Postgresql

PostgreSQL (Postgres) is an open source object-relational database known for reliability and data integrity. ACID-compliant, it supports foreign keys, joins, views, triggers and stored procedures.

Prerequisites

This example assumes that you have a Kubernetes cluster installed and running, and that you have installed the kubectl command line tool and helm somewhere in your path. Please see the getting started and Installing Helm for installation instructions for your platform.

Also, this example requires kubeblocks installed and running. Here is the steps to install kubeblocks, please replace "$kb_version" with the version you want to use.

# Add Helm repo 
helm repo add kubeblocks https://apecloud.github.io/helm-charts
# If github is not accessible or very slow for you, please use following repo instead
helm repo add kubeblocks https://jihulab.com/api/v4/projects/85949/packages/helm/stable

# Update helm repo
helm repo update

# Get the versions of KubeBlocks and select the one you want to use
helm search repo kubeblocks/kubeblocks --versions
# If you want to obtain the development versions of KubeBlocks, Please add the '--devel' parameter as the following command
helm search repo kubeblocks/kubeblocks --versions --devel

# Create dependent CRDs
kubectl create -f https://github.com/apecloud/kubeblocks/releases/download/v$kb_version/kubeblocks_crds.yaml
# If github is not accessible or very slow for you, please use following command instead
kubectl create -f https://jihulab.com/api/v4/projects/98723/packages/generic/kubeblocks/v$kb_version/kubeblocks_crds.yaml

# Install KubeBlocks
helm install kubeblocks kubeblocks/kubeblocks --namespace kb-system --create-namespace --version="$kb_version"

Examples

Create

Create a postgresql cluster with specified cluster definition

kubectl apply -f examples/postgresql/cluster.yaml

Starting from kubeblocks 0.9.0, we introduced a more flexible cluster creation method based on components, allowing customization of cluster topology, functionalities and scale according to specific requirements.

kubectl apply -f examples/postgresql/cluster-cmpd.yaml

Horizontal scaling

Horizontal scaling out or in specified components replicas in the cluster

kubectl apply -f examples/postgresql/horizontalscale.yaml

Vertical scaling

Vertical scaling up or down specified components requests and limits cpu or memory resource in the cluster

kubectl apply -f examples/postgresql/verticalscale.yaml

Expand volume

Increase size of volume storage with the specified components in the cluster

kubectl apply -f examples/postgresql/volumeexpand.yaml

Restart

Restart the specified components in the cluster

kubectl apply -f examples/postgresql/restart.yaml

Stop

Stop the cluster and release all the pods of the cluster, but the storage will be reserved

kubectl apply -f examples/postgresql/stop.yaml

Start

Start the stopped cluster

kubectl apply -f examples/postgresql/start.yaml

Switchover

Switchover a non-primary or non-leader instance as the new primary or leader of the cluster

kubectl apply -f examples/postgresql/switchover.yaml

Switchover-specified-instance

Switchover a specified instance as the new primary or leader of the cluster

kubectl apply -f examples/postgresql/switchover-specified-instance.yaml

Configure

Configure parameters with the specified components in the cluster

kubectl apply -f examples/postgresql/configure.yaml

BackupRepo

BackupRepo is the storage repository for backup data, using the full backup and restore function of KubeBlocks relies on BackupRepo

# Create a secret to save the access key
kubectl create secret generic <storage-provider>-credential-for-backuprepo\
  --from-literal=accessKeyId=<ACCESS KEY> \
  --from-literal=secretAccessKey=<SECRET KEY> \
  -n kb-system 
  
kubectl apply -f examples/postgresql/backuprepo.yaml

Backup

Create pg-basebackup or volume-snapshot backup for the cluster

kubectl apply -f examples/postgresql/backup.yaml

Create wal-g backup for the cluster

# Step 1: you cannot do wal-g backup for a brand-new cluster, you need to insert some data before backup
# step 2: config-wal-g backup to put the wal-g binary to postgresql pods and configure the archive_command
# Note: if there is horizontal scaling out new pods after step 2, you need to do config-wal-g again
kubectl apply -f examples/postgresql/config-wal-g.yaml
# Step 3: do wal-g backup
kubectl apply -f examples/postgresql/backup-wal-g.yaml
# Step 4:log in to the cluster, and manually upload wal with following sql statement
select pg_switch_wal();

Restore

Restore a new cluster from backup

# Get backup connection password
kubectl get backup pg-cluster-backup -ojsonpath='{.metadata.annotations.dataprotection\.kubeblocks\.io\/connection-password}' -n default

kubectl apply -f examples/postgresql/restore.yaml

Expose

Expose a cluster with a new endpoint

Enable

kubectl apply -f examples/postgresql/expose-enable.yaml

Disable

kubectl apply -f examples/postgresql/expose-disable.yaml

Upgrade

Upgrade pg cluster to a newer version

kubectl apply -f examples/postgresql/upgrade.yaml

Delete

If you want to delete the cluster and all its resource, you can modify the termination policy and then delete the cluster

kubectl patch cluster pg-cluster -p '{"spec":{"terminationPolicy":"WipeOut"}}' --type="merge"

kubectl delete cluster pg-cluster