X-Git-Url: http://git.scottworley.com/auto-upgrade-with-pinch/blobdiff_plain/77d31c62ec30b4b28f732a3ce72db6375a22e7f5..15d7ea954e9c4ca687f2175630724cf60346f758:/modules/auto-upgrade.nix?ds=inline diff --git a/modules/auto-upgrade.nix b/modules/auto-upgrade.nix index c9a8905..e41716b 100644 --- a/modules/auto-upgrade.nix +++ b/modules/auto-upgrade.nix @@ -1,82 +1,94 @@ +# auto-upgrade-with-pinch: Secure managed NixOS updates +# +# This program is free software: you can redistribute it and/or modify it +# under the terms of the GNU General Public License as published by the +# Free Software Foundation, version 3. + { config, lib, pkgs, ... }: with lib; let + local-pkgs = import ../. { inherit pkgs; }; cfg = config.system.autoUpgradeWithPinch; - pull-repo-script = path: repo: - pkgs.writeShellScript "pull-repo" '' - set -eo pipefail - - echo Pulling in ${escapeShellArg path} >&2 - - if [[ ! -e ${escapeShellArg path} ]];then - d=$(mktemp -d) - ${pkgs.git}/bin/git init "$d" - ${pkgs.git}/bin/git -C "$d" checkout -b \ - ${escapeShellArg repo.localBranch} - ${pkgs.git}/bin/git -C "$d" remote add \ - ${escapeShellArg repo.remoteName} \ - ${escapeShellArg repo.url} - ${pkgs.git}/bin/git -C "$d" branch -u \ - ${escapeShellArg repo.remoteBranch} - mkdir -p "$(dirname ${escapeShellArg path})" - mv "$d" ${escapeShellArg path} - fi - - cd ${escapeShellArg path} - - if [[ "$(${pkgs.git}/bin/git remote get-url \ - ${escapeShellArg repo.remoteName})" != \ - ${escapeShellArg repo.url} ]] - then - echo Expected git remote ${escapeShellArg repo.remoteName} \ - to point at ${escapeShellArg repo.url} \ - but it points at "$(${pkgs.git}/bin/git remote get-url \ - ${escapeShellArg repo.remoteName})" >&2 - ${ - { - abort = "exit 1"; - update = '' - echo Updating it >&2 - ${pkgs.git}/bin/git -C "$d" remote set-url \ - ${escapeShellArg repo.remoteName} \ - ${escapeShellArg repo.url} - ''; - }."${repo.onRemoteURLMismatch}" - } - fi - - ${pkgs.git}/bin/git fetch \ - ${escapeShellArg repo.remoteName} \ - ${escapeShellArg repo.remoteBranch} - - if [[ "$(${pkgs.git}/bin/git rev-parse --abbrev-ref HEAD)" != \ - ${escapeShellArg repo.localBranch} ]] - then - echo Could not merge because currently-checked-out \ - \""$(${pkgs.git}/bin/git rev-parse --abbrev-ref HEAD)"\" is not \ - \"${escapeShellArg repo.localBranch}\" - ${ - { - abort = "exit 1"; - continue = "exit 0"; - }."${repo.onBranchMismatch}" - } - fi + pull-repo-script = pkgs.writeShellScript "pull-repo" '' + set -eo pipefail + path=$1 + config=$2 - ${if repo.requireSignature then '' - PATH="${pkgs.keyedgit repo.signingKeys}/bin:$PATH" \ - ${pkgs.polite-merge}/bin/polite-merge --ff-only --verify-signatures - '' else '' - ${pkgs.polite-merge}/bin/polite-merge --ff-only - ''} - ''; + prop() { + ${pkgs.jq}/bin/jq -r ".$1" <<< "$config" + } + + echo Pulling in "$path" >&2 + + if [[ ! -e "$path" ]];then + d=$(mktemp -d) + ${pkgs.git}/bin/git init "$d" + ${pkgs.git}/bin/git -C "$d" checkout -b "$(prop localBranch)" + ${pkgs.git}/bin/git -C "$d" remote add "$(prop remoteName)" "$(prop url)" + ${pkgs.git}/bin/git -C "$d" branch -u "$(prop remoteBranch)" + mkdir -p "$(${pkgs.coreutils}/bin/dirname "$path")" + mv "$d" "$path" + fi + + cd "$path" + + if [[ "$(${pkgs.git}/bin/git remote get-url "$(prop remoteName)")" != "$(prop url)" ]]; then + echo Expected git remote "$(prop remoteName)" to point at "$(prop url)" \ + but it points at "$(${pkgs.git}/bin/git remote get-url "$(prop remoteName)")" >&2 + case "$(prop onRemoteURLMismatch)" in + abort) exit 1;; + update) echo Updating it >&2 + ${pkgs.git}/bin/git -C "$d" remote set-url "$(prop remoteName)" "$(prop url)";; + esac + fi + + ${pkgs.git}/bin/git fetch "$(prop remoteName)" "$(prop remoteBranch)" + + if [[ "$(${pkgs.git}/bin/git rev-parse --abbrev-ref HEAD)" != "$(prop localBranch)" ]];then + echo Could not merge because currently-checked-out \ + \""$(${pkgs.git}/bin/git rev-parse --abbrev-ref HEAD)"\" is not \ + \""$(prop localBranch)"\" + case "$(prop onBranchMismatch)" in + abort) exit 1;; + continue) exit 0;; + esac + fi + + if [[ "$(prop requireSignature)" == true ]]; then + ${pkgs.polite-merge}/bin/polite-merge \ + -c gpg.program=${escapeShellArg (local-pkgs.keyed-gpg cfg.signingKeys)} \ + merge --ff-only --verify-signatures + else + ${pkgs.polite-merge}/bin/polite-merge merge --ff-only + fi + ''; auto-upgrade-script = pkgs.writeShellScript "auto-upgrade" '' - ${pkgs.utillinux}/bin/flock /run/auto-upgrade-with-pinch ${ + ${pkgs.util-linux}/bin/flock /run/auto-upgrade-with-pinch ${ pkgs.writeShellScript "auto-upgrade-with-lock-held" '' set -eo pipefail + dry_run=false + pinch_args=() + if [[ "$1" == --dry-run ]];then + dry_run=true + pinch_args=( --dry-run ) + fi + + hydrate() { + if "$dry_run";then + echo "Would run: $*" + else + "$@" + fi + } + + die() { + echo "$*" >&2 + exit 1 + } + in_tmpdir() { d=$(${pkgs.coreutils}/bin/mktemp -d) pushd "$d" @@ -85,34 +97,108 @@ let ${pkgs.coreutils}/bin/rm -r "$d" } + ${optionalString (cfg.upgradeConfigOwnershipPolicy != "any") ('' + verify_ownership() { + if [[ "$1" != /* ]];then + die "Unexpected relative path: $1" + fi + if [[ "$1" != / ]];then + verify_ownership "$(${pkgs.coreutils}/bin/dirname "$1")" + fi + if [[ ! -e "$1" ]];then + die "Could not find upgrade config: $1 does not exist" + fi + if [[ -h "$1" ]];then + verify_ownership "$( + ${pkgs.coreutils}/bin/realpath --no-symlinks \ + "$(${pkgs.coreutils}/bin/dirname "$1")/$(${pkgs.coreutils}/bin/readlink "$1")" + )" + fi + perms="$(${pkgs.findutils}/bin/find "$1" -maxdepth 0 -printf "%M")" + if [[ "$perms" == d*t ]];then + die "Will not use upgrade config in sticky directory $1" + fi + owner=$(${pkgs.findutils}/bin/find "$1" -maxdepth 0 -printf "%u") + if [[ "$owner" != root ]];then + die "Will not use upgrade config not owned by root in $1" + fi + if [[ "$perms" == l* ]];then + return 0 # Root-owned symlinks are fine + fi + if [[ "$perms" == *w? ]];then + die "Will not use world-writable upgrade config in $1" + fi + ${ + { + root = '' + if [[ "$perms" == *w???? ]];then + die "Will not use group-writable upgrade config in $1" + fi + ''; + wheel = '' + if [[ "$perms" == *w???? ]];then + group=$(${pkgs.findutils}/bin/find "$1" -maxdepth 0 -printf "%g") + if [[ "$group" != wheel ]];then + die "Will not use non-wheel-group group-writable upgrade config in $1" + fi + fi + ''; + }."${cfg.upgradeConfigOwnershipPolicy}" + } + } + '' + + concatMapStringsSep "\n" (f: "verify_ownership ${escapeShellArg f}") + cfg.upgradeConfig)} + + config=$(${pkgs.nix}/bin/nix-instantiate --eval --strict --json -A config \ + --arg upgradeConfig ${ + escapeShellArg ("[" + + lib.concatMapStringsSep " " lib.strings.escapeNixString + cfg.upgradeConfig + "]") + } ${../upgrade-config.nix}) + + config_query() { + ${pkgs.jq}/bin/jq -r "$@" <<< "$config" + } + + repo_query() { + config_query --arg path "$1" ".repos[\$ARGS.named.path]$2" + } + + userenv_query() { + config_query --arg user "$1" ".userEnvironments[\$ARGS.named.user]$2" + } + # Pull updates - ${concatStringsSep "\n" (mapAttrsToList (path: repo: '' - /run/wrappers/bin/sudo -u ${escapeShellArg repo.user} \ - ${pull-repo-script path repo} - '') cfg.repos)} + while read path;do + hydrate /run/wrappers/bin/sudo -u "$(repo_query "$path" .user)" \ + ${pull-repo-script} "$path" "$(repo_query "$path" "")" + done < <( config_query '.repos | keys []' ) # Update channels - ${pkgs.pinch}/bin/pinch update ${escapeShellArgs cfg.pinchFiles} + config_query '.pinchFiles[]' | ${pkgs.findutils}/bin/xargs --no-run-if-empty --delimiter=\\n ${pkgs.pinch}/bin/pinch update "''${pinch_args[@]}" # Build - in_tmpdir ${config.system.build.nixos-rebuild}/bin/nixos-rebuild build - ${concatStringsSep "\n" (mapAttrsToList (user: env: '' - /run/wrappers/bin/sudo -u ${escapeShellArg user} \ - nix-build --no-out-link '' \ - -A ${escapeShellArg env.package} - '') cfg.userEnvironments)} + in_tmpdir hydrate ${config.system.build.nixos-rebuild}/bin/nixos-rebuild build + while read user;do + hydrate /run/wrappers/bin/sudo -u "$user" \ + ${pkgs.nix}/bin/nix-build --no-out-link '' -A "$(userenv_query "$user" .package)" + done < <( config_query '.userEnvironments | keys []' ) # Install - ${config.system.build.nixos-rebuild}/bin/nixos-rebuild switch - ${concatStringsSep "\n" (mapAttrsToList (user: env: '' - /run/wrappers/bin/sudo -u ${escapeShellArg user} \ - nix-env -f '' \ - ${optionalString (env.otherPackagesAction != "keep") "-r"} \ - -iA ${escapeShellArg env.package} - '') cfg.userEnvironments)} + hydrate ${config.system.build.nixos-rebuild}/bin/nixos-rebuild switch + while read user;do + remove_arg=-r + if [[ "$(userenv_query "$user" .otherPackagesAction)" == keep ]];then + remove_arg= + fi + hydrate /run/wrappers/bin/sudo -u "$user" \ + ${pkgs.nix}/bin/nix-env -f '' $remove_arg -iA "$(userenv_query "$user" .package)" + done < <( config_query '.userEnvironments | keys []' ) '' } ''; + in { options = { system.autoUpgradeWithPinch = { @@ -138,132 +224,37 @@ in { ''; }; - repos = mkOption { + signingKeys = mkOption { + type = types.listOf types.path; description = '' - Git repositories to pull before running pinch. These are maintained - as git checkouts at specified places in the filesystem with specified - ownership rather than kept read-only in the nix store so that humans - can use them both as points of intervention in the automation and to - author and push changes back up. + Files containing GPG keys that are authorized to sign updates. + Updates are only merged if the commit at the tip of the remote + ref is signed with one of these keys. ''; - type = types.attrsOf (types.submodule { - options = { - url = mkOption { - description = "Remote git repo."; - type = types.str; - }; - remoteName = mkOption { - description = ''Name of the git remote. Customarily "origin".''; - type = types.str; - default = "origin"; - }; - onRemoteURLMismatch = mkOption { - description = '' - What to do if the remote URL in the git repo doesn't match the - URL configured here. - ''; - type = types.enum [ "update" "abort" ]; - default = "update"; - }; - onBranchMismatch = mkOption { - description = '' - What to do if a different branch is currently checked out. - - (Changes from remoteBranch are only ever - merged into localBranch, so if a different - branch is checked out, no remote changes will be