🔧 Be more consistent when installing Helm charts

Always install Helm charts in their own namespace, and specify the
repo through a command-line flag instead of adding the repo.

prepare-vms/lib/commands.sh

@@ -728,15 +728,15 @@ _cmd_tmux() {
     ssh $SSHOPTS -t -L /tmp/tmux-$UID/default:/tmp/tmux-1001/default docker@$IP tmux new-session -As 0
 }
 
-_cmd helmprom "Install Helm and Prometheus"
+_cmd helmprom "Install Prometheus with Helm"
 _cmd_helmprom() {
     TAG=$1
     need_tag
     pssh "
     if i_am_first_node; then
-        sudo -u docker -H helm repo add prometheus-community https://prometheus-community.github.io/helm-charts/
-        sudo -u docker -H helm install prometheus prometheus-community/prometheus \
-            --namespace kube-system \
+        sudo -u docker -H helm upgrade --install prometheus prometheus \
+            --repo https://prometheus-community.github.io/helm-charts/ \
+            --namespace prometheus --create-namespace \
             --set server.service.type=NodePort \
             --set server.service.nodePort=30090 \
             --set server.persistentVolume.enabled=false \

slides/k8s/hpa-v2.md

@@ -152,11 +152,9 @@ class: extra-details
 
 - If it's not installed yet on the cluster, install Prometheus:
   ```bash
-    helm repo add prometheus-community
-         https://prometheus-community.github.io/helm-charts
-    helm upgrade prometheus prometheus-community/prometheus \
-         --install \
-         --namespace kube-system \
+    helm upgrade --install prometheus prometheus \
+         --repo https://prometheus-community.github.io/helm-charts \
+         --namespace prometheus --create-namespace \
          --set server.service.type=NodePort \
          --set server.service.nodePort=30090 \
          --set server.persistentVolume.enabled=false \
@@ -475,10 +473,11 @@ no custom metrics API (custom.metrics.k8s.io) registered
 
 - Install the Prometheus adapter:
   ```bash
-    helm upgrade prometheus-adapter prometheus-community/prometheus-adapter \
-         --install --namespace=kube-system \
-         --set prometheus.url=http://prometheus-server.kube-system.svc \
-         --set prometheus.port=80
+    helm upgrade --install prometheus-adapter prometheus-adapter \
+      --repo https://prometheus-community.github.io/helm-charts \
+      --namespace=prometheus-adapter --create-namespace \
+      --set prometheus.url=http://prometheus-server.prometheus.svc \
+      --set prometheus.port=80
   ```
 
 ]

slides/k8s/prometheus.md

@@ -218,27 +218,7 @@ We need to:
 
 ---
 
-## Step 2: add the `prometheus-community` repo
-
-- This will add the repository containing the chart for Prometheus
-
-- This command is idempotent
-
-  (it won't break anything if the repository was already added)
-
-.exercise[
-
-- Add the repository:
-  ```bash
-    helm repo add prometheus-community \
-         https://prometheus-community.github.io/helm-charts
-  ```
-
-]
-
----
-
-## Step 3: install Prometheus
+## Step 2: install Prometheus
 
 - The following command, just like the previous ones, is idempotent
 
@@ -248,9 +228,9 @@ We need to:
 
 - Install Prometheus on our cluster:
   ```bash
-    helm upgrade prometheus prometheus-community/prometheus \
-        --install \
-        --namespace kube-system \
+    helm upgrade prometheus --install prometheus \
+        --repo https://prometheus-community.github.io/helm-charts \
+        --namespace prometheus --create-namespace \
         --set server.service.type=NodePort \
         --set server.service.nodePort=30090 \
         --set server.persistentVolume.enabled=false \
@@ -267,24 +247,37 @@ class: extra-details
 
 ## Explaining all the Helm flags
 
-- `helm upgrade prometheus` → upgrade the release named `prometheus` ...
+- `helm upgrade prometheus` → upgrade the release named `prometheus`
   <br/>
   (a "release" is an instance of an app deployed with Helm)
 
-- `prometheus-community/...` → of a chart located in the `prometheus-community` repo ...
+- `--install` → if it doesn't exist, install it (instead of upgrading)
 
-- `.../prometheus` → in that repo, get the chart named `prometheus` ...
+- `prometheus` → use the chart named `prometheus`
 
-- `--install` → if the app doesn't exist, create it ...
+- `--repo ...` → the chart is located on the following repository
 
-- `--namespace kube-system` → put it in that specific namespace ...
+- `--namespace prometheus` → put it in that specific namespace
 
-- ... and set the following *values* when rendering the chart's templates:
+- `--create-namespace` → create the namespace if it doesn't exist
 
-  - `server.service.type=NodePort` → expose the Prometheus server with a NodePort
-  - `server.service.nodePort=30090` → set the specific NodePort number to use
-  - `server.persistentVolume.enabled=false` → do not use a PersistentVolumeClaim
-  - `alertmanager.enabled=false` → disable the alert manager entirely
+- `--set ...` → here are some *values* to be used when rendering the chart's templates
+
+---
+
+class: extra-details
+
+## Values for the Prometheus chart
+
+Helm *values* are parameters to customize our installation.
+
+- `server.service.type=NodePort` → expose the Prometheus server with a NodePort
+
+- `server.service.nodePort=30090` → set the specific NodePort number to use
+
+- `server.persistentVolume.enabled=false` → do not use a PersistentVolumeClaim
+
+- `alertmanager.enabled=false` → disable the alert manager entirely
 
 ---
 
@@ -301,6 +294,9 @@ class: extra-details
 
 - With your browser, connect to that port
 
+
+- It should be 30090 if we just installed Prometheus with the Helm chart!
+
 ]
 
 ---