This CF CLI Plugin rolls traffic from one app to another over a specified time interval. It is useful for blue green deployments or other situations where start / stop is not enough or too abrupt. It was created by Guido Westenberg and Josh Kruck.

This plugin makes no assumptions about either application, nor does it attempt to "help" you. Route mapping to both applications, and the relationship between those applications is left to you. There is a simple check that the applications share a route, this can be disabled with --no-route-check. Please use care when using cf scaleover, it is possible to hurt yourself.

Both applications must exist within the same space, and by default should share a route.

Select two apps in the same space, and roll traffic between them.

• --no-route-check (default TRUE) - Since both apps are live at the same time, there is assumed use of a shared route.
• --leave N (default 0/stopped) - How many blue instances should remain running when using scaleover to green?
• --wait-for-start (defaults FALSE) - Should scaleover wait for confirmation that the scaled up instace(s) are started before scaling down?
• --post-start-sleep Ns (default '0s') - How long should scaleover wait after the new instances are considered 'started' for the app itself to initialize/bootstrap? Supports standard duration strings (eg '10s', '1m', etc). Used ONLY in conjunction with --wait-for-start.
• --batch-size N (default 1) - How many instances should be scaled (both up/down) at a time?

$ cf apps
Getting apps in org test-org / space test-space as admin...
OK

name        requested state   instances   memory   disk   urls
node_v1.0   started           10/10       128M     1G     node_v1.0.10.244.0.34.xip.io, node-prod.10.244.0.34.xip.io
node_v1.1   stopped           0/1         128M     1G     node_v1.1.10.244.0.34.xip.io, node-prod.10.244.0.34.xip.io
$ cf scaleover node_v1.0 node_v1.1 20s
node_v1.0 (started) <<<<<<<<<<  node_v1.1 (stopped)
node_v1.0 (started) <<<<<< >>>> node_v1.1 (started)
node_v1.0 (started) <<< >>>>>>> node_v1.1 (started)
node_v1.0 (stopped)  >>>>>>>>>> node_v1.1 (started)
$ cf apps
Getting apps in org test-org / space test-space as admin...
OK

name        requested state   instances   memory   disk   urls
node_v1.0   stopped           0/1         128M     1G     node_v1.0.10.244.0.34.xip.io, node-prod.10.244.0.34.xip.io
node_v1.1   started           10/10       128M     1G     node_v1.1.10.244.0.34.xip.io, node-prod.10.244.0.34.xip.io

This node_v1.0 (started) <<< >>>>>>> node_v1.1 (started) bit in the middle is a way cool ascii art animation that's worth the price of admission alone.

$ cf add-plugin-repo CF-Community https://plugins.cloudfoundry.org/
$ cf install-plugin scaleover -r CF-Community

$ go get github.com/cloudfoundry/cli
$ go get github.com/krujos/scaleover-plugin
$ cd $GOPATH/src/github.com/krujos/scaleover-plugin
$ go build
$ cf install-plugin scaleover-plugin