Deploy in an offline or air-gapped environment

An air-gapped environment refers to a system that does not have access to the public internet. This guide goes through the special configuration steps for installing Charmed PostgreSQL k8s in an air-gapped environment.

Requirements

Canonical does not prescribe how you should set up your specific air-gapped environment. However, it is assumed that it meets the following conditions:

• A K8s cluster is running.
• DNS is configured to the local nameservers.
• Juju is configured to use local air-gapped services.
• The store-admin tool is installed and configured.
• Air-gapped CharmHub is installed and running.
• Local APT and LXD Images caches are reachable.
• An air-gapped container registry (such as Artifactory) is reachable from the K8s cluster over HTTPS
  • Note: Secure (HTTPS) OCI access is important, otherwise Juju won’t work!

Air-gapped setup summary

1. Export charms and resources
2. Transfer binary blobs
3. Import charms and resources
4. Deploy PostgreSQL

Air-gapped day-to-day example

1. Export charms and resources

Exporting K8s Charms and OCI Resources are currently independent processes. The store-admin tool is designed to simplify the process.

Future improvements are planned to the store-admin tool so that it could potentially export all necessary OCI resource(s) from the official CharmHub store. Other planned improvements include supporting the export of specific charm and resource revisions (PF-5369, PF-5185).

Charms

The necessary charm(s) can be exported as bundle or independently (charm-by-charm). See the Snap Proxy documentation:

• Offline Charmhub configuration > Export charm bundle
• Offline Charmhub configuration > Export charms

At the moment, the store-admin tool only exports and includes the OCI resources’ metadata into the blob:

Downloading postgresql-k8s-bundle revision 141 (14/edge)
[####################################]  100%
Downloading data-integrator revision 71 (edge)
[####################################]  100%
Downloading grafana-agent-k8s revision 93 (edge)
[####################################]  100%
Downloading resources for grafana-agent-k8s
Downloading oci-image resource agent-image revision 45
[####################################]  100%
Falling back to OCI image subpath from online Charmhub for 'agent-image' in charm 'grafana-agent-k8s'.
Downloading pgbouncer-k8s revision 301 (1/edge)
[####################################]  100%
Downloading resources for pgbouncer-k8s
Downloading oci-image resource pgbouncer-image revision 85
[####################################]  100%
Falling back to OCI image subpath from online Charmhub for 'pgbouncer-image' in charm 'pgbouncer-k8s'.
Downloading postgresql-k8s revision 406 (14/edge)
[####################################]  100%
Downloading resources for postgresql-k8s
Downloading oci-image resource postgresql-image revision 164
[####################################]  100%
Falling back to OCI image subpath from online Charmhub for 'postgresql-image' in charm 'postgresql-k8s'.
Downloading postgresql-test-app revision 254 (edge)
[####################################]  100%
Downloading s3-integrator revision 59 (edge)
[####################################]  100%
Downloading self-signed-certificates revision 200 (edge)
[####################################]  100%
Downloading sysbench revision 78 (edge)
[####################################]  100%
Successfully exported charm bundle postgresql-k8s-bundle: /home/ubuntu/snap/store-admin/common/export/postgresql-k8s-bundle-20241003T104903.tar.gz

OCI images

For manual OCI exports, follow the official Snap Store Proxy documentation: Offline Charmhub configuration > Export OCI images.

2. Transfer the binary blobs

Transfer the binary blobs using the way of your choice into the air-gapped environment.

cp /home/ubuntu/snap/store-admin/common/export/postgresql-k8s-bundle-20241003T104903.tar.gz /media/usb/
...
cp /media/usb/postgresql-k8s-bundle-20241003T104903.tar.gz /var/snap/snap-store-proxy/common/charms-to-push/

Note: always check checksum for the transferred blobs!

3. Import charms and resources

Charms

Upload the charm blobs into local air-gapped CharmHub:

sudo snap-store-proxy push-charm-bundle /var/snap/snap-store-proxy/common/charms-to-push/postgresql-k8s-bundle-20241003T104903.tar.gz

Note: when re-importing charms or importing other revisions, make sure to provide the --push-channel-map.

OCI resources

Upload the charm OCI into local Air-gapped OCI registry.

For the manual OCI import, please follow the official CharmHub guide.

For more details about exporting charms and resources, see:

Snap Store Proxy documentation > Offline Charmhub configuration > Import packages

4. Deploy PostgreSQL

Deploy and operate Juju charms normally:

juju deploy postgresql-k8s --trust

Additional resources

• Offline store (air-gapped mode) | Snap Store Proxy documentation
• https://documentation.ubuntu.com/snap-store-proxy/
• https://documentation.ubuntu.com/snap-store-proxy/en/airgap-charmhub/
• https://ubuntu.com/kubernetes/docs/install-offline
• Charmed Kubeflow > Install in an airgapped environment
• Wikipedia > Air gap (networking)