Edit a Docker image and push it to ECR. Sometimes you just want to pull a container image, edit a file, and push it back, outside of source control and CI/CD. This is how.

edit-docker-image.sh

# note: get your AWS credentials however you usually do that (e.g. aws configure or set the env vars)

REPO_URL=accountid.dkr.ecr.region.amazonaws.com/repo-name
EXISTING_TAG=version1
NEW_TAG=version1-hotfix

# get everything ready
mkdir -p ~/slipstream
cd ~/slipstream
`aws ecr get-login --no-include-email`

# pull the image from ECR
docker pull $REPO_URL:$EXISTING_TAG

# copy the desired file(s) from the image to the local dir
imageid=`docker create $REPO_URL:$EXISTING_TAG`
docker cp $imageid:/home/your/app/the/file.txt .

# edit the file and put it back into the image
vi file.txt
docker cp file.txt $imageid:/home/your/app/the/file.txt

# now tag the edited image
docker commit $imageid $REPO_URL:$NEW_TAG

# double-check that the change is in the new image
docker run -it $REPO_URL:$NEW_TAG cat /home/your/app/the/file.txt

# push it back to ECR
docker push $REPO_URL:$NEW_TAG

# now redeploy your app with the new tag