trying out some new tool commands for easier immpermanence with bcache and my setup

hosts/i001/flake.nix

@@ -68,6 +68,7 @@
               ./hardware-configuration.nix
               ./hardware-mounts.nix
               ./impermanence.nix
+              ./impermanence-tools.nix
               # ./preservation.nix
               (
                 {

hosts/i001/impermanence-tools.nix

@@ -0,0 +1,67 @@
+{ config, lib, pkgs, ... }:
+let
+  cfg = config.impermanence.tools;
+
+  bcacheImpermanenceBin = pkgs.writeShellScriptBin "bcache-impermanence" (
+    builtins.readFile ./impermanence-tools.sh
+  );
+
+in
+{
+  options.impermanence.tools = {
+    enable = lib.mkEnableOption "bcachefs impermanence tools (GC + CLI)";
+
+    snapshotRoot = lib.mkOption {
+      type = lib.types.str;
+      default = "/.snapshots/old_roots";
+      description = "Root directory containing old root snapshots.";
+    };
+
+    gc = {
+      enable = lib.mkOption {
+        type = lib.types.bool;
+        default = true;
+        description = "Enable garbage collection of old root snapshots.";
+      };
+
+      keepPerMonth = lib.mkOption {
+        type = lib.types.int;
+        default = 1;
+        description = "Keep at least this many snapshots per calendar month (latest ones).";
+      };
+
+      keepRecentWeeks = lib.mkOption {
+        type = lib.types.int;
+        default = 4;
+        description = "Keep at least one snapshot per ISO week within this many recent weeks.";
+      };
+
+      keepRecentCount = lib.mkOption {
+        type = lib.types.int;
+        default = 5;
+        description = "Always keep at least this many most recent snapshots overall.";
+      };
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    environment.systemPackages = [ bcacheImpermanenceBin ];
+
+    systemd.services."bcache-impermanence-gc" = lib.mkIf cfg.gc.enable {
+      description = "Garbage collect bcachefs impermanence snapshots";
+      wantedBy = [ "multi-user.target" ];
+      after = [ "multi-user.target" ];
+      serviceConfig = {
+        Type = "oneshot";
+        Environment = "PATH=${lib.makeBinPath [ pkgs.coreutils pkgs.findutils pkgs.diffutils pkgs.bcachefs-tools ]}:/run/current-system/sw/bin";
+      };
+      script = ''
+        exec ${bcacheImpermanenceBin}/bin/bcache-impermanence gc \
+          --snapshot-root ${cfg.snapshotRoot} \
+          --keep-per-month ${toString cfg.gc.keepPerMonth} \
+          --keep-recent-weeks ${toString cfg.gc.keepRecentWeeks} \
+          --keep-recent-count ${toString cfg.gc.keepRecentCount}
+      '';
+    };
+  };
+}

