Dockerfile Build Doesn't Work But Works with Compose - docker

Question

I have a Dockerfile that won't build, but will work with docker-compose, I need it to work though with docker build command.
###############
# CACHE IMAGE #
###############
ARG GO_IMAGE=golang:1.17.3-alpine3.14
ARG BASE_IMAGE=alpine:3.14.2
FROM ${GO_IMAGE} AS cache
# Add the keys
ARG GITHUB_ID
ENV GITHUB_ID=$GITHUB_ID
ARG GITHUB_TOKEN
ENV GITHUB_TOKEN=$GITHUB_TOKEN
# Install Git
RUN apk add git
# TODO: ENCRYPT THE GITHUB_ID AND GITHUB_TOKEN
# Make Git Configuration
RUN git config \
--global \
url."https://${GITHUB_ID}:${GITHUB_TOKEN}#github.com/".insteadOf \
"https://github.com/"
WORKDIR /bin
COPY go.mod go.sum bin/
RUN go mod download
##############
# BASE IMAGE #
##############
FROM cache AS dataeng_github_metrics
COPY . /bin
WORKDIR /bin
# Setup Git Terminal Prompt & Go Build
RUN go build .
###############
# FINAL IMAGE #
###############
FROM ${BASE_IMAGE}
COPY --from=dataeng_github_metrics /bin/dataeng_github_metrics bin/
ENTRYPOINT [ "bin/dataeng_github_metrics" ]
The directory looks like this:
rics   Docker-Publish-Workflows-To-GHCR ●  tree .  1 ↵  8955  20:37:41
.
├── Dockerfile
├── Makefile
├── README.md
├── dataeng_github_metrics
├── go.mod
├── go.sum
├── infra
│ ├── README.md
│ ├── k8s
│ │ ├── README.md
│ │ ├── configmaps
│ │ │ ├── README.md
│ │ │ └── teams-payload-configmap.yaml
│ │ ├── cronworkflow
│ │ │ ├── README.md
│ │ │ └── argo_cron_workflow.yaml
│ │ ├── deployment
│ │ │ ├── README.md
│ │ │ ├── git-hub-contributions-deployment.yaml
│ │ │ └── postgres-deployment.yaml
│ │ └── volumeclaims
│ │ ├── README.md
│ │ ├── git-hub-contributions-claim0-persistentvolumeclaim.yaml
│ │ ├── git-hub-contributions-claim1-persistentvolumeclaim.yaml
│ │ └── git-hub-contributions-claim2-persistentvolumeclaim.yaml
│ ├── payloads
│ │ ├── README.md
│ │ ├── dataeng_github_metrics.csv
│ │ └── teams.yaml
│ └── terraform
│ ├── README.md
│ └── manifests
│ └── README.md
├── local
│ ├── README.md
│ ├── dependencies
│ │ └── wait-for-postgres.sh
│ ├── docker-compose.yaml
│ └── images
│ ├── ER_Diagram.png
│ ├── print_execution.png
│ └── print_query.png
└── main.go
What's weird to me is it fails at the COPY step for go.mod and go.sum, and I haven't a clue why it's not copying over the files:
Command to build Dockerfile in working directory:
docker build - < Dockerfile
[+] Building 0.7s (12/17)
=> [internal] load build definition from Dockerfile 0.0s
=> => transferring dockerfile: 928B 0.0s
=> [internal] load .dockerignore 0.0s
=> => transferring context: 2B 0.0s
=> [internal] load metadata for docker.io/library/alpine:3.14.2 0.4s
=> [internal] load metadata for docker.io/library/golang:1.17.3-alpine3.14 0.0s
=> [cache 1/7] FROM docker.io/library/golang:1.17.3-alpine3.14 0.0s
=> [internal] load build context 0.0s
=> => transferring context: 2B 0.0s
=> [stage-2 1/2] FROM docker.io/library/alpine:3.14.2#sha256:e1c082e3d3c45cccac829840a2594 0.0s
=> CACHED [cache 2/7] RUN apk add git 0.0s
=> CACHED [cache 3/7] RUN git config --global url."https://:#github.com/".insteadO 0.0s
=> CACHED [cache 4/7] WORKDIR /bin 0.0s
=> [cache 5/7] RUN pwd 0.2s
=> ERROR [cache 6/7] COPY go.mod go.sum ./
Why is it not letting me copy a file into my WORKDIR with docker build, but when I use docker-compose it works just fine.

Answer 1

Try running the Docker build like so:
docker build .
The build with - doesn't work as expected because no context is given. See Docker build docs:
This will read a Dockerfile from STDIN without context. Due to the lack of a context, no contents of any local directory will be sent to the Docker daemon. Since there is no context, a Dockerfile ADD only works if it refers to a remote URL.