Add Hetzner Cloud DataSource

The Hetzner Cloud metadata service is an AWS-style service available
over HTTP via the link local address 169.254.169.254.

https://hetzner.com/cloud
https://docs.hetzner.cloud/

2 files changed, 126 insertions, 0 deletions

diff --git a/cloudinit/sources/DataSourceHetzner.py b/cloudinit/sources/DataSourceHetzner.py
new file mode 100644
index 00000000..769fe131
--- /dev/null
+++ b/cloudinit/sources/DataSourceHetzner.py
@@ -0,0 +1,100 @@
+# Author: Jonas Keidel <jonas.keidel@hetzner.com>
+# Author: Markus Schade <markus.schade@hetzner.com>
+#
+# This file is part of cloud-init. See LICENSE file for license information.
+#
+"""Hetzner Cloud API Documentation.
+   https://docs.hetzner.cloud/"""
+
+from cloudinit import log as logging
+from cloudinit import net as cloudnet
+from cloudinit import sources
+from cloudinit import util
+
+import cloudinit.sources.helpers.hetzner as hc_helper
+
+LOG = logging.getLogger(__name__)
+
+BASE_URL_V1 = 'http://169.254.169.254/hetzner/v1'
+
+BUILTIN_DS_CONFIG = {
+    'metadata_url': BASE_URL_V1 + '/metadata',
+    'userdata_url': BASE_URL_V1 + '/userdata',
+}
+
+MD_RETRIES = 60
+MD_TIMEOUT = 2
+MD_WAIT_RETRY = 2
+
+
+class DataSourceHetzner(sources.DataSource):
+    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", "Hetzner"], {}),
+            BUILTIN_DS_CONFIG])
+        self.metadata_address = self.ds_cfg['metadata_url']
+        self.userdata_address = self.ds_cfg['userdata_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
+        self.dsmode = sources.DSMODE_NETWORK
+
+    def get_data(self):
+        nic = cloudnet.find_fallback_nic()
+        with cloudnet.EphemeralIPv4Network(nic, "169.254.0.1", 16,
+                                           "169.254.255.255"):
+            md = hc_helper.read_metadata(
+                self.metadata_address, timeout=self.timeout,
+                sec_between=self.wait_retry, retries=self.retries)
+            ud = hc_helper.read_userdata(
+                self.userdata_address, timeout=self.timeout,
+                sec_between=self.wait_retry, retries=self.retries)
+
+        self.userdata_raw = ud
+        self.metadata_full = md
+
+        """hostname is name provided by user at launch.  The API enforces
+        it is a valid hostname, but it is not guaranteed to be resolvable
+        in dns or fully qualified."""
+        self.metadata['instance-id'] = md['instance-id']
+        self.metadata['local-hostname'] = md['hostname']
+        self.metadata['network-config'] = md.get('network-config', None)
+        self.metadata['public-keys'] = md.get('public-keys', None)
+        self.vendordata_raw = md.get("vendor_data", None)
+
+        return True
+
+    @property
+    def network_config(self):
+        """Configure the networking. This needs to be done each boot, since
+           the IP information may have changed due to snapshot and/or
+           migration.
+        """
+
+        if self._network_config:
+            return self._network_config
+
+        _net_config = self.metadata['network-config']
+        if not _net_config:
+            raise Exception("Unable to get meta-data from server....")
+
+        self._network_config = _net_config
+
+        return self._network_config
+
+
+# Used to match classes to dependencies
+datasources = [
+    (DataSourceHetzner, (sources.DEP_FILESYSTEM, )),
+]
+
+
+# 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
diff --git a/cloudinit/sources/helpers/hetzner.py b/cloudinit/sources/helpers/hetzner.py
new file mode 100644
index 00000000..2554530d
--- /dev/null
+++ b/cloudinit/sources/helpers/hetzner.py
@@ -0,0 +1,26 @@
+# Author: Jonas Keidel <jonas.keidel@hetzner.com>
+# Author: Markus Schade <markus.schade@hetzner.com>
+#
+# This file is part of cloud-init. See LICENSE file for license information.
+
+from cloudinit import log as logging
+from cloudinit import url_helper
+from cloudinit import util
+
+LOG = logging.getLogger(__name__)
+
+
+def read_metadata(url, timeout=2, sec_between=2, retries=30):
+    response = url_helper.readurl(url, timeout=timeout,
+                                  sec_between=sec_between, retries=retries)
+    if not response.ok():
+        raise RuntimeError("unable to read metadata at %s" % url)
+    return util.load_yaml(response.contents.decode())
+
+
+def read_userdata(url, timeout=2, sec_between=2, retries=30):
+    response = url_helper.readurl(url, timeout=timeout,
+                                  sec_between=sec_between, retries=retries)
+    if not response.ok():
+        raise RuntimeError("unable to read userdata at %s" % url)
+    return response.contents