{ config, lib, pkgs, ... }: # TODO unify logging of shell scripts to user and journal # TODO move all scripts to ${etcDir}, so ControlMaster connections # immediately pick up new authenticators # TODO when authorized_keys changes, then restart ssh # (or kill already connected users somehow) with import <stockholm/lib>; let cfg = config.krebs.git; out = { options.krebs.git = api; config = with lib; mkIf cfg.enable (mkMerge [ (mkIf cfg.cgit.enable cgit-imp) git-imp ]); }; api = { enable = mkEnableOption "krebs.git"; cgit = mkOption { type = types.submodule { options = { enable = mkEnableOption "krebs.git.cgit" // { default = true; }; fcgiwrap = { group = mkOption { type = types.group; default = { name = "fcgiwrap"; }; }; user = mkOption { type = types.user; default = { name = "fcgiwrap"; home = toString pkgs.empty; }; }; }; settings = mkOption { apply = flip removeAttrs ["_module"]; default = {}; type = subtypes.cgit-settings; }; }; }; default = {}; description = '' Cgit is an attempt to create a fast web interface for the git version control system, using a built in cache to decrease pressure on the git server. cgit in this module is being served via fastcgi nginx.This module deploys a http://cgit.<hostname> nginx configuration and enables nginx if not yet enabled. ''; }; dataDir = mkOption { type = types.str; default = "/var/lib/git"; description = "Directory used to store repositories."; }; etcDir = mkOption { type = mkOptionType { name = "${types.absolute-pathname.name} starting with `/etc/'"; check = x: types.absolute-pathname.check x && hasPrefix "/etc/" x; merge = mergeOneOption; }; default = "/etc/git"; }; repos = mkOption { type = types.attrsOf subtypes.repo; default = {}; example = literalExample '' { testing = { name = "testing"; hooks.post-update = ''' #! /bin/sh set -euf echo post-update hook: $* >&2 '''; }; testing2 = { name = "testing2"; }; } ''; description = '' Repositories. ''; }; rules = mkOption { type = types.listOf subtypes.rule; default = []; example = literalExample '' singleton { user = [ config.krebs.users.tv ]; repo = [ testing ]; # see literal example of repos perm = push "refs/*" (with git; [ non-fast-forward create delete merge ]); } ''; description = '' access and permission rules for git repositories. ''; }; user = mkOption { type = types.user; default = { name = "git"; home = toString pkgs.empty; }; }; }; # TODO put into krebs/4lib/types.nix? subtypes = { cgit-settings = types.submodule { # A setting's value of `null` means cgit's default should be used. options = { about-filter = mkOption { type = types.nullOr types.package; default = null; }; cache-root = mkOption { type = types.absolute-pathname; default = "/tmp/cgit"; }; cache-size = mkOption { type = types.uint; default = 1000; }; css = mkOption { type = types.absolute-pathname; default = "/static/cgit.css"; }; enable-commit-graph = mkOption { type = types.bool; default = true; }; enable-index-links = mkOption { type = types.bool; default = true; }; enable-index-owner = mkOption { type = types.bool; default = false; }; enable-log-filecount = mkOption { type = types.bool; default = true; }; enable-log-linecount = mkOption { type = types.bool; default = true; }; enable-remote-branches = mkOption { type = types.bool; default = true; }; logo = mkOption { type = types.absolute-pathname; default = "/static/cgit.png"; }; max-stats = mkOption { type = types.nullOr (types.enum ["week" "month" "quarter" "year"]); default = "year"; }; readme = mkOption { type = types.listOf types.str; default = []; }; robots = mkOption { type = types.nullOr (types.listOf types.str); default = ["nofollow" "noindex"]; }; root-desc = mkOption { type = types.nullOr types.str; default = null; }; root-title = mkOption { type = types.nullOr types.str; default = null; }; source-filter = mkOption { type = types.nullOr types.absolute-pathname; default = null; example = literalExample "\${pkgs.cgit}/lib/cgit/filters/syntax-highlighting.py"; }; virtual-root = mkOption { type = types.nullOr types.absolute-pathname; default = "/"; }; }; }; repo = types.submodule ({ config, ... }: { options = { admins = mkOption { type = types.listOf types.user; default = []; description = '' List of users that should be able to do everything with this repo. This option is currently not used by krebs.git but instead can be used to create rules. See e.g. <stockholm/lass/2configs/git.nix> for an example. ''; }; cgit = { desc = mkOption { type = types.nullOr types.str; default = null; description = '' Repository description. ''; }; path = mkOption { type = types.str; default = "${cfg.dataDir}/${config.name}"; description = '' An absolute path to the repository directory. For non-bare repositories this is the .git-directory. ''; }; section = mkOption { type = types.nullOr types.str; default = null; description = '' Repository section. ''; }; url = mkOption { type = types.str; default = config.name; description = '' The relative url used to access the repository. ''; }; }; collaborators = mkOption { type = types.listOf types.user; default = []; description = '' List of users that should be able to fetch from this repo. This option is currently not used by krebs.git but instead can be used to create rules. See e.g. <stockholm/tv/2configs/git.nix> for an example. ''; }; name = mkOption { type = types.str; description = '' Repository name. ''; }; hooks = mkOption { type = types.attrsOf types.str; default = {}; description = '' Repository-specific hooks. ''; }; public = mkOption { type = types.bool; default = false; description = '' Allow everybody to read the repository via HTTP if cgit enabled. ''; # TODO allow every configured user to fetch the repository via SSH. }; }; }); rule = types.submodule ({ config, ... }: { options = { user = mkOption { type = types.listOf types.user; description = '' List of users this rule should apply to. Checked by authorize-command. ''; }; repo = mkOption { type = types.listOf subtypes.repo; description = '' List of repos this rule should apply to. Checked by authorize-command. ''; }; perm = mkOption { type = types.submodule { # TODO generate enum argument from krebs/4lib/git.nix options = { allow-commands = mkOption { type = types.listOf (types.enum (with git; [ git-receive-pack git-upload-pack ])); default = []; description = '' List of commands the rule's users are allowed to execute. Checked by authorize-command. ''; }; allow-receive-ref = mkOption { type = types.nullOr types.str; default = null; description = '' Ref that can receive objects. Checked by authorize-push. ''; }; allow-receive-modes = mkOption { type = types.listOf (types.enum (with git; [ fast-forward non-fast-forward create delete merge ])); default = []; description = '' List of allowed receive modes. Checked by pre-receive hook. ''; }; }; }; description = '' Permissions granted. ''; }; }; }); }; git-imp = { system.activationScripts.git-init = "${init-script}"; # TODO maybe put all scripts here and then use PATH? environment.etc.${removePrefix "/etc/" cfg.etcDir}.source = scriptFarm "git-ssh-authorizers" { authorize-command = makeAuthorizeScript (map (rule: [ (map getName (toList rule.user)) (map getName (toList rule.repo)) (map getName rule.perm.allow-commands) ]) cfg.rules); authorize-push = makeAuthorizeScript (map (rule: [ (map getName (toList rule.user)) (map getName (toList rule.repo)) (toList rule.perm.allow-receive-ref) (map getName rule.perm.allow-receive-modes) ]) (filter (rule: rule.perm.allow-receive-ref != null) cfg.rules)); }; users.users.${cfg.user.name} = { inherit (cfg.user) home name uid; description = "Git repository hosting user"; extraGroups = [ # To allow running cgit-clear-cache via hooks. cfg.cgit.fcgiwrap.group.name ]; shell = "/bin/sh"; openssh.authorizedKeys.keys = unique (sort lessThan (map (makeAuthorizedKey git-ssh-command) (filter (user: isString user.pubkey) (concatMap (getAttr "user") cfg.rules)))); }; }; cgit-imp = { users = { groups.