I have a requirement in composer to poll a task till it finds a zip file in a bucket and run the subsequent tasks after the condition is met
The best i could get is GoogleCloudStoragePrefixSensor. But this is with prefix and doesn't work for this requirement.
If you wish to poll, then consider periodically (on a schedule) listing the files in the bucket and seeing which ones end with ".zip". Alternatively, if you are willing to only accept new files that arrive, consider setting up a notification via PubSub such that when a new file arrives in the bucket, a function is executed which checks the file name.