@dduvall raised the concern that the one off instances would lack caching. Currently for pip/npm/bundle we point the caches to the `jenkins-bot` and it is being reused by builds. With Nodepool, there is no cache which would force us to download from the package managers.
Some ideas:
* a shared NFS directory, but the cache can easily be poisoned, corrupted.
* observes dependencies being used, collect them and build a cache daily. Share it via a read-only NFS dir. A couple problems: that needs work to collect the deps, package managers would attempt to write to the read-only cache dir whenever there is a dep which is not fulfilled.
* Use a proxy. Beside setting up the proxy itself, the jobs would need `http_proxy` / `https_proxy` to be set. The compiled packages would most likely not be cached though :-/