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ArangoDeploymentReplication Custom Resource
Datacenter-to-Datacenter Replication is only available in the Enterprise Edition.
The ArangoDB Replication Operator creates and maintains ArangoDB
arangosync
configurations in a Kubernetes cluster, given a replication specification.
This replication specification is a CustomResource
following
a CustomResourceDefinition
created by the operator.
Example of a minimal replication definition for two ArangoDB clusters with sync in the same Kubernetes cluster:
apiVersion: "replication.database.arangodb.com/v1alpha"
kind: "ArangoDeploymentReplication"
metadata:
name: "replication-from-a-to-b"
spec:
source:
deploymentName: cluster-a
auth:
keyfileSecretName: cluster-a-sync-auth
destination:
deploymentName: cluster-b
This definition results in:
- the arangosync
SyncMaster
in deploymentcluster-b
is called to configure a synchronization from the syncmasters incluster-a
to the syncmasters incluster-b
, using the client authentication certificate stored inSecret
cluster-a-sync-auth
. To accesscluster-a
, the JWT secret found in the deployment ofcluster-a
is used. To accesscluster-b
, the JWT secret found in the deployment ofcluster-b
is used.
Example replication definition for replicating from a source that is outside the current Kubernetes cluster to a destination that is in the same Kubernetes cluster:
apiVersion: "replication.database.arangodb.com/v1alpha"
kind: "ArangoDeploymentReplication"
metadata:
name: "replication-from-a-to-b"
spec:
source:
masterEndpoint: ["https://163.172.149.229:31888", "https://51.15.225.110:31888", "https://51.15.229.133:31888"]
auth:
keyfileSecretName: cluster-a-sync-auth
tls:
caSecretName: cluster-a-sync-ca
destination:
deploymentName: cluster-b
This definition results in:
- the arangosync
SyncMaster
in deploymentcluster-b
is called to configure a synchronization from the syncmasters located at the given list of endpoint URLs to the syncmasterscluster-b
, using the client authentication certificate stored inSecret
cluster-a-sync-auth
. To accesscluster-a
, the keyfile (containing a client authentication certificate) is used. To accesscluster-b
, the JWT secret found in the deployment ofcluster-b
is used.
Specification reference
Below you’ll find all settings of the ArangoDeploymentReplication
custom resource.
spec.source.deploymentName: string
This setting specifies the name of an ArangoDeployment
resource that runs a cluster
with sync enabled.
This cluster configured as the replication source.
spec.source.masterEndpoint: []string
This setting specifies zero or more master endpoint URLs of the source cluster.
Use this setting if the source cluster is not running inside a Kubernetes cluster
that is reachable from the Kubernetes cluster the ArangoDeploymentReplication
resource is deployed in.
Specifying this setting and spec.source.deploymentName
at the same time is not allowed.
spec.source.auth.keyfileSecretName: string
This setting specifies the name of a Secret
containing a client authentication certificate called tls.keyfile
used to authenticate
with the SyncMaster at the specified source.
If spec.source.auth.userSecretName
has not been set,
the client authentication certificate found in the secret with this name is also used to configure
the synchronization and fetch the synchronization status.
This setting is required.
spec.source.auth.userSecretName: string
This setting specifies the name of a Secret
containing a username
& password
used to authenticate
with the SyncMaster at the specified source in order to configure synchronization and fetch synchronization status.
The user identified by the username must have write access in the _system
database of the source ArangoDB cluster.
spec.source.tls.caSecretName: string
This setting specifies the name of a Secret
containing a TLS CA certificate ca.crt
used to verify
the TLS connection created by the SyncMaster at the specified source.
This setting is required, unless spec.source.deploymentName
has been set.
spec.destination.deploymentName: string
This setting specifies the name of an ArangoDeployment
resource that runs a cluster
with sync enabled.
This cluster configured as the replication destination.
spec.destination.masterEndpoint: []string
This setting specifies zero or more master endpoint URLs of the destination cluster.
Use this setting if the destination cluster is not running inside a Kubernetes cluster
that is reachable from the Kubernetes cluster the ArangoDeploymentReplication
resource is deployed in.
