【Docker】環境変数ENVとARG

DockerFileビルド時に引数で変数を渡す場合はARG
ENVの場合、Dockerfile内の途中で書き換えることができる

yuta@DESKTOP-V36210S:/mnt/c/container/Docker/test$ cat Dockerfile
FROM alpine

ARG ARGTEST=1
ENV ENVTEST=aaa

RUN echo $ARGTEST
RUN echo $ENVTEST
yuta@DESKTOP-V36210S:/mnt/c/container/Docker/test$

yuta@DESKTOP-V36210S:/mnt/c/container/Docker/test$ docker build --build-arg ARGTEST="666" --rm .
Sending build context to Docker daemon  2.048kB
Step 1/5 : FROM alpine
 ---> a187dde48cd2      
Step 2/5 : ARG ARGTEST=1
 ---> Using cache       
 ---> e9466e527a97      
Step 3/5 : ENV ENVTEST=aaa
 ---> Using cache
 ---> 41a897b281e3
Step 4/5 : RUN echo $ARGTEST
 ---> Running in 4a5aed9cc706
666
Removing intermediate container 4a5aed9cc706
 ---> 8023877d59ff
Step 5/5 : RUN echo $ENVTEST
 ---> Running in 716e54e6dbc0
aaa
Removing intermediate container 716e54e6dbc0
 ---> 73c68f8b4ad4
Successfully built 73c68f8b4ad4
yuta@DESKTOP-V36210S:/mnt/c/container/Docker/test$

https://techblog.recochoku.jp/1979