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Dockerfile ENV
cat dockerfile
FROM alpine
ENV appDescription This app is a sample of using ENV instructions
ENV appName=env-demo
ENV note1="The First Note First" note2=The\ Second\ Note\ Second \
note3="The Third Note Third"
ENV changeMe="Old Value"
CMD ["sh"]
build dockerfile
➜ Dockerfile git:(main) ✗ docker build -t sangam14/env-dockerfile -f dockerfile.env .
[+] Building 0.1s (5/5) FINISHED
=> [internal] load build definition from dockerfile.env 0.0s
=> => transferring dockerfile: 279B 0.0s
=> [internal] load .dockerignore 0.0s
=> => transferring context: 2B 0.0s
=> [internal] load metadata for docker.io/library/alpine:latest 0.0s
=> CACHED [1/1] FROM docker.io/library/alpine 0.0s
=> exporting to image 0.0s
=> => exporting layers 0.0s
=> => writing image sha256:6f9741e9b952495e61c515945c4acd85d85aef1e631b7d37c348c26e9f5d216d 0.0s
=> => naming to docker.io/sangam14/env-dockerfile 0.0s
inspect Env Config
docker image inspect --format '{{json .Config}}' sangam14/env-dockerfile | jq '.Env'
[
"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
"appDescription=This app is a sample of using ENV instructions",
"appName=env-demo",
"note1=The First Note First",
"note2=The Second Note Second",
"note3=The Third Note Third",
"changeMe=Old Value"
]
change envirmonment variable
docker run --rm --env changeMe="New Value" --env adhoc="run time" sangam14/env-dockerfile env
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
HOSTNAME=12804862fac4
changeMe=New Value
adhoc=run time
appDescription=This app is a sample of using ENV instructions
appName=env-demo
note1=The First Note First
note2=The Second Note Second
note3=The Third Note Third
HOME=/root
Last updated 03 Jun 2024, 13:43 +0530 .