Continuous Deployment - Golang on Docker

I’m trying to build and deploy Docker Containers with go binaries. Docker Hub says that the circleci/golang image used as a build environment comes with docker installed. However, the build fails on docker build . with the error: Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running? I rebuild with SSH and discover that systemctl is not installed and there is no docker group. Wouldn’t these be basic to an image with Docker installed? How should I fix the issue? (aside from installing systemctl and creating a new group in my config file)?