- Software System
-
Highest level of abstraction that delivers value to its users, whether they are human or not. A software system is composed of one or more `Application`s.
- Application
-
An abstraction that encapsulates the value delivered by the software system. An application is composed of one or more `Component`s.
- Component
-
A component is a set of kubernetes resources, for hosting code or data, that needs to be running in order for the overall software system to work. Each component is a seperately deployable and runnable unit.
The following table defines common labels applications deployed on OpenShift should use Labels that are marked REC are recommended. Those marked OPT are optional. The labels should not be relied upon for operational purposes.
You can find more information on the Kubernetes labels, prefixed with app.kubernetes.io, in the Kubernetes documentation.
|
Tip
|
Labels must be applied to ALL resources, DeploymentConfigs, BuildConfigs, Services, Routes, ConfigMaps, PersistenVolumeClaims etc., including any custom resource definitions (CRDs). |
| Name | Status | Description | Example |
|---|---|---|---|
app.kubernetes.io/part-of |
REC |
The name of the top level software system this resource is part of |
ticketmonster |
app.kubernetes.io/name |
REC |
The name, reflecting component. |
mysql |
app.kubernetes.io/component |
REC |
This is the role/type of the component |
frontend |
app.kubernetes.io/managed-by |
OPT |
The tool being used to manage the operation of the component |
odo |
app.kubernetes.io/instance |
REC |
A unique name identifying the application, usually used if different from |
accounts |
app.kubernetes.io/version |
OPT |
The current version of the component (e.g., a semantic version, revision hash, etc.) |
1.0.0 |
app.openshift.io/runtime |
OPT |
The runtime to be used to bootstrap the component |
spring-boot |
app.openshift.io/runtime-version: |
OPT |
The version of the runtime |
e.g. |
app.kubernetes.io/component label
| Value | Description |
|---|---|
frontend |
Serves the UI or part of the UI for an application |
backend |
Usually an application code that is running on a runtime or framework. |
database |
Data persistence |
integration |
Integration middleware such as API gateways or single-sign-on software |
cache |
|
queue |
| Name | Status | Description | Example |
|---|---|---|---|
app.openshift.io/vcs-uri |
REC |
URI for the source code under version control |
git://git.kernel.org/pub/scm/linux.git |
app.openshift.io/vcs-ref |
REC |
Identifier for the version of the source code. Can be branch, tag or commit SHA for the application. If omitted master head of the default branch is assumed |
v1.0.0 |
app.openshift.io/connects-to: |
OPT |
The |
e.g. |
console.alpha.openshift.io/overview-app-route |
OPT |
Annotate the route that you would like to be primary on the console UI |
console.alpha.openshift.io/overview-app-route: ‘true’ |
Node.js based rest service with a database (mongodb) backing
@startuml
rectangle cool-service {
database mongodb [
\t<b>mongodb for storing data
----
<b>app.kubernetes.io/part-of :</b>cool-service
<b>app.kubernetes.io/name :</b> mongodb
<b>app.kubernetes.io/component :</b> database
<b>app.kubernetes.io/managed-by :</b> odo
<b>app.kubernetes.io/version :</b> 3.6
]
rectangle nodejs [
\t\t<b>The node.js service with code</b>
----
<b>app.kubernetes.io/part-of :</b> cool-service
<b>app.kubernetes.io/name :</b> nodejs
<b>app.kubernetes.io/component :</b> frontend
<b>app.kubernetes.io/managed-by :</b> odo
<b>app.kubernetes.io/version</b> : 1.0.1
<b>app.openshift.io/runtime</b>: nodejs
<b> app.openshift.io/runtime-version</b>: 10.14.1
----
<b>app.openshift.io/vcs-uri :</b> git://[email protected]:gorkem/cool-service.git
<b>app.openshift.io/vcs-ref :</b> master
<b>app.openshift.io/connects-to :</b> mongodb
]
nodejs --> mongodb
}
@enduml
@startuml
left to right direction
rectangle coolstore {
together {
rectangle inventory {
database postgresql [
<b>postgresql database
----
<b>app.kubernetes.io/part-of :</b> coolstore
<b>app.kubernetes.io/instance :</b> inventoryDB
<b>app.kubernetes.io/name :</b> postgresql
<b>app.kubernetes.io/component :</b> database
<b>app.kubernetes.io/managed-by :</b> odo
<b>app.kubernetes.io/version :</b> 11
]
rectangle nodeservice [
<b>The node.js service with code</b>
----
<b>app.kubernetes.io/part-of :</b> coolstore
<b>app.kubernetes.io/instance :</b> inventory
<b>app.kubernetes.io/name :</b> nodejs
<b>app.kubernetes.io/component :</b> backend
<b>app.kubernetes.io/managed-by :</b> odo
<b>app.kubernetes.io/version</b> : 10
<b>app.openshift.io/runtime</b>: nodejs
<b>app.openshift.io/runtime-version</b>: 10.14.1
----
<b>app.openshift.io/vcs-uri :</b> git://[email protected]:gorkem/inventory-service.git
<b>app.openshift.io/vcs-ref :</b> master
]
}
}
together {
rectangle cart{
node cart [
<b>The node.js service with code</b>
----
<b>app.kubernetes.io/part-of :</b> coolstore
<b>app.kubernetes.io/instance :</b> cart
<b>app.kubernetes.io/name :</b> nodejs
<b>app.kubernetes.io/component :</b> backend
<b>app.kubernetes.io/managed-by :</b> odo
<b>app.kubernetes.io/version</b> : 10
<b>app.openshift.io/runtime</b>: nodejs
<b> app.openshift.io/runtime-version</b>: 10.14.1
----
<b>app.openshift.io/vcs-uri :</b> git://[email protected]:gorkem/cart-service.git
<b>app.openshift.io/vcs-ref :</b> master
<b>app.openshift.io/connects-to :</b> '["inventory"]'
]
cart --> inventory
}
}
together {
rectangle catalog {
database catalogdb [
<b>mongodb for storing data
----
<b>app.kubernetes.io/part-of :</b> coolstore
<b>app.kubernetes.io/instance :</b> catalogDB
<b>app.kubernetes.io/name :</b> mongodb
<b>app.kubernetes.io/component :</b> database
<b>app.kubernetes.io/managed-by :</b> odo
<b>app.kubernetes.io/version :</b> 3.6
]
rectangle catalog [
<b>The node.js service with code</b>
----
<b>app.kubernetes.io/part-of :</b> coolstore
<b>app.kubernetes.io/instance :</b> catalog
<b>app.kubernetes.io/name :</b> nodejs
<b>app.kubernetes.io/component :</b> frontend
<b>app.kubernetes.io/managed-by :</b> odo
<b>app.kubernetes.io/version</b> : 10
<b>app.openshift.io/runtime</b>: nodejs
<b> app.openshift.io/runtime-version</b>: 10.14.1
----
<b>app.openshift.io/vcs-uri :</b> git://[email protected]:gorkem/catalog-service.git
<b>app.openshift.io/vcs-ref :</b> master
<b>app.openshift.io/connects-to :</b> '["cart"]'
]
catalog --> cart
}
}
}
@enduml
|
Tip
|
The label app.kubernetes.io/instance should lead to a meaningful identifier. The label
app.kubernetes.io/part-of is used to identify the application grouping and
app.kubernetes.io/instance identifies the component name within the application grouping.
|