在Google Run的Docker容器中运行LimaCharlie Adapter遇文件名过长错误

尝试创建Docker容器运行LimaCharlie Adapter接收syslog，运行时出现以下错误：

PS C:\Users\admin\code\syslog-to-limacharlie-docker-main> docker run syslog-to-limacharlie-docker-main
/bin/sh: 0: cannot open ./opt/lc_adapter syslog client_options.identity.installation_key=1-2-3-4-5 client_options.identity.oid=6-7-8-9-0 client_options.platform=text client_options.hostname=MySensor client_options.sensor_seed_key=MySensor port=8080 iface=0.0.0.0 is_udp=true: File name too long

原Dockerfile内容：

# Specify Ubuntu
FROM ubuntu:latest

# Update
RUN apt-get update \
&& apt-get install -y apt-utils file

# Open port
EXPOSE 8080

# Download LimaCharlie Adapter (will download as file name "64" to /opt/64)
ADD https://downloads.limacharlie.io/adapter/linux/64 /opt
RUN cd /opt
RUN mv /opt/64 /opt/lc_adapter

# Create logcollector.service file for LimaCharlie
RUN chmod +x /opt/lc_adapter
CMD [ "/bin/sh", "./opt/lc_adapter syslog client_options.identity.installation_key=1-2-3-4-5 client_options.identity.oid=6-7-8-9-0 client_options.platform=text client_options.hostname=MySensor client_options.sensor_seed_key=MySensor port=8080 iface=0.0.0.0 is_udp=true" ]

lc_adapter文件信息：

# file lc_adapter
lc_adapter: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, Go BuildID=2MLFP8X_NxNWUzoPPZVD/MjzxEyHS5R7MY7guaGpe/avSLCqnqTExmYGH0Zsvo/pJ5s9HhisDNA_DZr4fJT, with debug_info, not stripped

错误根源是CMD指令的数组格式使用错误：当使用exec格式（CMD ["executable", "param1", "param2"]）时，每个命令参数必须作为独立的数组元素，不能将整个命令行打包成单个参数。原Dockerfile中把./opt/lc_adapter及其所有参数放在同一个字符串里，导致/bin/sh把整个字符串当作要打开的文件名，从而触发“文件名过长”错误。

同时还存在相对路径问题：容器默认工作目录是/，./opt/lc_adapter会被解析为/./opt/lc_adapter，虽然能找到文件，但更规范的做法是使用绝对路径。

具体修复步骤：

• 拆分CMD的数组元素：将每个参数单独列为数组项
• 使用绝对路径调用lc_adapter：替换./opt/lc_adapter为/opt/lc_adapter
• 可选优化：合并RUN命令，清理APT缓存以减小镜像体积，移除无效的RUN cd /opt指令（每个RUN是独立shell会话，该指令不会改变后续步骤的工作目录）

修正后的Dockerfile：

# Specify Ubuntu
FROM ubuntu:latest

# Update and install dependencies, clean up cache
RUN apt-get update \
    && apt-get install -y apt-utils file \
    && rm -rf /var/lib/apt/lists/*

# Open port
EXPOSE 8080

# Download, rename and make LimaCharlie Adapter executable
ADD https://downloads.limacharlie.io/adapter/linux/64 /opt/lc_adapter
RUN chmod +x /opt/lc_adapter

# Run LimaCharlie Adapter with syslog configuration
CMD [ "/opt/lc_adapter", "syslog", "client_options.identity.installation_key=1-2-3-4-5", "client_options.identity.oid=6-7-8-9-0", "client_options.platform=text", "client_options.hostname=MySensor", "client_options.sensor_seed_key=MySensor", "port=8080", "iface=0.0.0.0", "is_udp=true" ]

内容的提问来源于stack exchange，提问作者Europa