clusterdefinition.md

Microsoft Azure Container Service Engine - Cluster Definition

Cluster Defintions for apiVersion "vlabs"

Here are the cluster definitions for apiVersion "vlabs":

apiVersion

Name	Required	Description
apiVersion	yes	The version of the template. For "vlabs" the value is "vlabs"

orchestratorProfile

orchestratorProfile describes the orchestrator settings.

Name	Required	Description
orchestratorType	yes	Specifies the orchestrator type for the cluster

Here are the valid values for the orchestrator types:

1. DCOS - this represents the DC/OS orchestrator. Older releases of DCOS 1.8 may be specified.
2. Kubernetes - this represents the Kubernetes orchestrator.
3. Swarm - this represents the Swarm orchestrator.
4. Swarm Mode - this represents the Swarm Mode orchestrator.
5. OpenShift - this represents the OpenShift orchestrator.

kubernetesConfig

kubernetesConfig describes Kubernetes specific configuration.

Name	Required	Description
addons	no	Configure various Kubernetes addons configuration (currently supported: tiller, kubernetes-dashboard). See addons configuration below
apiServerConfig	no	Configure various runtime configuration for apiserver. See apiServerConfig below
cloudControllerManagerConfig	no	Configure various runtime configuration for cloud-controller-manager. See cloudControllerManagerConfig below
clusterSubnet	no	The IP subnet used for allocating IP addresses for pod network interfaces. The subnet must be in the VNET address space. Default value is 10.244.0.0/16
containerRuntime	no	The container runtime to use as a backend. The default is docker. The other options are clear-containers and containerd
controllerManagerConfig	no	Configure various runtime configuration for controller-manager. See controllerManagerConfig below
customWindowsPackageURL	no	Configure custom windows Kubernetes release package URL for deployment on Windows
dnsServiceIP	no	IP address for kube-dns to listen on. If specified must be in the range of serviceCidr
dockerBridgeSubnet	no	The specific IP and subnet used for allocating IP addresses for the docker bridge network created on the kubernetes master and agents. Default value is 172.17.0.1/16. This value is used to configure the docker daemon using the --bip flag
dockerEngineVersion	no	Which version of docker-engine to use in your cluster, e.g. "17.03.*"
enableAggregatedAPIs	no	Enable Kubernetes Aggregated APIs.This is required by Service Catalog. (boolean - default == false)
enableDataEncryptionAtRest	no	Enable kubernetes data encryption at rest.This is currently an alpha feature. (boolean - default == false)
enableEncryptionWithExternalKms	no	Enable kubernetes data encryption at rest with external KMS.This is currently an alpha feature. (boolean - default == false)
enablePodSecurityPolicy	no	Enable kubernetes pod security policy.This is currently a beta feature. (boolean - default == false)
enableRbac	no	Enable Kubernetes RBAC (boolean - default == true)
etcdDiskSizeGB	no	Size in GB to assign to etcd data volume. Defaults (if no user value provided) are: 256 GB for clusters up to 3 nodes; 512 GB for clusters with between 4 and 10 nodes; 1024 GB for clusters with between 11 and 20 nodes; and 2048 GB for clusters with more than 20 nodes
etcdEncryptionKey	no	Enryption key to be used if enableDataEncryptionAtRest is enabled. Defaults to a random, generated, key
gcHighThreshold	no	Sets the --image-gc-high-threshold value on the kublet configuration. Default is 85. See kubelet Garbage Collection
gcLowThreshold	no	Sets the --image-gc-low-threshold value on the kublet configuration. Default is 80. See kubelet Garbage Collection
kubeletConfig	no	Configure various runtime configuration for kubelet. See kubeletConfig below
kubernetesImageBase	no	Specifies the base URL (everything preceding the actual image filename) of the kubernetes hyperkube image to use for cluster deployment, e.g., k8s-gcrio.azureedge.net/
networkPlugin	no	Specifies the network plugin implementation for the cluster. Valid values are: "azure" (default), which provides an Azure native networking experience "kubenet" for k8s software networking implementation. "flannel" for using CoreOS Flannel "cilium" for using the default Cilium CNI IPAM
networkPolicy	no	Specifies the network policy enforcement tool for the cluster (currently Linux-only). Valid values are: calico for Calico network policy. cilium for cilium network policy (Lin). See network policy examples for more information
privateCluster	no	Build a cluster without public addresses assigned. See privateClusters below.
schedulerConfig	no	Configure various runtime configuration for scheduler. See schedulerConfig below
serviceCidr	no	IP range for Service IPs, Default is "10.0.0.0/16". This range is never routed outside of a node so does not need to lie within clusterSubnet or the VNET
useInstanceMetadata	no	Use the Azure cloudprovider instance metadata service for appropriate resource discovery operations. Default is true
useManagedIdentity	no	Includes and uses MSI identities for all interactions with the Azure Resource Manager (ARM) API. Instead of using a static service principal written to /etc/kubernetes/azure.json, Kubernetes will use a dynamic, time-limited token fetched from the MSI extension running on master and agent nodes. This support is currently alpha and requires Kubernetes v1.9.1 or newer. (boolean - default == false)