hosts/i001/impermanence-tools.sh

@@ -0,0 +1,379 @@
+#!/usr/bin/env bash
+set -eu
+
+SNAPSHOT_ROOT="/.snapshots/old_roots"
+KEEP_PER_MONTH=1
+KEEP_RECENT_WEEKS=4
+KEEP_RECENT_COUNT=5
+DRY_RUN=0
+
+usage() {
+  cat <<EOF
+bcache-impermanence - tools for managing impermanence snapshots
+
+Usage:
+  bcache-impermanence gc [--snapshot-root DIR] [--keep-per-month N] [--keep-recent-weeks N] [--keep-recent-count N] [--dry-run]
+  bcache-impermanence ls [-n1] [--snapshot-root DIR]
+  bcache-impermanence diff [-s SNAPSHOT] [--snapshot-root DIR] [PATH_PREFIX...]
+
+Subcommands:
+  gc    Run garbage collection on old root snapshots.
+  ls    List snapshots (newest first). With -n1 prints only latest.
+  diff  Show diff between current system and a snapshot.
+
+Options:
+  --snapshot-root DIR        Override snapshot root directory (default: /.snapshots/old_roots).
+  --keep-per-month N         For gc: keep at least N snapshots per calendar month.
+  --keep-recent-weeks N      For gc: keep at least one snapshot per ISO week within the last N weeks.
+  --keep-recent-count N      For gc: always keep at least N most recent snapshots overall.
+  --dry-run                  For gc: show what would be deleted.
+EOF
+}
+
+ensure_deps() {
+  for cmd in date sort basename diff bcachefs; do
+    if ! command -v "$cmd" >/dev/null 2>&1; then
+      echo "Missing required command: $cmd" >&2
+      exit 1
+    fi
+  done
+}
+
+list_snapshots_desc() {
+  if [ ! -d "$SNAPSHOT_ROOT" ]; then
+    return 0
+  fi
+  for entry in "$SNAPSHOT_ROOT"/*; do
+    [ -d "$entry" ] || continue
+    basename "$entry"
+  done | sort -r
+}
+
+latest_snapshot_name() {
+  list_snapshots_desc | head -n1
+}
+
+cmd_ls() {
+  local n1=0
+  while [ "$#" -gt 0 ]; do
+    case "$1" in
+      -n1)
+        n1=1
+        ;;
+      --snapshot-root)
+        shift
+        [ "$#" -gt 0 ] || { echo "--snapshot-root requires a value" >&2; exit 1; }
+        SNAPSHOT_ROOT="$1"
+        ;;
+      --help|-h)
+        echo "Usage: bcache-impermanence ls [-n1] [--snapshot-root DIR]" >&2
+        exit 0
+        ;;
+      *)
+        echo "Unknown ls option: $1" >&2
+        exit 1
+        ;;
+    esac
+    shift
+  done
+
+  local snaps
+  snaps=$(list_snapshots_desc)
+
+  if [ -z "$snaps" ]; then
+    echo "No snapshots found in $SNAPSHOT_ROOT" >&2
+    exit 1
+  fi
+
+  if [ "$n1" -eq 1 ]; then
+    printf '%s
+' "$snaps" | head -n1
+  else
+    printf '%s
+' "$snaps"
+  fi
+}
+
+build_keep_set() {
+  # Prints snapshot names to keep, one per line, based on policies.
+  local now
+  now=$(date +%s)
+
+  local snaps
+  snaps=$(list_snapshots_desc)
+
+  if [ -z "$snaps" ]; then
+    return 0
+  fi
+
+  local tmpdir
+  tmpdir=$(mktemp -d)
+
+  # Always keep newest KEEP_RECENT_COUNT snapshots.
+  if [ "$KEEP_RECENT_COUNT" -gt 0 ]; then
+    printf '%s
+' "$snaps" | head -n "$KEEP_RECENT_COUNT" >"$tmpdir/keep_recent"
+  fi
+
