Description of problem: By default, dnsIP is 0.0.0.0 and the --cluster-dns flag is set to that of the host by looking for the first up, non-loopback interface and getting the first IPv4 address from it. When OCP was installed in mutiple NICs environment, '--cluster-dns' can be configured as a unwanted IP address. We can set '--clsuter-dns' value by setting dnsIP in /etc/origing/node/node-config.yaml. But we cannot use dnsIP from ocp 3.10, because if I configure dnsIP in config map then the IP was set to all nodes. Version-Release number of selected component (if applicable): How reproducible: Steps to Reproduce: 1. 2. 3. Actual results: Expected results: Want to set '--cluster-dns' to the specific IP address. Additional info:
Hello, I explain the issue more details. When openshift was installed in mutiple NICs environment, I set one NIC which used by openshift as the default GW in the node host. Because the nameserver IP in "/etc/resolv.conf" of node host will be configured with default GW NIC's IP address by "99-origin-dns.sh" script. I could see correct nameserver IP in "/etc/resolv.conf" of node host. But nameserver IP in "/etc/resolv.conf" of POD was different with that in "/etc/resolv.conf" of node host. dnsIP : Configures an IP address to be prepended to a pod’s /etc/resolv.conf by adding the address here. "dnsIP" is 0.0.0.0 by default. I could see nodeConfig.DNSIP was set from nodeConfig.NodeIP. [1] If nodeIP was not set, dnsIP can be set to that of the host by looking for the first up, non-loopback interface and getting the first IPv4 address from it. BTW from ocp 3.10, node configuration is controlled via a set of configmaps maintained in the openshift-node namespace. Since node configuration is managed on a per-node group basis, it is now no longer possible to specify many configuration variables that may have varied on a per host basis, such as openshift_node_ip, openshift_dns_ip, etc. So dnsIP can be random IP in multiple NICs environment. As a workaround, I could create a node group for each node host and set node_ip in that node group something like, {'name': 'node-config-node1', 'labels': ['...,...']}, 'edits': [{ 'key': 'kubeletArguments.node-ip','value': ['x.x.x.x']}]} But my customer hopes that dnsIP can be set same with nameserver IP in "/etc/resolv.conf" of node host. Thanks, [1] https://github.com/openshift/origin/pull/19734/files#diff-3f3631b751f92dbca795eba99e445c4fR33