Share resource requirements for examples (#806)

Resolves #240

examples/README.md

@@ -1,27 +1,37 @@
 # Examples
 
-These examples demonstrate how common patterns can be implemented in Cartographer.
-Each example demonstrates increasing assurance steps along the
-path to production. The suggested order is:
+These examples demonstrate how common patterns can be implemented in Cartographer. Each example demonstrates increasing
+assurance steps along the path to production. The suggested order is:
 
-- [Supply Chain: Source => Image => App](basic-sc/README.md): demonstrates how
-  one can set up a `ClusterSupplyChain` that monitors source code updates, creates
-  a new image for each update and deploys that image as a running application
+- [Supply Chain: Source => Image => App](basic-sc/README.md): demonstrates how one can set up a `ClusterSupplyChain`
+  that monitors source code updates, creates a new image for each update and deploys that image as a running application
   in the cluster.
 - [Runnable: Updating a Tekton Task without triggers](runnable-tekton/README.md):
-  demonstrates how Cartographer's `Runnable` wraps immutable objects to provide
-  updatable behavior. The example uses a Tekton Task that tests source code and
-  demonstrates how to create [TaskRuns](https://tekton.dev/docs/pipelines/taskruns/)
+  demonstrates how Cartographer's `Runnable` wraps immutable objects to provide updatable behavior. The example uses a
+  Tekton Task that tests source code and demonstrates how to
+  create [TaskRuns](https://tekton.dev/docs/pipelines/taskruns/)
   with objects that don't require triggers or events.
-- [Supply Chain: Source => Test => Image => App](testing-sc/README.md): expands upon
-  the example above by adding testing, assuring that only commits with passing tests
-  result in deployed apps.
-- [Supply Chain: Source => Image => Git](gitwriter-sc/README.md): whereas the first
-  example deploys an app, this example takes the app configuration and writes it to git. This
-  configuration can then be read by a Delivery in another cluster. This allows all
-  build processes to be isolated in a cluster completely separate from the
-  production cluster exposed to customers and end users.
-- [Delivery: Git => App](basic-delivery/README.md): this example picks up app
-  configuration that has been written to git (it is written to work with the gitwriter
-  example above). The configuration is then applied to the cluster. This minimizes
-  processes occuring in the production cluster exposed to customers and end users.
+- [Supply Chain: Source => Test => Image => App](testing-sc/README.md): expands upon the example above by adding
+  testing, assuring that only commits with passing tests result in deployed apps.
+- [Supply Chain: Source => Image => Git](gitwriter-sc/README.md): whereas the first example deploys an app, this example
+  takes the app configuration and writes it to git. This configuration can then be read by a Delivery in another
+  cluster. This allows all build processes to be isolated in a cluster completely separate from the production cluster
+  exposed to customers and end users.
+- [Delivery: Git => App](basic-delivery/README.md): this example picks up app configuration that has been written to
+  git (it is written to work with the gitwriter example above). The configuration is then applied to the cluster. This
+  minimizes processes occuring in the production cluster exposed to customers and end users.
+
+## Resource Requirements
+
+### Usage
+
+When the examples are run, they generally consume 4 cpu cores and 4 GiB of memory.
+
+### Requests
+
+The examples rely on a number of controllers being installed. These controllers create deployments which request
+resources from the kubernetes cluster at rest. All told, the controllers request 1.7 cpu cores and 1.6 GiB of memory
+"at rest".
+
+When Cartographer runs these examples in testing, we
+use [this overlay](../hack/overlays/remove-resource-requests-from-deployments.yaml) to remove these requests.

examples/basic-delivery/README.md

@@ -71,6 +71,9 @@ To install `cartographer`, refer to [README.md](../../README.md).
 5. [tree](https://github.com/ahmetb/kubectl-tree#installation) and
   [yq](https://github.com/kislyuk/yq#installation) for observing objects in the cluster and their fields.
 
+### Resource Requirements
+Read [here](../README.md#resource-requirements)
+
 ## Running the example in this directory
 
 ### Location of files

examples/basic-sc/README.md

@@ -88,6 +88,9 @@ supplychain, forms something powerful.
 
 5. [Tree](https://github.com/ahmetb/kubectl-tree), a tool that we will use to observe the objects created.
 
+### Resource Requirements
+Read [here](../README.md#resource-requirements)
+
 ## Running the example in this directory
 
 ### Location of files

examples/gitwriter-sc/README.md

@@ -60,6 +60,9 @@ TEKTON_VERSION=0.30.0 kubectl apply -f https://storage.googleapis.com/tekton-rel
 kapp deploy --yes -a tekton-git-cli -f https://raw.githubusercontent.com/tektoncd/catalog/main/task/git-cli/0.2/git-cli.yaml
 ```
 
+### Resource Requirements
+Read [here](../README.md#resource-requirements)
+
 ## Running the example in this directory
 
 ### Location of files

examples/runnable-tekton/README.md

@@ -28,6 +28,9 @@ kind create cluster --image kindest/node:v1.21.1
 3. Install [Tekton](https://tekton.dev/docs/getting-started/#installation), which provides a
   mechanism to create pipelines and tasks for application testing, scanning, etc.
 
+### Resource Requirements
+Read [here](../README.md#resource-requirements)
+
 ## Running the example in this directory
 
 In order to demonstrate updatable testing, the example has a Tekton Task that will run `go test` on a

examples/testing-sc/README.md

@@ -48,6 +48,9 @@ objects would be set by the different personas in the system:
 
 2. Install [Tekton](https://tekton.dev/docs/getting-started/#installation)
 
+### Resource Requirements
+Read [here](../README.md#resource-requirements)
+
 ## Running the example in this directory
 
 ### Location of files