+  # Per-month: keep up to KEEP_PER_MONTH newest per month.
+  if [ "$KEEP_PER_MONTH" -gt 0 ]; then
+    # Iterate newest -> oldest.
+    while read -r snap; do
+      [ -n "$snap" ] || continue
+      local month
+      month=${snap%_*}  # YYYY-MM-DD
+      month=${month%-*} # YYYY-MM
+      local month_file="$tmpdir/month_$month"
+      local count=0
+      if [ -f "$month_file" ]; then
+        count=$(wc -l <"$month_file")
+      fi
+      if [ "$count" -lt "$KEEP_PER_MONTH" ]; then
+        echo "$snap" >>"$month_file"
+      fi
+    done <<EOF_SNAPS
+$snaps
+EOF_SNAPS
+  fi
+
+  # Recent weeks: keep latest snapshot per week within last KEEP_RECENT_WEEKS weeks.
+  if [ "$KEEP_RECENT_WEEKS" -gt 0 ]; then
+    local max_age
+    max_age=$(( KEEP_RECENT_WEEKS * 7 * 24 * 3600 ))
+    while read -r snap; do
+      [ -n "$snap" ] || continue
+      local ts
+      ts=$(date -d "${snap%_*} ${snap#*_}" +%s 2>/dev/null || true)
+      [ -n "$ts" ] || continue
+      local age
+      age=$(( now - ts ))
+      if [ "$age" -gt "$max_age" ]; then
+        continue
+      fi
+      local week
+      week=$(date -d "${snap%_*} ${snap#*_}" +"%G-%V" 2>/dev/null || true)
+      [ -n "$week" ] || continue
+      local week_file="$tmpdir/week_$week"
+      if [ ! -f "$week_file" ]; then
+        echo "$snap" >"$week_file"
+      fi
+    done <<EOF_SNAPS2
+$snaps
+EOF_SNAPS2
+  fi
+
+  # Aggregate and dedupe.
+  for f in "$tmpdir"/*; do
+    [ -f "$f" ] || continue
+    cat "$f"
+  done | sort -u
+
+  rm -rf "$tmpdir"
+}
+
+cmd_gc() {
+  while [ "$#" -gt 0 ]; do
+    case "$1" in
+      --snapshot-root)
+        shift
+        [ "$#" -gt 0 ] || { echo "--snapshot-root requires a value" >&2; exit 1; }
+        SNAPSHOT_ROOT="$1"
+        ;;
+      --keep-per-month)
+        shift
+        [ "$#" -gt 0 ] || { echo "--keep-per-month requires a value" >&2; exit 1; }
+        KEEP_PER_MONTH="$1"
+        ;;
+      --keep-recent-weeks)
+        shift
+        [ "$#" -gt 0 ] || { echo "--keep-recent-weeks requires a value" >&2; exit 1; }
+        KEEP_RECENT_WEEKS="$1"
+        ;;
+      --keep-recent-count)
+        shift
+        [ "$#" -gt 0 ] || { echo "--keep-recent-count requires a value" >&2; exit 1; }
+        KEEP_RECENT_COUNT="$1"
+        ;;
+      --dry-run)
+        DRY_RUN=1
+        ;;
+      --help|-h)
+        echo "Usage: bcache-impermanence gc [--snapshot-root DIR] [--keep-per-month N] [--keep-recent-weeks N] [--keep-recent-count N] [--dry-run]" >&2
+        exit 0
+        ;;
+      *)
+        echo "Unknown gc option: $1" >&2
+        exit 1
+        ;;
+    esac
+    shift
+  done
+
+  if [ ! -d "$SNAPSHOT_ROOT" ]; then
+    echo "Snapshot root $SNAPSHOT_ROOT does not exist; nothing to do" >&2
+    exit 0
+  fi
+
+  local snaps
+  snaps=$(list_snapshots_desc)
+  if [ -z "$snaps" ]; then
+    echo "No snapshots to process" >&2
+    exit 0
+  fi
+
+  local keep
+  keep=$(build_keep_set)