addons

addons describes various addons configuration. It is a child property of kubernetesConfig. Below is a list of currently available addons:

Name of addon	Enabled by default?	How many containers	Description
tiller	true	1	Delivers the Helm server-side component: tiller. See https://github.com/kubernetes/helm for more info
kubernetes-dashboard	true	1	Delivers the kubernetes dashboard component. See https://github.com/kubernetes/dashboard for more info
rescheduler	false	1	Delivers the kubernetes rescheduler component

To give a bit more info on the addons property: We've tried to expose the basic bits of data that allow useful configuration of these cluster features. Here are some example usage patterns that will unpack what addons provide:

To enable an addon (using "tiller" as an example):

"kubernetesConfig": {
    "addons": [
        {
            "name": "tiller",
            "enabled" : true
        }
    ]
}

As you can see above, addons is an array child property of kubernetesConfig. Each addon that you want to add custom configuration to would be represented as an object item in the array. For example, to disable both tiller and dashboard:

"kubernetesConfig": {
    "addons": [
        {
            "name": "tiller",
            "enabled" : false
        },
        {
            "name": "kubernetes-dashboard",
            "enabled" : false
        }
    ]
}

More usefully, let's add some custom configuration to both of the above addons:

"kubernetesConfig": {
    "addons": [
        {
            "name": "tiller",
            "containers": [
                {
                  "name": "tiller",
                  "image": "myDockerHubUser/tiller:v3.0.0-alpha",
                  "cpuRequests": "1",
                  "memoryRequests": "1024Mi",
                  "cpuLimits": "1",
                  "memoryLimits": "1024Mi"
                }
              ]
        },
        {
            "name": "kubernetes-dashboard",
            "containers": [
                {
                  "name": "kubernetes-dashboard",
                  "cpuRequests": "50m",
                  "memoryRequests": "512Mi",
                  "cpuLimits": "50m",
                  "memoryLimits": "512Mi"
                }
              ]
        }
    ]
}

Above you see custom configuration for both tiller and kubernetes-dashboard. Both include specific resource limit values across the following dimensions:

• cpuRequests
• memoryRequests
• cpuLimits
• memoryLimits

See https://kubernetes.io/docs/concepts/configuration/manage-compute-resources-container/ for more on Kubernetes resource limits.

Additionally above, we specified a custom docker image for tiller, let's say we want to build a cluster and test an alpha version of tiller in it.

Finally, the addons.enabled boolean property was omitted above; that's by design. If you specify a containers configuration, acs-engine assumes you're enabling the addon. The very first example above demonstrates a simple "enable this addon with default configuration" declaration.

kubeletConfig

kubeletConfig declares runtime configuration for the kubelet running on all master and agent nodes. It is a generic key/value object, and a child property of kubernetesConfig. An example custom kubelet config:

"kubernetesConfig": {
    "kubeletConfig": {
        "--eviction-hard": "memory.available<250Mi,nodefs.available<20%,nodefs.inodesFree<10%"
    }
}

See here for a reference of supported kubelet options.