merged.) - ''; - type = types.enum [ "continue" "abort" ]; - default = "continue"; - }; - user = mkOption { - description = "User as which to run 'git fetch'"; - type = types.str; - }; - localBranch = mkOption { - description = ""; - type = types.str; - default = "master"; - }; - remoteBranch = mkOption { - type = types.str; - default = "master"; - }; - requireSignature = mkOption { - type = types.bool; - default = true; - description = '' - Only pull when the tip of the remote ref is signed by a key - specifed in signingKeys. - ''; - }; - signingKeys = mkOption { - type = types.either types.path (types.listOf types.path); - description = '' - Files containing GPG keys that are authorized to sign updates. - Updates are only merged if the commit at the tip of the remote - ref is signed with one of these keys. - ''; - }; - }; - }); - example = { - "/etc/nixos" = { - url = "https://github.com/chkno/auto-upgrade-demo-nixos"; - user = "root"; - signingKeys = [ ./admins.asc ]; - }; - "/home/alice/.config/nixpkgs" = { - url = "https://github.com/chkno/auto-upgrade-demo-user-nixpkgs"; - user = "alice"; - signingKeys = [ ./admins.asc ./alice.asc ]; - }; - }; }; - pinchFiles = mkOption { + upgradeConfig = mkOption { + type = types.listOf types.path; description = '' - Pinch files to use for channel updates. Typically these are inside - repos' paths. + Configuration files that specify what git repo paths to pull, what + pinch files to update from, and what user environments to update. + These are specified in separate configuration files processed at + update time so that changes to this configuration take effect in + the same update cycle. ''; - type = types.listOf types.path; - example = [ "/etc/nixos/channels" ]; }; - userEnvironments = mkOption { + upgradeConfigOwnershipPolicy = mkOption { + type = types.enum [ "root" "wheel" "any" ]; + default = "root"; description = '' - User environments to update as part of an upgrade run. + Verify ownership of upgrade config files before using them for + system upgrades. + + root = Config must be writable only by root. + wheel = Config must be writable only by root and wheel. + any = No checks. Not recommended. ''; - type = types.attrsOf (types.submodule { - options = { - package = mkOption { - type = types.str; - default = "nixos.userPackages"; - description = '' - The name of the single package that will be updated. You'll - want to create an 'entire user environment' package as shown in - https://nixos.wiki/wiki/FAQ#How_can_I_manage_software_with_nix-env_like_with_configuration.nix.3F - ''; - }; - otherPackagesAction = mkOption { - type = types.enum [ "remove" "keep" "abort" ]; - default = "remove"; - description = '' - What to do with packages other than package. - - THIS DEFAULTS TO "remove", WHICH IS POTENTIALLY SOMEWHAT - DESTRUCTIVE! This is the default because it is the recommended - setting -- This module recommends managing your environment - through your one entire-environment package. - This keeps your environment declarative and ensures that all - packages receive regular updates. - ''; - # It seems like "upgrade" ought to be another choice here, powered - # by "nix-env --upgrade". But when I tried this, it didn't work. - }; - }; - }); - example = { alice = { }; }; }; }; }; @@ -285,7 +276,6 @@ in { ''; nixpkgs.overlays = [ - (import ../overlays/keyedgit.nix) (import ../overlays/pinch.nix) (import ../overlays/polite-merge.nix) (self: super: {