yandex-cloud-controller-manager

README

Kubernetes Cloud Controller Manager for Yandex.Cloud

Overview

yandex-cloud-controller-manager is the Kubernetes Cloud Controller Manager (CCM) implementation for Yandex.Cloud. It allows you to leverage many of the cloud provider features offered by Yandex.Cloud on your Kubernetes clusters. Read more about Kubernetes CCM here.

Currently yandex-cloud-controller-manager implements:

• NodeController - responsible for updating kubernetes nodes with cloud provider specific labels and addresses and deleting kubernetes nodes that were deleted on your cloud.
• ServiceController - responsible for creating LoadBalancers when a service of Type: LoadBalancer is created in Kubernetes.
• RouteController - responsible for creating routes to allow networking between Pods.

Work In Progress

This project is currently under active development. Use at your own risk! Contributions welcome!

Getting Started

Requirements

At the current state of Kubernetes, running Cloud Controller Manager (CCM) requires a few things. Please read through the requirements carefully as they are critical to running CCM on a Kubernetes cluster on Yandex.Cloud.

Version

Kubernetes 1.16+

Cloud resources

• All Kubernetes nodes MUST be located in the same Folder. For more details about folders - refer to official documentation
• Kubernetes node names MUST match the VM name. By default, the kubelet will name nodes based on the node hostname. On Yandex.Cloud, node hostname is set based on the VM name. So, it is important that the node name on Kubernetes matches corresponding VM name, otherwise CCM will not be able to find corresponding cloud resources.

Cluster configuration

• kubelet MUST run with --cloud-provider=external. This is to ensure that the kubelet is aware that it must be initialized by the CCM before it is scheduled any work.
• kube-apiserver and kube-controller-manager MUST NOT set the flag --cloud-provider which will default them to use no cloud provider natively.

WARNING: setting --cloud-provider=external will taint all nodes in a cluster with node.cloudprovider.kubernetes.io/uninitialized. It is the responsibility of CCM to untaint those nodes once it has finished initializing them. This means that most pods will be left unschedulable until the CCM is running.

Deployment

Caution: Yandex.Cloud's documentation refers to Network or VPC interchangeably. If a Subnet ID is required in the configuration, it will be explicitly stated.

Authentication and Configuration

The yandex-cloud-controller-manager requires a Service Account Json, Folder ID and a Cloud-unique cluster Name stored in the following environment variables:

• YANDEX_CLOUD_SERVICE_ACCOUNT_JSON
• YANDEX_CLOUD_FOLDER_ID
• YANDEX_CLUSTER_NAME

The default manifest is configured to set these environment variables from a secret named yandex-cloud:

