Get a block height from a consensus hash
    Returns the block height on success
    Returns {'error': ...} on failure

def get_block_from_consensus(consensus_hash, hostport=None, proxy=None):
    """
    Get a block height from a consensus hash
    Returns the block height on success
    Returns {'error': ...} on failure
    """
    assert hostport or proxy, 'Need hostport or proxy'
    if proxy is None:
        proxy = connect_hostport(hostport)

    consensus_schema = {
        'type': 'object',
        'properties': {
            'block_id': {
                'anyOf': [
                    {
                        'type': 'integer',
                        'minimum': 0,
                    },
                    {
                        'type': 'null',
                    },
                ],
            },
        },
        'required': [
            'block_id'
        ],
    }

    schema = json_response_schema( consensus_schema )
    resp = {}
    try:
        resp = proxy.get_block_from_consensus(consensus_hash)
        resp = json_validate( schema, resp )
        if json_is_error(resp):
            log.error("Failed to find block ID for %s" % consensus_hash)
            return resp

    except ValidationError as ve:
        if BLOCKSTACK_DEBUG:
            log.exception(ve)

        resp = {'error': 'Server response did not match expected schema.  You are likely communicating with an out-of-date Blockstack node.', 'http_status': 502}
        return resp
    
    except socket.timeout:
        log.error("Connection timed out")
        resp = {'error': 'Connection to remote host timed out.', 'http_status': 503}
        return resp

    except socket.error as se:
        log.error("Connection error {}".format(se.errno))
        resp = {'error': 'Connection to remote host failed.', 'http_status': 502}
        return resp

    except Exception as ee:
        if BLOCKSTACK_DEBUG:
            log.exception(ee)

        log.error("Caught exception while connecting to Blockstack node: {}".format(ee))
        resp = {'error': 'Failed to contact Blockstack node.  Try again with `--debug`.', 'http_status': 500}
        return resp

    return resp['block_id']