k8s-at-home, another project deprecated while at its prime

The open source community it capable of incredible things all working their main jobs then building things outside of work … but, it is all too common for people to also want to have a life outside of work.

We’ve lost another project just due to a lack of maintainers / availability.  It’s sad when it happens.  Even I didn’t have time to help out, and now it’s gone.

If only there were a way to pay people to maintain open source projects.

Think I’ll have a drink tonight in celebration of the k8s-at-home folks, thanks for everything you did.

Rearchitecting lido for kubernetes

Deployments

brokermanager
brokermanager-db
broker-tdameritrade
broker-tdameritrade-db
broker-tdameritrade-mq
broker-tdameritrade-www (oidc login)
broker-kraken
broker-kraken-db
broker-kraken-mq
broker-kraken-www (oidc login)
tradermanager
tradermanager-db
tradermanager-mq
tradermanager-www (gui)
trader-<algo>
trader-<algo>-mq

Making learning fun by creating a “gray area” niche goal

One time, as a way to motivate a coworker who was working to learn scripting, I shared with him an algorithm to generate all possible string combinations given a string of possible characters.  This, of course could be used potentially to try all possible passwords for nefarious means.

Within about 10 minutes I had a manager in the office, looking at the whiteboard, telling me they weren’t stupid, that they knew what all that was on the board and that I need to not be teaching the employees how to hack computers.  I noticed a coworker sneaking out of the room trying to hide their laughter.  I think we know who called the manager.

It still makes me laugh to this day.  I suppose they weren’t completely wrong, but in my mind I figure if you tell someone to make every possible key possible for a type of car, and try them all, at some point you’ll get into that car.  Is that teaching a master class on how to break into cars?  I guess, but it sure isn’t efficient, master class it is not.  However, as a fun script for someone new to scripting to use to learn with, it’s a fun algorithm to write.

Along those same “gray area” lines I share with you a goal to help motivate one to learn kubernetes.  I’ll give you the exact steps necessary to make it happen.  The goal is this: “Let’s put together a micro-services architected solution to help you keep track of movies or tv shows you’d like to get around to watching some day”.  I used to use a physical notepad for this back in the day, then a notepad app on my phone, but modern days allow for modern solutions.  No longer do you have to type the full name of a movie or tv show, you can now type a little and search for it, then when its found click on it to add it to your queue.

Here’s how to do it and the applications you’ll need (this is for an onprem setup, you are own your own if you are deploying apps the world is able to see from the internet, try not to do that):

  1. If you don’t know kubernetes sign up for the udemy class “Certified Kubernetes Administrator (CKA) with Practice Tests”, then go ahead and take the exam and get the CKA certification.
  2. Decide which extra computer you have laying around is to be your NAS, where your network storage will live, and install truenas core on it.  Then configure iscsi to work with kubernetes provisioned storage.  You’ll need to deploy democratic-csi into your cluster and install scsi-related utilities on to your worker nodes in the next step.
  3. Spin up a cluster using kubeadm then deploy Plex Media Server into your cluster.  Plex is used to give a netflix-like experience around viewing your home media collection.  I recommend the kube-plex helm chart and to deploy using gitops using argocd.  kube-plex will deploy a pms instance that will spin up extra streaming processes on the fly, but I recommend disabling that feature in the values.yaml, to avoid any potential file locking issues… at least in the beginning.  Also, instead of using a network share for your configuration setup taints and tolerances to direct the plex application to only spin up on one node, and use local storage there.  (Plex tends to have database corruption when using network storage, go for it later if you want, but set yourself up for success initially.)
  4. Next deploy sonarr and radarr using the helm charts out at k8s-at-home, these are similar apps that work with tv and movies respectively.  k8s-at-home is a cool group in that they have a common library among all their helm charts, so for example, if you wanted to setup a vpn on any particular application as a side pod you could, or using a single vpn pod that multiple pods can route through, or add an ingress, or mount an additional volume, etc.
  5. Now, you are done, you can browse to your sonarr and radarr installation and search for movies and tv shows you’d like to watch someday.  Be sure to setup cert-manager and external-dns as well to register them in your local onprem dns and configure a valid certificate.
  6. You might also want to setup a vpn such as wireguard in your cluster as well as forwarding the needed vpn-related port through your router so that you can browse to these apps on your phone while you are out and about, that way, if you hear of a movie you want to queue up for later viewing you can do so in the moment.
  7. Interestingly, you can also click on Connect in both sonarr and radarr to configure your plex server for some reason.

Kubernetes, a thought

We learn of Kubernetes as having been created at Google to take advantage of all extra hardware and cpu laying around.  That every bit of hardware available could be added to a cluster.  (Well, Kubernetes was a rewrite of an internal project but, let’s not get distracted.)

Then we learn all about Kubernetes using tools which spin up a cluster on our desktop, then spin up a cluster out in the cloud, then something onprem.

Today it occurred to me, as I have been installing kubernetes using ms hyperv, vmware, xcp-ng, etc looking for the right vm solution, and noticing as Microsoft pieces are fading away, no longer needed and no longer the best fit… that, many may have missed what Google was saying.  Why am I looking for a vm solution which can hotswap a vm from one vm server to another when Kubernetes already handles where to place a container?

