I'm working with Docker and just trying to get something simple done to get some practice in. Below is my outcome. I'm not sure what is causing this syntax error. Would anyone be willing to tell me what I am doing wrong and why this won't run?

: $ touch Dockerfile ~ :~$ nano Dockerfile .: $ cat Dockerfile FROM ubuntu MAINTAINER RUN apt-get -y install CMD echo "Hello World!" 1:~$ docker build -t vcolab10a . Sending build context to Docker daemon 17.92kB Step 1/4 : FROM ubuntu ---> f63181f19b2f Step 2/4 : MAINTAINER ---> Running in 6552ddb9790e Removing intermediate container 6552ddb9790e ---> f0893853dd13 Step 3/4 : RUN apt-get -y install ---> Running in 9fc668e8aa11 Reading package lists... Building dependency tree... Reading state information... o upgraded, o newly installed, 0 to remove and o not upgraded. Removing intermediate container 9fc668e8aa11 ---> c4eff5948d51 Step 4/4 : CMD echo "Hello World!" ---> Running in 6ec4e04d8bfb Removing intermediate container 6ec4e04d8bfb ---> 912efefaa36f Successfully built 912efefaa36f Successfully tagged vcolab10a:latest $ : $ docker run colab10a /bin/sh: 1: Syntax error: Unterminated quoted string +