OpenStack integrator charm

This charm acts as a proxy to OpenStack and provides an interface to provide a set of credentials for a somewhat limited project user to the applications that are related to this charm.

Usage

When on OpenStack, this charm can be deployed, granted trust via Juju to access OpenStack, and then related to an application that supports the interface.

For example, Charmed Kubernetes has support for this, and can be deployed with the following bundle overlay (download it here):

applications:
  openstack-integrator:
    charm: cs:~containers/openstack-integrator
    num_units: 1
    trust: true
relations:
  - ['openstack-integrator', 'kubernetes-master:openstack']
  - ['openstack-integrator', 'kubernetes-worker:openstack']

Using Juju 2.4 or later:

juju deploy cs:charmed-kubernetes --overlay ./k8s-openstack-overlay.yaml --trust

To deploy with earlier versions of Juju, you will need to provide the cloud credentials via the credentials, charm config options.

Resource Usage Note

By relating to this charm, other charms can directly allocate resources, such as PersistentDisk volumes and Load Balancers, which could lead to cloud charges and count against quotas. Because these resources are not managed by Juju, they will not be automatically deleted when the models or applications are destroyed, nor will they show up in Juju’s status or GUI. It is therefore up to the operator to manually delete these resources when they are no longer needed, using the OpenStack console or API.

Examples

Following are some examples using OpenStack integration with Charmed Kubernetes.

Creating a pod with a PersistentDisk-backed volume

This script creates a busybox pod with a persistent volume claim backed by OpenStack’s PersistentDisk.

#!/bin/bash

# create a persistent volume claim using the StorageClass which is
# automatically created by Charmed Kubernetes when it is related to
# the openstack-integrator
kubectl create -f - <<EOY
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: testclaim
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 100Mi
  storageClassName: cdk-cinder
EOY

# create the busybox pod with a volume using that PVC:
kubectl create -f - <<EOY
apiVersion: v1
kind: Pod
metadata:
  name: busybox
  namespace: default
spec:
  containers:
    - image: busybox
      command:
        - sleep
        - "3600"
      imagePullPolicy: IfNotPresent
      name: busybox
      volumeMounts:
        - mountPath: "/pv"
          name: testvolume
  restartPolicy: Always
  volumes:
    - name: testvolume
      persistentVolumeClaim:
        claimName: testclaim
EOY

Creating a service with a OpenStack load-balancer

The following script starts the hello-world pod behind a OpenStack-backed load-balancer.

kubectl create deployment hello-world --image=gcr.io/google-samples/node-hello:1.0
kubectl scale deployment hello-world --replicas=5
kubectl expose deployment hello-world --type=LoadBalancer --name=hello --port=8080
watch kubectl get svc hello -o wide

Configuration

bs-version

Description:

Used to override automatic version detection for block storage usage. Valid values are v1, v2, v3 and auto. When auto is specified automatic detection will select the highest supported version exposed by the underlying OpenStack cloud. If not set, will use the upstream default.

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credentials

Description:

The base64-encoded contents of a JSON file containing OpenStack credentials.

The credentials must contain the following keys: auth-url, region, username, password, project-name, user-domain-name, and project-domain-name.

It could also contain a base64-encoded CA certificate in endpoint-tls-ca key value.

This can be used from bundles with ‘include-base64://’ (see https://juju.is/docs/sdk/bundles), or from the command-line with ‘juju config openstack-integrator credentials=”$(base64 /path/to/file)”’.

It is strongly recommended that you use ‘juju trust’ instead, if available.

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endpoint-tls-ca

Description:

A CA certificate that can be used to verify the target cloud API endpoints. Use ‘include-base64://’ in a bundle to include a certificate. Otherwise, pass a base64-encoded certificate (base64 of “—–BEGIN” to “—–END”) as a config option in a Juju CLI invocation.

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floating-network-id

Description:

If set, it will be passed to integrated workloads to indicate that floating IPs should be created in the given network for load balancers that those workloads manage. For example, this will determine whether and where FIPs will be created by Kubernetes for LoadBalancer type services in the cluster.

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ignore-volume-az

Description:

Used to influence availability zone use when attaching Cinder volumes. When Nova and Cinder have different availability zones, this should be set to true. This is most commonly the case where there are many Nova availability zones but only one Cinder availability zone. If not set, will use the upstream default.

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lb-method

Description:

Algorithm that will be used by load balancers, which must be one of: ROUND_ROBIN, LEAST_CONNECTIONS, SOURCE_IP. This applies both to load balancers managed by this charm for applications related via the loadbalancer endpoint, as well as to load balancers managed by integrated workloads, such as Kubernetes.

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lb-subnet

Description:

Override the subnet (name or ID) in which this charm will create load balancers for other charms related on the loadbalancer endpoint. If not set, the subnet over which the requesting application is related will be used.

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manage-security-groups

Description:

Whether or not each load balancer should have its own security group, or if all load balancers should use the default security group for the project. This applies both to load balancers managed by this charm for applications related via the loadbalancer endpoint, as well as to load balancers managed by integrated workloads, such as Kubernetes.

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snapd_refresh

Description:

How often snapd handles updates for installed snaps. The default (an empty string) is 4x per day. Set to “max” to check once per month based on the charm deployment date. You may also set a custom string as described in the ‘refresh.timer’ section here: https://forum.snapcraft.io/t/system-options/87

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subnet-id

Description:

If set, it will be passed to integrated workloads to indicate in what subnet load balancers should be created. For example, this will determine what subnet Kubernetes uses for LoadBalancer type services in the cluster.

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trust-device-path

Description:

In most scenarios the block device names provided by Cinder (e.g. /dev/vda) can not be trusted. This boolean toggles this behavior. Setting it to true results in trusting the block device names provided by Cinder. The value of false results in the discovery of the device path based on its serial number and /dev/disk/by-id mapping and is the recommended approach. If not set, will use the upstream default.

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