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#!/bin/bash
# Copyright 2015 The Vanadium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style
# license that can be found in the LICENSE file.
# The shell library is used to execute veyron shell scripts.
# IMPORTANT: If your script registers its own "trap" handler, that handler must
# call shell::at_exit to clean up all temporary files and directories created by
# this library.
set -e
set -u
TMPDIR="${TMPDIR-/tmp}"
V23_SHELL_TMP_DIRS=${V23_SHELL_TMP_DIRS-$(mktemp "${TMPDIR}/XXXXXXXX")}
V23_SHELL_TMP_FILES=${V23_SHELL_TMP_FILES-$(mktemp "${TMPDIR}/XXXXXXXX")}
V23_SHELL_TMP_PIDS=${V23_SHELL_TMP_PIDS-$(mktemp "${TMPDIR}/XXXXXXXX")}
trap shell::at_exit INT TERM EXIT
# When a user of this library needs cleanup to be performed by root
# because different processes are running with different system
# identities, it should set this variable to root to escalate
# privilege appropriately.
SUDO_USER="$(whoami)"
# shell::at_exit is executed when the shell script exits. It is used,
# for example, to garbage collect any temporary files and directories
# created by invocations of shell::tmp_file and shell:tmp_dir.
shell::at_exit() {
# If the variable V23_SHELL_CMD_LOOP_AT_EXIT is non-empty, accept commands
# from the user in a command loop. This can preserve the state in the logs
# directories while the user examines them.
case "${V23_SHELL_CMD_LOOP_AT_EXIT-}" in
?*)
local cmdline
set +u
echo 'Entering debug shell. Type control-D or "exit" to exit.' >&2
while echo -n "test> " >&2; read cmdline; do
eval "$cmdline"
done
set -u
;;
esac
# Unset the trap so that it doesn't run again on exit.
trap - INT TERM EXIT
for pid in $(cat "${V23_SHELL_TMP_PIDS}"); do
sudo -u "${SUDO_USER}" kill "${pid}" &> /dev/null || true
done
for tmp_dir in $(cat "${V23_SHELL_TMP_DIRS}"); do
sudo -u "${SUDO_USER}" rm -rf "${tmp_dir}" &>/dev/null
done
for tmp_file in $(cat "${V23_SHELL_TMP_FILES}"); do
sudo -u "${SUDO_USER}" rm -f "${tmp_file}" &>/dev/null
done
sudo -u "${SUDO_USER}" rm -f "${V23_SHELL_TMP_DIRS}" "${V23_SHELL_TMP_FILES}" "${V23_SHELL_TMP_PIDS}" &>/dev/null
}
# shell::kill_child_processes kills all child processes.
# Note, child processes must set their own "at_exit: kill_child_processes"
# signal handlers in order for this to kill their descendants.
shell::kill_child_processes() {
# Attempt to shutdown child processes by sending the TERM signal.
if [[ -n "$(jobs -p -r)" ]]; then
shell::silence pkill -P $$
sleep 1
# Force shutdown of any remaining child processes using the KILL signal.
# Note, we only "sleep 1" and "kill -9" if there were child processes.
if [[ -n "$(jobs -p -r)" ]]; then
shell::silence sudo -u "${SUDO_USER}" pkill -9 -P $$
fi
fi
}
# shell::check_deps can be used to check which dependencies are
# missing on the host.
#
# Example:
# local -r DEPS=$(shell::check_deps git golang-go)
# if [[ -n "${DEPS} ]]; then
# sudo apt-get install $DEPS
# fi
shell::check_deps() {
local RESULT=""
case $(uname -s) in
"Linux")
set +e
for pkg in "$@"; do
dpkg -s "${pkg}" &> /dev/null
if [[ "$?" -ne 0 ]]; then
RESULT+=" ${pkg}"
fi
done
set -e
;;
"Darwin")
set +e
for pkg in "$@"; do
if [[ -z "$(brew ls --versions ${pkg})" ]]; then
RESULT+=" ${pkg}"
fi
done
set -e
;;
*)
echo "Operating system $(uname -s) is not supported."
exit 1
esac
echo "${RESULT}"
}
# shell::check_result can be used to obtain the exit status of a bash
# command. By the semantics of "set -e", a script exits immediately
# upon encountering a command that fails. This function should be used
# if instead, a script wants to take an action depending on the exit
# status.
#
# Example:
# local -r RESULT=$(shell::check_result <command>)
# if [[ "${RESULT}" -ne 0 ]]; then
# <handle failure>
# else
# <handle success>
# fi
shell::check_result() {
set +e
"$@" &> /dev/null
echo "$?"
set -e
}
# shell::tmp_dir can be used to create a temporary directory.
#
# Example:
# local -R TMP_DIR=$(shell::tmp_dir)
shell::tmp_dir() {
local -r RESULT=$(mktemp -d "${TMPDIR}/XXXXXXXX")
echo "${RESULT}" >> "${V23_SHELL_TMP_DIRS}"
echo "${RESULT}"
}
# shell::tmp_file can be used to create a temporary file.
#
# Example:
# local -R TMP_FILE=$(shell::tmp_file)
shell::tmp_file() {
local -r RESULT=$(mktemp "${TMPDIR}/XXXXXXXX")
echo "${RESULT}" >> "${V23_SHELL_TMP_FILES}"
echo "${RESULT}"
}
# shell::run_server is used to start a long running server process and
# to verify that it is still running after a set timeout period. This
# is useful for catching cases where the server either fails to start or
# fails soon after it has started.
# The script will return 0 if the command is running at that point in time
# and a non-zero value otherwise. It echos the server's pid.
#
# Example:
# shell::run_server 5 stdout stderr command arg1 arg2 || exit 1
shell::run_server() {
local -r TIMEOUT="$1"
local -r STDOUT="$2"
local -r STDERR="$3"
shift; shift; shift
if [[ "${STDOUT}" = "${STDERR}" ]]; then
"$@" > "${STDOUT}" 2>&1 &
else
"$@" > "${STDOUT}" 2> "${STDERR}" &
fi
local -r SERVER_PID=$!
echo "${SERVER_PID}" >> "${V23_SHELL_TMP_PIDS}"
echo "${SERVER_PID}"
for i in $(seq 1 "${TIMEOUT}"); do
sleep 1
local RESULT=$(shell::check_result kill -0 "${SERVER_PID}")
if [[ "${RESULT}" = "0" ]]; then
# server's up, can return early
return 0
fi
done
return "${RESULT}"
}
# shell::timed_wait_for is used to wait until the given pattern appears
# in the given file within a set timeout. It returns 0 if the pattern
# was successfully matched and 1 if the timeout expires before the pattern
# is found.
#
# Example:
# local -r LOG_FILE=$(shell::tmp_file)
# shell::run_server 1 "${LOG_FILE}" "${LOG_FILE}" <server> <args>...
# shell::timed_wait_for 1 "${LOG_FILE}" "server started"
shell::timed_wait_for() {
local -r TIMEOUT="$1"
local -r FILE="$2"
local -r PATTERN="$3"
for i in $(seq 1 "${TIMEOUT}"); do
sleep 1
grep -m 1 "${PATTERN}" "${FILE}" > /dev/null && return 0 || true
done
# grep has timed out.
echo "Timed out. Here's the file:"
echo "====BEGIN FILE==="
cat "${FILE}"
echo "====END FILE==="
return 1
}
# shell::silence runs the given command with the supplied arguments,
# redirecting all of its output to /dev/null and ignoring its exit
# code.
shell::silence() {
"$@" &> /dev/null || true
}