nixos/taskserver: Rewrite helper-tool in Python

In the comments of the pull request @nbp wrote:

"Why is it implemented in 3 different languages: Nix, Bash and C?"

And he's right, it doesn't make sense, because we were using C as a
runuser replacement and used Nix to generate the shellscript
boilerplates.

Writing this in Python gets rid of all of this and we also don't need
the boilerplate as well, because we're using Click to handle all the
command line stuff.

Note that this currently is a 1:1 implementation of what we had before.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
This commit is contained in:
aszlig 2016-04-11 11:52:02 +02:00
parent 85832de2e8
commit 2acf8677fa
No known key found for this signature in database
GPG key ID: D0EBD0EC8C2DC961
3 changed files with 299 additions and 327 deletions

View file

@ -80,9 +80,29 @@ let
mkShellStr = val: "'${replaceStrings ["'"] ["'\\''"] val}'";
nixos-taskserver = import ./helper-tool.nix {
inherit pkgs lib mkShellStr taskd;
config = cfg;
nixos-taskserver = pkgs.buildPythonPackage {
name = "nixos-taskserver";
namePrefix = "";
src = pkgs.runCommand "nixos-taskserver-src" {} ''
mkdir -p "$out"
cat "${pkgs.substituteAll {
src = ./helper-tool.py;
certtool = "${pkgs.gnutls}/bin/certtool";
inherit taskd;
inherit (cfg) dataDir user group;
inherit (cfg.server) fqdn;
}}" > "$out/main.py"
cat > "$out/setup.py" <<EOF
from setuptools import setup
setup(name="nixos-taskserver",
py_modules=["main"],
install_requires=["Click"],
entry_points="[console_scripts]\\nnixos-taskserver=main:cli")
EOF
'';
propagatedBuildInputs = [ pkgs.pythonPackages.click ];
};
ctlcmd = "${nixos-taskserver}/bin/nixos-taskserver --service-helper";

