Use smaller base image (e.g. alpine, slim or even distroless)

[GaryGSC]

This is generally a good thing for security and performance reasons. Smaller images lead to faster builds, faster deployments, faster startups, and smaller attack surfaces.

In regards to #214, I believe we can do this without impacting people's ability to drop in whatever container they'd like. However, as we make the example image a little more complicated, we distract from the CI/CD and IaC that's in here. 🤔

None of the these examples (alpine/slim or distroless) should affect our ability to use ARM-based containers (#389).

[GaryGSC]

This article has some interesting reasoning that would lead us to use node:18.11.0-slim (or whatever the version number is once 18 becomes the LTS release). Version 18 defaults to bullseye, so there's no reason to be explicit about that.

[GaryGSC]

I believe I'm suggesting that we use -slim variants. We can probably even build with them (as opposed to needing a multi-stage build where we build using the standard image and then copy built files into a -slim-based image).

Here's my reasoning:

• We fall into the use cases where the Node.js maintainers suggest that we use -slim images: we're working in environments where only our Node.js image will be deployed
• At BYU, we occasionally use binaries that rely on glibc (like for our OracleDB connections), which precludes -alpine images because they're based on musl
• The best examples we have of "complicated use-cases" at BYU are our images that use OracleDB binaries, which already build and run without issue using -slim
• The devs that would want to use tools like curl/wget are the same devs that would feel comfortable adding an apt-get update && apt-get install -y curl step
• Compared to the base image, -slim is almost as small as -alpine
• There's a tiny learning curve for alpine-based images (e.g. apk is the default package manager instead of apt-get)
• Distroless doesn't provide distinct releases based on specific Node.js versions, so we can't easily pin to minor or patch versions, therefore distroless images will be harder to manage than -slim images