From 2d25bcdf1b1bf9a26492e4454ab10ccfc3437f8c Mon Sep 17 00:00:00 2001
From: Apollon Oikonomopoulos <apollon@noc.grnet.gr>
Date: Mon, 18 Apr 2011 18:43:26 +0300
Subject: [PATCH] Network management design doc
Signed-off-by: Apollon Oikonomopoulos <apollon@noc.grnet.gr>
---
doc/design-network.rst | 90 ++++++++++++++++++++++++++++++++++++++++++
doc/index.rst | 1 +
2 files changed, 91 insertions(+)
create mode 100644 doc/design-network.rst
diff --git a/doc/design-network.rst b/doc/design-network.rst
new file mode 100644
index 000000000..d31d8d559
--- /dev/null
+++ b/doc/design-network.rst
@@ -0,0 +1,90 @@
+Network management
+==================
+::
+
+ gnt-network add --network=192.0.2.0/24 --gateway=192.0.2.1 \
+ --v6-network=2001:648:2ffc::/64 --v6-gateway=2001:648:2ffc::1 \
+ public
+
+ gnt-network reserve-ips public 192.0.2.2 192.0.2.10-192.0.2.20
+
+ gnt-network connect public nodegroup1 link100
+ gnt-network connect public nodegroup2 link200
+ gnt-network disconnect public nodegroup1 (only permitted if no instances are
+ currently using this network in the group)
+
+ gnt-network list
+ Name IPv4 Network IPv4 Gateway IPv6 Network IPv6Gateway
+ public 192.0.2.0/24 192.0.2.1 2001:db8:dead:beef::/64 2001:db8:dead:beef::1
+ private 10.0.1.0/24 - - -
+
+ gnt-network list-connected
+ Network Node Group Link
+ public nodegroup1 link100
+ public nodegroup2 link200
+ private nodegroup1 link50
+
+ gnt-network list-connected private
+ Network Node Group Link
+ private nodegroup1 link50
+
+ gnt-network info public
+ Name: public
+ IPv4 Network: 192.0.2.0/24
+ IPv4 Gateway: 192.0.2.1
+ IPv6 Network: 2001:db8:dead:beef::/64
+ IPv6 Gateway: 2001:db8:dead:beef::1
+ Connected to: nodegroup1 (link100), nodegroup2 (link200)
+ Total IPv4 count: 256
+ Free address count: 201 (80% free)
+ IPv4 pool status: XXX.........XXXXXXXXXXXXXX...XX.............
+ XXX..........XXX...........................X
+ ....XXX..........XXX.....................XXX
+ X: occupied .: free
+ Used by 22 instances:
+ inst1
+ inst2
+ inst32
+ ..
+
+NIC "network" parameter
+-----------------------
+
+1. "network" takes precedence over "link"
+
+2. manually setting "link" on a nic with existing "network" is not permitted
+
+3. as a safety guard, setting a "network" parameter on a nic with a "link" is only
+ permitted if the network's link on the instance's node group is the same as
+ the current nic's link
+
+4. "link" is updated on startup according to the network -> nodegroup mapping
+
+Default nic "network" parameter
+add default "network" argument? How do we deal with transitions?
+-> network and link may not be set at the same time
+-> setting network will unset link and vice-versa
+-> setting network is only permitted iff:
+
+ all NICs with a "default" link would result in having the same link right after setting "network".
+ i.e.: for instance in all_instances:
+ for nic in instance.nics:
+ if nic.link == instance.primary_node.group.networks[network]:
+ ...
+ else:
+ raise errors.OpPrereqError
+
+IAllocator changes
+------------------
+
+ - Make it network-aware, same as storage-aware
+ - Both, network and storage will act as *constraints*, i.e. "place me a node
+ that has access to network x and storage pool y on the cluster". The
+ iallocator will thus rule out node groups based on these constraints.
+
+
+Helper methods in lib/config.py
+-------------------------------
+
+ - ConfigWriter.GetInstancesByNodeGroup(group_uuid)
+ - ConfigWriter.GetInstancesInfoByNodeGroup(group_uuid)
diff --git a/doc/index.rst b/doc/index.rst
index c196ff746..a544522f0 100644
--- a/doc/index.rst
+++ b/doc/index.rst
@@ -22,6 +22,7 @@ Contents:
design-2.4.rst
cluster-merge.rst
design-shared-storage.rst
+ design-network.rst
locking.rst
hooks.rst
iallocator.rst
--
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