svcwatch - A Service Watcher

svcwatch is a small tool intended to help an application, running in a Kubernetes Pod, keep track of external IP address assigned to it by a Service.

svcwatch subscribes to the Kubernetes API and maintains a small JSON file on disk, that other processes can consume.

Usage

svcwatch can be run as a binary from the command line, or more typically from a container image.

$ podman run --rm -it quay.io/samba.org/svcwatch:latest -h
Usage of /svcwatch:
      --destination string   JSON file to update (default from: DESTINATION_PATH)
      --label-key string     Label key to watch (default from: SERVICE_LABEL_KEY)
      --label-value string   Label value (default from: SERVICE_LABEL_VALUE)
      --namespace string     Namespace (default from: SERVICE_NAMESPACE)

All of the options available as CLI options will default to sourcing settings from the environment variables listed above.

• The --destination option determines where svcwatch will write the output JSON file.
• The --label-key and --label-value options are used to determine what Service is to be monitored.
• The --namespace option determines what kubernetes namespace the Service will be found in.

Development Note

I looked for an existing tool to do this but, somewhat to my surprise, didn't find anything. If I overlooked something that already exists please let me know in the project's issues.