chore: Specify Alpine version in Dockerfiles

build/virt-controller/Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.23.4-alpine AS builder
+FROM golang:1.23.4-alpine3.21 AS builder
 
 WORKDIR /workspace
 
@@ -10,7 +10,7 @@ COPY cmd/ cmd/
 COPY pkg/ pkg/
 RUN --mount=type=cache,target=/root/.cache/go-build CGO_ENABLED=0 go build -a cmd/virt-controller/main.go
 
-FROM alpine
+FROM alpine:3.21.0
 
 ARG PRERUNNER_IMAGE
 ENV PRERUNNER_IMAGE=$PRERUNNER_IMAGE

build/virt-daemon/Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.23.4-alpine AS builder
+FROM golang:1.23.4-alpine3.21 AS builder
 
 WORKDIR /workspace
 
@@ -10,7 +10,7 @@ COPY cmd/ cmd/
 COPY pkg/ pkg/
 RUN --mount=type=cache,target=/root/.cache/go-build CGO_ENABLED=0 go build -a cmd/virt-daemon/main.go
 
-FROM alpine
+FROM alpine:3.21.0
 
 COPY --from=builder /workspace/main /usr/bin/virt-daemon
 ENTRYPOINT ["virt-daemon"]

build/virt-prerunner/Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.23.4-alpine AS builder
+FROM golang:1.23.4-alpine3.21 AS builder
 
 RUN apk add --no-cache gcc musl-dev
 
@@ -12,7 +12,7 @@ COPY cmd/ cmd/
 COPY pkg/ pkg/
 RUN --mount=type=cache,target=/root/.cache/go-build go build -a cmd/virt-prerunner/main.go
 
-FROM alpine
+FROM alpine:3.21.0
 
 RUN apk add --no-cache curl screen dnsmasq cdrkit iptables iproute2 qemu-virtiofsd dpkg util-linux s6-overlay nmap-ncat
 

build/virtink-container-disk-base/Dockerfile

@@ -1,4 +1,4 @@
-FROM alpine
+FROM alpine:3.21.0
 
 RUN apk add --no-cache qemu-img
 

build/virtink-container-rootfs-base/Dockerfile

@@ -1,4 +1,4 @@
-FROM alpine
+FROM alpine:3.21.0
 
 RUN apk add --no-cache e2fsprogs
 

build/virtink-kernel-base/Dockerfile

@@ -1,4 +1,4 @@
-FROM alpine
+FROM alpine:3.21.0
 
 ADD build/virtink-kernel-base/entrypoint.sh /entrypoint.sh
 ENTRYPOINT ["/entrypoint.sh"]