spurti-chopra

### Below is used for representation purpose and is not in any way a working Dockerfile. 

### Dockerfile - I
FROM ubuntu:18.04
ENV APP_USER=TEST
ENV APP_PORT=8080

RUN apt-get update
RUN apt-get install -y pkg1 pkg2 pkg3
RUN mkdir -p /usr/src/test-dir

spurti-chopra

### Below is used for representation purpose and is not in any way a working Dockerfile.

### Build the artifact using Dockerfile.build
docker build -t artifact-build -f Dockerfile.build

### Create the container using the image to obtain artifact
docker create --name artifact-container artifact-build

### Copy the artifact from container to host machine
docker cp artifact-conatiner:<src_path_of_artifact> <host_machine_path>

spurti-chopra

### Below is used for representation purpose and is not in any way a working Dockerfile. 
FROM alpine:latest
RUN apk update && apk add --no-cache gcc musl-dev
COPY <prg>.c .
RUN gcc -static -o <prg> <prg>.c

FROM alpine:latest
COPY --from=0 <prg> /usr/bin/<prg>
ENTRYPOINT ["/usr/bin/<prg>"]

spurti-chopra

## Dockerfile, with RUN uncombined
FROM ubuntu:16.04
ADD app.zip .         # App of 200 MB
RUN chmod 777 app.zip
RUN rm -rf app.zip

## Dockerfile, with RUN combined
FROM ubuntu:16.04
ADD app.zip .        # App of 200 MB
RUN chmod 777 app.zip && rm -rf app.zip

spurti-chopra

$ docker build -t app-unsquashed .
$ docker history app-unsquashed
IMAGE           CREATED       CREATED BY                                      SIZE                COMMENT
7ee5b606949f    1 hour ago    /bin/sh -c rm -rf app.zip                       0B
7df1dc446bd0    2 hour ago    /bin/sh -c chmod 777 app.zip                    210MB
71530d33b38b    2 huor ago    /bin/sh -c #(nop) ADD file:b12845ba907bbbc42…   210MB
b9e15a5d1e1a    8 days ago    /bin/sh -c #(nop)  CMD ["/bin/bash"]            0B
<missing>       8 days ago    /bin/sh -c mkdir -p /run/systemd && echo 'do…   7B
<missing>       8 days ago    /bin/sh -c sed -i 's/^#\s*\(deb.*universe\)$…   2.76kB
<missing>       8 days ago    /bin/sh -c rm -rf /var/lib/apt/lists/*          0B

spurti-chopra

$  docker build --squash -t app-squashed .
$  docker history app-squashed
IMAGE          CREATED      CREATED BY                                      SIZE   COMMENT
c3f98f9241fc   2 hours ago                                                  0B     merge sha256:7ee5b606949f15cdfc790a44b49ea83b2ae7c8be808eedfb74234b47a50e66f1 to sha256:b9e15a5d1e1a11a69061b1dc2e3641805a2dc54e1338faf7f87f4c2c21ed3e6a
<missing>      2 hours ago  /bin/sh -c rm -rf app.zip                       0B
<missing>      2 hours ago  /bin/sh -c chmod 777 app.zip                    0B
<missing>      2 hours ago  /bin/sh -c #(nop) ADD file:b12845ba907bbbc42…   0B
<missing>      8 days ago   /bin/sh -c #(nop)  CMD ["/bin/bash"]            0B
<missing>      8 days ago   /bin/sh -c mkdir -p /run/systemd && echo 'do…   7B
<missing>      8 days ago   /bin/sh -c sed -i 's/^#\s*\(deb.*universe\)$…   2.76kB