Merge pull request #2168 from dokku/2073_mh-zero-downtime

allow zero-downtime to be completely disabled.

docs/appendices/0.6.0-migration-guide.md

@@ -0,0 +1,9 @@
+# 0.6.0 Migration Guide
+
+## zero-downtime deployment
+- You can now **actually** disable zero-downtime deployments per-app and per-process-type
+  - Some config variables have been moved around
+    - `DOKKU_CHECKS_ENABLED` has been migrated to `DOKKU_CHECKS_SKIPPED`
+    - `DOKKU_CHECKS_DISABLED` is now a thing
+    - The values for the above can be a comma-separated list of process-types or the literal string `_all_`
+  - See the [updated `checks`](/dokku/checks-examples/) docs for more info

docs/checks-examples.md

@@ -3,9 +3,10 @@
 > New as of 0.5.0
 
 ```
-checks <app>                                                                                 Show zero-downtime status
-checks:disable <app>                                                                         Disable zero-downtime checks
-checks:enable <app>                                                                          Enable zero-downtime checks
+checks <app>                             Show zero-downtime status
+checks:disable <app> [process-type(s)]   Disable zero-downtime deployment for all processes (or comma-separated process-type list) ***WARNING: this will cause downtime during deployments***
+checks:enable <app> [process-type(s)]    Enable zero-downtime deployment for all processes (or comma-separated process-type list)
+checks:skip <app> [process-type(s)]      Skip zero-downtime checks for all processes (or comma-separated process-type list)
 ```
 
 Following a deploy, dokku will wait `10` seconds before routing traffic to the new container to give your application time to boot up. If the application is not running after this time, then the deploy is failed and your old container will continue serving traffic. You can modify this value globally or on a per-application basis:
@@ -15,10 +16,32 @@ dokku config:set --global DOKKU_DEFAULT_CHECKS_WAIT=30
 dokku config:set <app> DOKKU_DEFAULT_CHECKS_WAIT=30
 ```
 
-You can also choose to skip checks completely on a per-application basis:
+You can also choose to skip checks or disable zero-downtime completely on a per-application/per-process basis:
 
 ```shell
-dokku checks:disable <app>
+dokku checks:skip <app> worker,web
+```
+
+```shell
+dokku checks:disable <app> worker,web
+```
+> Note that `checks:disable` will now (as of 0.6.0) cause downtime for that process-type during deployments.
+
+Additionally, any given process can only be configured to skip OR disable zero-downtime. example:
+
+```shell
+$ dokku checks:skip testapp worker,web
+-----> Skipping zero downtime for app's (testapp) proctypes (worker,web)
+-----> Unsetting testapp
+-----> Unsetting DOKKU_CHECKS_DISABLED
+-----> Setting config vars
+       DOKKU_CHECKS_SKIPPED: worker,web
+$ dokku checks:disable testapp worker
+-----> Disabling zero downtime for app's (testapp) proctypes (worker)
+-----> Setting config vars
+       DOKKU_CHECKS_DISABLED: worker
+-----> Setting config vars
+       DOKKU_CHECKS_SKIPPED: web
 ```
 
 Dokku will wait `60` seconds before stopping the old container so that existing connections are given a chance to complete. You can modify this value globally or on a per-application basis:

docs/upgrading.md

@@ -7,6 +7,7 @@ If your version of dokku is pre 0.3.0 (check with `dokku version`), we recommend
 Before upgrading, check the migration guides to get comfortable with new features and prepare your deployment to be upgraded.
 
 - [0.5 Migration Guide](/dokku/appendices/0.5.0-migration-guide/)
+- [0.6 Migration Guide](/dokku/appendices/0.6.0-migration-guide/)
 
 ## Upgrade Instructions