OpenShift Runtime
Internal
Diagram
Master Node
The master node runs, in order, these services:
The master daemon (or daemons) must be started after etcd is started, they depend on etcd. They are started before the node service.
etcd Daemon
Unit: etcd.service
Unit File: /usr/lib/systemd/system/etcd.service
Working Directory: /var/lib/etcd
Configuration File: /etc/etcd/etcd.conf
Process:
/usr/bin/etcd --name=master1.rdu20.internal --data-dir=/var/lib/etcd --listen-client-urls=https://192.199.0.199:2379
master Daemons
Non-HA Deployment
In a non-HA deployment, the master api daemon and master controller daemon are coalesced in a single process. In HA environments, they are separated, so the master api daemon processes can be load-balanced among, while the master controller daemon run in an active/passive configuration, there is just one active master controller daemon instance in the cluster.
Depends On: "etcd.service" (etcd)
Unit: atomic-openshift-master.service
Unit File: /usr/lib/systemd/system/atomic-openshift-master.service
Working Directory: /var/lib/origin
Configuration Files:
- /etc/sysconfig/atomic-openshift-master, which contains command line options for the process, such as --loglevel, etc.
- /etc/origin/master/master-config.yaml
Process:
HA Deployment
master api Daemon
Depends On: "etcd.service" (etcd)
Unit: atomic-openshift-master-api.service
systemctl status atomic-openshift-master-api
Unit File: /usr/lib/systemd/system/atomic-openshift-master-api.service
Working Directory: /var/lib/origin
Configuration Files:
- /etc/sysconfig/atomic-openshift-master-api, which contains command line options for the process, such as --loglevel, etc.
- /etc/origin/master/master-config.yaml
Process:
/usr/bin/openshift start master api --config=/etc/origin/master/master-config.yaml --loglevel=2 --listen=https://0.0.0.0:443 --master=https://master1.rdu20.internal
master controller Daemon
Depends On: "etcd.service" (etcd), "atomic-openshift-master-api.service" (master api daemon)
Unit: atomic-openshift-master-controllers.service
systemctl status atomic-openshift-master-controllers
Unit File: /usr/lib/systemd/system/atomic-openshift-master-controllers.service
Working Directory: /var/lib/origin
Configuration Files:
- /etc/sysconfig/atomic-openshift-master-controllers, which contains command line options for the process, such as --loglevel, etc.
- /etc/origin/master/master-config.yaml
Process:
/usr/bin/openshift start master controllers --config=/etc/origin/master/master-config.yaml --loglevel=2 --listen=https://0.0.0.0:8444
node Daemon
See below
Regular Node
node Daemon
Depends On: "docker.service", "openvswitch.service"
Unit: atomic-openshift-node.service
systemctl status atomic-openshift-node
Unit File: /usr/lib/systemd/system/atomic-openshift-node.service
Working Directory: /var/lib/origin
Configuration Files:
- /etc/sysconfig/atomic-openshift-node, which contains command line options for the process, such as --loglevel, etc.
- /etc/origin/node/node-config.yaml
Process:
/usr/bin/openshift start node --config=/etc/origin/node/node-config.yaml --loglevel=2