♻️ Improve Tilt section

Split out the Tilt registry to separate YAML files.
Expand the Tilt section a bit to clarify what happens
when running on cluster-that-don't-look-like-dev-ones.

dockercoins/Tiltfile

@@ -1,39 +1,4 @@
-k8s_yaml(blob('''
-apiVersion: apps/v1
-kind: Deployment
-metadata:
-  labels:
-    app: registry
-  name: registry
-spec:
-  selector:
-    matchLabels:
-      app: registry
-  template:
-    metadata:
-      labels:
-        app: registry
-    spec:
-      containers:
-      - image: registry
-        name: registry
----
-apiVersion: v1
-kind: Service
-metadata:
-  labels:
-    app: registry
-  name: registry
-spec:
-  ports:
-  - port: 5000
-    protocol: TCP
-    targetPort: 5000
-    nodePort: 30555
-  selector:
-    app: registry
-  type: NodePort
-'''))
+k8s_yaml('../k8s/tilt-registry.yaml')
 default_registry('localhost:30555')
 docker_build('dockercoins/hasher', 'hasher')
 docker_build('dockercoins/rng', 'rng')

k8s/tilt-registry.yaml

@@ -0,0 +1,42 @@
+---
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: tilt-registry
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  labels:
+    app: tilt-registry
+  name: tilt-registry
+  namespace: tilt-registry
+spec:
+  selector:
+    matchLabels:
+      app: tilt-registry
+  template:
+    metadata:
+      labels:
+        app: tilt-registry
+    spec:
+      containers:
+      - image: registry
+        name: registry
+---
+apiVersion: v1
+kind: Service
+metadata:
+  labels:
+    app: tilt-registry
+  name: tilt-registry
+  namespace: tilt-registry
+spec:
+  ports:
+  - port: 5000
+    protocol: TCP
+    targetPort: 5000
+    nodePort: 30555
+  selector:
+    app: tilt-registry
+  type: NodePort

slides/k8s/tilt.md

@@ -181,17 +181,57 @@ Ah, right ...
 
 - The `dockercoins` directory in our repository has a `Tiltfile`
 
-- Go to that directory and try `tilt up`
+- That Tiltfile includes definitions for the DockerCoins app, including:
 
-- Tilt should refuse to start, but it will explain why
+  - building the images for the app
 
-- Edit the `Tiltfile` accordingly and try again
+  - Kubernetes manifests to deploy the app
 
-- Open the Tilt web UI
+  - a self-hosted registry to host the app image
 
-  (if running Tilt on a remote machine, you will need `tilt up --host 0.0.0.0`)
+- Let's try it out!
 
-- Watch as the Dockercoins app is built, pushed, started
+---
+
+## Running Tilt
+
+- If you're running on your local machine:
+  ```bash
+  tilt up
+  ```
+  Then press "space" or connect to http://localhost:10350/
+
+- If you're running on a remote machine:
+  ```bash
+  tilt up --host=0.0.0.0
+  ```
+  Then connect to the remote machine on port 10350
+
+- The Tilt web interface might complain about the Kubernetes context
+
+  ...If it does, don't worry, we'll fix that right away!
+
+---
+
+## Kubernetes contexts
+
+- Tilt is designed to run in dev environments
+
+- It will try to figure out if we're really in a dev environment:
+
+  - if Tilt thinks that are on a local dev cluster, it will start
+
+  - otherwise, it will give us a warning and it won't continue
+
+- In the latter case, we need to add one line to the Tiltfile
+
+  (to tell Tilt "it's okay, you can run safely in this environment!")
+
+- If this happens, add the line to the Tiltfile
+
+  (Tilt will tell you exactly what to add!)
+
+- We don't need to restart Tilt, it will detect the change immediately
 
 ---