Merge branch 'master' of code.ungleich.ch:ucloud/ucloud

network/README

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+The network base - experimental
+
+
+We want to have 1 "main" network for convience.
+
+We want to be able to create networks automatically, once a new
+customer is created -> need hooks!
+
+
+Mapping:
+
+- each network is a "virtual" network. We use vxlan by default, but
+  could be any technology!
+- we need a counter for vxlan mappings / network IDs -> cannot use
+
+Model in etcd:
+
+/v1/networks/
+
+
+Tests
+see
+https://vincent.bernat.ch/en/blog/2017-vxlan-linux
+
+
+#    local 2001:db8:1::1 \
+
+
+netid=100
+dev=wlp2s0
+dev=wlp0s20f3
+ip -6 link add vxlan${netid} type vxlan \
+    id ${netid} \
+    dstport 4789 \
+    group ff05::${netid} \
+    dev ${dev} \
+    ttl 5
+
+[root@diamond ~]# ip addr add 2a0a:e5c0:5::1/48 dev vxlan100
+root@manager:~/.ssh# ip addr add 2a0a:e5c0:5::2/48 dev vxlan100
+root@manager:~/.ssh# ping -c3 2a0a:e5c0:5::1
+PING 2a0a:e5c0:5::1(2a0a:e5c0:5::1) 56 data bytes
+64 bytes from 2a0a:e5c0:5::1: icmp_seq=1 ttl=64 time=15.6 ms
+64 bytes from 2a0a:e5c0:5::1: icmp_seq=2 ttl=64 time=30.3 ms
+64 bytes from 2a0a:e5c0:5::1: icmp_seq=3 ttl=64 time=84.4 ms
+
+--- 2a0a:e5c0:5::1 ping statistics ---
+3 packets transmitted, 3 received, 0% packet loss, time 2003ms
+rtt min/avg/max/mdev = 15.580/43.437/84.417/29.594 ms
+
+--> work even via wifi
+
+
+--------------------------------------------------------------------------------
+
+Creating a network:
+
+1) part of the initialisation / demo data (?)
+
+We should probably provide some demo sets that can easily be used.
+
+2) manual/hook based request
+
+- hosts might have different network interfaces (?)
+  -> this will make things very tricky -> don't support it
+- endpoint needs only support
+
+--------------------------------------------------------------------------------
+
+IPAM
+
+IP address management (IPAM) is related to networks, but needs to be
+decoupled to allow pure L2 networks.
+
+From a customer point of view, we probably want to do something like:
+
+- ORDERING an IPv6 network can include creating a virtual network and
+  an IPAM service
+
+Maybe "orders" should always be the first class citizen and ucloud
+internally "hooks" or binds things together.
+
+--------------------------------------------------------------------------------
+
+testing / hacking:
+
+- starting etcd as storage
+
+
+[18:07] diamond:~% etcdctl put /v1/network/200 "{ some_network }"
+OK
+[18:08] diamond:~% etcdctl watch -w=json --prefix /v1/network
+{"Header":{"cluster_id":14841639068965178418,"member_id":10276657743932975437,"revision":6,"raft_term":2},"Events":[{"kv":{"key":"L3YxL25ldHdvcmsvMjAw","create_revision":5,"mod_revision":6,"version":2,"value":"eyBzb21lX25ldHdvcmsgfQ=="}}],"CompactRevision":0,"Canceled":false,"Created":false}
+
+
+--------------------------------------------------------------------------------
+
+Flow for using and creating networks:
+
+- a network is created -> entry in etcd is created
+  -> we need to keep a counter/lock so that 2 processes don't create
+  the same network [Ahmed]
+  -> nothing to be done on the hosts
+- a VM using a network is created
+- a VM using a network is scheduled to some host
+- the local "spawn a VM" process needs to check whether there is a
+  vxlan interface existing -> if no, create it before creating the VM.
+  -> if no, also create the bridge
+  -> possibly adjusting the MTU (??)
+  -> both names should be in hexadecimal (i.e. brff01 or vxlanff01)
+  --> this way they are consistent with the multicast ipv6 address
+  --> attention, ip -6 link ... id XXX expects DECIMAL input
+
+--------------------------------------------------------------------------------
+If we also supply IPAM:
+
+- ipam needs to be created *after* the network is created
+- ipam is likely to be coupled to netbox (?)
+  --> we need a "get next /64 prefix" function
+- when an ipam service is created in etcd, we need to create a new
+  radvd instance on all routers (this will be a different service on
+  BSDs)
+- we will need to create a new vxlan device on the routers
+- we need to create a new / modify radvd.conf
+- only after all of the routers reloaded radvd the ipam service is
+  available!
+
+
+--------------------------------------------------------------------------------
+If the user requests an IPv4 VM:
+
+- we need to get the next free IPv4 address (again, netbox?)
+- we need to create a mapping entry on the routers for NAT64
+  --> this requires the VM to be in a network with IPAM
+  --> we always assume that the VM embeds itself using EUI64
+
+
+
+--------------------------------------------------------------------------------
+mac address handling!
+
+Example
+
+--------------------------------------------------------------------------------
+
+TODOs
+
+- create-vxlan-on-dev.sh -> the multicast group
+  needs to be ff05:: +int(vxlan_id)
+
+--------------------------------------------------------------------------------
+
+Python hints:
+
+>>> vxlan_id = 3400
+>>> b = ipaddress.IPv6Network("ff05::/16")
+>>> b[vxlan_id]
+IPv6Address('ff05::d48')
+
+we need / should assign hex values for vxlan ids in etcd!
+--> easier to read
+
+>>> b[0x3400]
+IPv6Address('ff05::3400')
+
+
+--------------------------------------------------------------------------------
+
+Bridge names are limited to 15 characters
+
+
+Maximum/highest number of vxlan:
+
+>>> 2**24
+16777216
+>>> (2**25)-1
+33554431
+
+>>> b[33554431]
+IPv6Address('ff05::1ff:ffff')
+
+Last interface:
+br1ffffff
+vxlan1ffffff
+
+root@manager:~/ucloud/network# ip -6 link add vxlan1ffffff type vxlan id 33554431 dstport 4789 group ff05::1ff:ffff dev wlp2s0 ttl 5
+Error: argument "33554431" is wrong: invalid id
+
+root@manager:~/ucloud/network# ip -6 link add vxlanffffff type vxlan id 16777215 dstport 4789 group ff05::ff:ffff dev wlp2s0 ttl 5
+
+
+# id needs to be decimal
+root@manager:~# ip -6 link add vxlanff01 type vxlan id ff01 dstport 4789 group ff05::ff01 dev ttl 5
+Error: argument "ff01" is wrong: invalid id
+root@manager:~# ip -6 link add vxlanff01 type vxlan id 65281 dstport 4789 group ff05::ff01 dev wlp2s0 ttl 5

network/create-vxlan-on-dev.sh

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+#!/bin/sh
+
+if [ $# -ne 2 ]; then
+    echo "$0 vxlanid dev"
+    echo "f.i. $0 100 eth0"
+    exit 1
+fi
+
+netid=$1; shift
+dev=$1; shift
+
+ip -6 link add vxlan${netid} type vxlan \
+    id ${netid} \
+    dstport 4789 \
+    group ff05::${netid} \
+    dev ${dev} \
+    ttl 5
+
+ip link set ${dev} up