nginx-ingress sli plugin

[warmfusion]

Lazily adapted from the apiserver example given to use the nginx-ingress metrics rules

What it do?

Adds a simple SLI plugin that uses the default nginx metrics for ingress controllers so people can throw an SLO that reflects their ingress quite easily.

How it do?

...
slos:
  - name: "my-public-ingress"
    objective: 99.9
    description: HTTP Availability for my ingress
    sli:
      plugin:
        id: "sloth-common/kubernetes/nginx-ingress/availability"
        options:
          filter: ingress="public-ingress",exported_namespace="my-awesome-website"

[warmfusion]

While this works do you think I should spend a bit more time on making the options a bit more focused, for example;

    sli:
      plugin:
        id: "sloth-common/kubernetes/nginx-ingress/availability"
        options:
          ingress: public-ingress
          host: www.example.com
          filter: additional=labels,and=keys

so folks can more directly target their particular ingress and host patterns..?

[warmfusion]

Arguments For My Previous;

• Ingress and Host are common patterns for users to define
• Clarity on options fields makes for better user experience when defining SLOs
• Easier to validate field input (eg host must be a domain name)

Arguments Against My Previous

• Lots of 'optional' fields makes for complex code and test cases
• Makes for quite an opinionated SLI measure tool...

For now - filter by itself will do, as I would assume a 'new' version of this SLI plugin could introduce the shiny new features in a backwards compatible manner with little effort, so i'm not going to add the additional optional keys for now.

Unless you have a feeling to the contrary?

[nlamirault]

any news for this plugin @slok ?

[warmfusion]

I made a tweak to the plugin so that it has a failsafe or on() vector(0) bullt in; this ensures that the error rate is 0 even if there are no errors reported from metrics and prevents NaN errors up the SLI calculation stack.