gcp integrator #3

Supports: xenial bionic

Add to new model

Description

This charm can grant select permissions to instances of applications
related to it which enable integration with GCP specific features,
such as firewalls, load balancing, block storage, object storage, etc.


Overview

This charm acts as a proxy to GCP and provides an interface to apply a
certain set of changes via roles, profiles, and tags to the instances of
the applications that are related to this charm.

Usage

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

For example, CDK has support for this, and can be deployed with the
following bundle overlay:

yaml applications: gcp-integrator: charm: cs:~containers/gcp-integrator num_units: 1 relations: - ['gcp-integrator', 'kubernetes-master'] - ['gcp-integrator', 'kubernetes-worker']

Then deploy CDK using this overlay:

juju deploy cs:canonical-kubernetes --overlay ./k8s-gcp-overlay.yaml

The charm then needs to be granted access to credentials that it can use to
setup integrations. Using Juju 2.4 or later, you can easily grant access to
the credentials used deploy the integrator itself:

juju trust gcp-integrator

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

Note: The credentials used must be enabled to use the API to inspect the instances connecting to it, enable a service account for those
instances, assign roles to those instances, and create custom roles.

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 Google Cloud console or API.

Examples

Following are some examples using GCP integration with CDK.

Creating a pod with a PersistentDisk-backed volume

This script creates a busybox pod with a persistent volume claim backed by
GCE's PersistentDisk.

```sh

!/bin/bash

create a storage class using the kubernetes.io/gce-pd provisioner

kubectl create -f - <<EOY
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
name: gce-standard provisioner: kubernetes.io/gce-pd
parameters:
type: pd-standard EOY

create a persistent volume claim using that storage class

kubectl create -f - <<EOY
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: testclaim spec:
accessModes: - ReadWriteOnce resources: requests: storage: 100Mi storageClassName: gce-standard 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 GCE load-balancer

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

```sh

!/bin/bash

kubectl run hello-world --replicas=5 --labels="run=load-balancer-example" --image=gcr.io/google-samples/node-hello:1.0 --port=8080
kubectl expose deployment hello-world --type=LoadBalancer --name=hello
watch kubectl get svc -o wide --selector=run=load-balancer-example
```


Configuration

credentials
(string) The base64-encoded contents of an GCP credentials JSON file. This can be used from bundles with 'include-base64://' (see https://jujucharms.com/docs/stable/charms-bundles#setting-charm-configurations-options-in-a-bundle), or from the command-line with 'juju config gcp credentials="$(base64 /path/to/file)"'. It is strongly recommended that you use 'juju trust' instead, if available.
snap_proxy
(string) HTTP/HTTPS web proxy for Snappy to use when accessing the snap store.
snap_proxy_url
(string) The address of a Snap Store Proxy to use for snaps e.g. http://snap-proxy.example.com
snapd_refresh
(string) 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