merge from master at 0.7.9-90-g61eb03fe

1 files changed, 53 insertions, 0 deletions

diff --git a/cloudinit/net/renderers.py b/cloudinit/net/renderers.py
new file mode 100644
index 00000000..5117b4a5
--- /dev/null
+++ b/cloudinit/net/renderers.py
@@ -0,0 +1,53 @@
+# This file is part of cloud-init. See LICENSE file for license information.
+
+from . import eni
+from . import netplan
+from . import RendererNotFoundError
+from . import sysconfig
+
+NAME_TO_RENDERER = {
+    "eni": eni,
+    "netplan": netplan,
+    "sysconfig": sysconfig,
+}
+
+DEFAULT_PRIORITY = ["eni", "sysconfig", "netplan"]
+
+
+def search(priority=None, target=None, first=False):
+    if priority is None:
+        priority = DEFAULT_PRIORITY
+
+    available = NAME_TO_RENDERER
+
+    unknown = [i for i in priority if i not in available]
+    if unknown:
+        raise ValueError(
+            "Unknown renderers provided in priority list: %s" % unknown)
+
+    found = []
+    for name in priority:
+        render_mod = available[name]
+        if render_mod.available(target):
+            cur = (name, render_mod.Renderer)
+            if first:
+                return cur
+            found.append(cur)
+
+    return found
+
+
+def select(priority=None, target=None):
+    found = search(priority, target=target, first=True)
+    if not found:
+        if priority is None:
+            priority = DEFAULT_PRIORITY
+        tmsg = ""
+        if target and target != "/":
+            tmsg = " in target=%s" % target
+        raise RendererNotFoundError(
+            "No available network renderers found%s. Searched "
+            "through list: %s" % (tmsg, priority))
+    return found
+
+# vi: ts=4 expandtab