Thanks for clarifying. It was this cross-cloud case I was considering.
What is the benefit of the "management-private-<cloud id>" group? It
seems superfluous to me if "management-private-ingress-<cloud id>" will
contain the public IPs of the members of the cluster.
On 15/02/2017 14:16, Svetoslav Neykov wrote:
My response below was based on my thinking about in-cloud access between
Brooklyn and the managed machines.
When the access is cross-cloud we indeed need _c_ security groups. Each one
containing _n_ records with the public IPs of the HA cluster members. These can
be managed by Brooklyn though.
To summarise (and get my thinking straight). In each cloud/availability zone we
could have:
1. "management-private-<cloud id>" SG assigned on the HA cluster member
machines. No records in the SG.
2. "management-private-ingress-<cloud id>" SG with first record allowing all traffic from
"management-private-<cloud id>" (above group) and _n_ more records allowing all traffic coming
from the public IPs of the HA member nodes. This one is assigned to all managed entities.
On adding a new member to the cluster:
1. Assign "management-private-<cloud id>" to the new machine - this is the
only action that needs to be done by the manager of the cluster
2. Go to each cloud and update the "management-private-ingress-<cloud id>"
group, adding the new public IP.
Svet.
On 15.02.2017 г., at 15:40, Svetoslav Neykov
<svetoslav.ney...@cloudsoftcorp.com> wrote:
You propose that the manager of the Brooklyn HA cluster maintain at least _c_
security groups (one per security group scope - e.g. AWS EC2 region - per
cloud).
Not quite. It's the number of "clouds HA cluster is deployed to". That's the
number of availability zones - usually a low number 1-2-3.
Each of these groups has _n_ records. When the HA cluster is resized each group
is modified to add or remove a record as appropriate.
No, they are empty. Adding a new cluster member is just assigning the SG to the
new machine. Then for each managed entity there's a record in its security
group to allow traffic from the HA security group.
For clouds where there are no running HA cluster members Brooklyn will
auto-create the security group and add it to entities' security groups but it
will be unused.
The manager of the HA cluster can wait for Brooklyn to create the "management"
SG (which will contain the cluster ID in its name which is not known in advance) and then
assign it to the HA cluster members or create one with a predefined name and configure
the name in each HA instance.
Svet.
On 15.02.2017 г., at 14:59, Sam Corbett <sam.corb...@cloudsoftcorp.com> wrote:
Interesting problem Svet. Your proposal is a neat way of sidestepping the
problem of updating many security groups as the set of HA nodes changes.
Let me rephrase it to see if I understand correctly.
Suppose we have:
* _n_ Brooklyn servers in an HA cluster (that could be across many clouds /
regions within a cloud)
* _c_ clouds that Brooklyn can deploy to
* _m_ instances across those clouds.
We want to avoid the n+1th Brooklyn node requiring _m_ security group updates.
You propose that the manager of the Brooklyn HA cluster maintain at least _c_
security groups (one per security group scope - e.g. AWS EC2 region - per
cloud). Each of these groups has _n_ records. When the HA cluster is resized
each group is modified to add or remove a record as appropriate.
Do I have this correct?
Sam
On 14/02/2017 15:42, Svetoslav Neykov wrote:
I'm trying to restrict access to the machines managed by Brooklyn using security groups -
tightening jclouds' default behaviour of opening the "inboundPorts" to any
source.
Brooklyn obviously needs to have access to all managed machines. This means it
needs to figure out the address it uses to access each machine and white list
it in the machine's security group.
This is kind of related to the email thread "[PROPOSAL] Separate management
addresses from the concept of an entity's public address" [1], but in reverse.
Instead of figuring out which machine IP to use I need to do the reverse - which Brooklyn
node IP will access the machine.
It becomes more complicated when HA is introduced into the mix. Any node that
becomes a master needs to be able to access the machines. This means the
security groups need to be updated in such cases.
Two questions follow:
1. How to determine which IP faces managed machines? There's no one fixed
answer here. Depending on the target cloud and location configuration it varies.
2. How to keep the list of IPs from above point in sync, for each of the
members of the HA cluster?
Don't think we can actually answer q1. That's why the solution I'm thinking of
is:
* Always open the external IP to the machines. The external IP is as reported by
"LocalhostExternalIpLoader".
* Assign a predefined SG to all machines in the HA cluster - manually/out of band, since the
machines are not managed by Brooklyn. Let Brooklyn know the SG name, defaulting to
"management-<cluster-id>". White list the SG as a source for all managed
machines. This will allow Brooklyn to access managed machines on both the public and private
IPs. It moves the responsibility of assigning the SG to new HA member machines to whoever is
managing the Brooklyn cluster. We could then update the management SG with **all** private IPs
in the HA cluster (need to advertise them in the meta data) or leave it again to the manager of
the cluster.
Would be really cool to have HA clusters manage/heal themselves.
Tangentially related - [2] which IP do we use for the "url" field int he HA
member nodes metadata in REST API (currently empty for the Karaf dist). If it's always
the public IP then it doesn't work for private/VPN instances. It is important for this
to be the right one because:
* Users are redirected to the master node
* Automated systems need to know which is the current master. On failover the
old master (if still around) will redirect to the new master. Workaround is to
keep a local copy of the HA members and iterate over them until it hits MASTER
- but it's still important that the URLs are accessible.
Svet
[1]
https://lists.apache.org/list.html?dev@brooklyn.apache.org:lte=1y:%5BPROPOSAL%5D%20Separate%20management%20addresses%20from%20the%20concept%20of%20an%20entity%27s%20public%20address
[2] https://issues.apache.org/jira/browse/BROOKLYN-436
