[ci-workers] README cleanups

contrib/ci-workers/README.md

@@ -5,29 +5,29 @@ installation for use as a Buildbot worker in Zcash's CI.
 
 # Criteria for Adding Workers
 
-a. Don't add workers until users complain about a problem on a platform
+a. Don't add workers until users complain about a problem on a platform that
-   that doesn't yet have workers or if we anticipate many users will use
+   doesn't yet have workers. However, if we anticipate many users will use a
-   a platform, we may pre-emptively add an unsupported worker for it.
+   platform, we may pre-emptively add an unsupported worker for it.
 
 b. Prioritize the platforms that seem to have the most users.
 
-c. When adding workers start by adding workers for the "most common"
+c. When adding workers, start by adding workers for the "most common" variant of
-   variant of any distro, then if users later encounter problems with a
+   any distro. Then if users later encounter problems with a sub-variant, we can
-   sub-variant, we can consider adding new workers at that point.
+   consider adding new workers at that point. Example: add Ubuntu Desktop before
-   Example: add Ubuntu Desktop before Xubuntu, on the assumption the
+   Xubuntu, on the assumption the former has a larger population base, and the
-   former has a larger population base.
+   latter only materially differs in the GUI.
 
 # Setting up a latent worker on Amazon EC2
 
-- Add a regular (non-latent) worker to the master.cfg for dev-ci.z.cash, and
+1. Add a regular (non-latent) worker to the master.cfg for dev-ci.z.cash, and
    deploy the changes.
   - This enables the Ansible playbook to run to completion, ending in the worker
     connecting to the master.
 
-- Start a basic EC2 instance using the template AMI for the target OS.
+2. Start a basic EC2 instance using the template AMI for the target OS.
   - Choose the smallest instance size, it won't be used for building Zcash.
 
-- Figure out which user to log into the instance with.
+3. Figure out which user to log into the instance with.
   - E.g. for the Ubuntu template, use "ubuntu" instead of "root"
   - If you get an Ansible error later with a message like "Failed to connect to
     the host via ssh: Received message too long 1349281121\r\n", that means the
@@ -35,28 +35,28 @@ c. When adding workers start by adding workers for the "most common"
     Ansible protocol is balking. Try manually logging in with the same
     credentials to diagnose.
 
-- Create `inventory/hosts` containing the following:
+4. Create `inventory/hosts` containing the following:
 
     [zcash-ci-worker-unix]
     some-name ansible_host=<INSTANCE_IP> ansible_ssh_user=<USERNAME>
 
-- Run `ansible-playbook -e buildbot_worker_host_template=templates/host.ec2.j2 -i inventory/hosts unix.yml`,
+5. Run `ansible-playbook -e buildbot_worker_host_template=templates/host.ec2.j2 -i inventory/hosts unix.yml`,
    passing in the worker's Buildbot name and password.
   - After a successful run, the worker should be connected to dev-ci.z.cash and
     visible in its worker list.
 
-- Create an AMI from the instance. This is the worker AMI to put into the
+6. Create an AMI from the instance. This is the worker AMI to put into the
    master.cfg for dev-ci.z.cash.
   - 16 GB of storage should be sufficient.
 
-- SSH into the instance, and edit the worker config to connect to ci.z.cash.
+7. SSH into the instance, and edit the worker config to connect to ci.z.cash.
 
-- Create an AMI from the instance. This is the worker AMI to put into the
+8. Create an AMI from the instance. This is the worker AMI to put into the
    master.cfg for ci.z.cash.
   - 16 GB of storage should be sufficient.
 
-- Delete the instance (it is no longer needed).
+9. Delete the instance (it is no longer needed).
 
-- Edit the master.cfg to turn the new worker into a latent (using the new AMI
+10. Edit the master.cfg to turn the new worker into a latent (using the new AMI
     IDs), add it to the appropriate worker groups, set up new builders etc.
   - Deploy this via the normal PR review process.