Some things I learnt recently...
In Cilium, if a pod runs with the hostNetwork set to true, it will run with the same IP of the host. Such pods runs unrestricted, without policy enforcement by default. That is because those pods do …
There are a lot of Git commands that displays delta, and all of them support preprocessing files before doing the diffing.
Preprocessors are run based on file extensions. In my case, I want to …
In its default configuration, a Linux machine running Docker runs containers in a dedicated virtual ethernet network that is bridged to the host network. Even with ports not bound to the host network …
All containers that are part of a pod have the same network namespace, and (can) bind to all IPs in that namespace. Kubernetes does not offer any implicit filtering between pod network namespace and …
SQS queues have producers (sometimes referred as publishers) and consumers. Both entities need to know the queue ARN (the Amazon ID system) to connect to. Sometimes it is desirable to not share the …
Let’s consider the scenario of a NAT server doing the forwarding between an internal network and internet, and a client that sits in the internal network which runs the ftp client. To simulate …
You can use heredoc markers to define strings in HCL that span multiple lines. There is also a way to automatically strip out all extra indentation that may have in it, by using the <<- …
At work we use CoreDNS to forward queries to the VPC resolver, as we run most of our services in Kubernetes. What that means is that we are routing all DNS queries through a few machines, and we …
The difference between the two functions is that the result of template cannot be chained with another function, while include can.
Please note that the template function is included in the Go …
A EC2 instance that you launch is only allowed to receive traffic if the destination IP matches what the DHCP server assigned. Similarly, a EC2 instance is allowed to use a certain IP as source only …
In some of our pods we use a temporary storage, to exchange data between the containers that belong to the same pod.
> k describe pod customersite
.......
Volumes:
...
sockets:
Type: …On Route53 you can configure record sets with associated weights as A records.
To test that the above weights translate in the right resolutions, we need to start from the …
At work we run a lot of Nginx pods, which we use to serve static files to our web apps. We specify memory limits for all pods we run and, to get an estimate of what those numbers should be, I have …
While it is possible to craft a role using wildcards in the resource names, it will not work to restrict pod/exec permissions. Let’s test this:
Let’s start with some basic RBAC rules and …
One thing that is annoying sometimes, when you want to quickly analyze with SQL some data, is that you likely have to work out what the schema is before running any insert.
With sqlite-utils, you can …
script is a binary included in Ubuntu that can be used to record activity in a shell. It can optionally record timings too, to get exactly the same experience when replaying the recorded activity. …
You can remove specific elements from a list or a set with this syntax
$ terraform console
> [for i in [1, 2, 3, 4, 5]: i if i != 3]
[
1,
2,
4,
5,
]
> toset([for i in toset([1, 2, 3, …Useful feature when you are developing against a cluster API is to act as the pod where your feature will be deployed.
In Kubernetes every pod is automatically assigned a service account. This is …
JQ can be used to create JSON objects of a certain shape, with the help of a few command line options.
You can use --argjson to load JSON objects into variables that can then be referenced by $name. …
ArgoCD exposes its own set of K8s custom resources when installed on a cluster:
k get crds
NAME CREATED AT
applications.argoproj.io …