feat: add arm binaries

Dockerfile

@@ -1,6 +1,7 @@
 # Stage 1 Build myks
-FROM golang:1.21 AS builder
-
+FROM --platform=$BUILDPLATFORM golang:1.21 AS builder
+ARG TARGETOS
+ARG TARGETARCH
 WORKDIR /app
 
 COPY . .
@@ -9,40 +10,44 @@ RUN go mod download \
  && go mod verify
 
 RUN CGO_ENABLED=0 \
-    go build -trimpath -o myks main.go
+    GOOS=${TARGETOS} GOARCH=${TARGETARCH} go build -trimpath -o myks main.go
 
 
 # Stage 2 Download tools
-FROM debian:bookworm AS download-tools
+FROM --platform=$BUILDPLATFORM debian:bookworm AS download-tools
+
+ARG TARGETOS
+ARG TARGETARCH
+ARG HELM_VERSION=3.11.2
+ARG VENDIR_VERSION=0.33.1
+ARG YTT_VERSION=0.45.0
 
 RUN apt-get update \
  && apt-get install --no-install-recommends -y \
       ca-certificates \
       curl \
       unzip
 
-ARG HELM_VERSION=3.11.2
-ARG VENDIR_VERSION=0.33.1
-ARG YTT_VERSION=0.45.0
-
 WORKDIR /tools
 
 SHELL ["/bin/bash", "-o", "pipefail", "-c"]
 
 RUN curl -fsSL \
-      https://get.helm.sh/helm-v${HELM_VERSION}-linux-amd64.tar.gz \
-    | tar -xzf - --strip-components=1 linux-amd64/helm
+      https://get.helm.sh/helm-v${HELM_VERSION}-${TARGETOS}-${TARGETARCH}.tar.gz \
+    | tar -xzf - --strip-components=1 ${TARGETOS}-${TARGETARCH}/helm
 RUN curl -fsSL \
-      https://github.com/vmware-tanzu/carvel-vendir/releases/download/v${VENDIR_VERSION}/vendir-linux-amd64 \
+      https://github.com/vmware-tanzu/carvel-vendir/releases/download/v${VENDIR_VERSION}/vendir-${TARGETOS}-${TARGETARCH} \
     > vendir
 RUN curl -fsSL \
-      https://github.com/vmware-tanzu/carvel-ytt/releases/download/v${YTT_VERSION}/ytt-linux-amd64 \
+      https://github.com/vmware-tanzu/carvel-ytt/releases/download/v${YTT_VERSION}/ytt-${TARGETOS}-${TARGETARCH} \
     > ytt
 RUN chmod +x *
 
 
 # Stage 3: Bring it all together
-FROM debian:bookworm
+FROM --platform=$BUILDPLATFORM debian:bookworm
+
+WORKDIR /app
 
 RUN apt-get update \
  && apt-get install --no-install-recommends -y \