Query and display GCE metadata, clone from ec2metadata.py

gcemetadata.py

#!/usr/bin/python3
#
#    Query and display GCE metadata, clone from ec2metadata.py
#

from urllib import request as urllib_request

metadata_url = "http://metadata.google.internal/computeMetadata/v1/instance/"


METAOPTS = ["cpu-platform", "machine-type", "service-accounts", "tags", "zone"]


class Error(Exception):
    pass


def _get(uri, decode=True):
    url = "%s/%s" % (metadata_url, uri)

    request = urllib_request.Request(url)
    request.add_header("Metadata-Flavor", "Google")

    resp = urllib_request.urlopen(request)
    value = resp.read()

    if decode:
        value = value.decode()

    return value


def get(metaopt):
    """
    Return value of metaops
    """

    if metaopt not in METAOPTS:
        raise Error("Unknow metaopt", metaopt, METAOPTS)

    if metaopt == "service-accounts":
        return _get("service-accounts/default/email")

    if metaopt in ["machine-type", "zone"]:
        return _get(metaopt, True).split("/")[-1]

    return _get(metaopt)


def display(metaopts, prefix=True):
    """
    Display metaopts (list) values in optional prefix
    """

    for metaopt in metaopts:
        value = get(metaopt)

        if not value:
            value = "unavailable"

        if prefix:
            print("%s: %s" % (metaopt, value))
        else:
            print(value)


def main():
    display(METAOPTS)


if __name__ == "__main__":
    main()