Charmed OSM upgrade to v12 procedure

At this point, OSM LTS is operational and ready to use.

## Upgrade of 10.1 LTS to 12 LTS

This procedure covers both the upgrade of 10.1 to 12 LTS.  There are two installation methods, each with its own set of procedures:

* [Kubernetes Installation Option](#kubernetes-installation-to-12)

* [Charmed Installation Option](#charmed-installation-to-12)

### Kubernetes Installation to 12

TBD

### Charmed Installation to 12

#### Back up the Databases <a name="charm-12-db">

First of all we will stop OSM services, so no changes are done while we do the backup.

```bash

juju scale-application grafana 0

juju scale-application prometheus 0

juju scale-application kafka-k8s 0

juju scale-application keystone 0

juju scale-application lcm 0

juju scale-application mon 0

juju scale-application nbi 0

juju scale-application ng-ui 0

juju scale-application pla 0

juju scale-application pol 0

juju scale-application ro 0

juju scale-application zookeeper-k8s 0

```

Wait for all the applications to scale to 0.  The output of `juju status` should look similar to the following, with only `mariadb-k8s` and `mongodb-k8s` units left.

```

Model  Controller  Cloud/Region        Version  SLA          Timestamp

osm    osm-vca     microk8s/localhost  2.8.13   unsupported  20:57:44Z

App            Version                         Status  Scale  Charm          Store       Rev  OS          Address         Notes

grafana        docker.io/ubuntu/grafana@sh...  active      0  grafana        jujucharms    4  kubernetes  10.152.183.45    

kafka-k8s      rocks.canonical.com:443/wur...  active      0  kafka-k8s      jujucharms   21  kubernetes  10.152.183.248   

keystone       keystone:10.0.3                 active      0  keystone       jujucharms    9  kubernetes  10.152.183.114   

lcm            lcm:10.0.3                      active      0  lcm            jujucharms    8  kubernetes  10.152.183.70    

mariadb-k8s    rocks.canonical.com:443/mar...  active      1  mariadb-k8s    jujucharms   35  kubernetes  10.152.183.177   

mon            mon:10.0.3                      active      0  mon            jujucharms    5  kubernetes  10.152.183.227   

mongodb-k8s    mongo:latest                    active      1  mongodb-k8s    jujucharms   29  kubernetes  10.152.183.63    

nbi            nbi:10.0.3                      active      0  nbi            jujucharms   12  kubernetes  10.152.183.163   

ng-ui          ng-ui:10.0.3                    active      0  ng-ui          jujucharms   21  kubernetes  10.152.183.180   

pla            pla:10.0.3                      active      0  pla            jujucharms    9  kubernetes  10.152.183.7     

pol            pol:10.0.3                      active      0  pol            jujucharms    4  kubernetes  10.152.183.104   

prometheus     docker.io/ed1000/prometheus...  active      0  prometheus     jujucharms    4  kubernetes  10.152.183.120   

ro             ro:10.0.3                       active      0  ro             jujucharms    4  kubernetes  10.152.183.159   

zookeeper-k8s  rocks.canonical.com:443/k8s...  active      0  zookeeper-k8s  jujucharms   37  kubernetes  10.152.183.201   

Unit            Workload  Agent  Address       Ports      Message

mariadb-k8s/0*  active    idle   10.1.244.152  3306/TCP   ready

mongodb-k8s/0*  active    idle   10.1.244.156  27017/TCP  ready

```

Now, the databases can be backed up using the following commands:

```bash

mariadb_unit=$(juju status |  grep -i mariadb | tail -1 | awk -F" " '{print $1}' | tr -d '[*]')

mariadb_pod=$(microk8s.kubectl get pod -n osm | grep -i mariadb | tail -1 | awk -F" " '{print $1}')

juju run-action $mariadb_unit backup --wait -m osm

microk8s.kubectl cp osm/$mariadb_pod:/var/lib/mysql/backup.sql.gz backup.sql.gz

mongodb_unit=$(juju status | grep -i mongodb | tail -1 | awk -F" " '{print $1}'| tr -d '[*]')

mongodb_pod=$(microk8s.kubectl get pod -n osm | grep -i mongodb | tail -1 | awk -F" " '{print $1}')

microk8s.kubectl exec -n osm -it $mongodb_pod -- mongodump --gzip --archive=/data/backup.archive

microk8s.kubectl cp osm/$mongodb_pod:/data/backup.archive backup.archive

```

#### Upgrade OSM Application <a name="charm-12-osm">

```bash

juju attach-resource -m osm lcm image=opensourcemano/lcm:12

juju attach-resource -m osm mon image=opensourcemano/mon:12

juju attach-resource -m osm nbi image=opensourcemano/nbi:12

juju attach-resource -m osm ng-ui image=opensourcemano/ng-ui:12

juju attach-resource -m osm pla image=opensourcemano/pla:12

juju attach-resource -m osm pol image=opensourcemano/pol:12

juju attach-resource -m osm ro image=opensourcemano/ro:12

juju attach-resource -m osm keystone keystone-image=opensourcemano/keystone:12

```

At this point, OSM has been upgraded.

## Testing Upgrade

### Changing Credentials