$ cat <<EOF | kubectl apply -f -
apiVersion: v1
kind: Secret
metadata:
  labels:
    k8s-app: yandex-cloud-controller-manager
  name: yandex-cloud
  namespace: kube-system
stringData:
  service-account-json: |
    {
       "id": "ajesh3orip69r0vctpf5",
       "service_account_id": "aje3qbblkdf2u2avn4n7",
       "created_at": "2020-01-20T07:43:49Z",
       "key_algorithm": "RSA_2048",
       "public_key": "-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAozah4aqf9xkMLRRtNJjz\nZ+xooLV6GLGaHbkl3796r2zWbgm1aNU3xILGeStdTM5XbB651OAfq7YyHoDSiZkj\nBP6W2ZYNO/WjK9N13rWhtFjNiDulLh3LAU47qNy75OsC3SjW58MVHPNriIgB0HLA\nHRE6cguUJtUcKWqOKhoKQVJxXLOhsdjmEEdnHtd9ro3UCcPM7r6fc+MmkCaZgTNl\nkItkDDxodTIqj3Go2EiEyO2DaMye+GqTzSNJOYaHFH4DYhCCgE1/SCY356nER2qH\nymbAGkD2fAp2eGoCEM67AgqrWFEm/yI+FlIvcrn7wC6+NfWUVqPb+N4wuiehCRBO\n8wIDAQAB\n-----END PUBLIC KEY-----\n",
       "private_key": "-----BEGIN PRIVATE KEY-----\nMIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQCjNqHhqp/3GQwt\nFG00mPNn7GigtXoYsZoduSXfv3qvbNZuCbVo1TfEgsZ5K11MzldsHrnU4B+rtjIe\ngNKJmSME/pbZlg079aMr03XetaG0WM2IO6UuHcsBTjuo3Lvk6wLdKNbnwxUc82uI\niAHQcsAdETpyC5Qm1Rwpao4qGgpBUnFcs6Gx2OYQR2ce132ujdQJw8zuvp9z4yaQ\nJpmBM2WQi2QMPGh1MiqPcajYSITI7YNozJ74apPNI0k5hocUfgNiEIKATX9IJjfn\nqcRHaofKZsAaQPZ8CnZ4agIQzrsCCqtYUSb/Ij4WUi9yufvALr419ZRWo9v43jC6\nJ6EJEE7zAgMBAAECggEAF0hi3XNesHw1PXUNgxRSnL+fyVU6Hq2vQ5A28+03zjCj\ngj0GUPchpnnVYFGsVJmW5QiZD+INAozSJ4HPBuv+j+bVlCKQrr4C0eyvgt68O6Lz\nZvzDOonrfLsxTYx3jVdtKCl8RsGQkHm1HFvyjk7gUwUzJjO6pbN++fWGZEEkt16W\nFHaGldz2MvZKOwQwj0WUcjF4X8PWTvJ0Ar1i5XoAm35GN+2ziwJKcNt+DsJ3N6MW\ngAkivYE8f44T3fQFg5M1RC6v2Jp2lmtVRxYRI0rcie+HyxJVcHgWTZPdTkwGWKDD\nnRU2OTJoZCJf3BunFtB1P8W+GlmLFdBjTppFhgqI6QKBgQDO61fX49qVRDmORYor\nVWh1tZkw546llwkNqLAe1QoLhqjHGctUs3lOczDqI82PwGKb423JdgKmr9nzrCZW\nq5a/BulHdsGsvkSBGK091fhQYRQnaTF7bnXoyVI8qUerGiV/a8/7W1SM+WIJayZ3\nr5Z9xV9LH/Wy7uWW7Xr2LvP97wKBgQDJ7VuYZVJ17hPIqEaR3P1Jvka+RvusWTPw\n1o6O935tW28Q/S2J661Dv92mTNmll/beyFS1ZkHdQ/1c/92Pr1bM/A4CrQoNDvad\nhd2MnyzVYyHc4p6Yd6VmZisbPpTfa7ZJMzYUN27nj+yPxJyZ/EoLlcXaXcPV3kFo\nZsubNT0DPQKBgQCz/nLmgPWWnMd4ZDOB6IS6yCKfMP6cOtsMP64c0/Mt/ZB5yY1f\ne9PNE1T8h/J71r2wn1DUS8yYlSYB2sFq6U5zk55/pOVq0AQlTIL+5E9iFGCEu/Po\nTDlTKzVXQWXviAoQYoeEPnk5PII0cToAKQS/GV8AqaeAZGHhPWmWF1f1jwKBgHQx\nJ6aejv+bGjk5Uzo1rm3TloOA9uqqfa/U1j0//rjQhy2AccbOHWpBqjo6OHcH5Z82\nKUAkcjvvFoiAFq7KVykm1K0HgyQWeyQTVnPHWBYFsAOZR2c2Wa99lMpdjW6uXTrr\nw++IIkIO2DG2EeKtgLH/4dSQZdLXzE1V8U0DKnOFAoGAQNCBpnE1WHR9H5APr5SF\nuD35dTm3O2OvczlbB0MUhx8R7qPpvLwA5HRSIKAKxobUbGpdgCy6WuncRWg+TjaD\n8zlwZvG2+vtntCFPcIT6ZpGH6k9ppXOPJBxaHZRHJSoilGhF1KvrmY8T5WxTVuyM\nnmypFU40LHcTmvw/a6JY+BM=\n-----END PRIVATE KEY-----\n"
    }
  folder-id: "b1g4c2a3g6vkffp3qacq"
EOF

Installation - with RBAC

kubectl apply -f manifests/yandex-cloud-controller-manager-rbac.yaml
kubectl apply -f manifests/yandex-cloud-controller-manager.yaml

Installation - without RBAC

kubectl apply -f manifests/yandex-cloud-controller-manager.yaml

NOTE: the deployments in manifests folder are meant to serve as an example. They will work in a majority of cases but may not work out of the box for your cluster.

