Appendix A - Common object stores for backups ============================================= You can store the :ref:`Appendix A - Common object stores for backups ` files in any service that is supported by the Barman Cloud infrastructure. That is: - :ref:`Amazon S3 <#aws-s3>` - :ref:`Microsoft Azure Blob Storage ` - :ref:`Google Cloud Storage ` You can also use any compatible implementation of the supported services. The required setup depends on the chosen storage provider and is discussed in the following sections. AWS S3 ------ `AWS Simple Storage Service (S3) `_ is a very popular object storage service offered by Amazon. As far as CloudNativePG backup is concerned, you can define the permissions to store backups in S3 buckets in two ways: - If CloudNativePG is running in EKS. you may want to use the `IRSA authentication method `_ - Alternatively, you can use the ``ACCESS_KEY_ID`` and ``ACCESS_SECRET_KEY`` credentials AWS Access key ^^^^^^^^^^^^^^ You will need the following information about your environment: - ``ACCESS_KEY_ID`` : the ID of the access key that will be used to upload files into S3 - ``ACCESS_SECRET_KEY`` : the secret part of the access key mentioned above - ``ACCESS_SESSION_TOKEN`` : the optional session token, in case it is required The access key used must have permission to upload files into the bucket. Given that, you must create a Kubernetes secret with the credentials, and you can do that with the following command: .. code:: sh kubectl create secret generic aws-creds \ --from-literal=ACCESS_KEY_ID= \ --from-literal=ACCESS_SECRET_KEY= # --from-literal=ACCESS_SESSION_TOKEN= # if required The credentials will be stored inside Kubernetes and will be encrypted if encryption at rest is configured in your installation. Once that secret has been created, you can configure your cluster like in the following example: .. code:: yaml apiVersion: postgresql.cnpg.io/v1 kind: Cluster [...] spec: backup: barmanObjectStore: destinationPath: "" s3Credentials: accessKeyId: name: aws-creds key: ACCESS_KEY_ID secretAccessKey: name: aws-creds key: ACCESS_SECRET_KEY The destination path can be any URL pointing to a folder where the instance can upload the WAL files, e.g. ``s3://BUCKET_NAME/path/to/folder`` . IAM Role for Service Account (IRSA) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ In order to use IRSA you need to set an ``annotation`` in the ``ServiceAccount`` of the Postgres cluster. We can configure CloudNativePG to inject them using the ``serviceAccountTemplate`` stanza: .. code:: yaml apiVersion: postgresql.cnpg.io/v1 kind: Cluster metadata: [...] spec: serviceAccountTemplate: metadata: annotations: eks.amazonaws.com/role-arn: arn:[...] [...] S3 lifecycle policy ^^^^^^^^^^^^^^^^^^^ Barman Cloud writes objects to S3, then does not update them until they are deleted by the Barman Cloud retention policy. A recommended approach for an S3 lifecycle policy is to expire the current version of objects a few days longer than the Barman retention policy, enable object versioning, and expire non-current versions after a number of days. Such a policy protects against accidental deletion, and also allows for restricting permissions to the CloudNativePG workload so that it may delete objects from S3 without granting permissions to permanently delete objects. Other S3-compatible Object Storages providers ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ In case you’re using S3-compatible object storage, like **MinIO** or **Linode Object Storage**, you can specify an endpoint instead of using the default S3 one. In this example, it will use the ``bucket`` of **Linode** in the region ``us-east1`` . .. code:: yaml apiVersion: postgresql.cnpg.io/v1 kind: Cluster [...] spec: backup: barmanObjectStore: destinationPath: "s3://bucket/" endpointURL: "https://us-east1.linodeobjects.com" s3Credentials: [...] In case you’re using **Digital Ocean Spaces**, you will have to use the Path-style syntax. In this example, it will use the ``bucket`` from **Digital Ocean Spaces** in the region ``SFO3`` . .. code:: yaml apiVersion: postgresql.cnpg.io/v1 kind: Cluster [...] spec: backup: barmanObjectStore: destinationPath: "s3://[your-bucket-name]/[your-backup-folder]/" endpointURL: "https://sfo3.digitaloceanspaces.com" s3Credentials: [...] .. Important:: Suppose you configure an Object Storage provider which uses a certificate signed with a private CA, like when using MinIO via HTTPS. In that case, you need to set the option `endpointCA` referring to a secret containing the CA bundle so that Barman can verify the certificate correctly. .. Note:: If you want ConfigMaps and Secrets to be **automatically** reloaded by instances, you can add a label with key `cnpg.io/reload` to the Secrets/ConfigMaps. Otherwise, you will have to reload the instances using the `kubectl cnpg reload` subcommand. Azure Blob Storage ------------------ `Azure Blob Storage `_ is the obect storage service provided by Microsoft. In order to access your storage account for backup and recovery of CloudNativePG managed databases, you will need one of the following combinations of credentials: - :ref:`Connection String ` - Storage account name and :ref:`Storage account access key ` - Storage account name and :ref:`Storage account SAS Token ` - Storage account name and `Azure AD Workload Identity `_ properly configured. Using **Azure AD Workload Identity**, you can avoid saving the credentials into a Kubernetes Secret, and have a Cluster configuration adding the ``inheritFromAzureAD`` as follows: .. code:: yaml apiVersion: postgresql.cnpg.io/v1 kind: Cluster [...] spec: backup: barmanObjectStore: destinationPath: "" azureCredentials: inheritFromAzureAD: true On the other side, using both **Storage account access key** or **Storage account SAS Token**, the credentials need to be stored inside a Kubernetes Secret, adding data entries only when needed. The following command performs that: :: kubectl create secret generic azure-creds \ --from-literal=AZURE_STORAGE_ACCOUNT= \ --from-literal=AZURE_STORAGE_KEY= \ --from-literal=AZURE_STORAGE_SAS_TOKEN= \ --from-literal=AZURE_STORAGE_CONNECTION_STRING= The credentials will be encrypted at rest, if this feature is enabled in the used Kubernetes cluster. Given the previous secret, the provided credentials can be injected inside the cluster configuration: .. code:: yaml apiVersion: postgresql.cnpg.io/v1 kind: Cluster [...] spec: backup: barmanObjectStore: destinationPath: "" azureCredentials: connectionString: name: azure-creds key: AZURE_CONNECTION_STRING storageAccount: name: azure-creds key: AZURE_STORAGE_ACCOUNT storageKey: name: azure-creds key: AZURE_STORAGE_KEY storageSasToken: name: azure-creds key: AZURE_STORAGE_SAS_TOKEN When using the Azure Blob Storage, the ``destinationPath`` fulfills the following structure: :: ://..core.windows.net/ where ```` is ``/`` . The **account name**, which is also called **storage account name**, is included in the used host name. Other Azure Blob Storage compatible providers ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ If you are using a different implementation of the Azure Blob Storage APIs, the ``destinationPath`` will have the following structure: :: ://:// In that case, ```` is the first component of the path. This is required if you are testing the Azure support via the Azure Storage Emulator or `Azurite `_ . Google Cloud Storage -------------------- Currently, the CloudNativePG operator supports two authentication methods for `Google Cloud Storage `_ : - the first one assumes that the pod is running inside a Google Kubernetes Engine cluster - the second one leverages the environment variable ``GOOGLE_APPLICATION_CREDENTIALS`` Running inside Google Kubernetes Engine ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ When running inside Google Kubernetes Engine you can configure your backups to simply rely on `Workload Identity `_ , without having to set any credentials. In particular, you need to: - set ``.spec.backup.barmanObjectStore.googleCredentials.gkeEnvironment`` to ``true`` - set the ``iam.gke.io/gcp-service-account`` annotation in the ``serviceAccountTemplate`` stanza Please use the following example as a reference: .. code:: yaml apiVersion: