General Usage Engine Private Edition Preparations (4.1)

Add Helm Repository

Add the helm repository where the Usage Engine Private Edition helm chart is located like this:

helm repo add digitalroute https://digitalroute-public.github.io/usage-engine-private-edition

Although not a strict requirement, the install commands used throughout this installation guide assumes that the repository has been added like this.

Container Images

Usage Engine Private Edition consists of the following container images hosted in the Digital Route AWS ECR registry:

Name	Description
`462803626708.dkr.ecr.eu-west-1.amazonaws.com/usage-engine-private-edition:<version>`	This is the container image used by the platform pod.
`462803626708.dkr.ecr.eu-west-1.amazonaws.com/usage-engine-private-edition:<version>-ec`	This is the container image used by EC pods.
`462803626708.dkr.ecr.eu-west-1.amazonaws.com/usage-engine-private-edition:<version>-operator`	This is the container image used by the uepe-operator pod.
`462803626708.dkr.ecr.eu-west-1.amazonaws.com/usage-engine-private-edition:<version>-ui`	This is the container image used by the desktop-online pod.

Where <version> is the desired Usage Engine Private Edition version. For instance 4.0.0.

Since Usage Engine Private Edition 3.1, the container images have multi-architecture support (AMD and ARM).

Hosting Container Images in Your Own Container Registry

If you have your own container registry, it is recommended that you host the Usage Engine Private Edition container images there rather than in the Digital Route AWS ECR registry.

In order to access the container images in the Digital Route AWS ECR registry, you will need to authenticate yourself first. Here is how you can do this using the docker CLI:

docker login -u AWS \
-p $(AWS_ACCESS_KEY_ID=<your aws access key> AWS_SECRET_ACCESS_KEY=<your aws secret access key> aws ecr get-login-password --region eu-west-1) \
462803626708.dkr.ecr.eu-west-1.amazonaws.com

Where <your aws access key> and <your aws secret access key> are the access keys provided by Digital Route (see General Pre-requisites | ECR Access Keys in case you have not received any access keys yet).

Once authenticated, you can pull the container images, re-tag them and then finally push them to your own container image repository.

Depending on how your container registry is configured, you probably need to set up an image pull secret that allows the Kubernetes cluster to pull the container images from your container registry in runtime.

Image Pull Secret for Digital Route AWS ECR

On the other hand, if you do not have your own container image registry, then you need to set up an image pull secret that allows the Kubernetes cluster to pull the container images from the Digital Route AWS ECR in runtime.

Such a secret can be created like this:

kubectl create secret docker-registry ecr-cred \
    --docker-server=https://462803626708.dkr.ecr.eu-west-1.amazonaws.com  \
    --docker-username=AWS \
    --docker-password=$(AWS_ACCESS_KEY_ID=<your aws access key> AWS_SECRET_ACCESS_KEY=<your aws secret access key> aws ecr get-login-password --region eu-west-1) \
    -n uepe

Where <your aws access key> and <your aws secret access key> are the access keys provided by Digital Route (see General Pre-requisites | ECR Access Keys in case you have not received any access keys yet).

Since AWS ECR credentials expire after 12 hours, the image pull secret needs to be refreshed regularly. This can be automated through a cron job. The following yaml spec is an example of such a cron job:

Where <your aws access key> and <your aws secret access key> are the access keys provided by Digital Route (see General Pre-requisites | ECR Access Keys in case you have not received any access keys yet).

Simply put the above yaml spec into a file called ecr-credentials-sync.yaml, and then use the following command to create it in your Kubernetes cluster:

System Database

The Usage Engine Private Edition helm chart is capable of automatically creating the system database at install time. However, that assumes that you are able to supply database administrator credentials (see Bootstrapping System Credentials).

If, for one reason or another, you are unable to supply that, the system database must be created manually prior to installing the Usage Engine Private Edition helm chart.

A tool called uepe-sys-db-tool.jar is provided to facilitate this.

To use it, simply go to Release Information, download it for the relevant version, and then execute it like this:

The instructions on screen will guide you through the process of configuring the database, and once done, a set of database scripts will be generated. These database scripts can then be used to create the system database.

TLS

It is strongly recommended to install Usage Engine Private Edition with TLS enabled, and there are two different ways of providing the required certificate:

cert-manager
Secret

Here follows an explanation of the preparations required for each of the two.

cert-manager

The most automated and secure way to provide the certificate is to use https://cert-manager.io/ .

