🪓 Split the Helm exercises in two parts

slides/exercises/helm-brief.md

@@ -1,9 +0,0 @@
-## Exercise - Helm Charts
-
-- Create a Helm chart to deploy a generic microservice
-
-- Deploy dockercoins by instanciating that chart multiple times
-
-- Bonus: create a "meta" Helm chart to install the 5 components of dockercoins
-
-- Bonus: use an external chart for the redis component

slides/exercises/helm-details.md

@@ -1,82 +0,0 @@
-# Exercise - Helm Charts
-
-- We want to deploy dockercoins with a Helm chart
-
-- We want to have a "generic chart" and instantiate it 5 times
-
-  (once for each service)
-
-- We will pass values to the chart to customize it for each component
-
-  (to indicate which image to use, which ports to expose, etc.)
-
-- We'll use `helm create` as a starting point for our generic chart
-
----
-
-
-  (using `helm create` to get a generic chart and tweaking that chart)
-
-- Deploy dockercoins by instanciating that chart multiple times
-
-  (one time per service, so 5 times total)
-
-- Create a "meta" Helm chart to install the 5 components of dockercoins
-
-  (using chart dependencies and aliases)
-
-- Bonus: use Bitnami's redis chart for the dockercoins redis component
-
----
-
-## Goal
-
-- Have a directory with the generic chart
-
-  (e.g. `generic-chart`)
-
-- Have 5 value files
-
-  (e.g. `hasher.yml`, `redis.yml`, `rng.yml`, `webui.yml`, `worker.yml`)
-
-- Be able to install dockercoins by running 5 times:
-
-  `helm install X ./generic-chart --values=X.yml`
-
----
-
-## Hints
-
-- There are many little things to tweak in the generic chart
-
-  (service names, port numbers, healthchecks...)
-
-- Check the training slides if you need a refresher!
-
----
-
-## Bonus 1
-
-- Create a "meta chart" or "umbrella chart" to install all 5 components
-
-  (so that dockercoins can be installed with a single `helm install` command)
-
-- This will require expressing dependencies, and using the `alias` keyword
-
----
-
-## Bonus 2
-
-- Replace the `redis` component with an external chart
-
-  (e.g. Bitnami's redis chart)
-
-- This will require to pass extra values to that chart
-
-  (to disable persistence, replication, password authentication)
-
-- This will also require to either:
-
-  - import the chart and tweak it to change the service name
-
-  - add an ExternalName service pointing to the new redis component

slides/exercises/helm-generic-chart-brief.md

@@ -0,0 +1,13 @@
+## Exercise - Helm Charts
+
+- Create a Helm chart to deploy a generic microservice
+
+- Deploy dockercoins by instanciating that chart multiple times
+
+- Bonus: have as little values as possible
+
+- Bonus: handle healthchecks for HTTP services
+
+- Bonus: make it easy to change image versions
+
+- Bonus: make it easy to use images on a different registry

slides/exercises/helm-generic-chart-details.md

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+# Exercise - Helm Charts
+
+- We want to deploy dockercoins with a Helm chart
+
+- We want to have a "generic chart" and instantiate it 5 times
+
+  (once for each service)
+
+- We will pass values to the chart to customize it for each component
+
+  (to indicate which image to use, which ports to expose, etc.)
+
+- We'll use `helm create` as a starting point for our generic chart
+
+---
+
+## Goal
+
+- Have a directory with the generic chart
+
+  (e.g. `generic-chart`)
+
+- Have 5 value files
+
+  (e.g. `hasher.yml`, `redis.yml`, `rng.yml`, `webui.yml`, `worker.yml`)
+
+- Be able to install dockercoins by running 5 times:
+
+  `helm install X ./generic-chart --values=X.yml`
+
+---
+
+## Hints
+
+- There are many little things to tweak in the generic chart
+
+  (service names, port numbers, healthchecks...)
+
+- Check the training slides if you need a refresher!
+
+---
+
+## Bonus 1
+
+- Minimize the amount of values that have to be set
+
+- Option 1: no values at all for `rng` and `hasher`
+
+  (default values assume HTTP service listening on port 80)
+
+- Option 2: no values at all for `worker`
+
+  (default values assume worker container with no service)
+
+
+---
+
+## Bonus 2
+
+- Handle healthchecks
+
+- Make sure that healthchecks are enabled in HTTP services
+
+- ...But not in Redis or in the worker
+
+---
+
+## Bonus 3
+
+- Make it easy to change image versions
+
+- E.g. change `v0.1` to `v0.2` by changing only *one* thing in *one* place
+
+---
+
+## Bonus 4
+
+- Make it easy to use images on a different registry
+
+- We can assume that the images will always have the same names
+
+  (`hasher`, `rng`, `webui`, `worker`)
+
+- And the same tag
+
+  (`v0.1`)

slides/exercises/helm-umbrella-chart-brief.md

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+## Exercise - Umbrella Charts
+
+- Create a Helm chart with dependencies on other charts
+
+  (leveraging the generic chart created earlier)
+
+- Deploy dockercoins with that chart
+
+- Bonus: use an external chart for the redis component

slides/exercises/helm-umbrella-chart-details.md

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+# Exercise - Umbrella Charts
+
+- We want to deploy dockercoins with a single Helm chart
+
+- That chart will reuse the "generic chart" created previously
+
+- This will require expressing dependencies, and using the `alias` keyword
+
+- It will also require minor changes in the templates
+
+---
+
+## Goal
+
+- We want to be able to install a copy of dockercoins with:
+  ```bash
+  helm install dockercoins ./umbrella-chart
+  ```
+
+- It should leverage the generic chart created earlier
+
+  (and instanciate it five times, one time per component of dockercoins)
+
+- The values YAML files created earlier should be merged in a single one
+
+---
+
+## Bonus
+
+- We want to replace our redis component with a better one
+
+- We're going to use Bitnami's redis chart
+
+  (find it on the Artifact Hub)
+
+- However, a lot of adjustments will be required!
+
+  (check following slides if you need hints)
+
+---
+
+## Hints (1/2)
+
+- We will probably have to disable persistence
+
+  - by default, the chart enables persistence
+
+  - this works only if we have a default StorageClass
+
+  - this can be disabled by setting a value
+
+- We will also have to disable authentication
+
+  - by default, the chart generates a password for Redis
+
+  - the dockercoins code doesn't use one
+
+  - this can also be changed by setting a value
+
+---
+
+## Hints (2/2)
+
+- The dockercoins code connects to `redis`
+
+- The chart generates different service names
+
+- Option 1:
+
+  - vendor the chart in our umbrella chart
+  - change the service name in the chart
+
+- Option 2:
+
+  - add a Service of type ExternalName
+  - it will be a DNS alias from `redis` to `redis-whatever.NAMESPACE.svc.cluster.local`
+  - for extra points, make the domain configurable