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@ -1,324 +0,0 @@
{ config, pkgs, lib, mkShellStr, taskd }:
let
commandName = "nixos-taskserver";
mkShellName = lib.replaceStrings ["-"] ["_"];
genClientKey = ''
umask 0077
if tmpdir="$(${pkgs.coreutils}/bin/mktemp -d)"; then
trap "rm -rf '$tmpdir'" EXIT
${pkgs.gnutls}/bin/certtool -p --bits 2048 --outfile "$tmpdir/key"
cat > "$tmpdir/template" <<-\ \ EOF
organization = $organisation
cn = ${config.server.fqdn}
tls_www_client
encryption_key
signing_key
EOF
${pkgs.gnutls}/bin/certtool -c \
--load-privkey "$tmpdir/key" \
--load-ca-privkey "${config.dataDir}/keys/ca.key" \
--load-ca-certificate "${config.dataDir}/keys/ca.cert" \
--template "$tmpdir/template" \
--outfile "$tmpdir/cert"
mkdir -m 0700 -p "${config.dataDir}/keys/user/$organisation/$user"
chown root:root "${config.dataDir}/keys/user/$organisation/$user"
cat "$tmpdir/key" \
> "${config.dataDir}/keys/user/$organisation/$user/private.key"
cat "$tmpdir/cert" \
> "${config.dataDir}/keys/user/$organisation/$user/public.cert"
rm -rf "$tmpdir"
trap - EXIT
else
echo "Unable to create temporary directory for client" \
"certificate creation." >&2
exit 1
fi
'';
mkSubCommand = name: { args, description, script }: let
mkArg = pos: arg: "local ${arg}=\"\$${toString pos}\"";
mkDesc = line: "echo ${mkShellStr " ${line}"} >&2";
usagePosArgs = lib.concatMapStringsSep " " (a: "<${a}>") args;
in ''
subcmd_${mkShellName name}() {
${lib.concatImapStringsSep "\n " mkArg args}
${script}
}
usage_${mkShellName name}() {
echo " ${commandName} ${name} ${usagePosArgs}" >&2
${lib.concatMapStringsSep "\n " mkDesc description}
}
'';
mkCStr = val: "\"${lib.escape ["\\" "\""] val}\"";
taskdUser = let
runUser = pkgs.writeText "runuser.c" ''
#include <sys/types.h>
#include <pwd.h>
#include <grp.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
int main(int argc, char **argv) {
struct passwd *userinfo;
struct group *groupinfo;
errno = 0;
if ((userinfo = getpwnam(${mkCStr config.user})) == NULL) {
if (errno == 0)
fputs(${mkCStr "User name `${config.user}' not found."}, stderr);
else
perror("getpwnam");
return EXIT_FAILURE;
}
errno = 0;
if ((groupinfo = getgrnam(${mkCStr config.group})) == NULL) {
if (errno == 0)
fputs(${mkCStr "Group name `${config.group}' not found."}, stderr);
else
perror("getgrnam");
return EXIT_FAILURE;
}
if (setgid(groupinfo->gr_gid) == -1) {
perror("setgid");
return EXIT_FAILURE;
}
if (setuid(userinfo->pw_uid) == -1) {
perror("setgid");
return EXIT_FAILURE;
}
argv[0] = "taskd";
if (execv(${mkCStr taskd}, argv) == -1) {
perror("execv");
return EXIT_FAILURE;
}
/* never reached */
return EXIT_SUCCESS;
}
'';
in pkgs.runCommand "taskd-user" {} ''
cc -Wall -std=c11 "${runUser}" -o "$out"
'';
subcommands = {
list-users = {
args = [ "organisation" ];
description = [
"List all users belonging to the specified organisation."
];
script = ''
legend "The following users exist for $organisation:"
${pkgs.findutils}/bin/find \
"${config.dataDir}/orgs/$organisation/users" \
-mindepth 2 -maxdepth 2 -name config \
-exec ${pkgs.gnused}/bin/sed -ne 's/^user *= *//p' {} +
'';
};
list-orgs = {
args = [];
description = [
"List available organisations"
];
script = ''
legend "The following organisations exist:"
${pkgs.findutils}/bin/find \
"${config.dataDir}/orgs" -mindepth 1 -maxdepth 1 \
-type d
'';
};
get-uuid = {
args = [ "organisation" "user" ];
description = [
"Get the UUID of the specified user belonging to the specified"
"organisation."
];
script = ''
for uuid in "${config.dataDir}/orgs/$organisation/users"/*; do
usr="$(${pkgs.gnused}/bin/sed -ne 's/^user *= *//p' "$uuid/config")"
if [ "$usr" = "$user" ]; then
legend "User $user has the following UUID:"
