Install Percona server for MongoDB on Kubernetes¶
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Clone the percona-server-mongodb-operator repository:
$ git clone -b v1.20.0 https://github.com/percona/percona-server-mongodb-operator $ cd percona-server-mongodb-operator
Note
It is crucial to specify the right branch with
-b
option while cloning the code on this step. Please be careful. -
The Custom Resource Definition for Percona Server for MongoDB should be created from the
deploy/crd.yaml
file. The Custom Resource Definition extends the standard set of resources which Kubernetes “knows” about with the new items, in our case these items are the core of the operator. Apply it as follows:$ kubectl apply --server-side -f deploy/crd.yaml
This step should be done only once; the step does not need to be repeated with any other Operator deployments.
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Create a namespace and set the context for the namespace. The resource names must be unique within the namespace and provide a way to divide cluster resources between users spread across multiple projects.
So, create the namespace and save it in the namespace context for subsequent commands as follows (replace the
<namespace name>
placeholder with some descriptive name):$ kubectl create namespace <namespace name> $ kubectl config set-context $(kubectl config current-context) --namespace=<namespace name>
At success, you will see the message that
namespace/<namespace name>
was created, and the context was modified. -
The role-based access control (RBAC) for Percona Server for MongoDB is configured with the
deploy/rbac.yaml
file. Role-based access is based on defined roles and the available actions which correspond to each role. The role and actions are defined for Kubernetes resources in the yaml file. Further details about users and roles can be found in Kubernetes documentation .$ kubectl apply -f deploy/rbac.yaml
Note
Setting RBAC requires your user to have cluster-admin role privileges. For example, those using Google Kubernetes Engine can grant user needed privileges with the following command:
$ kubectl create clusterrolebinding cluster-admin-binding --clusterrole=cluster-admin --user=$(gcloud config get-value core/account)
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Start the operator within Kubernetes:
$ kubectl apply -f deploy/operator.yaml
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Add the MongoDB Users secrets to Kubernetes. These secrets should be placed as plain text in the stringData section of the
deploy/secrets.yaml
file as login name and passwords for the user accounts (see Kubernetes documentation for details).After editing the yaml file, MongoDB Users secrets should be created using the following command:
$ kubectl create -f deploy/secrets.yaml
More details about secrets can be found in Users.
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Now certificates should be generated. By default, the Operator generates certificates automatically, and no actions are required at this step. Still, you can generate and apply your own certificates as secrets according to the TLS instructions.
-
After the operator is started, Percona Server for MongoDB cluster can be created with the following command:
$ kubectl apply -f deploy/cr.yaml
The creation process may take some time. When the process is over your cluster will obtain the
ready
status. You can check it with the following command:$ kubectl get psmdb
Expected output
NAME ENDPOINT STATUS AGE my-cluster-name my-cluster-name-mongos.default.svc.cluster.local ready 5m26s
Verifying the cluster operation¶
It may take ten minutes to get the cluster started. When kubectl get psmdb
command finally shows you the cluster status as ready
, you can try to connect
to the cluster.
To connect to Percona Server for MongoDB you need to construct the MongoDB connection URI string. It includes the credentials of the admin user, which are stored in the Secrets object.
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List the Secrets objects
$ kubectl get secrets -n <namespace>
The Secrets object you are interested in has the
my-cluster-name-secrets
name by default. -
View the Secret contents to retrieve the admin user credentials.
The command returns the YAML file with generated Secrets, including the$ kubectl get secret my-cluster-name-secrets -o yaml
MONGODB_DATABASE_ADMIN_USER
andMONGODB_DATABASE_ADMIN_PASSWORD
strings, which should look as follows:Sample output
... data: ... MONGODB_DATABASE_ADMIN_PASSWORD: aDAzQ0pCY3NSWEZ2ZUIzS1I= MONGODB_DATABASE_ADMIN_USER: ZGF0YWJhc2VBZG1pbg==
The actual login name and password on the output are base64-encoded. To bring it back to a human-readable form, run:
$ echo 'MONGODB_DATABASE_ADMIN_USER' | base64 --decode $ echo 'MONGODB_DATABASE_ADMIN_PASSWORD' | base64 --decode
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Run a container with a MongoDB client and connect its console output to your terminal. The following command does this, naming the new Pod
percona-client
:$ kubectl run -i --rm --tty percona-client --image=percona/percona-server-mongodb:7.0.18-11 --restart=Never -- bash -il
Executing it may require some time to deploy the corresponding Pod.
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Now run
mongosh
tool inside thepercona-client
command shell using the admin user credentialds you obtained from the Secret, and a proper namespace name instead of the<namespace name>
placeholder. The command will look different depending on whether sharding is on (the default behavior) or off:$ mongosh "mongodb://databaseAdmin:databaseAdminPassword@my-cluster-name-mongos.<namespace name>.svc.cluster.local/admin?ssl=false"
$ mongosh "mongodb+srv://databaseAdmin:databaseAdminPassword@my-cluster-name-rs0.<namespace name>.svc.cluster.local/admin?replicaSet=rs0&ssl=false"