小编kev*_*sir的帖子

我这里有一个 dockerfile：

FROM golang:1.13-alpine as build
ARG DIR=somevalue
RUN echo $DIR

输出是

Sending build context to Docker daemon  57.37MB
Step 1/3 : FROM golang:1.13-alpine as build
 ---> 2e384b27f926
Step 2/3 : ARG DIR=somevalue
 ---> Running in 3cd3457a795f
Removing intermediate container 3cd3457a795f
 ---> ecfa2f50c4fa
Step 3/3 : RUN echo $DIR
 ---> Running in aab4e31e0e14

Removing intermediate container aab4e31e0e14
 ---> 5351cb77c245
Successfully built 5351cb77c245

当我尝试 DIR 到另一个名称示例 DIR1 时，DIR 始终为空，它也是空的。Docker 版本在这里

 Client:

 Version:           18.09.8
 API version:       1.39
 Go version:        go1.11
 Git commit: …