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Helm Chart

PGO: The Postgres Operator Helm Chart

Overview

PGO, the Postgres Operator from Crunchy Data, comes with a container called pgo-deployer which handles a variety of lifecycle actions for the PostgreSQL Operator, including:

  • Installation
  • Upgrading
  • Uninstallation

After configuring the values.yaml file with you configuration options, the installer will be run using the helm command line tool and takes care of setting up all of the objects required to run the PostgreSQL Operator.

The postgres-operator Helm chart is available in the Helm directory in the PostgreSQL Operator repository.

Requirements

RBAC

The Helm chart will create the ServiceAccount, ClusterRole, and ClusterRoleBinding that are required to run the pgo-deployer. If you have already configured the ServiceAccount and ClusterRoleBinding for the installation process (e.g. from a previous installation), you can disable their creation using the rbac.create and serviceAccount.create variables in the values.yaml file. If these options are disabled, you must provide the name of your preconfigured ServiceAccount using serviceAccount.name.

Namespace

In order to install the PostgreSQL Operator using the Helm chart you will need to first create the namespace in which the pgo-deployer will be run. By default, it will run in the namespace that is provided to helm at the command line.

kubectl create namespace <namespace>
helm install postgres-operator -n <namespace> /path/to/chart_dir

The PostgreSQL Operator has the ability to manage PostgreSQL clusters across multiple Kubernetes Namespaces, including the ability to add and remove Namespaces that it watches. Doing so does require the PostgreSQL Operator to have elevated privileges, and as such, the PostgreSQL Operator comes with three “namespace modes” to select what level of privileges to provide. Detailed information about these “namespace modes” can be found in the Namespace section here.

Config Map

The pgo-deployer uses a Kubernetes ConfigMap to pass configuration options into the installer. The values in your values.yaml file will be used to populate the configuation options in the ConfigMap.

Configuration - values.yaml

The values.yaml file contains all of the configuration parametes for deploying the PostgreSQL Operator. The values.yaml file contains the defaults that should work in most Kubernetes environments, but it may require some customization.

For a detailed description of each configuration parameter, please read the PostgreSQL Operator Installer Configuration Reference

Installation

Once you have configured the PostgreSQL Operator Installer to your specification, you can install the PostgreSQL Operator with the following command:

helm install <name> -n <namespace> /path/to/chart_dir
Take note of the name used when installing, this name will be used to upgrade and uninstall the PostgreSQL Operator.

Install the pgo Client

To use the pgo Client, there are a few additional steps to take in order to get it to work with your PostgreSQL Operator installation. For convenience, you can download and run the client-setup.sh script in your local environment:

curl https://raw.githubusercontent.com/CrunchyData/postgres-operator/master/installers/kubectl/client-setup.sh > client-setup.sh
chmod +x client-setup.sh
./client-setup.sh
Running this script can cause existing pgo client binary, pgouser, client.crt, and client.key files to be overwritten.

The client-setup.sh script performs the following tasks:

  • Sets $PGO_OPERATOR_NAMESPACE to pgo if it is unset. This is the default namespace that the PostgreSQL Operator is deployed to
  • Checks for valid Operating Systems and determines which pgo binary to download
  • Creates a directory in $HOME/.pgo/$PGO_OPERATOR_NAMESPACE (e.g. /home/hippo/.pgo/pgo)
  • Downloads the pgo binary, saves it to in $HOME/.pgo/$PGO_OPERATOR_NAMESPACE, and sets it to be executable
  • Pulls the TLS keypair from the PostgreSQL Operator pgo.tls Secret so that the pgo client can communicate with the PostgreSQL Operator. These are saved as client.crt and client.key in the $HOME/.pgo/$PGO_OPERATOR_NAMESPACE path.
  • Pulls the pgouser credentials from the pgouser-admin secret and saves them in the format username:password in a file called pgouser
  • client.crt, client.key, and pgouser are all set to be read/write by the file owner. All other permissions are removed.
  • Sets the following environmental variables with the following values:
export PGOUSER=$HOME/.pgo/$PGO_OPERATOR_NAMESPACE/pgouser
export PGO_CA_CERT=$HOME/.pgo/$PGO_OPERATOR_NAMESPACE/client.crt
export PGO_CLIENT_CERT=$HOME/.pgo/$PGO_OPERATOR_NAMESPACE/client.crt
export PGO_CLIENT_KEY=$HOME/.pgo/$PGO_OPERATOR_NAMESPACE/client.key

For convenience, after the script has finished, you can permanently add these environmental variables to your environment:

cat <<EOF >> ~/.bashrc
export PATH="$HOME/.pgo/$PGO_OPERATOR_NAMESPACE:$PATH"
export PGOUSER="$HOME/.pgo/$PGO_OPERATOR_NAMESPACE/pgouser"
export PGO_CA_CERT="$HOME/.pgo/$PGO_OPERATOR_NAMESPACE/client.crt"
export PGO_CLIENT_CERT="$HOME/.pgo/$PGO_OPERATOR_NAMESPACE/client.crt"
export PGO_CLIENT_KEY="$HOME/.pgo/$PGO_OPERATOR_NAMESPACE/client.key"
EOF

By default, the client-setup.sh script targets the user that is stored in the pgouser-admin secret in the pgo ($PGO_OPERATOR_NAMESPACE) Namespace. If you wish to use a different Secret, you can set the PGO_USER_ADMIN environmental variable.

For more detailed information about installing the pgo client, please see Installing the pgo client.

Verify the Installation

One way to verify the installation was successful is to execute the pgo version command.

In a new console window, run the following command to set up a port forward:

kubectl -n pgo port-forward svc/postgres-operator 8443:8443

In another console window, run the pgo version command:

pgo version

If successful, you should see output similar to this:

pgo client version 4.7.17
pgo-apiserver version 4.7.17

Upgrade and Uninstall

Once install has be completed using Helm, it will also be used to upgrade and uninstall your PostgreSQL Operator.

The name and namespace in the following sections should match the options provided at install.

Upgrade

To make changes to your deployment of the PostgreSQL Operator you will use the helm upgrade command. Once the configuration changes have been made to you values.yaml file, you can run the following command to implement them in the deployment:

helm upgrade <name> -n <namespace> /path/to/updated_chart

Uninstall

To uninstall the PostgreSQL Operator you will use the helm uninstall command. This will uninstall the operator and clean up resources used by the pgo-deployer.

helm uninstall <name> -n <namespace>

Debugging

When the pgo-deployer job does not complete successfully, the resources that are created and normally cleaned up by Helm will be left in your Kubernetes cluster. This will allow you to use the failed job and its logs to debug the issue. The following command will show the logs for the pgo-deployer job:

kubectl logs -n <namespace> job.batch/pgo-deploy

You can also view the logs as the job is running by using the kubectl -f follow flag:

kubectl logs -n <namespace> job.batch/pgo-deploy -f

These logs will provide feedback if there are any misconfigurations in your install. Once you have finished debugging the failed job and fixed any configuration issues, you can take steps to re-run your install, upgrade, or uninstall. By running another command the resources from the failed install will be cleaned up so that a successfull install can run.