Dynamic Dockerfile for any local Go project

GoDockerfile

ARG GO_VERSION=1.20
ARG BASE_IMAGE=golang:${GO_VERSION}-bullseye
ARG APP_NAME=app
ARG APP_PORT=3000

FROM ${BASE_IMAGE} AS build

WORKDIR /app

COPY go.mod go.sum ./

RUN --mount=type=cache,target=/go/pkg/mod \
    --mount=type=cache,target=/root/.cache/go-build \
    go mod download

FROM build AS dev

RUN go install github.com/cosmtrek/air@latest \
    && go install github.com/go-delve/delve/cmd/dlv@latest

COPY . .

CMD ["air", "-c", ".air.toml"]

FROM build AS build-production

# Non-root user
RUN useradd -u 1001 nobody

COPY . .

RUN go build \
    -ldflags="-linkmode external -extldflags -static" \
    -tags netgo \
    -o ${APP_NAME}

FROM scratch

ENV GIN_MODE=release

WORKDIR /

COPY --from=build-production /etc/passwd /etc/passwd

COPY --from=build-production /app/${APP_NAME} /${APP_NAME}

USER nobody

EXPOSE ${APP_PORT}

CMD ["/${APP_NAME}"]