Dockerfile

# syntax=docker/dockerfile:1

# Comments are provided throughout this file to help you get started.
# If you need more help, visit the Dockerfile reference guide at
# https://docs.docker.com/engine/reference/builder/

################################################################################
# Create a stage for building the application.
ARG GO_VERSION=1.22.2
FROM golang:${GO_VERSION} AS build
WORKDIR /src

# Download dependencies as a separate step to take advantage of Docker's caching.
# Leverage a cache mount to /go/pkg/mod/ to speed up subsequent builds.
# Leverage bind mounts to go.sum and go.mod to avoid having to copy them into
# the container.
RUN --mount=type=cache,target=/go/pkg/mod/ \
    --mount=type=bind,source=go.sum,target=go.sum \
    --mount=type=bind,source=go.mod,target=go.mod \
    go mod download -x

# Build the application.
# Leverage a cache mount to /go/pkg/mod/ to speed up subsequent builds.
# Leverage a bind mount to the current directory to avoid having to copy the
# source code into the container.
RUN --mount=type=cache,target=/go/pkg/mod/ \
    --mount=type=bind,target=. \
    CGO_ENABLED=0 go build -o /bin/server ./cmd

FROM alpine:latest AS final

RUN apk --update add \
        ca-certificates \
        tzdata \
        && \
        update-ca-certificates

# Create a non-privileged user that the app will run under.
# See https://docs.docker.com/go/dockerfile-user-best-practices/
ARG UID=10001
RUN adduser \
    --disabled-password \
    --gecos "" \
    --home "/nonexistent" \
    --shell "/sbin/nologin" \
    --no-create-home \
    --uid "${UID}" \
    appuser


RUN mkdir -p /data
RUN chown -R appuser:appuser /data


USER appuser

# Copy the executable from the "build" stage.
COPY --from=build /bin/server /bin/

# Expose the port that the application listens on.
EXPOSE 5566
EXPOSE 8080

# What the container should run when it is started.
ENTRYPOINT [ "/bin/server" ]