Datasource for UpCloud (#743)

New datasource utilizing UpCloud metadata API, including relevant unit
tests and documentation.

1 files changed, 165 insertions, 0 deletions

diff --git a/cloudinit/sources/DataSourceUpCloud.py b/cloudinit/sources/DataSourceUpCloud.py
new file mode 100644
index 00000000..209b9672
--- /dev/null
+++ b/cloudinit/sources/DataSourceUpCloud.py
@@ -0,0 +1,165 @@
+# Author: Antti Myyrä <antti.myyra@upcloud.com>
+#
+# This file is part of cloud-init. See LICENSE file for license information.
+
+# UpCloud server metadata API:
+# https://developers.upcloud.com/1.3/8-servers/#metadata-service
+
+from cloudinit import log as logging
+from cloudinit import sources
+from cloudinit import util
+from cloudinit import net as cloudnet
+from cloudinit.net.dhcp import EphemeralDHCPv4, NoDHCPLeaseError
+
+
+from cloudinit.sources.helpers import upcloud as uc_helper
+
+LOG = logging.getLogger(__name__)
+
+BUILTIN_DS_CONFIG = {"metadata_url": "http://169.254.169.254/metadata/v1.json"}
+
+# Wait for a up to a minute, retrying the meta-data server
+# every 2 seconds.
+MD_RETRIES = 30
+MD_TIMEOUT = 2
+MD_WAIT_RETRY = 2
+
+
+class DataSourceUpCloud(sources.DataSource):
+
+    dsname = "UpCloud"
+
+    # We'll perform DHCP setup only in init-local, see DataSourceUpCloudLocal
+    perform_dhcp_setup = False
+
+    def __init__(self, sys_cfg, distro, paths):
+        sources.DataSource.__init__(self, sys_cfg, distro, paths)
+        self.distro = distro
+        self.metadata = dict()
+        self.ds_cfg = util.mergemanydict(
+            [
+                util.get_cfg_by_path(sys_cfg, ["datasource", "UpCloud"], {}),
+                BUILTIN_DS_CONFIG,
+            ]
+        )
+        self.metadata_address = self.ds_cfg["metadata_url"]
+        self.retries = self.ds_cfg.get("retries", MD_RETRIES)
+        self.timeout = self.ds_cfg.get("timeout", MD_TIMEOUT)
+        self.wait_retry = self.ds_cfg.get("wait_retry", MD_WAIT_RETRY)
+        self._network_config = None
+
+    def _get_sysinfo(self):
+        return uc_helper.read_sysinfo()
+
+    def _read_metadata(self):
+        return uc_helper.read_metadata(
+            self.metadata_address,
+            timeout=self.timeout,
+            sec_between=self.wait_retry,
+            retries=self.retries,
+        )
+
+    def _get_data(self):
+        (is_upcloud, server_uuid) = self._get_sysinfo()
+
+        # only proceed if we know we are on UpCloud
+        if not is_upcloud:
+            return False
+
+        LOG.info("Running on UpCloud. server_uuid=%s", server_uuid)
+
+        if self.perform_dhcp_setup:  # Setup networking in init-local stage.
+            try:
+                LOG.debug("Finding a fallback NIC")
+                nic = cloudnet.find_fallback_nic()
+                LOG.debug("Discovering metadata via DHCP interface %s", nic)
+                with EphemeralDHCPv4(nic):
+                    md = util.log_time(
+                        logfunc=LOG.debug,
+                        msg="Reading from metadata service",
+                        func=self._read_metadata,
+                    )
+            except (NoDHCPLeaseError, sources.InvalidMetaDataException) as e:
+                util.logexc(LOG, str(e))
+                return False
+        else:
+            try:
+                LOG.debug(
+                    "Discovering metadata without DHCP-configured networking"
+                )
+                md = util.log_time(
+                    logfunc=LOG.debug,
+                    msg="Reading from metadata service",
+                    func=self._read_metadata,
+                )
+            except sources.InvalidMetaDataException as e:
+                util.logexc(LOG, str(e))
+                LOG.info(
+                    "No DHCP-enabled interfaces available, "
+                    "unable to fetch metadata for %s",
+                    server_uuid,
+                )
+                return False
+
+        self.metadata_full = md
+        self.metadata["instance-id"] = md.get("instance_id", server_uuid)
+        self.metadata["local-hostname"] = md.get("hostname")
+        self.metadata["network"] = md.get("network")
+        self.metadata["public-keys"] = md.get("public_keys")
+        self.metadata["availability_zone"] = md.get("region", "default")
+        self.vendordata_raw = md.get("vendor_data", None)
+        self.userdata_raw = md.get("user_data", None)
+
+        return True
+
+    def check_instance_id(self, sys_cfg):
+        return sources.instance_id_matches_system_uuid(self.get_instance_id())
+
+    @property
+    def network_config(self):
+        """
+        Configure the networking. This needs to be done each boot,
+        since the IP and interface information might have changed
+        due to reconfiguration.
+        """
+
+        if self._network_config:
+            return self._network_config
+
+        raw_network_config = self.metadata.get("network")
+        if not raw_network_config:
+            raise Exception("Unable to get network meta-data from server....")
+
+        self._network_config = uc_helper.convert_network_config(
+            raw_network_config,
+        )
+
+        return self._network_config
+
+
+class DataSourceUpCloudLocal(DataSourceUpCloud):
+    """
+    Run in init-local using a DHCP discovery prior to metadata crawl.
+
+    In init-local, no network is available. This subclass sets up minimal
+    networking with dhclient on a viable nic so that it can talk to the
+    metadata service. If the metadata service provides network configuration
+    then render the network configuration for that instance based on metadata.
+    """
+
+    perform_dhcp_setup = True  # Get metadata network config if present
+
+
+# Used to match classes to dependencies
+datasources = [
+    (DataSourceUpCloudLocal, (sources.DEP_FILESYSTEM, )),
+    (DataSourceUpCloud, (sources.DEP_FILESYSTEM, sources.DEP_NETWORK)),
+]
+
+
+# Return a list of data sources that match this set of dependencies
+def get_datasource_list(depends):
+    return sources.list_from_depends(depends, datasources)
+
+
+# vi: ts=4 expandtab