NOTE cert-manager is a better solution to what follows.

I wrote about deploying Secure (TLS) gRPC services with Vultr Kubernetes Engine (VKE). This week, I’ve reproduced this deployment using Linode Kubernetes Engine (LKE).

Thanks to the consistency provided by Kubernetes, the Kubernetes programming is almost identical. The main differences are between the CLI’s provided by these platforms. Both are good. They’re just different.

I’m going to include the linode-cli commands I’m using in this post as I found it slightly more quirky.

Yesterday I discussed a Linode Prometheus Exporter and tantalized use of Prometheus AlertManager.

Success:

Configure

The process is straightforward although I found the Prometheus (config) documentation slightly unwieldy to navigate :-(

The overall process is documented.

Here are the steps I took:

• Configure Prometheus
• Configure AlertManager
• Revise Docker Compose

Configure Prometheus

Added the following to prometheus.yml:

rule_files:
- "/etc/alertmanager/rules/linode.yml"

alerting:
  alertmanagers:
    - scheme: http
      static_configs:
        - targets:
            - "alertmanager:9093"

Rules must be defined in separate rules files. See below for the content for linode.yml and an explanation.

I enjoy using Prometheus and have toyed around with it for some time particularly in combination with Kubernetes. I signed up with Linode [referral] compelled by the addition of a managed Kubernetes service called Linode Kubernetes Engine (LKE). I have an anxiety that I’ll inadvertently leave resources running (unused) on a cloud platform. Instead of refreshing the relevant billing page, it struck me that Prometheus may (not yet proven) help.

The hypothesis is that a combination of a cloud-specific Prometheus exporter reporting aggregate uses of e.g. Linodes (instances), NodeBalancers, Kubernetes clusters etc., could form the basis of an alert mechanism using Prometheus’ alerting.