docker build [option] [path]

docker build -t docker.io/acoinfo/demo:v1 .

[+] Building 1.1s (5/5) FINISHED                                                
 => [internal] load build definition from Dockerfile                       0.0s
 => => transferring dockerfile: 502B                                       0.0s
 => [internal] load .dockerignore                                          0.0s
 => => transferring context: 2B                                            0.0s
 => [internal] load metadata for docker.io/library/openjdk:8               1.0s
 => CACHED [1/1] FROM docker.io/library/openjdk:8@sha256:86e863cc57215cfb  0.0s
 => exporting to image                                                     0.0s
 => => exporting layers                                                    0.0s
 => => writing image sha256:f118838bdeb12eb212e0a176d3d2d18f72dabb9958ca9  0.0s
 => => naming to docker.io/acoinfo/demo:v1                                 0.0s