postgresql.cnpg.io/v1 kind: Cluster [...] spec: [...] backup: barmanObjectStore: destinationPath: "gs://" googleCredentials: gkeEnvironment: true serviceAccountTemplate: metadata: annotations: iam.gke.io/gcp-service-account: [...].iam.gserviceaccount.com [...] Using authentication ^^^^^^^^^^^^^^^^^^^^ Following the `instruction from Google `_ you will get a JSON file that contains all the required information to authenticate. The content of the JSON file must be provided using a ``Secret`` that can be created with the following command: .. code:: shell kubectl create secret generic backup-creds --from-file=gcsCredentials=gcs_credentials_file.json This will create the ``Secret`` with the name ``backup-creds`` to be used in the yaml file like this: .. code:: yaml apiVersion: postgresql.cnpg.io/v1 kind: Cluster [...] spec: backup: barmanObjectStore: destinationPath: "gs://" googleCredentials: applicationCredentials: name: backup-creds key: gcsCredentials Now the operator will use the credentials to authenticate against Google Cloud Storage. .. Important:: This way of authentication will create a JSON file inside the container with all the needed information to access your Google Cloud Storage bucket, meaning that if someone gets access to the pod will also have write permissions to the bucket. MinIO Gateway ------------- Optionally, you can use MinIO Gateway as a common interface which relays backup objects to other cloud storage solutions, like S3 or GCS. For more information, please refer to `MinIO official documentation `_ . Specifically, the CloudNativePG cluster can directly point to a local MinIO Gateway as an endpoint, using previously created credentials and service. MinIO secrets will be used by both the PostgreSQL cluster and the MinIO instance. Therefore, you must create them in the same namespace: .. code:: sh kubectl create secret generic minio-creds \ --from-literal=MINIO_ACCESS_KEY= \ --from-literal=MINIO_SECRET_KEY= .. Note:: Cloud Object Storage credentials will be used only by MinIO Gateway in this case. .. Important:: In order to allow PostgreSQL to reach MinIO Gateway, it is necessary to create a `ClusterIP` service on port `9000` bound to the MinIO Gateway instance. For example: .. code:: yaml apiVersion: v1 kind: Service metadata: name: minio-gateway-service spec: type: ClusterIP ports: - port: 9000 targetPort: 9000 protocol: TCP selector: app: minio .. Warning:: At the time of writing this documentation, the official `MinIO Operator `_ for Kubernetes does not support the gateway feature. As such, we will use a ``deployment`` instead. The MinIO deployment will use cloud storage credentials to upload objects to the remote bucket and relay backup files to different locations. Here is an example using AWS S3 as Cloud Object Storage: .. code:: yaml apiVersion: apps/v1 kind: Deployment [...] spec: containers: - name: minio image: minio/minio:RELEASE.2020-06-03T22-13-49Z args: - gateway - s3 env: # MinIO access key and secret key - name: MINIO_ACCESS_KEY valueFrom: secretKeyRef: name: minio-creds key: MINIO_ACCESS_KEY - name: MINIO_SECRET_KEY valueFrom: secretKeyRef: name: minio-creds key: MINIO_SECRET_KEY # AWS credentials - name: AWS_ACCESS_KEY_ID valueFrom: secretKeyRef: name: aws-creds key: ACCESS_KEY_ID - name: AWS_SECRET_ACCESS_KEY valueFrom: secretKeyRef: name: aws-creds key: ACCESS_SECRET_KEY # Uncomment the below section if session token is required # - name: AWS_SESSION_TOKEN # valueFrom: # secretKeyRef: # name: aws-creds # key: ACCESS_SESSION_TOKEN ports: - containerPort: 9000 Proceed by configuring MinIO Gateway service as the ``endpointURL`` in the ``Cluster`` definition, then choose a bucket name to replace ``BUCKET_NAME`` : .. code:: yaml apiVersion: postgresql.cnpg.io/v1 kind: Cluster [...] spec: backup: barmanObjectStore: destinationPath: s3://BUCKET_NAME/ endpointURL: http://minio-gateway-service:9000 s3Credentials: accessKeyId: name: minio-creds key: MINIO_ACCESS_KEY secretAccessKey: name: minio-creds key: MINIO_SECRET_KEY [...] Verify on ``s3://BUCKET_NAME/`` the presence of archived WAL files before proceeding with a backup.