Specifying this setting and spec.destination.deploymentName
at the same time is not allowed.
spec.destination.auth.keyfileSecretName: string
This setting specifies the name of a Secret
containing a client authentication certificate called tls.keyfile
used to authenticate
with the SyncMaster at the specified destination.
If spec.destination.auth.userSecretName
has not been set,
the client authentication certificate found in the secret with this name is also used to configure
the synchronization and fetch the synchronization status.
This setting is required, unless spec.destination.deploymentName
or spec.destination.auth.userSecretName
has been set.
Specifying this setting and spec.destination.userSecretName
at the same time is not allowed.
spec.destination.auth.userSecretName: string
This setting specifies the name of a Secret
containing a username
& password
used to authenticate
with the SyncMaster at the specified destination in order to configure synchronization and fetch synchronization status.
The user identified by the username must have write access in the _system
database of the destination ArangoDB cluster.
Specifying this setting and spec.destination.keyfileSecretName
at the same time is not allowed.
spec.destination.tls.caSecretName: string
This setting specifies the name of a Secret
containing a TLS CA certificate ca.crt
used to verify
the TLS connection created by the SyncMaster at the specified destination.
This setting is required, unless spec.destination.deploymentName
has been set.
Authentication details
The authentication settings in a ArangoDeploymentReplication
resource are used for two distinct purposes.
The first use is the authentication of the syncmasters at the destination with the syncmasters at the source.
This is always done using a client authentication certificate which is found in a tls.keyfile
field
in a secret identified by spec.source.auth.keyfileSecretName
.
The second use is the authentication of the ArangoDB Replication operator with the syncmasters at the source
or destination. These connections are made to configure synchronization, stop configuration and fetch the status
of the configuration.
The method used for this authentication is derived as follows (where X
is either source
or destination
):
- If
spec.X.userSecretName
is set, the username + password found in theSecret
identified by this name is used. - If
spec.X.keyfileSecretName
is set, the client authentication certificate (keyfile) found in theSecret
identifier by this name is used. - If
spec.X.deploymentName
is set, the JWT secret found in the deployment is used.
Creating client authentication certificate keyfiles
The client authentication certificates needed for the Secrets
identified by spec.source.auth.keyfileSecretName
& spec.destination.auth.keyfileSecretName
are normal ArangoDB keyfiles that can be created by the arangosync create client-auth keyfile
command.
In order to do so, you must have access to the client authentication CA of the source/destination.
If the client authentication CA at the source/destination also contains a private key (ca.key
), the ArangoDeployment operator
can be used to create such a keyfile for you, without the need to have arangosync
installed locally.
Read the following paragraphs for instructions on how to do that.
Creating and using access packages
An access package is a YAML file that contains:
- A client authentication certificate, wrapped in a
Secret
in atls.keyfile
data field. - A TLS certificate authority public key, wrapped in a
Secret
in aca.crt
data field.
The format of the access package is such that it can be inserted into a Kubernetes cluster using the standard kubectl
tool.
To create an access package that can be used to authenticate with the ArangoDB SyncMasters of an ArangoDeployment
,
add a name of a non-existing Secret
to the spec.sync.externalAccess.accessPackageSecretNames
field of the ArangoDeployment
.
In response, a Secret
is created in that Kubernetes cluster, with the given name, that contains a accessPackage.yaml
data field
that contains a Kubernetes resource specification that can be inserted into the other Kubernetes cluster.
The process for creating and using an access package for authentication at the source cluster is as follows:
- Edit the
ArangoDeployment
resource of the source cluster, setspec.sync.externalAccess.accessPackageSecretNames
to["my-access-package"]
- Wait for the
ArangoDeployment
operator to create aSecret
namedmy-access-package
. - Extract the access package from the Kubernetes source cluster using:
kubectl get secret my-access-package --template='{{index .data "accessPackage.yaml"}}' | base64 -D > accessPackage.yaml
- Insert the secrets found in the access package in the Kubernetes destination cluster using:
kubectl apply -f accessPackage.yaml
As a result, the destination Kubernetes cluster will have 2 additional Secrets
. One contains a client authentication certificate
formatted as a keyfile. Another contains the public key of the TLS CA certificate of the source cluster.