feat: replace buster with bookworm container (#672)

Dockerfile.buster → Dockerfile.bookworm

@@ -1,4 +1,4 @@
-# Copyright 2020 Google LLC
+# Copyright 2024 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -23,11 +23,10 @@ ARG TARGETARCH
 
 RUN go get ./...
 RUN CGO_ENABLED=0 GOOS=${TARGETOS} GOARCH=${TARGETARCH} \
-    go build -ldflags "-X github.com/GoogleCloudPlatform/alloydb-auth-proxy/cmd.metadataString=container.buster"
+    go build -ldflags "-X github.com/GoogleCloudPlatform/alloydb-auth-proxy/cmd.metadataString=container.bookworm"
 
 # Final stage
-FROM gcr.io/cloud-marketplace-containers/google/debian10@sha256:bf5274d185680301f076431113bb7f7e21c7748dec0e066166d4bd02a8ff1c09
-
+FROM gcr.io/cloud-marketplace-containers/google/debian12@sha256:9df4cf8df3a3466796d76692ddda1fdcbe5018a2810d332c9a99e2ee2325b6cf
 LABEL org.opencontainers.image.source="https://github.com/GoogleCloudPlatform/alloydb-auth-proxy"
 
 RUN apt-get update && apt-get install -y ca-certificates

README.md

@@ -150,8 +150,8 @@ currently supported:
 
 - `$VERSION` (default)
 - `$VERSION-alpine`
-- `$VERSION-buster`
 - `$VERSION-bullseye`
+- `$VERSION-bookworm`
 
 <!-- {x-release-please-start-version} -->
 The `$VERSION` is the Proxy version without the leading "v" (e.g.,
@@ -169,7 +169,8 @@ We recommend pinning to a specific version tag and using automation with a CI
 pipeline to update regularly.
 
 The default container image uses [distroless][] with a non-root user. If you
-need a shell or related tools, use the Alpine or Buster images listed above.
+need a shell or related tools, use the Alpine or Debian-based containers
+(bullseye or bookworm) images listed above.
 
 [distroless]: https://github.com/GoogleContainerTools/distroless