populate_chroot: set of scripts to make bento

config.sh.sample

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+CHROOT_DIR=/home/chroot
+REMOTE_IP=myserver.example

populate_chroot.sh

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+#!/bin/sh
+
+if test -f config.sh
+then
+    . ./config.sh
+else
+    echo "You are missing config.sh"
+    exit 2
+fi
+
+if [ "$(id -u)" -ne 0 ]
+then
+  echo "you need to be root to run this script"
+  exit 1
+fi
+
+cd hosts
+# load all hosts or the one defined in environment variable NAME
+if [ -z "$NAME" ]
+then
+  NAME=*
+fi
+
+for i in $NAME
+do
+    echo "Copying $i"
+
+    # we only want directories
+    if [ -d "$i" ]
+    then
+
+      # create the script that will check for updates
+      cat > "$i/update.sh" <<EOF
+#!/bin/sh
+set -e
+
+install -d -o root -g root -m 700 /var/bento
+cd /var/bento
+touch .state
+
+STATE="\$(echo "ls -l last_change_date" | sftp ${i}@${REMOTE_IP})"
+CURRENT_STATE="\$(cat /var/bento/.state)"
+
+if [ "\$STATE" = "\$CURRENT_STATE" ]
+then
+    echo "no update required"
+else
+    echo "update required"
+    sftp ${i}@${REMOTE_IP}:/bootstrap.sh .
+    /bin/sh bootstrap.sh
+    echo "\$STATE" > /var/bento/.state
+fi
+EOF
+
+      # script used to download changes and rebuild
+      # also used to run it manually the first time to configure the system
+      cat > "$i/bootstrap.sh" <<EOF
+#!/bin/sh
+set -e
+
+install -d -o root -g root -m 700 /var/bento
+cd /var/bento
+
+sftp -r ${i}@${REMOTE_IP}:/ .
+
+# for flakes
+test -d .git || git init
+git add .
+
+# check the current build if it exists
+if test -L result
+then
+    RESULT="\$(readlink -f result)"
+fi
+
+if test -f flake.nix
+then
+    nixos-rebuild build --flake .#bento-machine
+    if [ ! "\${RESULT}" = "\$(readlink -f result)" ]
+    then
+        nixos-rebuild switch --flake .#bento-machine
+    fi
+else
+    nixos-rebuild build --no-flake -I nixos-config=./configuration.nix --upgrade
+    if [ ! "\${RESULT}" = "\$(readlink -f result)" ]
+    then
+        nixos-rebuild switch --no-flake -I nixos-config=./configuration.nix --upgrade
+    fi
+fi
+EOF
+
+      # to make flakes using caching, we must avoid repositories to change everytime
+      # we must ignore files that change everytime
+      cat > "$i/.gitignore" <<EOF
+bootstrap.sh
+update.sh
+.state
+result
+last_change_date
+EOF
+
+      # copy files in the chroot
+      rsync --delete -avL "$i/" "${CHROOT_DIR}/${i}/"
+
+      # sftp chroot requires the home directory to be owned by root
+      install -d -o root -g root -m 755 "${CHROOT_DIR}/${i}"
+      touch "${CHROOT_DIR}/${i}/last_change_date"
+    fi
+done