Add Cloud Controller Manager

2026-07-19 04:49:19 +00:00 · 2019-04-10 03:15:33 -05:00
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+# The Cloud Controller Manager
+
+- Kubernetes has many features that are cloud-specific
+
+  (e.g. providing cloud load balancers when a Service of type LoadBalancer is created)
+
+- These features were initially implemented in API server and controller manager
+
+- Since Kubernetes 1.6, these features are available through a separated process:
+
+  the *Cloud Controller Manager*
+
+- The CCM is optional, but if we run in a cloud, we probably want it!
+
+---
+
+## Cloud Controller Manager duties
+
+- Creating and updating cloud load balancers
+
+- Configuring routing tables in the cloud network (specific to GCE)
+
+- Updating node labels to indicate region, zone, instance type ...
+
+- Obtain node name, internal and external addresses from cloud metadata service
+
+- Deleting nodes from Kubernetes when they're deleted in the cloud
+
+- Managing *some* volumes (e.g. ELBs, AzureDisks ...)
+
+  (Eventually, volumes will be managed by the CSI)
+
+---
+
+## In-tree vs. out-of-tree
+
+- A number of cloud providers are supported "in-tree"
+
+  (in the main kubernetes/kubernetes repository on GitHub)
+
+- More cloud providers are supported "out-of-tree"
+
+  (with code in different repositories)
+
+- There is an [ongoing effort](https://github.com/kubernetes/kubernetes/tree/master/pkg/cloudprovider) to move everything to out-of-tree providers
+
+---
+
+## In-tree providers
+
+The following providers are actively maintained:
+
+- Amazon Web Services
+- Azure
+- Google Compute Engine
+- IBM Cloud
+- OpenStack
+- VMware vSphere
+
+These ones are less actively maintained:
+
+- Apache CloudStack
+- oVirt
+- VMware Photon
+
+---
+
+## Out-of-tree providers
+
+The list includes the following providers:
+
+- DigitalOcean
+
+- keepalived (not exactly a cloud; provides VIPs for load balancers)
+
+- Linode
+
+- Oracle Cloud Infrastructure
+
+(And possibly others; there is no central registry for these.)
+
+---
+
+## Audience questions
+
+- What kind of clouds are you using / planning to use?
+
+- What kind of details would you like to see in this section?
+
+- Would you appreciate to get details on clouds that you don't / won't use?
+
+---
+
+## Cloud Controller Manager in practice
+
+- Write a configuration file
+
+  (typically `/etc/kubernetes/cloud.conf`)
+
+- Run the CCM process
+
+  (on self-hosted clusters, this can be a DaemonSet selecting the control plane nodes)
+
+- Start kubelet with `--cloud-provider=external`
+
+- When using managed clusters, this is done automatically
+
+- There is very little documentation to write the configuration file
+
+  (except for OpenStack)
+
+---
+
+## Bootstrapping challenges
+
+- When a node joins the cluster, it needs to obtain a signed TLS certificate
+
+- That certificate must contain the node's addresses
+
+- These addresses are provided by the Cloud Controller Manager
+
+  (at least the external address)
+
+- To get these addresses, the node needs to communicate with the control plane
+
+- ... Which means joining the cluster
+
+(The problem didn't occur when cloud-specific code was running in kubelet: kubelet could obtain the required information directly from the cloud provider's metadata service.)
+
+---
+
+## More information about CCM
+
+- CCM configuration and operation is highly specific to each cloud provider
+
+  (which is why this section remains very generic)
+
+- The Kubernetes documentation has *some* information:
+
+  - [architecture and diagrams](https://kubernetes.io/docs/concepts/architecture/cloud-controller/)
+
+  - [configuration](https://kubernetes.io/docs/concepts/cluster-administration/cloud-providers/) (mainly for OpenStack)
+
+  - [deployment](https://kubernetes.io/docs/tasks/administer-cluster/running-cloud-controller/)