Merge branch '22864-kubernetes-service' into 'master'

Introduce deployment services, starting with a KubernetesService

## What does this MR do?

Adds a minimal `KubernetesService` and introduces the idea of deployment services, generally.

## Are there points in the code the reviewer needs to double check?

## Why was this MR needed?

Two issues scheduled for 8.15 both require a Kubernetes service - #22864 and #23580 - but they use it for very different things. Add a minimal kubernetes service to avoid conflicts later.

## Screenshots

![Screen_Shot_2016-12-14_at_12.44.13](/uploads/77d38baf2a196118f0cf7e2b996a65f3/Screen_Shot_2016-12-14_at_12.44.13.png)

## Does this MR meet the acceptance criteria?

- [x] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [x] API support added
- Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if it does - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?

Closes #22985

See merge request !7994

3 files changed, 39 insertions, 0 deletions

diff --git a/doc/project_services/img/kubernetes_configuration.png b/doc/project_services/img/kubernetes_configuration.png
new file mode 100644
index 00000000000..349a2dc8456
--- /dev/null
+++ b/doc/project_services/img/kubernetes_configuration.png
diff --git a/doc/project_services/kubernetes.md b/doc/project_services/kubernetes.md
new file mode 100644
index 00000000000..cb577b608b4
--- /dev/null
+++ b/doc/project_services/kubernetes.md
@@ -0,0 +1,38 @@
+# GitLab Kubernetes / OpenShift integration
+
+GitLab can be configured to interact with Kubernetes, or other systems using the
+Kubernetes API (such as OpenShift).
+
+Each project can be configured to connect to a different Kubernetes cluster, see
+the [configuration](#configuration) section.
+
+If you have a single cluster that you want to use for all your projects,
+you can pre-fill the settings page with a default template. To configure the
+template, see the [Services Templates](services-templates.md) document.
+
+## Configuration
+
+![Kubernetes configuration settings](img/kubernetes_configuration.png)
+
+The Kubernetes service takes the following arguments:
+
+1. Kubernetes namespace
+1. API URL
+1. Service token
+1. Custom CA bundle
+
+The API URL is the URL that GitLab uses to access the Kubernetes API. Kubernetes
+exposes several APIs - we want the "base" URL that is common to all of them,
+e.g., `https://kubernetes.example.com` rather than `https://kubernetes.example.com/api/v1`.
+
+GitLab authenticates against Kubernetes using service tokens, which are
+scoped to a particular `namespace`. If you don't have a service token yet,
+you can follow the
+[Kubernetes documentation](http://kubernetes.io/docs/user-guide/service-accounts/)
+to create one. You can also view or create service tokens in the
+[Kubernetes dashboard](http://kubernetes.io/docs/user-guide/ui/) - visit
+`Config -> Secrets`.
+
+Fill in the service token and namespace according to the values you just got.
+If the API is using a self-signed TLS certificate, you'll also need to include
+the `ca.crt` contents as the `Custom CA bundle`.
diff --git a/doc/project_services/project_services.md b/doc/project_services/project_services.md
index 890f7525b0e..a7bcd186a8c 100644
--- a/doc/project_services/project_services.md
+++ b/doc/project_services/project_services.md
@@ -42,6 +42,7 @@ further configuration instructions and details. Contributions are welcome.
 | [Irker (IRC gateway)](irker.md) | Send IRC messages, on update, to a list of recipients through an Irker gateway |
 | [JIRA](jira.md) | JIRA issue tracker |
 | JetBrains TeamCity CI | A continuous integration and build server |
+| [Kubernetes](kubernetes.md) | A containerized deployment service |
 | [Mattermost slash commands](mattermost_slash_commands.md) | Mattermost chat and ChatOps slash commands |
 | PivotalTracker | Project Management Software (Source Commits Endpoint) |
 | Pushover | Pushover makes it easy to get real-time notifications on your Android device, iPhone, iPad, and Desktop |