hexdump boot-packet.bin -e'"%07.8_ad " 8/1 "%03d " " " 8/1 "%03d " " |"' -e'16/1 "%_p" "|\n"' -v |
hexdump one byte decimal display
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Category Archives: Networking
Extract Function Refactoring using inline functions.
The Extract Function refactoring is the starting point for much of my code clean up. Once a “Main” function gets sufficiently complicated, I pull pieces of it out into their own functions, often with an eye to making them methods of the involved classes.
While working with some rust code, I encountered an opportunity to execute this refactoring on some logging code. Here’s how I executed it.
Continue readingNetwork Policy to Explicitly Allow access from all Namespaces
The Default network policy in OpenShift allows all access from all pods in all namespaces via the cluster IP. However, once you start enforcing policy on a project, all policy decision need to be made explicit. If you want to still allow access from all projects, you can use the following policy file.
kind: NetworkPolicy apiVersion: networking.k8s.io/v1 metadata: name: allow-all-namespaces spec: ingress: - from: - namespaceSelector: {} |
Deploying a Minimalistic Flask Application to OpenShift
Some colleagues and I were discussing the network access policy of OpenShift. I realized it would be very helpful to have a trivial app that I could deploy to OpenShift that would then try to make a call to another service. So I wrote it using Python3 and Flask. Now that I have it working, I want to deploy it in OpenShift, again, in a trivial manner.
I would not deploy a Flask App into production without a Web server to front it. But that is what I am going to do for this test app.
Continue readingSimplifying the network
I seem to have a bad Ethernet port on the NUC. Since I have an external Ethernet adapter as well, this is not a show stopper, but it does change the approach I am going to make to my home network. As always: Simplification is preferred. Here’s the current approach:
Continue readingShift on Stack: api_port failure
I finally got a right-sized flavor for an OpenShift deployment: 25 GB Disk, 4 VCPU, 16 GB Ram. With that, I tore down the old cluster and tried to redeploy. Right now, the deploy is failing at the stage of the controller nodes querying the API port. What is going on?
Read moreInjecting a Host Entry in podman-run
How does an application find its database? For all but the most embedded of solutions, the database exposes a port on a network. In a containerized development process, one container needs to find another container’s network address. But podman only exposes the IP address of a pod, not the hostname. How can we avoid hardcoding IP addresses of remote services into our containers?
Continue readingUsing nmcli to set nameservers
Using a customer nameserver often requires disabling the DHCP based resolv.conf modifications. Here is what I got to work.
Continue readingTripleO Networks from Simplest to Not-So-Simple
If you read the TripleO setup for network isolation, it lists eight distinct networks. Why does TripleO need so many networks? Lets take it from the ground up.
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Mapping Network Ports from Physical to Logical
The Workstation on top of my server rack has 3 Ethernet ports. One is built in to the mother board, and and two are on a card. I want to use these three ports for different purposes. How can I tell which is which internally? The answer lies in /sys/bus/pci/devices/.