${cfg.cgit.fcgiwrap.group.name} = { inherit (cfg.cgit.fcgiwrap.group) name gid; }; users.${cfg.cgit.fcgiwrap.user.name} = { inherit (cfg.cgit.fcgiwrap.user) home name uid; group = cfg.cgit.fcgiwrap.group.name; }; }; services.fcgiwrap = { enable = true; user = cfg.cgit.fcgiwrap.user.name; group = cfg.cgit.fcgiwrap.group.name; # socketAddress = "/run/fcgiwrap.sock" (default) # socketType = "unix" (default) }; environment.etc."cgitrc".text = let repo-to-cgitrc = _: repo: optionals (isPublicRepo repo) (concatLists [ [""] # empty line [(kv-to-cgitrc "repo.url" repo.cgit.url)] (mapAttrsToList kv-to-cgitrc (mapAttrs' (k: nameValuePair "repo.${k}") (removeAttrs repo.cgit ["url"]))) ]); kv-to-cgitrc = k: v: getAttr (typeOf v) { bool = kv-to-cgitrc k (if v then 1 else 0); null = []; # This will be removed by `flatten`. list = { readme = map (x: "readme=${x}") v; }.${k} or "${k}=${concatStringsSep ", " v}"; int = "${k}=${toString v}"; set = if subtypes.cgit-settings.check v then "${k}=${v}" else error "kv-to-cgitrc: unhandled type: set"; string = "${k}=${v}"; }; in concatStringsSep "\n" (flatten ( mapAttrsToList kv-to-cgitrc cfg.cgit.settings ++ mapAttrsToList repo-to-cgitrc cfg.repos )); environment.systemPackages = [ (pkgs.cgit-clear-cache.override { inherit (cfg.cgit.settings) cache-root; }) ]; system.activationScripts.cgit = '' mkdir -m 0770 -p ${cfg.cgit.settings.cache-root} chmod 0770 ${cfg.cgit.settings.cache-root} chown ${toString cfg.cgit.fcgiwrap.user.name}:${toString cfg.cgit.fcgiwrap.group.name} ${cfg.cgit.settings.cache-root} ''; services.nginx.virtualHosts.cgit = { serverAliases = [ "cgit.${config.networking.hostName}" "cgit.${config.networking.hostName}.r" ]; locations."/".extraConfig = '' include ${pkgs.nginx}/conf/fastcgi_params; fastcgi_param SCRIPT_FILENAME ${pkgs.writeDash "cgit-wrapper" '' set -efu exec 3>&1 ${pkgs.cgit}/cgit/cgit.cgi "$@" 2>&1 >&3 3>&- \ | ${pkgs.gnused}/bin/sed \ ' \|^${pkgs.cgit}/cgit/cgit.cgi: Relink |d ' exec 3>&- ''}; fastcgi_param PATH_INFO $uri; fastcgi_param QUERY_STRING $args; fastcgi_param HTTP_HOST $server_name; fastcgi_pass unix:${config.services.fcgiwrap.socketAddress}; ''; # Smart HTTP transport. Regex based on. # https://github.com/git/git/blob/v2.27.0/http-backend.c#L708-L721 locations."~ \"^/[0-9A-Za-z._-]+/(HEAD|info/refs|objects/info/(alternates|http-alternates|packs)|[0-9a-f]{2}/([0-9a-f]{38}|[0-9a-f]{62})|pack/pack-([0-9a-f]{40}|[0-9a-f]{64})\\.(pack|idx)|git-upload-pack|git-receive-pack)$\"".extraConfig = '' include ${pkgs.nginx}/conf/fastcgi_params; fastcgi_param GIT_HTTP_EXPORT_ALL ""; fastcgi_param GIT_PROJECT_ROOT ${cfg.dataDir}; fastcgi_param PATH_INFO $fastcgi_script_name; fastcgi_param SCRIPT_FILENAME ${pkgs.git}/bin/git-http-backend; fastcgi_pass unix:${config.services.fcgiwrap.socketAddress}; ''; locations."/static/".extraConfig = '' root ${pkgs.cgit}/cgit; rewrite ^/static(/.*)$ $1 break; ''; }; }; getName = x: x.name; isPublicRepo = getAttr "public"; # TODO this is also in ./cgit.nix makeAuthorizedKey = git-ssh-command: user@{ name, pubkey, ... }: # TODO assert name # TODO assert pubkey let options = concatStringsSep "," [ ''command="exec ${git-ssh-command} ${name}"'' "no-agent-forwarding" "no-port-forwarding" "no-pty" "no-X11-forwarding" ]; in "${options} ${pubkey}"; # [case-pattern] -> shell-script # Create a shell script that succeeds (exit 0) when all its arguments # match the case patterns (in the given order). makeAuthorizeScript = let # TODO escape to-pattern = x: concatStringsSep "|" (toList x); go = i: ps: if ps == [] then "exit 0" else '' case ''$${toString i} in ${to-pattern (head ps)}) ${go (i + 1) (tail ps)} esac''; in patterns: '' #! /bin/sh set -euf ${concatStringsSep "\n" (map (go 1) patterns)} exit -1 ''; reponames = rules: sort lessThan (unique (map (x: x.repo.name) rules)); # TODO use pkgs.write (from nix-writers) scriptFarm = farm-name: scripts: let makeScript = script-name: script-string: { name = script-name; path = pkgs.writeScript "${farm-name}_${script-name}" script-string; }; in