Merge branch 'environments-and-deployments' into 'master'

Add environments and deployments

This MR is a continuation of https://gitlab.com/gitlab-org/gitlab-ce/issues/17009.

The current implementation is as follow:
1. We have two new tables: `environments` and `deployments`.
2. We have a new tab: `Environments` under `Pipelines` where you can see all you environments and add a new one.
3. We add a new option to `.gitlab-ci.yml` to track where we should create a deployment for environment.
4. If environment in `.gitlab-ci.yml` is specified it will create a deployment. **If environment does not exist it will be created.** (this got changed)
5. The deployment is always successful and shows the time of the action, in that case a build that presumably should do deployment. In the future we could extend deployment with statuses: success, failure. We could extend deployments with information that this is partial or full deployment.
6. User have to create environments that he will track first.
7. User can remove environments.
8. User can retry/rollback past deployment (in that case we retry past build). The new build when succeeds it will create a new deployment.
9. Currently environment have only one parameter: `name`. In the future it should have: `variables`, `credentials` and possibly `runners` and maybe other resources.
10. Currently deployment have this parameters: `sha`, `ref`, `deployable (in this case a build)`, `user (who triggered a deployment)`, `created_at`.

The `.gitlab-ci.yml`:
```
deploy to production:
  stage: deploy
  script: dpl travis...
  environment: production
```

What needs to be done:
- [x] Write initial implementation
- [x] Improve implementation (@ayufan)
- [x] Write tests (@ayufan)
- [x] Improve UX of the forms (cc @markpundsack) - reviewed by @markpundsack
- [x] Improve implementation of the views (cc @jschatz1) - done by @iamphill 
- [x] Write .gitlab-ci.yml documentation for `environments` - done by @ayufan
- [ ] Write user documentation (@ayufan and @markpundsack)

See merge request !4605

1 files changed, 27 insertions, 0 deletions

diff --git a/doc/ci/yaml/README.md b/doc/ci/yaml/README.md
index d71ce6d6b13..9c98f9c98c6 100644
--- a/doc/ci/yaml/README.md
+++ b/doc/ci/yaml/README.md
@@ -28,6 +28,7 @@ If you want a quick introduction to GitLab CI, follow our
     - [only and except](#only-and-except)
     - [tags](#tags)
     - [when](#when)
+    - [environment](#environment)
     - [artifacts](#artifacts)
         - [artifacts:name](#artifacts-name)
         - [artifacts:when](#artifacts-when)
@@ -354,6 +355,7 @@ job_name:
 | cache         | no | Define list of files that should be cached between subsequent runs |
 | before_script | no | Override a set of commands that are executed before build |
 | after_script  | no | Override a set of commands that are executed after build |
+| environment   | no | Defines a name of environment to which deployment is done by this build |
 
 ### script
 
@@ -525,6 +527,31 @@ The above script will:
 1. Execute `cleanup_build_job` only when `build_job` fails
 2. Always execute `cleanup_job` as the last step in pipeline.
 
+### environment
+
+>**Note:**
+Introduced in GitLab v8.9.0.
+
+`environment` is used to define that job does deployment to specific environment.
+This allows to easily track all deployments to your environments straight from GitLab.
+
+If `environment` is specified and no environment under that name does exist a new one will be created automatically.
+
+The `environment` name must contain only letters, digits, '-' and '_'.
+
+---
+
+**Example configurations**
+
+```
+deploy to production:
+  stage: deploy
+  script: git push production HEAD:master
+  environment: production
+```
+
+The `deploy to production` job will be marked as doing deployment to `production` environment.
+
 ### artifacts
 
 >**Notes:**