feat: add slim image

Dockerfile

@@ -1,7 +1,10 @@
 ## Using the builder this way keeps us from having to install wget and adding an extra
 ## fat step that just does a chmod on the kubelet binary
 
-FROM alpine:latest as builder-amd64
+ARG BASE_IMAGE=registry.k8s.io/build-image/debian-iptables:bookworm-v1.0.0
+ARG SLIM_PACKAGES="ca-certificates libcap2 ethtool iproute2 nfs-common socat util-linux"
+
+FROM alpine:latest AS builder-amd64
 
 ARG TARGETARCH
 ARG KUBELET_VER
@@ -13,7 +16,7 @@ RUN wget -q -O /kubelet ${KUBELET_URL} \
   && echo "${KUBELET_SHA512_AMD64}  /kubelet" | sha512sum -cw \
   && chmod +x /kubelet
 
-FROM alpine:latest as builder-arm64
+FROM alpine:latest AS builder-arm64
 
 ARG TARGETARCH
 ARG KUBELET_VER
@@ -26,35 +29,46 @@ RUN wget -q -O /kubelet ${KUBELET_URL} \
   && chmod +x /kubelet
 
 ARG TARGETARCH
-FROM builder-${TARGETARCH} as builder
+FROM builder-${TARGETARCH} AS builder
+
+########################
 
-FROM registry.k8s.io/build-image/debian-iptables:bookworm-v1.0.0 as container
+FROM ${BASE_IMAGE} AS container-fat
 
 RUN clean-install \
   --allow-change-held-packages \
-  procps \
+  ${SLIM_PACKAGES} \
   bash \
-  ca-certificates \
-  libcap2 \
+  ceph-common \
   cifs-utils \
   e2fsprogs \
-  xfsprogs \
   ethtool \
   glusterfs-client \
-  iproute2 \
   jq \
-  nfs-common \
-  socat \
+  procps \
   ucf \
   udev \
-  util-linux \
-  ceph-common
+  xfsprogs
 
 COPY --from=builder /kubelet /usr/local/bin/kubelet
 
 # Add wrapper for iscsiadm
 COPY files/iscsiadm /usr/local/sbin/iscsiadm
 
-LABEL org.opencontainers.image.source https://github.com/siderolabs/kubelet
+LABEL org.opencontainers.image.source="https://github.com/siderolabs/kubelet"
+
+ENTRYPOINT ["/usr/local/bin/kubelet"]
+
+########################
+
+FROM ${BASE_IMAGE} AS container-slim
+
+RUN clean-install \
+  --allow-change-held-packages \
+  ${SLIM_PACKAGES}
+
+COPY --from=builder /kubelet /usr/local/bin/kubelet
+
+LABEL org.opencontainers.image.source="https://github.com/siderolabs/kubelet"
 
 ENTRYPOINT ["/usr/local/bin/kubelet"]

Makefile

@@ -9,6 +9,18 @@ KUBELET_VER := v1.31.0-rc.1
 KUBELET_SHA512_AMD64 := b52716aadd95d73c408b3b30baae288fd10f8c024424671392e233f00316d3f0546a6c6780e81f5ddac039020bcc80dfa85202939ac70ccec74a7b6bbdf26097
 KUBELET_SHA512_ARM64 := 2122ffaca810410ff0ac2cb0b6c1b05908fcdeda1dc64f310ae982a58278917a51f77fdfdc89713fbf5c3fe0ee16c9626c0464bb358a863900a38a19b8a421f7
 
+# For kubelet versions >= 1.31.0, the slim image is the default one, and previous image is labeled as -fat.
+# For kubelet versions < 1.31.0, the fat image is the default one, and previous image is labeled as -slim.
+USE_SLIM := $(shell (printf "%s\n" "$(KUBELET_VER)" "v1.30.99" | sort -V -C) && echo false || echo true)
+
+ifeq ($(USE_SLIM),true)
+	SLIM_TAG_SUFFIX :=
+	FAT_TAG_SUFFIX := -fat
+else
+	SLIM_TAG_SUFFIX := -slim
+	FAT_TAG_SUFFIX :=
+endif
+
 BUILD := docker buildx build
 PLATFORM ?= linux/amd64,linux/arm64
 PROGRESS ?= auto
@@ -38,7 +50,8 @@ local-%: ## Builds the specified target defined in the Dockerfile using the loca
 	@$(MAKE) target-$* TARGET_ARGS="--output=type=local,dest=$(DEST) $(TARGET_ARGS)"
 
 docker-%: ## Builds the specified target defined in the Dockerfile using the default output type.
-	@$(MAKE) target-$* TARGET_ARGS="--tag $(REGISTRY_AND_USERNAME)/$(NAME):$(TAG) $(TARGET_ARGS)"
+	@$(MAKE) target-$*-fat TARGET_ARGS="--tag $(REGISTRY_AND_USERNAME)/$(NAME):$(TAG)$(FAT_TAG_SUFFIX) $(TARGET_ARGS)"
+	@$(MAKE) target-$*-slim TARGET_ARGS="--tag $(REGISTRY_AND_USERNAME)/$(NAME):$(TAG)$(SLIM_TAG_SUFFIX) $(TARGET_ARGS)"
 
 .PHONY: container
 container:

files/iscsiadm

@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/usr/bin/sh
 
 iscsid_pid=$(pgrep iscsid)