Below is a list of kubelet options that acs-engine will configure by default:

kubelet option	default value
"--cloud-config"	"/etc/kubernetes/azure.json"
"--cloud-provider"	"azure"
"--cluster-domain"	"cluster.local"
"--pod-infra-container-image"	"pause-amd64:version"
"--max-pods"	"30", or "100" if using kubenet --network-plugin (i.e., "networkPlugin": "kubenet")
"--eviction-hard"	"memory.available<100Mi,nodefs.available<10%,nodefs.inodesFree<5%"
"--node-status-update-frequency"	"10s"
"--image-gc-high-threshold"	"85"
"--image-gc-low-threshold"	"850"
"--non-masquerade-cidr"	"10.0.0.0/8"
"--azure-container-registry-config"	"/etc/kubernetes/azure.json"
"--pod-max-pids"	"100" (need to activate the feature in --feature-gates=SupportPodPidsLimit=true)
"--feature-gates"	No default (can be a comma-separated list). On agent nodes Accelerators=true will be applied in the --feature-gates option for k8s versions before 1.11.0

Below is a list of kubelet options that are not currently user-configurable, either because a higher order configuration vector is available that enforces kubelet configuration, or because a static configuration is required to build a functional cluster:

kubelet option	default value
"--address"	"0.0.0.0"
"--allow-privileged"	"true"
"--pod-manifest-path"	"/etc/kubernetes/manifests"
"--network-plugin"	"cni"
"--node-labels"	(based on Azure node metadata)
"--cgroups-per-qos"	"true"
"--enforce-node-allocatable"	"pods"
"--kubeconfig"	"/var/lib/kubelet/kubeconfig"
"--register-node" (master nodes only)	"true"
"--register-with-taints" (master nodes only)	"node-role.kubernetes.io/master=true:NoSchedule"
"--keep-terminated-pod-volumes"	"false"

controllerManagerConfig

controllerManagerConfig declares runtime configuration for the kube-controller-manager daemon running on all master nodes. Like kubeletConfig it is a generic key/value object, and a child property of kubernetesConfig. An example custom controller-manager config:

"kubernetesConfig": {
    "controllerManagerConfig": {
        "--node-monitor-grace-period": "40s",
        "--pod-eviction-timeout": "5m0s",
        "--route-reconciliation-period": "10s"
        "--terminated-pod-gc-threshold": "5000"
    }
}

See here for a reference of supported controller-manager options.

Below is a list of controller-manager options that acs-engine will configure by default:

controller-manager option	default value
"--node-monitor-grace-period"	"40s"
"--pod-eviction-timeout"	"5m0s"
"--route-reconciliation-period"	"10s"
"--terminated-pod-gc-threshold"	"5000"
"--feature-gates"	No default (can be a comma-separated list)

Below is a list of controller-manager options that are not currently user-configurable, either because a higher order configuration vector is available that enforces controller-manager configuration, or because a static configuration is required to build a functional cluster:

controller-manager option	default value
"--kubeconfig"	"/var/lib/kubelet/kubeconfig"
"--allocate-node-cidrs"	"false"
"--cluster-cidr"	"10.240.0.0/12"
"--cluster-name"	auto-generated using api model properties
"--cloud-provider"	"azure"
"--cloud-config"	"/etc/kubernetes/azure.json"
"--root-ca-file"	"/etc/kubernetes/certs/ca.crt"
"--cluster-signing-cert-file"	"/etc/kubernetes/certs/ca.crt"
"--cluster-signing-key-file"	"/etc/kubernetes/certs/ca.key"
"--service-account-private-key-file"	"/etc/kubernetes/certs/apiserver.key"
"--leader-elect"	"true"
"--v"	"2"
"--profiling"	"false"
"--use-service-account-credentials"	"false" ("true" if kubernetesConfig.enableRbac is true)

cloudControllerManagerConfig

cloudControllerManagerConfig declares runtime configuration for the cloud-controller-manager daemon running on all master nodes in a Cloud Controller Manager configuration. Like kubeletConfig it is a generic key/value object, and a child property of kubernetesConfig. An example custom cloud-controller-manager config:

"kubernetesConfig": {
    "cloudControllerManagerConfig": {
        "--route-reconciliation-period": "1m"
    }
}

See here for a reference of supported controller-manager options.