Why not just install Kubernetes to my vm servers to create one large cluster?  I can then spin up multiple Kubernetes clusters if I want to, using the same gitops methods I’ve been using.  There is no need for a hyper-v layer, no need for vms.  It is an enlightening thought.

Still, there may be a need for vms… maybe, we still need:

  • an identity server (for user accounts)
  • dns (which external-dns can update)
  • certificate authority (which cert-manager can use)
  • servers for non-containerized, legacy, apps
  • dhcp (for client systems)

We could run one app in the “one cluster to rule them all”, a dns app, in addition to a controller which can spin up clusters.  Hashicorp vault could be our certification authority.  Our identity service provider could be almost anything, even Google.  We could use keycloak locally and point to Google as the backend provider.  The only dhcp that Kubernetes needs is built in.

Perhaps:

  • Subnet for root cluster & dns, bare metal
  • Subnet for legacy servers, vm based
  • Subnet for client systems, dhcp

Next steps:

  • Sidero to install Kubernetes to bare metal cluster https://www.sidero.dev/
  • vcluster to deploy clusters within the bare metal cluster https://youtu.be/JqBjpvp268Y

mapping dns via argocd applicationset and external-dns

When using ArgoCD and an ApplicationSet to deploy external-dns to all clusters, as part of a grouping of addons common to all clusters, it can be useful to configure the DNS filter using variables:

        helm:
          releaseName: "external-dns"
          parameters:
          - name: external-dns.domainFilters
            value: "{ {{name}}.k.home.net }"
          - name: external-dns.txtOwnerId
            value: '{{name}}'
          - name: external-dns.rfc2136.zone
            value: '{{name}}.k.home.net'

This will place the cluster name as part of the dns name used by external-dns, resulting in the following type of FQDNs used by clusters:

app.dev.k.home.net
app.test.k.home.net
app.prod.k.home.net

Though, for my core cluster with components used by all clusters, I like to leave out the cluster name so all core components are at the k.<domain> level:

argocd.k.home.net
harbor.k.home.net
keycloak.k.home.net

git-based homedir folder structure (and git repos) using lessons learned

After reinstalling everything including my main linux workbench system it became the right time to finally get my home directory into git.  Taking all lessons learned up till this point it seemed a good idea to cleanup my git repo strategy as well.  The revised strategy:

[Git repos]

Personal:
- workbench-<user>

Team (i for infrastructure):
- i-ansible
- i-jenkins (needed ?)
- i-kubernetes (needed?)
- i-terraform
- i-tanzu

Project related: (source code)
- p-lido (use tagging dev/test/prod)
    doc
    src

Jenkins project pipelines:
- j-lifecycle-cluster-decommission
- j-lifecycle-cluster-deploy
- j-lifecycle-cluster-update
- j-lido-dev
- j-lido-test
- j-lido-prod

Cluster app deployments:
- k-core
- k-dev
- k-exp
- k-prod

[Folder structure]

i-ansible (git repo)
  doc
  bin
  plays ( ~/a )

i-jenkins (git repo) (needed ?)
  doc
  bin
  pipelines ( ~/j )

i-kubernetes (git repo) (needed ?)
  doc
  bin
  manage ( ~/k )
  templates

i-terraform (git repo)
  doc
  bin
  plans (~/p)
    k-dev

i-tanzu (git repo)
  doc
  bin
  application.yaml (-> appofapps)
  apps (~/t)
    appofapps/ (inc all clusters)
    k-dev/cluster.yaml

src
  <gitrepo>/<user> (~/mysrc) (these are each git repos)
  <gitrepo>/<team> (~/s) (these are each git repos)
    j-lifecycle-cluster-decommission
    j-lifecycle-cluster-deploy
    - deploy cluster
    - create git repo
    - create adgroups
    - register with argocd global
    j-lifecycle-cluster-update
    j-lido-dev
    j-lido-test
    j-lido-prod
    k-dev
      application.yaml (-> appofapps)
      apps
        appofapps/ (inc all apps)
    k-exp
      application.yaml (-> appofapps)
      apps
        appofapps/ (inc all apps)
    k-prod
      application.yaml (-> appofapps)
      apps
        appofapps/ (inc all apps)

workbench-<user> (git repo)
  doc
  bin

kubernetes disaster recovery

Deploying via git using argocd or flux makes disaster recovery fairly straightforward.

Using gitops means you can delete a kubernetes cluster, spin up a new one,  and have everything deployed back out in minutes.  But what about recovering the pvcs used before?

If you are using an infrastructure which implements csi, then you are able to allocate pvcs using storage managed outside of the cluster.  And, it turns out, reattaching to those pvcs is possible but you have to plan ahead.

Instead of writing yaml to spin up a pvc automatically, create the pv and pvc using manually set values.  Or spin up the pvcs automatically and then go back and modify the yaml to set recoverable values.  The howto is right up top in the csi documentation: https://kubernetes.io/blog/2019/01/15/container-storage-interface-ga/

Similarly, it is common for applications to spin up with randomly set admin passwords and such.  However, imagine a recovery scenario where a new cluster is stood up, you don’t want a new password stood up.  Use a vault with a password and reference the vault.

These two steps do add a little work, it’s the idea of taking a little more time to do things right, and in a production environment you want this.

Infrastructure side solution: https://velero.io/

Todo:  Create a video deleting a cluster and recovering all apps with a new cluster, recovering pvcs also (without any extra work on the recovery side).