Dockerfile.dev

FROM golang:1.21 as builder

# Create and change to the app directory.
WORKDIR /app

# Retrieve application dependencies using go modules.
# Allows container builds to reuse downloaded dependencies.
COPY go.* ./
RUN go mod download

# Copy local code to the container image.
COPY . ./

RUN go mod tidy -go=1.21

# Build the binary.
# -mod=readonly ensures immutable go.mod and go.sum in container builds.
RUN CGO_ENABLED=0 GOOS=linux go build -mod=readonly -v -o metadataservice

# Use the official Alpine image for a lean production container.
# https://hub.docker.com/_/alpine
# https://docs.docker.com/develop/develop-images/multistage-build/#use-multi-stage-builds
FROM alpine:3.19
RUN apk add --no-cache ca-certificates

# Run as a non-root user (>10000 to avoid conflicts with the host's user table)
USER 10001:10001

# Copy the binary to the production image from the builder stage.
COPY --from=builder /app/metadataservice /metadataservice

# Run the web service on container startup.
ENTRYPOINT ["/metadataservice"]
CMD ["serve"]