Use mongodb charm in k8s installer

- Update JUJU_AGENT_VERSION to 2.8.6
- Use mongodb charm and update needed osm pod specs to point at it

Change-Id: I7c03ae7de6611fcacef35716646ff08bfc1ff988
Signed-off-by: David Garcia <david.garcia@canonical.com>
diff --git a/installers/charmed_install.sh b/installers/charmed_install.sh
index b56ed16..9d41e3e 100755
--- a/installers/charmed_install.sh
+++ b/installers/charmed_install.sh
@@ -15,6 +15,7 @@
 
 # set -eux
 
+JUJU_AGENT_VERSION=2.8.6
 K8S_CLOUD_NAME="k8s-cloud"
 KUBECTL="microk8s.kubectl"
 IMAGES_OVERLAY_FILE=~/.osm/images-overlay.yaml
@@ -91,7 +92,7 @@
         cat $KUBECFG | juju add-k8s $K8S_CLOUD_NAME $ADD_K8S_OPTS
         [ -v BOOTSTRAP_NEEDED ] && juju bootstrap $K8S_CLOUD_NAME $CONTROLLER_NAME \
             --config controller-service-type=loadbalancer \
-            --agent-version=2.8.1
+            --agent-version=$JUJU_AGENT_VERSION
     else
         sg ${KUBEGRP} -c "echo ${DEFAULT_IP}-${DEFAULT_IP} | microk8s.enable metallb"
         sg ${KUBEGRP} -c "microk8s.enable ingress"
@@ -115,7 +116,7 @@
 
         [ ! -v BOOTSTRAP_NEEDED ] && sg ${KUBEGRP} -c "microk8s.config" | juju add-k8s $K8S_CLOUD_NAME $ADD_K8S_OPTS
         [ -v BOOTSTRAP_NEEDED ] && sg ${KUBEGRP} -c \
-            "juju bootstrap microk8s $CONTROLLER_NAME --config controller-service-type=loadbalancer --agent-version=2.8.1" \
+            "juju bootstrap microk8s $CONTROLLER_NAME --config controller-service-type=loadbalancer --agent-version=$JUJU_AGENT_VERSION" \
             && K8S_CLOUD_NAME=microk8s
     fi