Cloud Pak for Data

I have installed ICP4D on and ICP base - and then migrated the whole thing to a new set of machines, with different hostnames and IP addresses.  Maybe that's not supported, but it's part of our IBM virtual machine infrastructure.

So, naturally, nothing works.  I would like to know where the hostnames/IPs are stored in the ICP or ICP4D configuration. I assume (perhaps wrongly) that at startup, the master node needs to read a config file with all of the IP addresses for all of the cluster members.  Is that a crazy idea?

Is there such a file?

Or do I need to try to issue Docker commands to update all of the existing node configurations.

Or maybe I need to purge all nodes?

I just think there must be a solution for customers who move their clusters. Basically I have to update 8 IP addresses.  How hard can that be?

------------------------------
Kameron Cole
------------------------------

#CloudPakforDataGroup

Hi,

It's actually quite complicated, as the security certificates are generated using hostnames/IPs and currently ICP does not support IP/hostname changes:

https://www.ibm.com/support/knowledgecenter/en/SSBS6K_3.2.0/installing/change_node.html

Thanks

------------------------------
TOMASZ HANUSIAK
------------------------------

Original Message:
Sent: Fri September 13, 2019 01:55 PM
From: Kameron Cole
Subject: where are the IP addresses configured?

I have installed ICP4D on and ICP base - and then migrated the whole thing to a new set of machines, with different hostnames and IP addresses.  Maybe that's not supported, but it's part of our IBM virtual machine infrastructure.

So, naturally, nothing works.  I would like to know where the hostnames/IPs are stored in the ICP or ICP4D configuration. I assume (perhaps wrongly) that at startup, the master node needs to read a config file with all of the IP addresses for all of the cluster members.  Is that a crazy idea?

Is there such a file?

Or do I need to try to issue Docker commands to update all of the existing node configurations.

Or maybe I need to purge all nodes?

I just think there must be a solution for customers who move their clusters. Basically I have to update 8 IP addresses.  How hard can that be?

------------------------------
Kameron Cole
------------------------------

#CloudPakforDataGroup

Kameron - please see this: https://www.ibm.com/support/knowledgecenter/SSBS6K_3.1.1/installing/change_node.html

------------------------------
IMRAN HOSSAIN
------------------------------

Original Message:
Sent: Fri September 13, 2019 01:55 PM
From: Kameron Cole
Subject: where are the IP addresses configured?

I have installed ICP4D on and ICP base - and then migrated the whole thing to a new set of machines, with different hostnames and IP addresses.  Maybe that's not supported, but it's part of our IBM virtual machine infrastructure.

So, naturally, nothing works.  I would like to know where the hostnames/IPs are stored in the ICP or ICP4D configuration. I assume (perhaps wrongly) that at startup, the master node needs to read a config file with all of the IP addresses for all of the cluster members.  Is that a crazy idea?

Is there such a file?

Or do I need to try to issue Docker commands to update all of the existing node configurations.

Or maybe I need to purge all nodes?

I just think there must be a solution for customers who move their clusters. Basically I have to update 8 IP addresses.  How hard can that be?

------------------------------
Kameron Cole
------------------------------

#CloudPakforDataGroup

Since we are talking about IP addresses, then I have a client that sees calls made to IP addresses as part of the setup? Is there a list of calls/IPS that Cloudpak for data calls out?

------------------------------
paul YOUNG
------------------------------

Original Message:
Sent: Mon September 16, 2019 03:42 AM
From: IMRAN HOSSAIN
Subject: where are the IP addresses configured?

Kameron - please see this: https://www.ibm.com/support/knowledgecenter/SSBS6K_3.1.1/installing/change_node.html

------------------------------
IMRAN HOSSAIN

Original Message:
Sent: Fri September 13, 2019 01:55 PM
From: Kameron Cole
Subject: where are the IP addresses configured?

I have installed ICP4D on and ICP base - and then migrated the whole thing to a new set of machines, with different hostnames and IP addresses.  Maybe that's not supported, but it's part of our IBM virtual machine infrastructure.

So, naturally, nothing works.  I would like to know where the hostnames/IPs are stored in the ICP or ICP4D configuration. I assume (perhaps wrongly) that at startup, the master node needs to read a config file with all of the IP addresses for all of the cluster members.  Is that a crazy idea?

Is there such a file?

Or do I need to try to issue Docker commands to update all of the existing node configurations.

Or maybe I need to purge all nodes?

I just think there must be a solution for customers who move their clusters. Basically I have to update 8 IP addresses.  How hard can that be?

------------------------------
Kameron Cole
------------------------------

#CloudPakforDataGroup

Thanks for everyone for the replies.

The documentation is a little unclear.  First this statement is very clear:

"You cannot change the IP address or host name of a node after your IBM® Cloud Private cluster is installed."

Can't get clearer than that. But then the next statement seems to contradict the first:

"However, you can complete the following steps to change the IP address or host name of a node in your cluster"

From a linguist's perspective, these two statements are contradictory.  The section "change the IP address or host name of a node" is identical in both statements.

