl create -f prod_issuer.yaml

Update ingress.yml to use "letsencrypt-prod" issuer:

  annotations: "letsencrypt-prod"

Apply the changes:

kubectl apply -f ingress.yaml

Verify that things look good:

kubectl describe ingress
kubectl describe certificate


Keep Maven dependencies up to date

Software development projects come usually with lots of dependencies and keeping them up to date can be burdensome if done manually. Fortunately there are tools to help you. For Node.js projects there are e.g. npm-check and npm-check-updates and for Maven projects there are OWASP/Dependency-Check and Versions Maven plugins. Here's a short introduction how to setup your Maven project to automatically check dependencies for vulnerabilities and if there's outdated dependencies.


OWASP dependency-check is an open source solution the OWASP Top 10 2013 entry: "A9 - Using Components with Known Vulnerabilities".

Dependency-check can currently be used to scan Java and .NET applications to identify the use of known vulnerable components. The dependency-check plugin is, by default, tied to the verify or site phase depending on if it is configured as a build or reporting plugin.

The example below can be executed using mvn verify:


The example fails the build for CVSS greater than or equal to 8 and skips scanning the provided and runtime scoped dependencies.

Versions Maven Plugin

The Versions Maven Plugin is the de facto standard way to manage versions of artifacts in a project's POM. From high-level comparisons between remote repositories up to low-level timestamp-locking for SNAPSHOT versions, its massive list of goals allows us to take care of every aspect of our projects involving dependencies.

The example configuration of versions-maven-plugin:


You could use goals that modify the pom.xml as described in the usage documentation but often it's easier to check versions manually  as you might not be able to update all of the suggested dependencies.

The display-dependency-updates goal will check all the dependencies used in your project and display a list of those dependencies with newer versions available.

Check new dependencies with:

mvn versions:display-dependency-updates

Check new plugin versions with:

mvn versions:display-plugin-updates


Using OWASP/Dependency-Check in your Continuous Integration build flow to automatically check dependencies for vulnerabilities and running periodically Versions Maven Plugin to check if there are outdated dependencies helps you to keep your project up to date and secure. Small but important things to remember while developing and maintaining a software project.