Add instructions for setup with home-manager and mise

.gitignore

@@ -48,3 +48,4 @@ build-iPhoneSimulator/
 
 # unless supporting rvm < 1.11.0 or doing something fancy, ignore this:
 .rvmrc
+/.idea

README.md

@@ -1,7 +1,8 @@
 # bambrew
+
 Bambrew - Bamboo Engineering's development environment setup tooling
 
-# First time setup
+# Mac First time setup
 
 1. Ask an existing `bambooengineering/umbrella` administrator to grant you repo access
 1. Setup a GitHub [personal access token][1]
@@ -11,4 +12,31 @@ Bambrew - Bamboo Engineering's development environment setup tooling
 sh -c "$(curl -fsSL https://github.com/bambooengineering/bambrew/raw/master/run_bamstrap)"
 ```
 
+# Linux first time setup
+
+Linux setup is largely done with Nix home-manager (not full NixOS). The steps below amount to
+setting up home-manager, git and getting a checkout of the main repo. After that, it is all a script
+in that repo.
+
+The script in this repo will achieve that. The steps are:
+
+1. Run this to get `home-manager` and the main repo ready:
+   ```bash
+   SILVERCAT_GIT_CHECKOUTS_DIR= ~/code/gh/bambooengineering sudo sh -c "$(curl -fsSL https://github.com/bambooengineering/bambrew/raw/master/run_bamstrap_linux)"
+   ```
+2. Add this to the top of your `~/.config/home-manager/home.nix` file:
+    ```nix
+    imports = [
+        /home/<username>/.umbrella/bambrew/assets/nix/silvercat.nix
+    ];
+    ```
+3. Run the following command to install the silvercat `home-manager` packages and system utilities.
+   Note, this is idempotent and should be quick once completed the first time. You should run it
+   regularly.
+   ```bash
+   ~/.umbrella/bambrew/scripts/setup.sh
+   ```
+
+That's it. Read the bambrew docs on starting up the development environment.
+
 [1]: https://help.github.com/en/github/authenticating-to-github/creating-a-personal-access-token-for-the-command-line

run_bamstrap_linux

@@ -0,0 +1,63 @@
+#!/bin/bash
+
+set -e
+
+if [ "$(id -u)" = 0 ]; then
+  echo "Aborting! Must not be run as root"
+  exit 4
+fi
+
+if [ -z "$USER" ]; then
+  echo "Aborting! No USER environment variable set"
+  exit 3;
+fi
+
+if [ -z "$SILVERCAT_GIT_CHECKOUTS_DIR" ]; then
+  echo "Aborting! No SILVERCAT_GIT_CHECKOUTS_DIR environment variable set"
+  echo "Set it to any directory where you want to clone all Silvercat repos."
+  echo "For example: export SILVERCAT_GIT_CHECKOUTS_DIR=~/code/gh/bambooengineering"
+  exit 3;
+fi
+
+if [ ! -f "$HOME/.ssh/id_rsa.pub" ]; then
+  if [ ! -f "$HOME/.ssh/id_ed25519.pub" ]; then
+    echo "Ensure you have your GitHub SSH key at ~/.ssh/id_rsa.pub or ~/.ssh/id_ed25519.pub"
+    exit 1
+  fi
+fi
+
+if [ ! -d "nix" ]; then
+  echo "Installing nix..."
+  sh <(curl -L https://nixos.org/nix/install) --daemon
+  echo "Done installing nix! Open a new shell then run this script again."
+  exit 1
+fi
+
+if [ -x "$(command -v home-manager)" ]; then
+  echo "Installing home-manager..."
+  nix-channel --add https://github.com/nix-community/home-manager/archive/master.tar.gz home-manager
+  nix-channel --update
+  nix-shell '<home-manager>' -A install
+  home-manager switch
+
+  echo "Now you must set up your machine to clone GitHub repos. You can do this one of two ways:
+
+  1. Copy your ssh key into /home/<username>/.ssh. Typically, this is your ~/.ssh/id_ed25519 file.
+     You may need a USB key for this.
+     You can also run this to add your passphrase to the ssh-agent:
+       ssh-add ~/.ssh/id_ed25519
+  2. Use gh as installed above and run: gh auth login
+     This will then prompt you to authenticate with github, which you can do via the browser."
+
+  echo "After you have done that, run this script again."
+  exit 1
+fi
+
+if [ ! -d "~/.umbrella" ]; then
+  echo "Cloning umbrella into $SILVERCAT_GIT_CHECKOUTS_DIR..."
+  mkdir -p "$SILVERCAT_GIT_CHECKOUTS_DIR"
+  nix shell -p git -c "git clone [email protected]:bambooengineering/umbrella.git $SILVERCAT_GIT_CHECKOUTS_DIR/umbrella"
+  ln -s "$SILVERCAT_GIT_CHECKOUTS_DIR/umbrella" ~/.umbrella
+fi
+
+echo "Completed checkout. Now add the silvercat.nix to your home-manager config and "