multicluster

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Manages the multicluster setup for Linkerd.

This command provides subcommands to manage the multicluster support functionality of Linkerd. You can use it to install the service mirror components on a cluster, manage credentials and link clusters together.

Examples

# Install multicluster addons.
linkerd --context=cluster-a multicluster install | kubectl --context=cluster-a apply -f -

# Extract mirroring cluster credentials from cluster A and install them on cluster B
linkerd --context=cluster-a multicluster link --cluster-name=target | kubectl apply --context=cluster-b -f -

Subcommands

allow

Outputs credential resources that allow service-mirror controllers to connect to this cluster

Flags

Flag	Usage
`--ignore-cluster`	Ignore cluster configuration
`--namespace`	The destination namespace for the service account.
`--service-account-name`	The name of the multicluster access service account

check

Check the multicluster extension for potential problems.

The check command will perform a series of checks to validate that the multicluster extension is configured correctly. If the command encounters a failure it will print additional information about the failure and exit with a non-zero exit code.

Examples

# Check that the multicluster extension is configured correctly
linkerd multicluster check

Flags

Flag	Usage
`--namespace` `-n`
`--output` `-o`	Output format. One of: basic, json
`--proxy`
`--wait`	Maximum allowed time for all tests to pass

gateways

Display stats information about the gateways in target clusters

Flags

Flag	Usage
`--cluster-name`	the name of the target cluster
`--gateway-namespace`	the namespace in which the gateway resides on the target cluster
`--time-window` `-t`	Time window (for example: “15s”, “1m”, “10m”, “1h”). Needs to be at least 15s.

install

Output Kubernetes configs to install the Linkerd multicluster add-on

Examples

# Default install.
linkerd multicluster install | kubectl apply -f -

The installation can be configured by using the --set, --values, --set-string and --set-file flags.
A full list of configurable values can be found at https://github.com/linkerd/linkerd2/blob/main/multicluster/charts/linkerd-multicluster/README.md

Flags

Flag	Usage
`--gateway`	If the gateway component should be installed
`--gateway-nginx-image`	The nginx image to be used
`--gateway-nginx-image-version`	The version of nginx to be used
`--gateway-port`	The port on the gateway used for all incoming traffic
`--gateway-probe-port`	The liveness check port of the gateway
`--gateway-probe-seconds`	The interval at which the gateway will be checked for being alive in seconds
`--gateway-service-type`	Overwrite Service type for gateway service
`--namespace`	The namespace in which the multicluster add-on is to be installed. Must not be the control plane namespace.
`--service-mirror-credentials`	Whether to install the service account which can be used by service mirror components in source clusters to discover exported services
`--set`	set values on the command line (can specify multiple or separate values with commas: key1=val1,key2=val2)
`--set-file`	set values from respective files specified via the command line (can specify multiple or separate values with commas: key1=path1,key2=path2)
`--set-string`	set STRING values on the command line (can specify multiple or separate values with commas: key1=val1,key2=val2)
`--values` `-f`	specify values in a YAML file or a URL (can specify multiple)
`--wait`	Wait for core control-plane components to be available

link

Outputs resources that allow another cluster to mirror services from this one

Examples

# To link the west cluster to east
linkerd --context=east multicluster link --cluster-name east | kubectl --context=west apply -f -

The command can be configured by using the --set, --values, --set-string and --set-file flags.
A full list of configurable values can be found at https://github.com/linkerd/linkerd2/blob/main/multicluster/charts/linkerd-multicluster-link/README.md

Flags

Flag	Usage
`--api-server-address`	The api server address of the target cluster
`--cluster-name`	Cluster name
`--control-plane-version`	(Development) Tag to be used for the service mirror controller image
`--gateway-addresses`	If specified overwrites gateway addresses when gateway service is not type LoadBalancer (comma separated list)
`--gateway-name`	The name of the gateway service
`--gateway-namespace`	The namespace of the gateway service
`--log-level`	Log level for the Multicluster components
`--namespace`	The namespace for the service account
`--registry`	Docker registry to pull service mirror controller image from
`--selector` `-l`	Selector (label query) to filter which services in the target cluster to mirror
`--service-account-name`	The name of the service account associated with the credentials
`--service-mirror-retry-limit`	The number of times a failed update from the target cluster is allowed to be retried
`--set`	set values on the command line (can specify multiple or separate values with commas: key1=val1,key2=val2)
`--set-file`	set values from respective files specified via the command line (can specify multiple or separate values with commas: key1=path1,key2=path2)
`--set-string`	set STRING values on the command line (can specify multiple or separate values with commas: key1=val1,key2=val2)
`--values` `-f`	specify values in a YAML file or a URL (can specify multiple)

uninstall

Output Kubernetes configs to uninstall the Linkerd multicluster add-on

Flags

Flag	Usage
`--namespace`	The namespace in which the multicluster add-on is to be installed. Must not be the control plane namespace.

unlink

Outputs link resources for deletion

Flags

Flag	Usage
`--cluster-name`	Cluster name
`--namespace`	The namespace for the service account