Tests: Do not use `lttng_pgrep` when testing working directory

This allows the tests to avoid modifying other lttng-relayds that may
be running on the system (e.g., during parallel testing).

Change-Id: I3736d96f54f3da2b887d88526f60056a020528a2
Signed-off-by: Kienan Stewart <kstewart@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

diff --git a/tests/regression/tools/working-directory/test_relayd_working_directory b/tests/regression/tools/working-directory/test_relayd_working_directory
index b66ea0d250f0880fc9005c83bcced51a6916d2f5..9509820134475240326dcb5ac784db641e80d20b 100755 (executable)
--- a/tests/regression/tools/working-directory/test_relayd_working_directory
+++ b/tests/regression/tools/working-directory/test_relayd_working_directory
@@ -11,7 +11,7 @@ TESTDIR=$CURDIR/../../../
 
 DIR=$(readlink -f "$TESTDIR")
 
-NUM_TESTS=35
+NUM_TESTS=36
 
 source $TESTDIR/utils/utils.sh
 
@@ -26,30 +26,18 @@ function test_relayd()
        local pid
        local cwd
 
-
        diag "Test lttng-relayd normal mode change working directory"
+       start_lttng_relayd "--working-directory $working_dir"
+       # When the relayd is successfully started, the PID will be appended
+       # to `LTTNG_RELAYD_PIDS`. Use the last (most recent) PID for checking
+       # the working directory. If relayd fails to start, there will be either
+       # no PID, or a different lttng-relayd PID without the same working
+       # directory and the test will fail.
+       pid="${LTTNG_RELAYD_PIDS[-1]}"
 
-       # There is no rendez-vous mechanism that can guarantee the good timing
-       # to check if the workdir directory was changed.
-       # In the case of lttng-sessiond this would be achieved using the
-       # --sig-parent option but lttng-relayd does not have this feature yet.
-       # Fall back on using polling of the value and unblock when the value is
-       # the one we expect. In case of a failure the test will hang.
-       $relayd_bin_path --working-directory "$working_dir" > /dev/null 2>&1 &
-       pid=$!
-       LTTNG_RELAYD_PIDS+=($pid)
-
-       while true; do
-               cwd=$(readlink "/proc/${pid}/cwd")
-               if test "$working_dir" = "$cwd"; then
-                       # Working dir for process is valid
-                       break
-               fi
-               sleep 0.1
-       done
-
-       # If we are here the test passed
-       pass "Working directory changed"
+       cwd=$(readlink "/proc/${pid}/cwd")
+       test "$working_dir" = "$cwd"
+       ok "${?}" "Working directory changed"
 
        stop_lttng_relayd
        rm -rf "$working_dir"
@@ -64,12 +52,16 @@ function test_relayd_daemon()
        diag "Test lttng-relayd daemon mode change working directory"
 
        start_lttng_relayd_opt 1 "-d" "--working-directory $working_dir"
-
-       pid=$(lttng_pgrep "$RELAYD_MATCH")
+       # When the relayd is successfully started, the PID will be appended
+       # to `LTTNG_RELAYD_PIDS`. Use the last (most recent) PID for checking
+       # the working directory. If relayd fails to start, there will be either
+       # no PID, or a different lttng-relayd PID without the same working
+       # directory and the test will fail.
+       pid="${LTTNG_RELAYD_PIDS[-1]}"
+       ps -p "${pid}" >/dev/null
        ok $? "Found lttng-relayd"
 
        cwd=$(readlink "/proc/${pid}/cwd")
-
        is "${cwd:-no working directory found}" "$working_dir" "Working directory changed"
 
        stop_lttng_relayd
@@ -84,9 +76,14 @@ function test_relayd_daemon_no_working_dir()
 
        diag "Test lttng-relayd daemon mode change working directory"
 
-       start_lttng_relayd_opt 1 "-d" ""
-
-       pid=$(lttng_pgrep "$RELAYD_MATCH")
+       start_lttng_relayd_opt 1 "-d"
+       # When the relayd is successfully started, the PID will be appended
+       # to `LTTNG_RELAYD_PIDS`. Use the last (most recent) PID for checking
+       # the working directory. If relayd fails to start, there will be either
+       # no PID, or a different lttng-relayd PID without the same working
+       # directory and the test will fail.
+       pid="${LTTNG_RELAYD_PIDS[-1]}"
+       ps -p $pid >/dev/null
        ok $? "Found lttng-relayd"
 
        cwd=$(readlink "/proc/${pid}/cwd")
@@ -105,8 +102,13 @@ function test_relayd_background()
        diag "Test lttng-relayd background mode change working directory"
 
        start_lttng_relayd_opt 1 "-b" "--working-directory $working_dir"
-
-       pid=$(lttng_pgrep "$RELAYD_MATCH")
+       # When the relayd is successfully started, the PID will be appended
+       # to `LTTNG_RELAYD_PIDS`. Use the last (most recent) PID for checking
+       # the working directory. If relayd fails to start, there will be either
+       # no PID, or a different lttng-relayd PID without the same working
+       # directory and the test will fail.
+       pid="${LTTNG_RELAYD_PIDS[-1]}"
+       ps -p "${pid}" >/dev/null
        ok $? "Found lttng-relayd"
 
        cwd=$(readlink "/proc/${pid}/cwd")
@@ -124,9 +126,14 @@ function test_relayd_background_no_working_dir()
 
        diag "Test lttng-relayd background working directory"
 
