use multistage docker builds

Author: Sameer Naik

.dockerignore

@@ -0,0 +1,8 @@
+# Top level files and directories
+/.circleci/
+/.git/
+/.dockerignore
+/.gcloudignore
+/cloudbuild.yaml
+/site
+/Dockerfile

.gcloudignore

@@ -0,0 +1,2 @@
+#!include:.dockerignore
+!Dockerfile

Dockerfile

@@ -1,4 +1,11 @@
-FROM nginx
+FROM python:3 AS builder
+
+RUN pip install mkdocs
+
+COPY . /docs
 
-ADD site/ /usr/share/nginx/html/
+RUN mkdocs build --clean --config-file /docs/mkdocs.yml
+
+FROM nginx
 
+COPY --from=builder /docs/site/ /usr/share/nginx/html/

cloudbuild.yaml

@@ -1,8 +1,4 @@
 steps:
-- name: 'gcr.io/triggermesh/mkdocs:latest'
-  args: ['mkdocs', 'build']
-- name: 'debian'
-  args: ['ls', '/workspace/site']
 - name: 'gcr.io/cloud-builders/docker'
   args: ['build', '-t', 'gcr.io/$PROJECT_ID/www:$REVISION_ID', '-t', 'gcr.io/$PROJECT_ID/www:latest', '.']
 - name: 'gcr.io/cloud-builders/docker'