If it is not already installed in your Kubernetes cluster, follow these instructions on how to install the cert-manager https://cert-manager.io/docs/installation/helm/ chart. Make sure to install a version that is listed in the Compatibility Matrix (4.1).

Cert-manager must be backed by a certificate authority (CA) to sign the certificates. Once configured with a CA, cert-manager will automatically sign and renew certificates for the system as needed. Configuring cert-manager with a CA is done by creating an Issuer or ClusterIssuer resource (this resource will be referenced later when installing Usage Engine Private Edition).

Refer to https://cert-manager.io/docs/configuration/ for a all the details.

It’s also possible to use an issuer specifiction that will issue a self-signed certificate:

Note that this is only recommended for testing purposes and not in production.

Regardless of the chosen issuer specification, to create the issuer, simply put the specification in a yaml file (here we call it example-issuer.yaml), and then execute a command like this:

Based on the example above the created ClusterIssuer can be inspected like this:

Secret

If you do not want to automate the certificate provisioning with cert-manager, you can instead manually install a public certificate in a Kubernetes Secret and then refer to that when installing Usage Engine Private Edition.

The Secret must include a keystore file (keystore.jks) in JKS format as well as separate files for key (tls.key) and certificate (tls.crt).

This is an example script that can generate a Secret like that (make sure to set the parameters at the beginning of the script before executing it):

Note that this will generate a self-signed certificate, which is not suitable for use in publicly exposed interfaces.

Once the Secret has been generated, its content can be inspected like this:

Bootstrapping System Credentials

Usage Engine Private Edition uses a number of system credentials in order to function as expected.

These system credentials are kept in a Kubernetes secret called env-secrets located in the same namespace as where Usage Engine Private Edition is being installed.

This secret can be populated in three different ways:

Manually creating and populating it prior to installing Usage Engine Private Edition.
Providing the credential(s) as helm values at install time. In which case the secret will be automatically created (if it does not already exist) and populated with the corresponding helm value(s). Be aware that storing credentials in a values.yaml file in version control is not secure. If you still need to do this you should consider using tools like https://github.com/mozilla/sops .
Letting it be automatically populated at install time. In which case the secret will be automatically created and populated. Passwords will consist of eight randomly generated characters.

Note that the three options are not mutually exclusive. It is possible to populate some credentials in advance, some through helm values, and let some be automatically generated.

Here follows an explanation of the system credentials used by Usage Engine Private Edition:

Secret Key	Corresponding Helm Value	Description
`jdbcUser`	`platform.db.jdbcUser`	The user that Usage Engine Private Edition uses when connecting to the system database.
`jdbcPassword`	`platform.db.jdbcPassword`	The password of the user that Usage Engine Private Edition uses when connecting to the system database. See `jdbcUser`. If you created the system database manually (see the preparations for System Database), then you need to make sure to use the same password here.
`mzownerPassword`	`postgres.mzownerPassword` or `oracle.mzownerPassword`	The password of the user owning the system database schema. If you created the system database manually (see the preparations for System Database), then you need to make sure to use the same password here.
`postgresqlPassword`	`postgres.adminPassword`	The PostgreSQL database administrator password. Only relevant when using PostgreSQL to store the system database. Required in order to have the system database automatically created when installing Usage Engine Private Edition. If you created the system database manually (see the preparations for System Database), then you do not need to set this at all.
`oraclePassword`	`oracle.adminPassword`	The Oracle database administrator password. Only relevant when using Oracle to store the system database. Required in order to have the system database automatically created when installing Usage Engine Private Edition. If you created the system database manually (see the preparations for System Database), then you do not need to set this at all.
`saphanaPassword`	`saphana.adminPassword`	The SAP HANA database administrator password. Only relevant when using SAP HANA to store the system database. Required in order to have the system database automatically created when installing Usage Engine Private Edition. If you created the system database manually (see the preparations for System Database), then you do not need to set this at all.
`operatorPassword`	`operator.operatorPassword`	The password of the `mzk8soperator` user. This user is used for internal communication between the Operator and the Platform.
`tlsKeystorePassword`	`platform.tls.key.storepassword`	Keystore password. Used when installing Usage Engine Private Edition with TLS enabled. You need to make sure that this password matches how the certificate was set up when preparing for TLS.
`tlsKeyPassword`	`platform.tls.key.password`	Key password. Used when installing Usage Engine Private Edition with TLS enabled. You need to make sure that this password matches how the certificate was set up when preparing for TLS.

This is an example of how to create and populate the secret with some credentials:

To inspect the content of the secret, simply execute the following command:

To retrieve a given credential in cleartext, simply execute a command like this: