_chroot-alpine-readme

# Welcome to Alpine, BNNA Edition

BNNA's Alpine is slightly different from the stock filesystem.

We've tried to strike a good balance between the minimalism of Alpine,
a few utilities to help you get started here, and an easy way to downsize.

## Table of Contents

- Default Shell
- Developer Utilities
- Installed Packages
- SSH Config
- Uinstall it all

## Default Shell

`screen` and `fish` are set in `~/.profile`.

- `screen` is the default session manager.
  - Next tab: ctrl+a, n
  - New tab: ctrl+a, c
- `fish` is the default shell.
  - immediate typeahead
  - search with up and down arrows

However, it is not POSIX-compatible.
If you need to paste in shell script snippets, drop down to `sh` first.

## Developer Utilities

`~/.config/envman/PATH.env` is sourced to set the `PATH`.

It includes the following:

```text
~/bin/
~/.local/bin/
```

`~/bin` is recommended for your own scripts and programs.

`~/.local/bin` and `~/.local/opt/<program>/bin` will be used
for scripts and programs you install.

### Helpful Commands & Aliases

```text
# install the latest versions of developer tools, direct from the release api
# (bun, caddy, duckdns, flutter, go, gh, hugo, jq, lsd, node, ollama,
# powershell, python, rg, rust, sclient, vim-essentials, zig, + many more)

webi
```

```text
# add aliases
aliasman

# like cat, but with syntax highlighting
bat

# show the external ip address
myip

# like grep, but respects .gitignore, .ignore, etc
rg

# creates, enables, and starts an openrc daemon for the given command
# ex: serviceman add --name 'my-app' -- node ./server.js
serviceman

# show current public key
ssh-pubkey

# add file or url to ~/.ssh/authorized_keys
ssh-authorize

# allows user programs to listen on privileged ports via libcap
setcap-netbind

# to lint shell scripts
shellcheck

# to format shell scripts
shfmt

# vim-sensible, vim-ale, and other automatic plugins
~/.vim/
```

### Aliases

```text
cat       # bat (cat with syntax highlighting)
diffy     # diff -y --suppress-common-lines
rnd       # random string
rnd16     # random hex string
rnd32     # random base32 (Crockford) string
rnd58     # random base58 (cryptocurrency) string
rnd62     # random base62 (GitHub token) string
rnd64     # random (url-safe) base64 string
rnd64rfc  # random (rfc) base64 string
ts        # timestamp as YYYY-MM-DD_hh.mm.ss
vi        # vim
```

## Installed Packages

We've added a number of packages that are not included in the Alpine base.

We document those here to prevent any surpises and to make it easier for you
to take control and make it yours.

### System Packages

DO NOT remove unless you know exactly what you're doing - otherwise your
instance may become unrecoverable.

```text
sudo       # to run any command as root
openssh    # to be able to remote into your instance
logrotate  # to prevent running out of storage from logs
```

### Convenience Packages

```text
curl fish git htop less screen vim wget xz unzip

libcap   # for setcap-netbind
```

## SSH

```text
/etc/ssh/sshd_config
~/.ssh/authorized_keys
~/.ssh/config
~/.ssh/config.d/bnna.d/example.sshconfig
```

### Keys generated on first boot

```text
~/.ssh/id_ed25519
~/.ssh/id_ed25519.pub
~/.ssh/id_ecdsa
~/.ssh/id_ecdsa.pub
```

### Key-only login

```text
PermitRootLogin prohibit-password
PasswordAuthentication no
KbdInteractiveAuthentication no
```

### Port Forwarding Enabled

```text
AllowTcpForwarding yes
GatewayPorts yes
```

## Uninstall it all

To uninstall the non-stock files and programs which are not necessary to use the instance:

```sh
rm -f ~/.profile ~/.bashrc ~/.npmrc
rm -rf ~/.config/envman ~/.config/fish
rm -rf ~/bin ~/.local/bin ~/.local/opt

sudo --no-cache apk del curl fish git htop less screen vim wget xz unzip

rm -f ~/README.md
```

This will keep:
- `openssh` - needed to access the instance
- `sudo` and `libcap` - needed if you keep access to a user account
- `logrotate` - needed if your services have logs

To remove the 'app' user and only run as `root`, see the SSH configuration above, and then remove the following:

```sh
sudo cp -RPp ~/.ssh /root/
sudo chown -R root:root /root/
rm /etc/sudoers.d/app
deluser --remove-home app
delgroup app
```