pkgs.linkFarm farm-name (mapAttrsToList makeScript scripts); git-ssh-command = pkgs.writeScript "git-ssh-command" '' #! /bin/sh set -euf PATH=${makeBinPath (with pkgs; [ coreutils git gnugrep gnused systemd ])} abort() { echo "error: $1" >&2 systemd-cat -p err -t git echo "error: $1" exit -1 } GIT_SSH_USER=$1 systemd-cat -p info -t git echo \ "authorizing $GIT_SSH_USER $SSH_CONNECTION $SSH_ORIGINAL_COMMAND" # References: The Base Definitions volume of # POSIX.1‐2013, Section 3.278, Portable Filename Character Set portable_filename_bre="^[A-Za-z0-9._-]\\+$" command=$(echo "$SSH_ORIGINAL_COMMAND" \ | sed -n 's/^\([^ ]*\) '"'"'\(.*\)'"'"'/\1/p' \ | grep "$portable_filename_bre" \ || abort 'cannot read command') GIT_SSH_REPO=$(echo "$SSH_ORIGINAL_COMMAND" \ | sed -n 's/^\([^ ]*\) '"'"'\(.*\)'"'"'/\2/p' \ | grep "$portable_filename_bre" \ || abort 'cannot read reponame') ${cfg.etcDir}/authorize-command \ "$GIT_SSH_USER" "$GIT_SSH_REPO" "$command" \ || abort 'access denied' repodir=${escapeShellArg cfg.dataDir}/$GIT_SSH_REPO systemd-cat -p info -t git \ echo "authorized exec $command $repodir" export GIT_SSH_USER export GIT_SSH_REPO exec "$command" "$repodir" ''; init-script = pkgs.writeScript "git-init" '' #! /bin/sh set -euf PATH=${makeBinPath (with pkgs; [ coreutils findutils gawk git gnugrep gnused ])} dataDir=${escapeShellArg cfg.dataDir} mkdir -p "$dataDir" # Notice how the presence of hooks symlinks determine whether # we manage a repositry or not. # Make sure that no existing repository has hooks. We can delete # symlinks because we assume we created them. find "$dataDir" -mindepth 2 -maxdepth 2 -name hooks -type l -delete bad_hooks=$(find "$dataDir" -mindepth 2 -maxdepth 2 -name hooks) if echo "$bad_hooks" | grep -q .; then printf 'error: unknown hooks:\n%s\n' \ "$(echo "$bad_hooks" | sed 's/^/ /')" \ >&2 exit -1 fi # Initialize repositories. ${concatMapStringsSep "\n" (repo: let hooks = scriptFarm "git-hooks" (makeHooks repo); in '' reponame=${escapeShellArg repo.name} repodir=$dataDir/$reponame mode=${toString (if isPublicRepo repo then 0711 else 0700)} if ! test -d "$repodir"; then mkdir -m "$mode" "$repodir" git init --bare --template=/var/empty "$repodir" # TODO fix correctly with stringAfter chown -R ${toString config.users.users.git.uid}:nogroup "$repodir" fi ln -s ${hooks} "$repodir/hooks" '' ) (attrValues cfg.repos)} # Warn about repositories that exist but aren't mentioned in the # current configuration (and thus didn't receive a hooks symlink). unknown_repos=$(find "$dataDir" -mindepth 1 -maxdepth 1 \ -type d \! -exec test -e '{}/hooks' \; -print) if echo "$unknown_repos" | grep -q .; then printf 'warning: stale repositories:\n%s\n' \ "$(echo "$unknown_repos" | sed 's/^/ /')" \ >&2 fi ''; makeHooks = repo: removeAttrs repo.hooks [ "pre-receive" ] // { pre-receive = '' #! /bin/sh set -euf PATH=${makeBinPath (with pkgs; [ coreutils # env git systemd ])} accept() { #systemd-cat -p info -t git echo "authorized $1" accept_string="''${accept_string+$accept_string }authorized $1" } reject() { #systemd-cat -p err -t git echo "denied $1" #echo 'access denied' >&2 #exit_code=-1 reject_string="''${reject_string+$reject_string }access denied: $1" } empty=0000000000000000000000000000000000000000 accept_string= reject_string= while read oldrev newrev ref; do if [ $oldrev = $empty ]; then receive_mode=create elif [ $newrev = $empty ]; then receive_mode=delete elif [ "$(git merge-base $oldrev $newrev)" = $oldrev ]; then receive_mode=fast-forward else receive_mode=non-fast-forward fi if ${cfg.etcDir}/authorize-push \ "$GIT_SSH_USER" "$GIT_SSH_REPO" "$ref" "$receive_mode"; then accept "$receive_mode $ref" else reject "$receive_mode $ref" fi done if [ -n "$reject_string" ]; then systemd-cat -p err -t git echo "$reject_string" exit -1 fi systemd-cat -p info -t git echo "$accept_string" ${optionalString (hasAttr "post-receive" repo.hooks) '' # custom post-receive hook ${repo.hooks.post-receive}''} ''; }; in out