ready

README

Ready

Ready is a container that waits for a list of pods with specific labels to become available. It exits successfully when all pods are ready, writing a comma-separated list of their IP addresses to a file. It exits unsuccessfully if a timeout was exceeded before all pods were ready.

Usage

The container relies on command line arguments to specify the labels pods should match. These arguments are in the form of key=value,key2=value2 where commas are treated as ANDs and spaces delineate separate pods. For example,

go run ready.go role=server,proxy=envoy role=client role=client

Will wait for three pods:

1. pod with labels role=server AND proxy=envoy
2. pod with label role=client
3. another pod with label role=client

Meanwhile, users can set environment variables to override some defaults:

• $READY_TIMEOUT specifies the maximum amount of time the container should wait for pods to become ready. This time is specified in a human-readable format that is parsable by Go's time.ParseDuration. For example, "1m" represents 1 minute and "3h" represents 3 hours. If this timeout is reached before the pods are ready, the container will exit with a code of 1.

• $READY_OUTPUT_FILE specifies the absolute path of the output file. This will contain a comma-separated list of IP addresses for matching pods. This defaults to /tmp/loadtest_workers.

• $KUBE_CONFIG specifies the path to a Kubernetes config file. This can be omitted when running in a Kubernetes cluster. If running outside a cluster, this is required. It will likely be ~/.kube/config when developing locally on Linux.

Building

This image requires some utility code outside of this directory. Therefore, the test-infra/ directory should be used as the build context:

cd ../../../  # should be test-infra/
docker build -f containers/init/ready/Dockerfile .