Happens a lot in documentation.  I think it means that you can't change the IP "on the fly" - instead, you have to remove the node, change the IP, and then add the node back. So, the first statement is not correct - you CAN indeed change the IP address of nodes in the cluster, by removing and the re-adding.

This becomes evident (after the document writers thought about it) in the last statement:

"You cannot remove and add back a master node after your IBM® Cloud Private cluster is installed. Therefore, you cannot change the IP address or host name of a master node that is part of an installed cluster. "

Since you can't remove/re-add the master node, you really, REALLY, can't change this IP.

Thanks again!  This answers a very important question for me, and for my customers.

But now I don't understand the concept of moving a cluster from one cloud to another.  I suppose this implies that the machines in your new cloud infrastructure must have the same IPs.

------------------------------
Kameron Cole
------------------------------

Original Message:
Sent: Fri September 13, 2019 01:55 PM
From: Kameron Cole
Subject: where are the IP addresses configured?

I have installed ICP4D on and ICP base - and then migrated the whole thing to a new set of machines, with different hostnames and IP addresses.  Maybe that's not supported, but it's part of our IBM virtual machine infrastructure.

So, naturally, nothing works.  I would like to know where the hostnames/IPs are stored in the ICP or ICP4D configuration. I assume (perhaps wrongly) that at startup, the master node needs to read a config file with all of the IP addresses for all of the cluster members.  Is that a crazy idea?

Is there such a file?

Or do I need to try to issue Docker commands to update all of the existing node configurations.

Or maybe I need to purge all nodes?

I just think there must be a solution for customers who move their clusters. Basically I have to update 8 IP addresses.  How hard can that be?

------------------------------
Kameron Cole
------------------------------

#CloudPakforDataGroup

Hi,

Yes, there is some contradiction in this text, and I have raised that to the documentation team.
Talking about moving between clouds, we are really looking at using the OpenShift platform, which at this point doesn't  support changing IPs, however they provide a mechanism for re-setting up a node:
https://access.redhat.com/solutions/3373671

OpenShift currently doesn't support IP address nor hostname change.

The technical reason behind this is, OpenShift uses TLS for internal communications and TLS certs have IP address and hostname at the setup time. Most TLS communications use hostname, so hostname change breaks these TLS communication. OpenShift setup dnsmasq with node IP address and needs to redirect DNS traffic to that node IP address. IP address change breaks DNS configuration.

To sum up:

• TLS needs static hostname (and static IP address in some cases)
• DNS needs static IP address

We recommend to use static IP address and hostname for OpenShift.
If we need to change IP address and/or hostname, re-setup it as a new node.

https://docs.openshift.com/container-platform/3.7/install_config/adding_hosts_to_existing_cluster.html

I will update you when I find the definite/clear answers.

Thanks

------------------------------
TOMASZ HANUSIAK
------------------------------

Original Message:
Sent: Mon September 16, 2019 10:11 AM
From: Kameron Cole
Subject: where are the IP addresses configured?

Thanks for everyone for the replies.

The documentation is a little unclear.  First this statement is very clear:

"You cannot change the IP address or host name of a node after your IBM® Cloud Private cluster is installed."

Can't get clearer than that. But then the next statement seems to contradict the first:

"However, you can complete the following steps to change the IP address or host name of a node in your cluster"

From a linguist's perspective, these two statements are contradictory.  The section "change the IP address or host name of a node" is identical in both statements.

Happens a lot in documentation.  I think it means that you can't change the IP "on the fly" - instead, you have to remove the node, change the IP, and then add the node back. So, the first statement is not correct - you CAN indeed change the IP address of nodes in the cluster, by removing and the re-adding.

This becomes evident (after the document writers thought about it) in the last statement:

"You cannot remove and add back a master node after your IBM® Cloud Private cluster is installed. Therefore, you cannot change the IP address or host name of a master node that is part of an installed cluster. "

Since you can't remove/re-add the master node, you really, REALLY, can't change this IP.

Thanks again!  This answers a very important question for me, and for my customers.

But now I don't understand the concept of moving a cluster from one cloud to another.  I suppose this implies that the machines in your new cloud infrastructure must have the same IPs.

------------------------------
Kameron Cole

Original Message:
Sent: Fri September 13, 2019 01:55 PM
From: Kameron Cole
Subject: where are the IP addresses configured?

I have installed ICP4D on and ICP base - and then migrated the whole thing to a new set of machines, with different hostnames and IP addresses.  Maybe that's not supported, but it's part of our IBM virtual machine infrastructure.

So, naturally, nothing works.  I would like to know where the hostnames/IPs are stored in the ICP or ICP4D configuration. I assume (perhaps wrongly) that at startup, the master node needs to read a config file with all of the IP addresses for all of the cluster members.  Is that a crazy idea?

Is there such a file?

Or do I need to try to issue Docker commands to update all of the existing node configurations.

Or maybe I need to purge all nodes?

I just think there must be a solution for customers who move their clusters. Basically I have to update 8 IP addresses.  How hard can that be?

------------------------------
Kameron Cole
------------------------------

#CloudPakforDataGroup