adding an small docker reference

docker/reference.md

@@ -0,0 +1,23 @@
+After running the tests with docker, you will need Docker installed and the docker image downloaded.
+
+## Install docker
+`sudo apt install docker.io && sudo usermod -aG docker $(whoami)`
+
+## Download image
+`docker pull cartoimages/engine-xenial-pg101`
+
+## Update image
+- Edit the docker image file with your desired changes
+- Build image: 
+  - `docker build -t cartoimages/engine-xenial-pg101 -f docker/Dockerfile-xenial-pg101 docker/`
+- Upload to docker hub:
+  - Login into docker hub: 
+    - `docker login`
+  - Create tag: 
+    - `docker tag cartoimages/engine-xenial-pg101 cartoimages/engine-xenial-pg101`
+  - Upload: 
+    - `docker push cartoimages/engine-xenial-pg101`
+
+
+## Useful commands 
+We have some useful commands created in package.json

package.json

@@ -65,10 +65,10 @@
     "preinstall": "make pre-install",
     "test": "make test-all",
     "update-internal-deps": "rm -rf node_modules && rm -f yarn.lock && yarn",
-    "docker-install": "sudo apt install docker.io && sudo usermod -aG docker $(whoami)",
-    "docker-pull": "docker pull cartoimages/windshaft-testing",
-    "docker-test": "docker run -v `pwd`:/srv cartoimages/windshaft-testing bash docker-test.sh && docker ps --filter status=dead --filter status=exited -aq | xargs -r docker rm -v",
-    "docker-bash": "docker run  -it -v `pwd`:/srv cartoimages/windshaft-testing bash"
+    "docker-pull": "docker pull cartoimages/engine-xenial-pg101",
+    "docker-test": "docker run -v `pwd`:/srv cartoimages/engine-xenial-pg101 bash docker-test.sh && docker ps --filter status=dead --filter status=exited -aq | xargs -r docker rm -v",
+    "docker-bash": "docker run  -it -v `pwd`:/srv cartoimages/engine-xenial-pg101 bash",
+    "docker-build": "docker build -t cartoimages/engine-xenial-pg101 -f docker/Dockerfile-xenial-pg101 docker/"
   },
   "engines": {
     "node": ">=6.9",