Replace registry:2 with registry

registry used to be registry v1, but now it defaults to v2.
We can therefore drop the tag.

slides/k8s/ourapponkube.md

@@ -50,8 +50,7 @@ In this part, we will:
 
 ## Using the open source registry
 
-- We need to run a `registry:2` container
-  <br/>(make sure you specify tag `:2` to run the new version!)
+- We need to run a `registry` container
 
 - It will store images and layers to the local filesystem
   <br/>(but you can add a config file to use S3, Swift, etc.)
@@ -75,7 +74,7 @@ In this part, we will:
 
 - Create the registry service:
   ```bash
-  kubectl run registry --image=registry:2
+  kubectl run registry --image=registry
   ```
 
 - Expose it on a NodePort:

slides/swarm/compose2swarm.md

@@ -63,7 +63,7 @@ We need a registry to move images around.
 Without a stack file, it would be deployed with the following command:
 
 ```bash
-docker service create --publish 5000:5000 registry:2
+docker service create --publish 5000:5000 registry
 ```
 
 Now, we are going to deploy it with the following stack file:
@@ -73,7 +73,7 @@ version: "3"
 
 services:
   registry:
-    image: registry:2
+    image: registry
     ports:
       - "5000:5000"
 ```

slides/swarm/hostingregistry.md

@@ -1,7 +1,6 @@
 # Hosting our own registry
 
-- We need to run a `registry:2` container
-  <br/>(make sure you specify tag `:2` to run the new version!)
+- We need to run a `registry` container
 
 - It will store images and layers to the local filesystem
   <br/>(but you can add a config file to use S3, Swift, etc.)
@@ -28,7 +27,7 @@
 
 - Create the registry service:
   ```bash
-  docker service create --name registry --publish 5000:5000 registry:2
+  docker service create --name registry --publish 5000:5000 registry
   ```
 
 - Now try the following command; it should return `{"repositories":[]}`:

stacks/registry.yml

@@ -2,7 +2,7 @@ version: "3"
 
 services:
   registry:
-    image: registry:2
+    image: registry
     ports:
       - "5000:5000"