Subsystem-specific information

Node Controller

CCM environment variables

• YANDEX_CLOUD_INTERNAL_NETWORK_IDS – comma separated list of NetworkIDs. Will be used to select InternalIPs when scanning an Yandex Instance and populating the corresponding Kubernetes Node.
  • Optional.
  • If present, we iterate over all Instance's interfaces and select networkID-matching addresses.
  • If not present, we use an IP address from the first interface as an InternalIP.
• YANDEX_CLOUD_EXTERNAL_NETWORK_IDS – comma separated list of NetworkIDs. Will be used to select ExternalIPs when scanning an Yandex Instance and populating the corresponding Kubernetes Node.
  • Optional.
  • If present, we iterate over all Instance's interfaces and select networkID-matching private addresses.
  • If not present, we use public address from the first interface that has one-to-one NAT enabled, or none at all.

Service Controller

Operation peculiarities

Due to Yandex.Cloud's TargetGroup's inability to create duplicate (same SubnetID and IP address) Targets, this CCM takes all Nodes in the clusters, finds its Yandex.Cloud Instance counterpart via the API, scans the Instance's Interfaces and determines all possible sets of NetworkIDs that exist on these instances. After doing so, it creates multiple TargetGroups that are named after aforementioned NetworkIDs and include Targets from said Networks.

Due to API limitations, only one subnet from each zone must be present in each NetworkID present on Instance's network interfaces.

CCM environment variables

• YANDEX_CLOUD_DEFAULT_LB_TARGET_GROUP_NETWORK_ID – default NetworkID to use for TargetGroup for created NetworkLoadBalancers.
  • Mandatory.
• YANDEX_CLOUD_DEFAULT_LB_LISTENER_SUBNET_ID – default SubnetID to use for created NetworkLoadBalancers' listeners.
  • Caution! All newly created NLBs will be INTERNAL. This can be overriden via yandex.cpi.flant.com/loadbalancer-external Service annotation.

Service annotations

• yandex.cpi.flant.com/target-group-network-id – override YANDEX_CLOUD_DEFAULT_LB_TARGET_GROUP_NETWORK_ID on a per-service basis.
• yandex.cpi.flant.com/listener-subnet-id – default SubnetID to use for Listeners in created NetworkLoadBalancers. NetworkLoadBalancers will be INTERNAL.
• yandex.cpi.flant.com/listener-address-ipv4 – select pre-defined IPv4 address. Works both on internal and external NetworkLoadBalancers.
• yandex.cpi.flant.com/loadbalancer-external – override YANDEX_CLOUD_DEFAULT_LB_LISTENER_SUBNET_ID per-service.
• yandex.cpi.flant.com/target-group-name-prefix - set target group for LB to target group with name yandex.cpi.flant.com/target-group-name-prefix annotation value + yandex cluster name + YANDEX_CLOUD_DEFAULT_LB_TARGET_GROUP_NETWORK_ID.
• yandex.cpi.flant.com/healthcheck-interval-seconds - healthcheck interval(default 2).
• yandex.cpi.flant.com/healthcheck-timeout-seconds - healthcheck timeout(default 1).
• yandex.cpi.flant.com/healthcheck-unhealthy-threshold - healthcheck unhealthy threshold(default 2).
• yandex.cpi.flant.com/healthcheck-healthy-threshold - healthcheck healthy threshold(default 2).

Node annotations

• yandex.cpi.flant.com/target-group-name-prefix - set node to the non-default target group add this annotation to the node. Yandex CCM creates new target groups with name yandex.cpi.flant.com/target-group-name-prefix annotation value + yandex cluster name + network id of instance interfaces.

Warning

1. If masters are created with their own target groups, then you need to attach the node.kubernetes.io/exclude-from-external-load-balancers: "" label on them so that the controller does not try to add the master to a new target group for balancers

2. If you want to add a balancer for the masters yourself, so that ycc could also hang its own balancers on the masters, create a target group in advance by the name mask ${CLUSTER-NAME}${VPC.ID}

Development

The yandex-cloud-controller-manager is written in Google's Go programming language. Currently, it is developed and tested on Go 1.13.6. If you haven't set up a Go development environment yet, please follow these instructions.

Download Source

$ go get -u github.com/deckhouse/yandex-cloud-controller-manager
$ cd $(go env GOPATH)/src/github.com/deckhouse/yandex-cloud-controller-manager

Dependency management

yandex-cloud-controller-manager uses Go modules to manage dependencies.

Build Binary

To build yandex-cloud-controller-manager binary, run:

$ make build

Building Docker images

To build Docker image, use the following make target:

$ DOCKER_TAG=dev make docker-build