echo "$(${pkgs.coreutils}/bin/basename "$uuid")"
exit 0
fi
done
echo "No UUID found for user $user." >&2
exit 1
'';
};
export-user = {
args = [ "organisation" "user" ];
description = [
"Export user of the specified organisation as a series of shell"
"commands that can be used on the client side to easily import"
"the certificates."
""
"Note that the private key will be exported as well, so use this"
"with care!"
];
script = ''
if ! subcmd_quiet list-users "$organisation" | grep -qxF "$user"; then
exists "User $user doesn't exist in organisation $organisation."
fi
uuid="$(subcmd_quiet get-uuid "$organisation" "$user")" || exit 1
cat <<COMMANDS
taskdatadir="\''${TASKDATA:-\$HOME/.task}"
umask 0077
mkdir -p "\$taskdatadir/keys"
cat > "\$taskdatadir/keys/public.cert" <<EOF
$(cat "${config.dataDir}/keys/user/$organisation/$user/public.cert")
EOF
cat > "\$taskdatadir/keys/private.key" <<EOF
$(${pkgs.gnused}/bin/sed -ne '/^---* *BEGIN /,/^---* *END /p' \
"${config.dataDir}/keys/user/$organisation/$user/private.key")
EOF
cat > "\$taskdatadir/keys/ca.cert" <<EOF
$(cat "${config.dataDir}/keys/ca.cert")
EOF
task config taskd.certificate -- "\$taskdatadir/keys/public.cert"
task config taskd.key -- "\$taskdatadir/keys/private.key"
task config taskd.ca -- "\$taskdatadir/keys/ca.cert"
task config taskd.credentials -- "$organisation/$user/$uuid"
COMMANDS
'';
};
add-org = {
args = [ "name" ];
description = [
"Create an organisation with the specified name."
];
script = ''
if [ -e "orgs/$name" ]; then
exists "Organisation with name $name already exists."
fi
${taskdUser} add org "$name"
'';
};
add-user = {
args = [ "organisation" "user" ];
description = [
"Create a user for the given organisation and print the UUID along"
"with the client certificate and key."
];
script = ''
if subcmd list-users "$organisation" | grep -qxF "$user"; then
exists "User $user already exists in organisation $organisation."
fi
${taskdUser} add user "$organisation" "$user"
${genClientKey}
'';
};
add-group = {
args = [ "organisation" "group" ];
description = [
"Create a group for the given organisation."
];
script = ''
if [ -e "orgs/$organisation/groups/$group" ]; then
exists "Group $group already exists in organisation $organisation."
fi
${taskdUser} add group "$organisation" "$group"
'';
};
};
mkCase = name: { args, ... }: let
mkPosArg = pos: lib.const "\"\$${toString (pos + 1)}\"";
cmdArgs = lib.concatImapStringsSep " " mkPosArg args;
in ''
${name})
if [ $# -ne ${toString ((lib.length args) + 1)} ]; then
echo "Wrong number of arguments to ${name}." >&2
echo >&2
usage_${mkShellName name}
exit 1
fi
subcmd "${name}" ${cmdArgs};;
'';
in pkgs.writeScriptBin commandName ''
#!${pkgs.stdenv.shell}
export TASKDDATA=${mkShellStr config.dataDir}
quiet=0
# Deliberately undocumented, because we don't want people to use this as
# it's only used in and specific to the preStart script of the Taskserver
# service.
if [ "$1" = "--service-helper" ]; then
quiet=1
exists() {
exit 0
}
shift
else
exists() {
echo "$@" >&2
exit 1
}
fi
legend() {
if [ $quiet -eq 0 ]; then
echo "$@" >&2
fi
}
subcmd() {
local cmdname="''${1//-/_}"
shift
"subcmd_$cmdname" "$@"
}
subcmd_quiet() {
local prev_quiet=$quiet
quiet=1
subcmd "$@"
local ret=$?
quiet=$prev_quiet
return $ret
}
${lib.concatStrings (lib.mapAttrsToList mkSubCommand subcommands)}
case "$1" in
${lib.concatStrings (lib.mapAttrsToList mkCase subcommands)}
*) echo "Usage: ${commandName} <subcommand> [<args>]" >&2
echo >&2
echo "A tool to manage taskserver users on NixOS" >&2
echo >&2
echo "The following subcommands are available:" >&2
${lib.concatMapStringsSep "\n " (c: "usage_${mkShellName c}")
(lib.attrNames subcommands)}
exit 1
esac
''

