Upscaling OpenShift application nodes (#571)

* scale-up: playbook for upscaling app nodes

* scale-up: removed debug

* scale-up: made suggested changes

* scale-up: indentation fix

* upscaling: process split into two playbooks that are executed by a bash script

- upscaling_run.sh: bash script, usage displayed using -h parameter
- upscaling_pre-tasks: check that new value is higher, change inventory variable
- upscaling_scale-up: rerun provisioning and installation, verify change

* upscaling_run: fixed openshift-ansible-contrib directory name

* upscaling_run: inventory can be entered as relative path

* upscaling_scale-up: fixed formatting

* upscaling: minor changes

* upscaling: moved to .../provisioning/openstack directory, README updated, minor changes made

* README: minor changes

* README: formatting

* uspcaling: minor fix

* upscaling: fix

* upscaling: added customisations, fixes

- openshift-ansible-contrib and openshift-ansible paths are customisable
- fixed implicit incrementation by 1

* upscaling: fixes

* upscaling: fixes

* upscaling: another fix

* upscaling: another fix

* upscaling: fix

* upscaling: back to a single playbook, README updated

* minor fix

* pre_tasks: added labels for autoscaling

* scale-up: fixes

* scale-up: fixed host variables, post-verification is only based on labels

* scale-up: added openshift-ansible path customisation

- path has to be absolute, cannot contain '/' at the end

* scale-up: fix

* scale-up: debug removed

* README: added docs on openshift_ansible_dir, note about bastion

* static_inventory: newly added nodes are added to new_nodes group

- note: re-running provisioning fails when trying to install docker

* removing new line

* scale-up: running byo/config.yml or scaleup.yml based on the situation

- (whether there is an existing deployment or not)

* openstack.yml: indentation fix

* added refresh inventory

* upscaling: new_nodes only contains new does, it is not used during the first deployment

* static_inventory: make sure that new nodes end up only in their new_nodes group

* bug fixes

* another fix

* fixed condition

* scale-up, static_inventory role: all app node data gathered before provisioning

* upscaling: bug fixes

* upscaling: another fixes

* fixes

* upscaling: fix

* upscaling: fix

* upscaling: another logic fix

* bug fix for non-scaling deployments

1 files changed, 21 insertions, 0 deletions

diff --git a/playbooks/provisioning/openstack/README.md b/playbooks/provisioning/openstack/README.md
index c6633df06..5e45add51 100644
--- a/playbooks/provisioning/openstack/README.md
+++ b/playbooks/provisioning/openstack/README.md
@@ -568,6 +568,27 @@ In order to access UI, the ssh-tunnel service will be created and started on the
 control node. Make sure to remove these changes and the service manually, when not
 needed anymore.
 
+## Scale Deployment up/down
+
+### Scaling up
+
+One can scale up the number of application nodes by executing the ansible playbook
+`openshift-ansible-contrib/playbooks/provisioning/openstack/scale-up.yaml`.
+This process can be done even if there is currently no deployment available.
+The `increment_by` variable is used to specify by how much the deployment should
+be scaled up (if none exists, it serves as a target number of application nodes).
+The path to `openshift-ansible` directory can be customised by the `openshift_ansible_dir`
+variable. Its value must be an absolute path to `openshift-ansible` and it cannot
+contain the '/' symbol at the end. 
+
+Usage:
+
+```
+ansible-playbook -i <path to inventory> openshift-ansible-contrib/playbooks/provisioning/openstack/scale-up.yaml` [-e increment_by=<number>] [-e openshift_ansible_dir=<path to openshift-ansible>]
+```
+
+Note: This playbook works only without a bastion node (`openstack_use_bastion: False`).
+
 ## License
 
 As the rest of the openshift-ansible-contrib repository, the code here is