Below is a list of cloud-controller-manager options that acs-engine will configure by default:

controller-manager option	default value
"--route-reconciliation-period"	"10s"

Below is a list of cloud-controller-manager options that are not currently user-configurable, either because a higher order configuration vector is available that enforces controller-manager configuration, or because a static configuration is required to build a functional cluster:

controller-manager option	default value
"--kubeconfig"	"/var/lib/kubelet/kubeconfig"
"--allocate-node-cidrs"	"false"
"--cluster-cidr"	"10.240.0.0/12"
"--cluster-name"	auto-generated using api model properties
"--cloud-provider"	"azure"
"--cloud-config"	"/etc/kubernetes/azure.json"
"--leader-elect"	"true"
"--v"	"2"

apiServerConfig

apiServerConfig declares runtime configuration for the kube-apiserver daemon running on all master nodes. Like kubeletConfig and controllerManagerConfig it is a generic key/value object, and a child property of kubernetesConfig. An example custom apiserver config:

"kubernetesConfig": {
    "apiServerConfig": {
        "--request-timeout": "30s"
    }
}

Or perhaps you want to customize/override the set of admission-control flags passed to the API Server by default, you can omit the options you don't want and specify only the ones you need as follows:

"orchestratorProfile": {
      "orchestratorType": "Kubernetes",
      "orchestratorRelease": "1.8",
      "kubernetesConfig": {
        "apiServerConfig": {
          "--admission-control":  "NamespaceLifecycle,LimitRanger,ServiceAccount,DefaultStorageClass,ResourceQuota,AlwaysPullImages"
        }
      }
    }

See here for a reference of supported apiserver options.

Below is a list of apiserver options that acs-engine will configure by default:

apiserver option	default value
"--admission-control"	"NamespaceLifecycle,LimitRanger,ServiceAccount,DefaultStorageClass,ResourceQuota,DenyEscalatingExec,AlwaysPullImages" (Kubernetes versions prior to 1.9.0
"--enable-admission-plugins"*	"NamespaceLifecycle,LimitRanger,ServiceAccount,DefaultStorageClass,DefaultTolerationSeconds,MutatingAdmissionWebhook,ValidatingAdmissionWebhook,ResourceQuota,DenyEscalatingExec,AlwaysPullImages" (Kubernetes versions 1.9.0 and later
"--authorization-mode"	"Node", "RBAC" (the latter if enabledRbac is true)
"--audit-log-maxage"	"30"
"--audit-log-maxbackup"	"10"
"--audit-log-maxsize"	"100"
"--feature-gates"	No default (can be a comma-separated list)
"--oidc-username-claim"	"oid" (if has AADProfile)
"--oidc-groups-claim"	"groups" (if has AADProfile)
"--oidc-client-id"	calculated value that represents OID client ID (if has AADProfile)
"--oidc-issuer-url"	calculated value that represents OID issuer URL (if has AADProfile)

* In Kubernetes versions 1.10.0 and later the --admission-control flag is deprecated and --enable-admission-plugins is used in its stead.

Below is a list of apiserver options that are not currently user-configurable, either because a higher order configuration vector is available that enforces apiserver configuration, or because a static configuration is required to build a functional cluster:

apiserver option	default value
"--bind-address"	"0.0.0.0"
"--advertise-address"	calculated value that represents listening URI for API server
"--allow-privileged"	"true"
"--anonymous-auth"	"false
"--audit-log-path"	"/var/log/apiserver/audit.log"
"--insecure-port"	"8080"
"--secure-port"	"443"
"--service-account-lookup"	"true"
"--etcd-cafile"	"/etc/kubernetes/certs/ca.crt"
"--etcd-certfile"	"/etc/kubernetes/certs/etcdclient.crt"
"--etcd-keyfile"	"/etc/kubernetes/certs/etcdclient.key"
"--etcd-servers"	calculated value that represents etcd servers
"--profiling"	"false"
"--repair-malformed-updates"	"false"
"--tls-cert-file"	"/etc/kubernetes/certs/apiserver.crt"
"--tls-private-key-file"	"/etc/kubernetes/certs/apiserver.key"
"--client-ca-file"	"/etc/kubernetes/certs/ca.crt"
"--service-account-key-file"	"/etc/kubernetes/certs/apiserver.key"
"--kubelet-client-certificate"	"/etc/kubernetes/certs/client.crt"
"--kubelet-client-key"	"/etc/kubernetes/certs/client.key"
"--service-cluster-ip-range"	see serviceCIDR
"--storage-backend"	calculated value that represents etcd version
"--v"	"4"
"--experimental-encryption-provider-config"	"/etc/kubernetes/encryption-config.yaml" (if enableDataEncryptionAtRest is true)
"--experimental-encryption-provider-config"	"/etc/kubernetes/encryption-config.yaml" (if enableEncryptionWithExternalKms is true)
"--requestheader-client-ca-file"	"/etc/kubernetes/certs/proxy-ca.crt" (if enableAggregatedAPIs is true)
"--proxy-client-cert-file"	"/etc/kubernetes/certs/proxy.crt" (if enableAggregatedAPIs is true)
"--proxy-client-key-file"	"/etc/kubernetes/certs/proxy.key" (if enableAggregatedAPIs is true)
"--requestheader-allowed-names"	"" (if enableAggregatedAPIs is true)
"--requestheader-extra-headers-prefix"	"X-Remote-Extra-" (if enableAggregatedAPIs is true)
"--requestheader-group-headers"	"X-Remote-Group" (if enableAggregatedAPIs is true)
"--requestheader-username-headers"	"X-Remote-User" (if enableAggregatedAPIs is true)
"--cloud-provider"	"azure" (unless useCloudControllerManager is true)
"--cloud-config"	"/etc/kubernetes/azure.json" (unless useCloudControllerManager is true)

