Run processes without screen
This introduces new run_process() and screen_service() functions and sets the
groundwork to change how DevStack starts services. screen_service() is simply a
direct call to the screen portion of the old screen_it() function and is intended
to run commands that only need to run under screen, such as log file watchers.
run_process() is a replacement for screen_it() (which remains until all of the
services are updated). The usage is similar but requires updates to every current
screen_it() call to remove everything that requires the command to be interpreted
by a shell.
The old run_process() and _run_process() functions are still present as
old_run_process() and _old_run_process() to support the deprecated screen_it()
function. These will all go away in the future once all services have been
confirmed to have been changed over.
There is a similar new set of stop process functions stop_process() and
screen_stop_service(). The old screen_stop() will also remain for the deprecation
period.
As an initial test/demostration this review also includes the changes for
lib/cinder to demonstrate what is required for every service.
I included the scripts I used to test this; tests/fake-service.sh and
tests/run-process.sh are quite rough around the edges and may bite. They should
mature into productive members of the testing ecosystem someday.
Change-Id: I03322bf0208353ebd267811735c66f13a516637b
diff --git a/tests/run-process.sh b/tests/run-process.sh
new file mode 100755
index 0000000..cdffc3a
--- /dev/null
+++ b/tests/run-process.sh
@@ -0,0 +1,109 @@
+#!/bin/bash
+# tests/exec.sh - Test DevStack screen_it() and screen_stop()
+#
+# exec.sh start|stop|status
+#
+# Set USE_SCREEN to change the default
+#
+# This script emulates the basic exec envirnment in ``stack.sh`` to test
+# the process spawn and kill operations.
+
+if [[ -z $1 ]]; then
+ echo "$0 start|stop"
+ exit 1
+fi
+
+TOP_DIR=$(cd $(dirname "$0")/.. && pwd)
+source $TOP_DIR/functions
+
+USE_SCREEN=${USE_SCREEN:-False}
+
+ENABLED_SERVICES=fake-service
+
+SERVICE_DIR=/tmp
+SCREEN_NAME=test
+SCREEN_LOGDIR=${SERVICE_DIR}/${SCREEN_NAME}
+
+
+# Kill background processes on exit
+trap clean EXIT
+clean() {
+ local r=$?
+ jobs -p
+ kill >/dev/null 2>&1 $(jobs -p)
+ exit $r
+}
+
+
+# Exit on any errors so that errors don't compound
+trap failed ERR
+failed() {
+ local r=$?
+ jobs -p
+ kill >/dev/null 2>&1 $(jobs -p)
+ set +o xtrace
+ [ -n "$LOGFILE" ] && echo "${0##*/} failed: full log in $LOGFILE"
+ exit $r
+}
+
+function status {
+ if [[ -r $SERVICE_DIR/$SCREEN_NAME/fake-service.pid ]]; then
+ pstree -pg $(cat $SERVICE_DIR/$SCREEN_NAME/fake-service.pid)
+ fi
+ ps -ef | grep fake
+}
+
+function setup_screen {
+if [[ ! -d $SERVICE_DIR/$SCREEN_NAME ]]; then
+ rm -rf $SERVICE_DIR/$SCREEN_NAME
+ mkdir -p $SERVICE_DIR/$SCREEN_NAME
+fi
+
+if [[ "$USE_SCREEN" == "True" ]]; then
+ # Create a new named screen to run processes in
+ screen -d -m -S $SCREEN_NAME -t shell -s /bin/bash
+ sleep 1
+
+ # Set a reasonable status bar
+ if [ -z "$SCREEN_HARDSTATUS" ]; then
+ SCREEN_HARDSTATUS='%{= .} %-Lw%{= .}%> %n%f %t*%{= .}%+Lw%< %-=%{g}(%{d}%H/%l%{g})'
+ fi
+ screen -r $SCREEN_NAME -X hardstatus alwayslastline "$SCREEN_HARDSTATUS"
+fi
+
+# Clear screen rc file
+SCREENRC=$TOP_DIR/tests/$SCREEN_NAME-screenrc
+if [[ -e $SCREENRC ]]; then
+ echo -n > $SCREENRC
+fi
+}
+
+# Mimic logging
+ # Set up output redirection without log files
+ # Copy stdout to fd 3
+ exec 3>&1
+ if [[ "$VERBOSE" != "True" ]]; then
+ # Throw away stdout and stderr
+ #exec 1>/dev/null 2>&1
+ :
+ fi
+ # Always send summary fd to original stdout
+ exec 6>&3
+
+
+if [[ "$1" == "start" ]]; then
+ echo "Start service"
+ setup_screen
+ screen_it fake-service "$TOP_DIR/tests/fake-service.sh"
+ sleep 1
+ status
+elif [[ "$1" == "stop" ]]; then
+ echo "Stop service"
+ screen_stop fake-service
+ status
+elif [[ "$1" == "status" ]]; then
+ status
+else
+ echo "Unknown command"
+ exit 1
+fi