+
+  local tmpkeep
+  tmpkeep=$(mktemp -d)
+  while read -r k; do
+    [ -n "$k" ] || continue
+    : >"$tmpkeep/$k"
+  done <<EOF_KEEP
+$keep
+EOF_KEEP
+
+  local deleted=0
+  while read -r snap; do
+    [ -n "$snap" ] || continue
+    if [ -f "$tmpkeep/$snap" ]; then
+      continue
+    fi
+    local full
+    full="$SNAPSHOT_ROOT/$snap"
+    if [ "$DRY_RUN" -eq 1 ]; then
+      echo "[dry-run] Would delete $full"
+    else
+      echo "Deleting snapshot $full"
+      if ! bcachefs subvolume delete "$full"; then
+        echo "Failed to delete $full" >&2
+      else
+        deleted=$((deleted + 1))
+      fi
+    fi
+  done <<EOF_SNAPS
+$snaps
+EOF_SNAPS
+
+  rm -rf "$tmpkeep"
+  echo "GC complete; deleted $deleted snapshots"
+}
+
+cmd_diff() {
+  local snapshot_name=""
+
+  while [ "$#" -gt 0 ]; do
+    case "$1" in
+      -s)
+        shift
+        [ "$#" -gt 0 ] || { echo "-s requires a snapshot name" >&2; exit 1; }
+        snapshot_name="$1"
+        ;;
+      --snapshot-root)
+        shift
+        [ "$#" -gt 0 ] || { echo "--snapshot-root requires a value" >&2; exit 1; }
+        SNAPSHOT_ROOT="$1"
+        ;;
+      --help|-h)
+        echo "Usage: bcache-impermanence diff [-s SNAPSHOT] [--snapshot-root DIR] [PATH_PREFIX...]" >&2
+        exit 0
+        ;;
+      --*)
+        echo "Unknown diff option: $1" >&2
+        exit 1
+        ;;
+      *)
+        break
+        ;;
+    esac
+    shift
+  done
+
+  if [ -z "$snapshot_name" ]; then
+    snapshot_name=$(latest_snapshot_name || true)
+  fi
+
+  if [ -z "$snapshot_name" ]; then
+    echo "No snapshots found for diff" >&2
+    exit 1
+  fi
+
+  local snapshot_dir
+  snapshot_dir="$SNAPSHOT_ROOT/$snapshot_name"
+
+  if [ ! -d "$snapshot_dir" ]; then
+    echo "Snapshot directory $snapshot_dir does not exist" >&2
+    exit 1
+  fi
+
+  if [ "$#" -eq 0 ]; then
+    set -- /
+  fi
+
+  local rc=0
+  while [ "$#" -gt 0 ]; do
+    local path
+    path="$1"
+    shift
+
+    case "$path" in
+      /*) : ;;
+      *)
+        echo "Path prefix must be absolute: $path" >&2
+        rc=2
+        continue
+        ;;
+    esac
+
+    local from
+    local to
+    from="$snapshot_dir$path"
+    to="$path"
+
+    echo "--- Diff for $path (snapshot $snapshot_name) ---"
+    if ! diff -ru --new-file "$from" "$to"; then
+      local diff_rc=$?
+      if [ "$diff_rc" -gt 1 ]; then
+        echo "Error running diff for $path" >&2
+        rc=$diff_rc
+      fi
+    fi
+  done
+
+  exit "$rc"
+}
+
+main() {
+  if [ "$#" -lt 1 ]; then
+    usage
+    exit 1
+  fi
+
+  ensure_deps
+
+  local cmd
+  cmd="$1"
+  shift || true
+
+  case "$cmd" in
+    gc)
+      cmd_gc "$@"
+      ;;
+    ls)
+      cmd_ls "$@"
+      ;;
+    diff)
+      cmd_diff "$@"
+      ;;
+    --help|-h|help)
+      usage
+      ;;
+    *)
+      echo "Unknown subcommand: $cmd" >&2
+      usage
+      exit 1
+      ;;
+  esac
+}
+
+main "$@"

