Docker部署.NET6 Alpine控制台应用报[./Filename]未找到错误解决

基于.NET 6.0开发控制台应用，编写的Dockerfile可正常完成镜像构建，但部署到服务器启动时抛出报错：/bin/sh: [./Filename]: not found。
此前项目使用.NET Core 3.1、以runtime-deps:3.1-alpine为基础镜像时可正常运行，当前使用的Dockerfile内容如下：

FROM mcr.microsoft.com/dotnet/runtime:6.0-alpine as base
WORKDIR /app

RUN apk add --no-cache ca-certificates icu-libs

RUN apk add --no-cache tzdata
RUN apk add --no-cache bash

ENV TZ=America/Chicago
#This will update the image to avoid security issues.
RUN apk update
RUN apk upgrade
RUN apk add bash
ENV DOTNET_SYSTEM_GLOBALIZATION_INVARIANT=false

FROM mcr.microsoft.com/dotnet/sdk:6.0-alpine AS build
WORKDIR /src

COPY ["Filename/Filename.csproj", "Filename/"]


RUN dotnet restore "Filename/Filename.csproj" --configfile NuGet.Config 
COPY . .
WORKDIR "/src/Filename"
RUN dotnet build "Filename.csproj" -c Release -o /app/build

FROM build AS publish
RUN dotnet publish "Filename.csproj" -c Release -o /app/publish  --runtime alpine-x64 --self-contained true /p:PublishTrimmed=true /p:PublishSingleFile=true

FROM base AS final
WORKDIR /app
COPY --from=publish /app/publish .
#ENTRYPOINT ["dotnet", "Filename.dll"]
ENTRYPOINT [./"Filename"]

• ENTRYPOINT语法错误是直接诱因
  Docker的exec模式ENTRYPOINT要求传入合法的JSON数组，每个数组元素（命令、参数）必须单独用双引号包裹。当前写法ENTRYPOINT [./"Filename"]属于非法JSON格式，Docker无法识别为exec模式，会自动降级为shell模式执行，等价于运行/bin/sh -c "[./Filename]"，shell会把[./Filename]整体作为一个命令名去系统路径中查找，自然会抛出not found错误。
• 存在隐含的权限/冗余问题
  • base阶段重复执行bash安装操作，属于无效冗余步骤，会徒增镜像体积
  • 发布时指定了自包含部署、单文件打包，最终镜像不需要携带完整.NET Runtime，使用runtime镜像作为base属于不必要的体积浪费
  • COPY到镜像内的单文件程序默认没有可执行权限，即使修正ENTRYPOINT语法，也可能因为权限不足触发not found类报错（Alpine环境下无执行权限的文件不会返回常规的Permission denied，很多场景下会直接提示文件不存在）

1. 修正ENTRYPOINT为合法的exec格式，将最后一行启动命令改为：

   ENTRYPOINT ["./Filename"]
   

2. 在final阶段COPY完发布文件后，增加给单文件程序授予可执行权限的步骤
3. 清理冗余的安装步骤，若使用自包含单文件部署，可将base镜像替换为体积更小的mcr.microsoft.com/dotnet/runtime-deps:6.0-alpine

修正后的完整Dockerfile参考：

FROM mcr.microsoft.com/dotnet/runtime-deps:6.0-alpine as base
WORKDIR /app

RUN apk add --no-cache ca-certificates icu-libs tzdata bash \
    && apk update \
    && apk upgrade \
    && rm -rf /var/cache/apk/*

ENV TZ=America/Chicago
ENV DOTNET_SYSTEM_GLOBALIZATION_INVARIANT=false

FROM mcr.microsoft.com/dotnet/sdk:6.0-alpine AS build
WORKDIR /src

COPY ["Filename/Filename.csproj", "Filename/"]
RUN dotnet restore "Filename/Filename.csproj" --configfile NuGet.Config 
COPY . .
WORKDIR "/src/Filename"
RUN dotnet build "Filename.csproj" -c Release -o /app/build

FROM build AS publish
RUN dotnet publish "Filename.csproj" -c Release -o /app/publish  --runtime alpine-x64 --self-contained true /p:PublishTrimmed=true /p:PublishSingleFile=true

FROM base AS final
WORKDIR /app
COPY --from=publish /app/publish .
RUN chmod +x ./Filename
ENTRYPOINT ["./Filename"]

内容的提问来源于stack exchange，提问作者Jayne