schedulerConfig

schedulerConfig declares runtime configuration for the kube-scheduler daemon running on all master nodes. Like kubeletConfig, controllerManagerConfig, and apiServerConfig it is a generic key/value object, and a child property of kubernetesConfig. An example custom apiserver config:

"kubernetesConfig": {
    "schedulerConfig": {
        "--v": "2"
    }
}

See here for a reference of supported kube-scheduler options.

Below is a list of scheduler options that acs-engine will configure by default:

kube-scheduler option	default value
"--v"	"2"
"--feature-gates"	No default (can be a comma-separated list)

Below is a list of kube-scheduler options that are not currently user-configurable, either because a higher order configuration vector is available that enforces kube-scheduler configuration, or because a static configuration is required to build a functional cluster:

kube-scheduler option	default value
"--kubeconfig"	"/var/lib/kubelet/kubeconfig"
"--leader-elect"	"true"
"--profiling"	"false"

We consider kubeletConfig, controllerManagerConfig, apiServerConfig, and schedulerConfig to be generic conveniences that add power/flexibility to cluster deployments. Their usage comes with no operational guarantees! They are manual tuning features that enable low-level configuration of a kubernetes cluster.

privateCluster

privateCluster defines a cluster without public addresses assigned. It is a child property of kubernetesConfig.

Name	Required	Description
enabled	no	Enable Private Cluster (boolean - default == false)
jumpboxProfile	no	Configure and auto-provision a jumpbox to access your private cluster. jumpboxProfile is ignored if enabled is false. See jumpboxProfile below

jumpboxProfile

jumpboxProfile describes the settings for a jumpbox deployed via acs-engine to access a private cluster. It is a child property of privateCluster.

Name	Required	Description
name	yes	This is the unique name for the jumpbox VM. Some resources deployed with the jumpbox are derived from this name
vmSize	yes	Describes a valid Azure VM Sizes
publicKey	yes	The public SSH key used for authenticating access to the jumpbox. Here are instructions for generating a public/private key pair
osDiskSizeGB	no	Describes the OS Disk Size in GB. Defaults to 30
storageProfile	no	Specifies the storage profile to use. Valid values are ManagedDisks or StorageAccount. Defaults to ManagedDisks
username	no	Describes the admin username to be used on the jumpbox. Defaults to azureuser

masterProfile

masterProfile describes the settings for master configuration.

Name	Required	Description
count	yes	Masters have count value of 1, 3, or 5 masters
dnsPrefix	yes	The dns prefix for the master FQDN. The master FQDN is used for SSH or commandline access. This must be a unique name. (bring your own VNET examples)
subjectAltNames	no	An array of fully qualified domain names using which a user can reach API server. These domains are added as Subject Alternative Names to the generated API server certificate. NOTE: These domains will not be automatically provisioned.
firstConsecutiveStaticIP	only required when vnetSubnetId specified	The IP address of the first master. IP Addresses will be assigned consecutively to additional master nodes
vmsize	yes	Describes a valid Azure VM Sizes. These are restricted to machines with at least 2 cores and 100GB of ephemeral disk space
osDiskSizeGB	no	Describes the OS Disk Size in GB
vnetSubnetId	no	Specifies the Id of an alternate VNET subnet. The subnet id must specify a valid VNET ID owned by the same subscription. (bring your own VNET examples)
extensions	no	This is an array of extensions. This indicates that the extension be run on a single master. The name in the extensions array must exactly match the extension name in the extensionProfiles
vnetCidr	no	Specifies the VNET cidr when using a custom VNET (bring your own VNET examples)
imageReference.name	no	The name of the Linux OS image. Needs to be used in conjunction with resourceGroup, below
imageReference.resourceGroup	no	Resource group that contains the Linux OS image. Needs to be used in conjunction with name, above
distro	no	Select Master(s) Operating System (Linux only). Currently supported values are: ubuntu and coreos (CoreOS support is currently experimental). Defaults to ubuntu if undefined. Currently supported OS and orchestrator configurations -- ubuntu: DCOS, Docker Swarm, Kubernetes; RHEL: OpenShift; coreos: Kubernetes. Example of CoreOS Master with CoreOS Agents