hosts/lio/flake.lock

@@ -31,11 +31,11 @@
       },
       "locked": {
         "dir": "flakes/beszel",
-        "lastModified": 1765815414,
+        "lastModified": 1765998800,
-        "narHash": "sha256-PVwVlVPMRPqVpd6G65u4VyGJWJL7JtcgX1r1NtfpWYE=",
+        "narHash": "sha256-tFJsYcZQMuin4gtqjPpdg4V4QlCvpzLQ0H1ct5LM9Rg=",
         "ref": "refs/heads/master",
-        "rev": "d4088ffaa8039f024dd851146b5b7b34c6253257",
+        "rev": "03487772acd9e0865207baf281f7a0478f6dbc16",
-        "revCount": 912,
+        "revCount": 944,
         "type": "git",
         "url": "https://git.joshuabell.xyz/ringofstorms/dotfiles"
       },
@@ -149,11 +149,11 @@
       },
       "locked": {
         "dir": "flakes/flatpaks",
-        "lastModified": 1765815414,
+        "lastModified": 1765998800,
-        "narHash": "sha256-PVwVlVPMRPqVpd6G65u4VyGJWJL7JtcgX1r1NtfpWYE=",
+        "narHash": "sha256-tFJsYcZQMuin4gtqjPpdg4V4QlCvpzLQ0H1ct5LM9Rg=",
         "ref": "refs/heads/master",
-        "rev": "d4088ffaa8039f024dd851146b5b7b34c6253257",
+        "rev": "03487772acd9e0865207baf281f7a0478f6dbc16",
-        "revCount": 912,
+        "revCount": 944,
         "type": "git",
         "url": "https://git.joshuabell.xyz/ringofstorms/dotfiles"
       },
@@ -190,11 +190,11 @@
         "nixpkgs": "nixpkgs_2"
       },
       "locked": {
-        "lastModified": 1765605144,
+        "lastModified": 1765979862,
-        "narHash": "sha256-RM2xs+1HdHxesjOelxoA3eSvXShC8pmBvtyTke4Ango=",
+        "narHash": "sha256-/r9/1KamvbHJx6I40H4HsSXnEcBAkj46ZwibhBx9kg0=",
         "owner": "rycee",
         "repo": "home-manager",
-        "rev": "90b62096f099b73043a747348c11dbfcfbdea949",
+        "rev": "d3135ab747fd9dac250ffb90b4a7e80634eacbe9",
         "type": "github"
       },
       "original": {
@@ -261,11 +261,11 @@
     },
     "nixpkgs-unstable": {
       "locked": {
-        "lastModified": 1765472234,
+        "lastModified": 1765779637,
-        "narHash": "sha256-9VvC20PJPsleGMewwcWYKGzDIyjckEz8uWmT0vCDYK0=",
+        "narHash": "sha256-KJ2wa/BLSrTqDjbfyNx70ov/HdgNBCBBSQP3BIzKnv4=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "2fbfb1d73d239d2402a8fe03963e37aab15abe8b",
+        "rev": "1306659b587dc277866c7b69eb97e5f07864d8c4",
         "type": "github"
       },
       "original": {
@@ -277,11 +277,11 @@
     },
     "nixpkgs_2": {
       "locked": {
-        "lastModified": 1764983851,
+        "lastModified": 1765762245,
-        "narHash": "sha256-y7RPKl/jJ/KAP/VKLMghMgXTlvNIJMHKskl8/Uuar7o=",
+        "narHash": "sha256-3iXM/zTqEskWtmZs3gqNiVtRTsEjYAedIaLL0mSBsrk=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "d9bc5c7dceb30d8d6fafa10aeb6aa8a48c218454",
+        "rev": "c8cfcd6ccd422e41cc631a0b73ed4d5a925c393d",
         "type": "github"
       },
       "original": {
@@ -293,11 +293,11 @@
     },
     "nixpkgs_3": {
       "locked": {
-        "lastModified": 1765762245,
+        "lastModified": 1765838191,
-        "narHash": "sha256-3iXM/zTqEskWtmZs3gqNiVtRTsEjYAedIaLL0mSBsrk=",
+        "narHash": "sha256-m5KWt1nOm76ILk/JSCxBM4MfK3rYY7Wq9/TZIIeGnT8=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "c8cfcd6ccd422e41cc631a0b73ed4d5a925c393d",
+        "rev": "c6f52ebd45e5925c188d1a20119978aa4ffd5ef6",
         "type": "github"
       },
       "original": {
@@ -309,11 +309,11 @@
     },
     "nixpkgs_4": {
       "locked": {
-        "lastModified": 1765644376,
+        "lastModified": 1765934234,
-        "narHash": "sha256-yqHBL2wYGwjGL2GUF2w3tofWl8qO9tZEuI4wSqbCrtE=",
+        "narHash": "sha256-pJjWUzNnjbIAMIc5gRFUuKCDQ9S1cuh3b2hKgA7Mc4A=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "23735a82a828372c4ef92c660864e82fbe2f5fbe",
+        "rev": "af84f9d270d404c17699522fab95bbf928a2d92f",
         "type": "github"
       },
       "original": {
@@ -1224,11 +1224,11 @@
       },
       "locked": {
         "dir": "flakes/opencode",
-        "lastModified": 1765815414,
+        "lastModified": 1765998800,
-        "narHash": "sha256-PVwVlVPMRPqVpd6G65u4VyGJWJL7JtcgX1r1NtfpWYE=",
+        "narHash": "sha256-tFJsYcZQMuin4gtqjPpdg4V4QlCvpzLQ0H1ct5LM9Rg=",
         "ref": "refs/heads/master",
-        "rev": "d4088ffaa8039f024dd851146b5b7b34c6253257",
+        "rev": "03487772acd9e0865207baf281f7a0478f6dbc16",
-        "revCount": 912,
+        "revCount": 944,
         "type": "git",
         "url": "https://git.joshuabell.xyz/ringofstorms/dotfiles"
       },
@@ -1243,11 +1243,11 @@
         "nixpkgs": "nixpkgs_4"
       },
       "locked": {
-        "lastModified": 1765814475,
+        "lastModified": 1765998786,
-        "narHash": "sha256-+HC5nvbpcrvTyWuJDLqC13KuDKMGwjmoYb2tm+hGDzQ=",
+        "narHash": "sha256-OxSKJ9QR7demkOF6hrWaf4yS3fMGlU/FbF12VYsX5Mk=",
         "owner": "sst",
         "repo": "opencode",
-        "rev": "56dde2cc835f509f77cbd800d080d6dbb2b8edc6",
+        "rev": "1f527312554c3015286811fc33bb5348d0a27dae",
         "type": "github"
       },
       "original": {
@@ -1433,11 +1433,11 @@
       },
       "locked": {
         "dir": "flakes/secrets",
-        "lastModified": 1765815414,
+        "lastModified": 1765998800,
-        "narHash": "sha256-PVwVlVPMRPqVpd6G65u4VyGJWJL7JtcgX1r1NtfpWYE=",
+        "narHash": "sha256-tFJsYcZQMuin4gtqjPpdg4V4QlCvpzLQ0H1ct5LM9Rg=",
         "ref": "refs/heads/master",
-        "rev": "d4088ffaa8039f024dd851146b5b7b34c6253257",
+        "rev": "03487772acd9e0865207baf281f7a0478f6dbc16",
-        "revCount": 912,
+        "revCount": 944,
         "type": "git",
         "url": "https://git.joshuabell.xyz/ringofstorms/dotfiles"
       },

