Allow building and pushing images on another branch

Before, all images are pushed with the SHA and the `latest` tag.

With this commit, pushing an image will tag it with the branch name as
well for easier use while developing.

Unfortunately, k8s doesn't support templating yet
(kubernetes/kubernetes#23896) so you'll still
have to manually change the image tag in the `manifest.yaml` file back
and forth but it's definitely easier than before.

Now, the workflow is:

1. Work on image
2. Push with `make release-all`
3. Edit `manifest.yaml` to use images for your branch to test
4. Edit it back when making a PR.

Makefile

@@ -5,10 +5,13 @@
 # image is named data8/jupyterhub-k8s-<name> where <name> is the name of the
 # component (eg. cull).
 #
+# All pushed are tagged with the SHA of the commit, as well as the name of the
+# current git branch.
+#
 # When creating a new image, first create the repo on Docker Hub under the
 # data8 org. Then, add it to the ALL_IMAGES variable below.
 
-.PHONY: help environment-check
+.PHONY: help
 
 ALL_IMAGES:=cull \
  hub
@@ -18,6 +21,9 @@ IMAGE_PREFIX:=jupyterhub-k8s-
 
 DHUB_ORG:=data8
 
+# Get current branch name
+BRANCH:=$(shell git symbolic-ref --short HEAD 2>/dev/null)
+
 # Grabs the SHA of the latest commit for tagging purposes
 GIT_MASTER_HEAD_SHA:=$(shell git rev-parse --short=12 --verify HEAD)
 
@@ -27,39 +33,33 @@ help:
  @echo "====================="
  @grep -E '^[a-zA-Z0-9_%/-]+:.*?## .*$$' $(MAKEFILE_LIST) | sort | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-15s\033[0m %s\n", $$1, $$2}'
 
-# This is a simple check that is used to prevent accidental pushes since
-# Travis should be building our images.
-environment-check:
- test -e ~/.jhub-k8s-images-builder
-
-refresh/%: ## pull the latest image from Docker Hub for a stack
-# skip if error: a stack might not be on dockerhub yet
- -docker pull $(DHUB_ORG)/$(IMAGE_PREFIX)$(notdir $@):latest
+refresh/%: ## pull the latest image from Docker Hub
+# skip if error: an image might not be on dockerhub yet
+ -docker pull $(DHUB_ORG)/$(IMAGE_PREFIX)$(notdir $@):$(BRANCH)
 
 refresh-all: $(ALL_IMAGES:%=refresh/%) ## refresh all images
 
 build/%: DARGS?=
 build/%: ## build the latest image for a component
  docker build $(DARGS) --rm --force-rm \
- -t $(DHUB_ORG)/$(IMAGE_PREFIX)$(notdir $@):latest \
+ -t $(DHUB_ORG)/$(IMAGE_PREFIX)$(notdir $@):$(BRANCH) \
  ./$(notdir $@)
 
 build-all: $(ALL_IMAGES:%=build/%) ## build all images
 
 tag/%: ## tag the latest component image with the HEAD git SHA
- docker tag $(DHUB_ORG)/$(IMAGE_PREFIX)$(notdir $@):latest \
+ docker tag $(DHUB_ORG)/$(IMAGE_PREFIX)$(notdir $@):$(BRANCH) \
  $(DHUB_ORG)/$(IMAGE_PREFIX)$(notdir $@):$(GIT_MASTER_HEAD_SHA)
 
 tag-all: $(ALL_IMAGES:%=tag/%) ## tag all images
 
 push/%: ## push the latest and HEAD git SHA tags for a component to Docker Hub
- docker push $(DHUB_ORG)/$(IMAGE_PREFIX)$(notdir $@):latest
+ docker push $(DHUB_ORG)/$(IMAGE_PREFIX)$(notdir $@):$(BRANCH)
  docker push $(DHUB_ORG)/$(IMAGE_PREFIX)$(notdir $@):$(GIT_MASTER_HEAD_SHA)
 
 push-all: $(ALL_IMAGES:%=push/%) ## push all images
 
-release-all: environment-check \
- refresh-all \
+release-all: refresh-all \
  build-all \
  tag-all \
  push-all

manifest.yaml

@@ -24,28 +24,28 @@ kind: Deployment
 metadata:
  name: hub-proxy-deployment
 spec:
-  replicas: 1
-  template:
-  metadata:
-  labels:
-  name: hub-proxy-pod
-  spec:
-  containers:
-  - name: hub-proxy-container
-  image: data8/jupyterhub-k8s-hub:latest
-  env:
-  - name: POD_NAMESPACE
-  valueFrom:
-  fieldRef:
-  fieldPath: metadata.namespace
-  - name: CULL_JHUB_TOKEN
-  valueFrom:
-  configMapKeyRef:
-  name: cull-config
-  key: auth.jhub-token.cull
-  ports:
-  - containerPort: 8000
-  name: hub-proxy-port
+ replicas: 1
+ template:
+ metadata:
+ labels:
+ name: hub-proxy-pod
+ spec:
+ containers:
+ - name: hub-proxy-container
+ image: data8/jupyterhub-k8s-hub:master
+ env:
+ - name: POD_NAMESPACE
+ valueFrom:
+ fieldRef:
+ fieldPath: metadata.namespace
+ - name: CULL_JHUB_TOKEN
+ valueFrom:
+ configMapKeyRef:
+ name: cull-config
+ key: auth.jhub-token.cull
+ ports:
+ - containerPort: 8000
+ name: hub-proxy-port
 ---
 apiVersion: extensions/v1beta1
 kind: Deployment
@@ -60,7 +60,7 @@ spec:
  spec:
  containers:
  - name: cull-container
- image: data8/jupyterhub-k8s-cull:latest
+ image: data8/jupyterhub-k8s-cull:master
  command:
  - /bin/sh
  - -c