agentPoolProfiles

A cluster can have 0 to 12 agent pool profiles. Agent Pool Profiles are used for creating agents with different capabilities such as VMSizes, VMSS or Availability Set, Public/Private access, user-defined OS Images, attached storage disks, attached managed disks, or Windows.

Name	Required	Description
availabilityProfile	no	Supported values are VirtualMachineScaleSets (default, except for Kubernetes clusters before version 1.10) and AvailabilitySet.
count	yes	Describes the node count
scaleSetPriority	no	Supported values are Regular (default) and Low. Only applies to clusters with availabilityProfile VirtualMachineScaleSets. Enables the usage of Low-priority VMs on Scale Sets.
scaleSetEvictionPolicy	no	Supported values are Delete (default) and Deallocate. Only applies to clusters with availabilityProfile of VirtualMachineScaleSets and scaleSetPriority of Low.
diskSizesGB	no	Describes an array of up to 4 attached disk sizes. Valid disk size values are between 1 and 1024
dnsPrefix	Required if agents are to be exposed publically with a load balancer	The dns prefix that forms the FQDN to access the loadbalancer for this agent pool. This must be a unique name among all agent pools. Not supported for Kubernetes clusters
name	yes	This is the unique name for the agent pool profile. The resources of the agent pool profile are derived from this name
ports	only required if needed for exposing services publically	Describes an array of ports need for exposing publically. A tcp probe is configured for each port and only opens to an agent node if the agent node is listening on that port. A maximum of 150 ports may be specified. Not supported for Kubernetes clusters
storageProfile	no	Specifies the storage profile to use. Valid values are ManagedDisks or StorageAccount. Defaults to ManagedDisks
vmsize	yes	Describes a valid Azure VM Sizes. These are restricted to machines with at least 2 cores
osDiskSizeGB	no	Describes the OS Disk Size in GB
vnetSubnetId	no	Specifies the Id of an alternate VNET subnet. The subnet id must specify a valid VNET ID owned by the same subscription. (bring your own VNET examples)
imageReference.name	no	The name of a a Linux OS image. Needs to be used in conjunction with resourceGroup, below
imageReference.resourceGroup	no	Resource group that contains the Linux OS image. Needs to be used in conjunction with name, above
osType	no	Specifies the agent pool's Operating System. Supported values are Windows and Linux. Defaults to Linux
distro	no	Specifies the agent pool's Linux distribution. Supported values are ubuntu and coreos (CoreOS support is currently experimental). Defaults to ubuntu if undefined, unless osType is defined as Windows (in which case distro is unused). Currently supported OS and orchestrator configurations -- ubuntu: DCOS, Docker Swarm, Kubernetes; RHEL: OpenShift; coreos: Kubernetes. Example of CoreOS Master with Windows and Linux (CoreOS and Ubuntu) Agents

linuxProfile

linuxProfile provides the linux configuration for each linux node in the cluster

Name	Required	Description
adminUsername	yes	Describes the username to be used on all linux clusters
ssh.publicKeys.keyData	yes	The public SSH key used for authenticating access to all Linux nodes in the cluster. Here are instructions for generating a public/private key pair
secrets	no	Specifies an array of key vaults to pull secrets from and what secrets to pull from each
customSearchDomain.name	no	describes the search domain to be used on all linux clusters
customSearchDomain.realmUser	no	describes the realm user with permissions to update dns registries on Windows Server DNS
customSearchDomain.realmPassword	no	describes the realm user password to update dns registries on Windows Server DNS
customNodesDNS.dnsServer	no	describes the IP address of the DNS Server

secrets

secrets details which certificates to install on the masters and nodes in the cluster.

A cluster can have a list of key vaults to install certs from.