-       start_lttng_relayd_opt 1 "-b" ""
-
-       pid=$(lttng_pgrep "$RELAYD_MATCH")
+       start_lttng_relayd_opt 1 "-b"
+       # When the relayd is successfully started, the PID will be appended
+       # to `LTTNG_RELAYD_PIDS`. Use the last (most recent) PID for checking
+       # the working directory. If relayd fails to start, there will be either
+       # no PID, or a different lttng-relayd PID without the same working
+       # directory and the test will fail.
+       pid="${LTTNG_RELAYD_PIDS[-1]}"
+       ps -p "${pid}" >/dev/null
        ok $? "Found lttng-relayd"
 
        cwd=$(readlink "/proc/${pid}/cwd")
@@ -162,8 +169,13 @@ function test_relayd_debug_permission()
 
                RELAYD_ERROR_OUTPUT_DEST=$(mktemp -t "tmp.${FUNCNAME[0]}_error_output.XXXXXX")
                start_lttng_relayd_opt 1 "-b" "-v --working-dir $working_dir"
-
-               pid=$(lttng_pgrep "$RELAYD_MATCH")
+               # When the relayd is successfully started, the PID will be appended
+               # to `LTTNG_RELAYD_PIDS`. Use the last (most recent) PID for checking
+               # the working directory. If relayd fails to start, there will be either
+               # no PID, or a different lttng-relayd PID without the same working
+               # directory and the test will fail.
+               pid="${LTTNG_RELAYD_PIDS[-1]}"
+               ps -p "${pid}" > /dev/null
                ok $? "Found lttng-relayd"
 
                cwd=$(readlink "/proc/${pid}/cwd")
@@ -193,11 +205,14 @@ function test_relayd_failure()
 
        diag "Test lttng-relayd normal mode change non-existing directory"
 
-       $relayd_bin_path -b --working-directory "$working_dir_imaginary" > "$output_dest" 2>&1
+       RELAYD_ERROR_OUTPUT_DEST="${output_dest}" start_lttng_relayd_opt 0 -b "--working-directory $working_dir_imaginary"
        test $? -eq "1"
        ok $? "Expect failure to start lttng-relayd for non-existent working directory"
 
-       pid=$(lttng_pgrep "$RELAYD_MATCH")
+       # When the relayd is successfully started, the PID will be appended
+       # to `LTTNG_RELAYD_PIDS`. Use the last (most recent) PID for checking
+       # the working directory. If relayd fails to start, there will be no PID.
+       pid="${LTTNG_RELAYD_PIDS[-1]}"
        if [ -z "$pid" ]; then
                pass "No lttng-relayd present"
        else
@@ -208,8 +223,7 @@ function test_relayd_failure()
        grep -q "$output_pattern" "$output_dest"
        ok $? "Found error message: invalid directory"
 
-       rm "$output_dest"
-       rm -rf "$working_dir"
+       rm -rf "$working_dir" "${output_dest}"
 }
 
 function test_relayd_env()
@@ -221,9 +235,15 @@ function test_relayd_env()
        diag "Test lttng-relayd change working directory from env. variable"
 
        export LTTNG_RELAYD_WORKING_DIRECTORY=${working_dir}
-       start_lttng_relayd_opt 1 "-b" ""
-
-       pid=$(lttng_pgrep "$RELAYD_MATCH")
+       start_lttng_relayd_opt 1 "-b"
+
+       # When the relayd is successfully started, the PID will be appended
+       # to `LTTNG_RELAYD_PIDS`. Use the last (most recent) PID for checking
+       # the working directory. If relayd fails to start, there will be either
+       # no PID, or a different lttng-relayd PID without the same working
+       # directory and the test will fail.
+       pid="${LTTNG_RELAYD_PIDS[-1]}"
+       ps -p "${pid}" >/dev/null
        ok $? "Found lttng-relayd"
 
        cwd=$(readlink "/proc/$pid/cwd")
@@ -246,7 +266,13 @@ function test_relayd_cmdline_overwrite_env()
        export LTTNG_RELAYD_WORKING_DIRECTORY=${working_dir_env}
        start_lttng_relayd_opt 1 "-b" "--working-dir ${working_dir_cmdline}"
 
-       pid=$(lttng_pgrep "$RELAYD_MATCH")
+       # When the relayd is successfully started, the PID will be appended
+       # to `LTTNG_RELAYD_PIDS`. Use the last (most recent) PID for checking
+       # the working directory. If relayd fails to start, there will be either
+       # no PID, or a different lttng-relayd PID without the same working
+       # directory and the test will fail.
+       pid="${LTTNG_RELAYD_PIDS[-1]}"
+       ps -p "${pid}" >/dev/null
        ok $? "Found lttng-relayd"
 
        cwd=$(readlink "/proc/$pid/cwd")