hosts/lio/flake.nix

@@ -148,6 +148,12 @@
                       common.homeManagerModules.starship
                       common.homeManagerModules.zoxide
                       common.homeManagerModules.zsh
+                      (
+                        { ... }:
+                        {
+                          programs.tmux.package = pkgs.unstable.tmux;
+                        }
+                      )
                     ];
 
                     extraSpecialArgs = {

utilities/nixos-installers/install_bcachefs.md

@@ -125,23 +125,3 @@ mount -t bcachefs --mkdir /dev/$DEVICE /usb_key
 echo "test" > /usb_key/key
 umount /usb_key && rmdir /usb_key
 ```
-
-
-
-## TODO remove notes
-
-```sh
-BOOT=sda1
-PRIMARY=sda2
-SWAP=sda3
-swapon /dev/$SWAP
-keyctl link @u @s
-DEV_B="/dev/disk/by-uuid/"$(lsblk -o name,uuid | grep $BOOT | awk '{print $2}')
-DEV_P="/dev/disk/by-uuid/"$(lsblk -o name,uuid | grep $PRIMARY | awk '{print $2}')
-mount -t bcachefs -o X-mount.subdir=@root $DEV_P /mnt
-mount -t vfat $DEV_B /mnt/boot --mkdir
-mount -t bcachefs -o X-mount.mkdir,X-mount.subdir=@nix,relatime $DEV_P /mnt/nix
-mount -t bcachefs -o X-mount.mkdir,X-mount.subdir=@snapshots,relatime $DEV_P /mnt/.snapshots
-mount -t bcachefs -o X-mount.mkdir,X-mount.subdir=@persist $DEV_P /mnt/persist
-nixos-install --flake "git+https://git.joshuabell.xyz/ringofstorms/dotfiles?dir=hosts/i001#i001"
-```