On linux boxes the certs are saved on under the directory "/var/lib/waagent/". 2 files are saved per certificate:

1. {thumbprint}.crt : this is the full cert chain saved in PEM format
2. {thumbprint}.prv : this is the private key saved in PEM format

Name	Required	Description
sourceVault.id	yes	The azure resource manager id of the key vault to pull secrets from
vaultCertificates.certificateUrl	yes	Keyvault URL to this cert including the version
format for sourceVault.id, can be obtained in cli, or found in the portal: /subscriptions/{subscription-id}/resourceGroups/{resource-group}/providers/Microsoft.KeyVault/vaults/{keyvaultname}

format for vaultCertificates.certificateUrl, can be obtained in cli, or found in the portal: https://{keyvaultname}.vault.azure.net:443/secrets/{secretName}/{version}

servicePrincipalProfile

servicePrincipalProfile describes an Azure Service credentials to be used by the cluster for self-configuration. See service principal for more details on creation.

Name	Required	Description
clientId	yes, for Kubernetes clusters	describes the Azure client id. It is recommended to use a separate client ID per cluster
secret	yes, for Kubernetes clusters	describes the Azure client secret. It is recommended to use a separate client secret per client id
objectId	optional, for Kubernetes clusters	describes the Azure service principal object id. It is required if enableEncryptionWithExternalKms is true

Cluster Defintions for apiVersion "2016-03-30"

Here are the cluster definitions for apiVersion "2016-03-30". This matches the api version of the Azure Container Service Engine.

apiVersion

Name	Required	Description
apiVersion	yes	The version of the template. For "2016-03-30" the value is "2016-03-30"

orchestratorProfile

orchestratorProfile describes the orchestrator settings.

Name	Required	Description
orchestratorType	yes	Specifies the orchestrator type for the cluster

Here are the valid values for the orchestrator types:

1. DCOS - this represents the DC/OS orchestrator.
2. Swarm - this represents the Swarm orchestrator.
3. Kubernetes - this represents the Kubernetes orchestrator.
4. Swarm Mode - this represents the Swarm Mode orchestrator.
5. OpenShift - this represents the OpenShift orchestrator

masterProfile

masterProfile describes the settings for master configuration.

Name	Required	Description
count	yes	Masters have count value of 1, 3, or 5 masters
dnsPrefix	yes	The dns prefix for the masters FQDN. The master FQDN is used for SSH or commandline access. This must be a unique name. (bring your own VNET examples)

agentPoolProfiles

For apiVersion "2016-03-30", a cluster may have only 1 agent pool profiles.

Name	Required	Description
count	yes	Describes the node count
dnsPrefix	required if agents are to be exposed publically with a load balancer	The dns prefix that forms the FQDN to access the loadbalancer for this agent pool. This must be a unique name among all agent pools
name	yes	The unique name for the agent pool profile. The resources of the agent pool profile are derived from this name
vmsize	yes	Describes a valid Azure VM Sizes. These are restricted to machines with at least 2 cores

linuxProfile

linuxProfile provides the linux configuration for each linux node in the cluster

Name	Required	Description
adminUsername	yes	Describes the username to be used on all linux clusters
ssh.publicKeys[0].keyData	yes	The public SSH key used for authenticating access to all Linux nodes in the cluster. Here are instructions for generating a public/private key pair

aadProfile

linuxProfile provides AAD integration configuration for the cluster, currently only available for Kubernetes orchestrator.

Name	Required	Description
clientAppID	yes	Describes the client AAD application ID
serverAppID	yes	Describes the server AAD application ID
tenantID	no	Describes the AAD tenant ID to use for authentication. If not specified, will use the tenant of the deployment subscription

extensionProfiles

A cluster can have 0 - N extensions in extension profiles. Extension profiles allow a user to easily add pre-packaged functionality into a cluster. An example would be configuring a monitoring solution on your cluster. You can think of extensions like a marketplace for acs clusters.

Name	Required	Description
name	yes	The name of the extension. This has to exactly match the name of a folder under the extensions folder
version	yes	The version of the extension. This has to exactly match the name of the folder under the extension name folder
extensionParameters	optional	Extension parameters may be required by extensions. The format of the parameters is also extension dependant
rootURL	optional	URL to the root location of extensions. The rootURL must have an extensions child folder that follows the extensions convention. The rootURL is mainly used for testing purposes

You can find more information, as well as a list of extensions on the extensions documentation.