Load balanced deployment update

Author: paulmwatson

README.md

@@ -110,36 +110,15 @@ We use [Black](https://github.com/psf/black) to format our code. You can install
 
 ### Deployment instructions
 
-Deployment is to dokku, a Heroku-like environment. To deploy, simply push to the git remote:
-
-    git push dokku
-
-Sensitive or environment-specific configuration variables are set as environment variables using `dokku config:set`, the important ones are:
-
-* SERVER_NAME - Flask uses this as the base hostname and port for the server - Flask Blueprint subdomains base from this. If it can't match the Host header in requests to this, it serves a 404 response.
-  - `pmg.org.za` in production
-  - `pmg.test:5000` in development
-  - Flask seems to use this for generating absolute URLs, except when the `X-Forwarded-Host` header is provided, in which case that hostname is used for absolute URLs.
-* SESSION_COOKIE_DOMAIN
-  - `pmg.org.za` in production
-  - `pmg.test` in dev
-* SQLALCHEMY_DATABASE_URI
-* FLASK_ENV=production
-* AWS_ACCESS_KEY_ID
-* AWS_SECRET_ACCESS_KEY
-* SENDGRID_API_KEY
-* MAIL_PASSWORD
-* SECURITY_PASSWORD_SALT
-* RUN_PERIODIC_TASKS=true
-* SOUNDCLOUD_APP_KEY_ID
-* SOUNDCLOUD_APP_KEY_SECRET
-* SOUNDCLOUD_USERNAME
-* SOUNDCLOUD_PASSWORD
-* SOUNDCLOUD_PERIOD_HOURS=6
-* MAX_SOUNDCLOUD_BATCH=10
-* S3_BUCKET=pmg-assets
-* STATIC_HOST=https://static.pmg.org.za/ or http://pmg-assets.s3-website-eu-west-1.amazonaws.com/
+Deployment is to dokku, a Heroku-like environment. PMG now runs on two servers with an AWS Application Load Balancer.
 
+    git remote add dokku-prod-2 dokku@pmg-aws2.pmg.org.za:pmg-prod
+    git remote add dokku-prod-3 dokku@pmg-aws3.pmg.org.za:pmg-prod
+
+To deploy push to one server, wait for it to complete, then push to the other server:
+
+    git push dokku-prod-2
+    git push dokku-prod-3
 
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