admiral

README

Admiral

Admiral is a lightweight service inspired by Kubewatch. It evolved out of a need for extra observability of AWS EKS Fargate. Lack of control & vision of the kubelet necessitates more consistent testing and reporting.

Our ultimate goal is providing a simple interface and pattern for automating routine Kubernetes operations.

Available features

• Observe the following kinds of Kubernetes Events
  • Kill (scheduled pod death)
  • BackOff (unscheduled pod timeout)
  • NodeNotReady (unscheduled node failure)
  • Unhealthy (unscheduled pod failure)
• Send messages to a webhook
• Stream logs from pods to a logstore (currently supports Grafana Loki)

Application structure

Presently, the application depends on a single configuration file: ${HOME}/.admiral.yaml, which looks something like this:

cluster: my-cluster
namespace: "" # Use all namespaces
events:
    handler:
        webhook:
            url: https://my.webhook.url
logstream:
    logstore:
        loki:
            url: https://loki.logging.svc.cluster.local:3100 # A svc named loki in the logging namespace
    apps: # The label "app" on a pod
        - my-app-deployment
ignorecontainers: [datadog-agent] # an array of container names to ignore
metrics:
  handler:
    prometheus: true
    pushgateway: "http://cluster.local:9091"
  apps:
    - my-app-name

Based on the config, the application instantiates a handler. For now, the only available handler is webhook. It then instantiates a controller watching the Kubernetes API server for a variety of defined events. Each controller adds their events to a queue, which is then popped by the handler and POSTed to the webhook.

Building

Admiral is a statically compiled golang application and building is as simple as:

CGO_ENABLED=0 GOOS=linux go build -o out/admiral ./cmd

You can also execute the above command with CMake:

make build

Running

Admiral should be invoked with the single command admiral. It has 2 external dependencies for success:

1. It needs access to a kubeconfig. Admiral will check the following locations for a kubeconfig:
   1. In-cluster (native Kubernetes RBAC if it is a pod)
   2. $HOME/.kube/config
2. It needs a configuration file at $HOME/.admiral.yaml