Dockerfile

FROM golang:1.21-bullseye AS builder

ARG TARGETOS
ARG TARGETARCH
ARG VERSION

WORKDIR /workspace

# Copy the Go Modules manifests
# cache deps before building and copying source so that we don't need to re-download as much
# and so that source changes don't invalidate our downloaded layer
COPY go.mod go.mod
COPY go.sum go.sum
RUN go mod download -x

# Copy the go source
COPY pkg/ pkg/
COPY main.go ./

# Build
# the GOARCH has not a default value to allow the binary be built according to the host where the command
# was called. For example, if we call make docker-build in a local env which has the Apple Silicon M1 SO
# the docker BUILDPLATFORM arg will be linux/arm64 when for Apple x86 it will be linux/amd64. Therefore,
# by leaving it empty we can ensure that the container and binary shipped on it will have the same platform.
RUN CGO_ENABLED=0 GOOS=${TARGETOS:-linux} GOARCH=${TARGETARCH} go build -ldflags="-w -s -X main.version=${VERSION}" -o ksops .

# Runtime
FROM alpine:latest
WORKDIR /
COPY --from=builder /workspace/ksops /usr/local/bin/ksops

ENTRYPOINT ["/usr/local/bin/ksops"]