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@ -0,0 +1,276 @@
import grp
import pwd
import os
import re
import string
import subprocess
import sys
from shutil import rmtree
from tempfile import NamedTemporaryFile
import click
CERTTOOL_COMMAND = "@certtool@"
TASKD_COMMAND = "@taskd@"
TASKD_DATA_DIR = "@dataDir@"
TASKD_USER = "@user@"
TASKD_GROUP = "@group@"
FQDN = "@fqdn@"
RE_CONFIGUSER = re.compile(r'^\s*user\s*=(.*)$')
def run_as_taskd_user():
uid = pwd.getpwnam(TASKD_USER).pw_uid
gid = grp.getgrnam(TASKD_GROUP).gr_gid
os.setgid(gid)
os.setuid(uid)
def taskd_cmd(cmd, *args, **kwargs):
return subprocess.call(
[TASKD_COMMAND, cmd, "--data", TASKD_DATA_DIR] + list(args),
preexec_fn=run_as_taskd_user,
**kwargs
)
def label(msg):
if sys.stdout.isatty() or sys.stderr.isatty():
sys.stderr.write(msg + "\n")
def mkpath(*args):
return os.path.join(TASKD_DATA_DIR, "orgs", *args)
def fetch_username(org, key):
for line in open(mkpath(org, "users", key, "config"), "r"):
match = RE_CONFIGUSER.match(line)
if match is None:
continue
return match.group(1).strip()
return None
def generate_key(org, user):
basedir = os.path.join(TASKD_DATA_DIR, "keys", org, user)
if os.path.exists(basedir):
raise OSError("Keyfile directory for {} already exists.".format(user))
privkey = os.path.join(basedir, "private.key")
pubcert = os.path.join(basedir, "public.cert")
cakey = os.path.join(TASKD_DATA_DIR, "keys", "ca.key")
cacert = os.path.join(TASKD_DATA_DIR, "keys", "ca.cert")
try:
os.makedirs(basedir, mode=0700)
cmd = [CERTTOOL_COMMAND, "-p", "--bits", "2048", "--outfile", privkey]
subprocess.call(cmd, preexec_fn=lambda: os.umask(0077))
template = NamedTemporaryFile(mode="w", prefix="certtool-template")
template.writelines(map(lambda l: l + "\n", [
"organization = {0}".format(org),
"cn = {}".format(FQDN),
"tls_www_client",
"encryption_key",
"signing_key"
]))
template.flush()
cmd = [CERTTOOL_COMMAND, "-c",
"--load-privkey", privkey,
"--load-ca-privkey", cakey,
"--load-ca-certificate", cacert,
"--template", template.name,
"--outfile", pubcert]
subprocess.call(cmd, preexec_fn=lambda: os.umask(0077))
except:
rmtree(basedir)
raise
def is_key_line(line, match):
return line.startswith("---") and line.lstrip("- ").startswith(match)
def getkey(*args):
path = os.path.join(TASKD_DATA_DIR, "keys", *args)
buf = []
for line in open(path, "r"):
if len(buf) == 0:
if is_key_line(line, "BEGIN"):
buf.append(line)
continue
buf.append(line)
if is_key_line(line, "END"):
return ''.join(buf)
raise IOError("Unable to get key from {}.".format(path))
def mktaskkey(cfg, path, keydata):
heredoc = 'cat > "{}" <<EOF\n{}EOF'.format(path, keydata)
cmd = 'task config taskd.{} -- "{}"'.format(cfg, path)
return heredoc + "\n" + cmd
@click.group()
@click.option('--service-helper', is_flag=True)
@click.pass_context
def cli(ctx, service_helper):
"""
Manage Taskserver users and certificates
"""
ctx.obj = {'is_service_helper': service_helper}
@cli.command("list-users")
@click.argument("organisation")
def list_users(organisation):
"""
List all users belonging to the specified organisation.
"""
label("The following users exist for {}:".format(organisation))
for key in os.listdir(mkpath(organisation, "users")):
name = fetch_username(organisation, key)
if name is not None:
sys.stdout.write(name + "\n")
@cli.command("list-orgs")
def list_orgs():
"""
List available organisations
"""
label("The following organisations exist:")
for org in os.listdir(mkpath()):
sys.stdout.write(org + "\n")
@cli.command("get-uuid")
@click.argument("organisation")
@click.argument("user")
def get_uuid(organisation, user):
"""
Get the UUID of the specified user belonging to the specified organisation.
"""
for key in os.listdir(mkpath(organisation, "users")):
name = fetch_username(organisation, key)
if name is not None and name == user:
label("User {} has the following UUID:".format(name))
sys.stdout.write(key + "\n")
return
sys.exit("No UUID found for user {}.".format(user))
@cli.command("export-user")
@click.argument("organisation")
@click.argument("user")
def export_user(organisation, user):
"""
Export user of the specified organisation as a series of shell commands
that can be used on the client side to easily import the certificates.
Note that the private key will be exported as well, so use this with care!
"""
name = key = None
for current_key in os.listdir(mkpath(organisation, "users")):
name = fetch_username(organisation, current_key)
if name is not None and name == user:
key = current_key
break
if name is None:
msg = "User {} doesn't exist in organisation {}."
sys.exit(msg.format(user, organisation))
pubcert = getkey(organisation, user, "public.cert")
privkey = getkey(organisation, user, "private.key")
cacert = getkey("ca.cert")
keydir = "${TASKDATA:-$HOME/.task}/keys"
credentials = '/'.join([organisation, user, key])
allow_unquoted = string.ascii_letters + string.digits + "/-_."
if not all((c in allow_unquoted) for c in credentials):
credentials = "'" + credentials.replace("'", r"'\''") + "'"
script = [
"umask 0077",
'mkdir -p "{}"'.format(keydir),
mktaskkey("certificate", os.path.join(keydir, "public.cert"), pubcert),
mktaskkey("key", os.path.join(keydir, "private.key"), privkey),
mktaskkey("ca", os.path.join(keydir, "ca.cert"), cacert),
"task config taskd.credentials -- {}".format(credentials)
]
sys.stdout.write('\n'.join(script))
@cli.command("add-org")
@click.argument("name")
@click.pass_obj
def add_org(obj, name):
"""
Create an organisation with the specified name.
"""
if os.path.exists(mkpath(name)):
if obj['is_service_helper']:
return
msg = "Organisation with name {} already exists."
sys.exit(msg.format(name))
taskd_cmd("add", "org", name)
@cli.command("add-user")
@click.argument("organisation")
@click.argument("user")
@click.pass_obj
def add_user(obj, organisation, user):
"""
Create a user for the given organisation along with a client certificate
and print the key of the new user.
The client certificate along with it's public key can be shown via the
'export-user' subcommand.
"""
if not os.path.exists(mkpath(organisation)):
sys.exit("Organisation {} does not exist.".format(organisation))
if os.path.exists(mkpath(organisation, "users")):
for key in os.listdir(mkpath(organisation, "users")):
name = fetch_username(organisation, key)
if name is not None and name == user:
if obj['is_service_helper']:
return
msg = "User {} already exists in organisation {}."
sys.exit(msg.format(user, organisation))
taskd_cmd("add", "user", organisation, user)
generate_key(organisation, user)
@cli.command("add-group")
@click.argument("organisation")
@click.argument("group")
@click.pass_obj
def add_group(obj, organisation, group):
"""
Create a group for the given organisation.
"""
if os.path.exists(mkpath(organisation, "groups", group)):
if obj['is_service_helper']:
return
msg = "Group {} already exists in organisation {}."
sys.exit(msg.format(group, organisation))
taskd_cmd("add", "group", organisation, group)
if __name__ == '__main__':
cli()