Switched the image from supervisord to s6-overlay because it provides a much smaller memory footprint.

s6-overlay vs supervisord — Memory Footprint Comparison

s6-overlay:
Uses only 1–2 MB of RAM. Its service processes typically consume around 200 KB RSS each.
Extremely lightweight, written in C, minimal overhead.

supervisord:
Consumes roughly 10–15 MB of RAM in real-world usage.
Implemented in Python, so it naturally has a higher baseline memory footprint (≈8–10× s6-overlay).

Dockerfile

@@ -1,4 +1,24 @@
-# 使用 Alpine 镜像
+# 构建阶段
+FROM alpine:latest AS builder
+ARG TARGETARCH
+ENV ARCH=$TARGETARCH
+
+# 安装构建依赖
+RUN set -ex &&\
+  apk add --no-cache wget xz
+
+# 下载并解压 s6-overlay
+RUN set -ex &&\
+  case "$ARCH" in \
+    amd64) S6_ARCH=x86_64 ;; \
+    arm64) S6_ARCH=aarch64 ;; \
+    armv7) S6_ARCH=armhf ;; \
+    *) S6_ARCH=x86_64 ;; \
+  esac &&\
+  wget -qO- https://github.com/just-containers/s6-overlay/releases/latest/download/s6-overlay-noarch.tar.xz | tar -C / -Jx &&\
+  wget -qO- https://github.com/just-containers/s6-overlay/releases/latest/download/s6-overlay-$S6_ARCH.tar.xz | tar -C / -Jx
+
+# 运行阶段
 FROM alpine:latest
 ARG TARGETARCH
 ENV ARCH=$TARGETARCH
@@ -6,12 +26,15 @@ ENV ARCH=$TARGETARCH
 # 设置工作目录
 WORKDIR /sing-box
 
+# 从构建阶段复制 s6-overlay 文件
+COPY --from=builder / /
+
 # 复制初始化脚本
 COPY docker_init.sh /sing-box/init.sh
 
-# 安装依赖并生成证书
+# 安装运行时依赖并生成证书
 RUN set -ex &&\
-  apk add --no-cache supervisor wget nginx bash openssl &&\
+  apk add --no-cache wget nginx bash openssl &&\
   mkdir -p /sing-box/cert /sing-box/conf /sing-box/subscribe /sing-box/logs &&\
   chmod +x /sing-box/init.sh &&\
   rm -rf /var/cache/apk/*