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userngo

These are simple Bash scripts userngo-alpine.sh and userngo-debian.sh that can be used to create a user "on the go" at startup in a Docker container, based on some environment variables, and use it to run the actual containerized application.

Examples

These scripts are meant to be used in a Dockerfile. See test-alpine.Dockerfile and test-debian.Dockerfile for usage examples. They are also useful for development.

To build the example images:

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docker build -t img-userngo-alpine -f test-alpine.Dockerfile .
docker build -t img-userngo-debian -f test-debian.Dockerfile .

To run as root user:

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docker run -it --rm img-userngo-alpine
docker run -it --rm img-userngo-debian

To run as custom user created "on the go":

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docker run -it --rm -eUSERNGO_{NAME=myuser,PSW=mypassword,{WHEEL,NOPASS}=true} img-userngo-alpine
docker run -it --rm -eUSERNGO_{NAME=myuser,PSW=mypassword,{SUDOER,NOPASSWD}=true} img-userngo-debian

To extend the images and run as unprivileged user:

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docker build -t img-userngo-alpine-unpriv:latest - << 'EOF'
FROM img-userngo-alpine
RUN adduser -Ds/bin/sh user
USER user
ENV USER=user HOME=/home/user
WORKDIR /home/user
EOF
docker run -it --rm img-userngo-alpine-unpriv

docker build -t img-userngo-debian-unpriv:latest - << 'EOF'
FROM img-userngo-debian
RUN useradd -Ums/bin/bash user
USER user
ENV USER=user HOME=/home/user
WORKDIR /home/user
EOF
docker run -it --rm img-userngo-debian-unpriv

💡 Tip: even if a Docker container is running entirely as unprivileged user, you can still use docker exec -ituroot mycontainer bash to run commands as root inside it.