Add run_process() to start services without screen
* USE_SCREEN defaults to True, set it to False to exec the services
directly via bash. SCREEN_DEV is still supported until the CI
scripts get updated.
* The extra logging file descriptors are properly closed in the child process
and stdout/stderr are redirected to the log files.
* The screen_rc() call is still present; this means that stack-screenrc will
have a complete record of what was started and rejoin-stack.sh may be able
to re-create the setup under screen.
* The python interpreter was unwilling to write to the log files without
unbufering stdout by using PYTHONUNBUFFERED. This feels hackish and should
be investigated further.
Change-Id: I012ed049f2c8b185a2e6929d73edc29e167bc21f
diff --git a/functions b/functions
index b94c611..d8b87d4 100644
--- a/functions
+++ b/functions
@@ -735,26 +735,69 @@
}
+# _run_process() is designed to be backgrounded by run_process() to simulate a
+# fork. It includes the dirty work of closing extra filehandles and preparing log
+# files to produce the same logs as screen_it(). The log filename is derived
+# from the service name and global-and-now-misnamed SCREEN_LOGDIR
+# _run_process service "command-line"
+function _run_process() {
+ local service=$1
+ local command="$2"
+
+ # Undo logging redirections and close the extra descriptors
+ exec 1>&3
+ exec 2>&3
+ exec 3>&-
+ exec 6>&-
+
+ if [[ -n ${SCREEN_LOGDIR} ]]; then
+ exec 1>&${SCREEN_LOGDIR}/screen-${1}.${CURRENT_LOG_TIME}.log 2>&1
+ ln -sf ${SCREEN_LOGDIR}/screen-${1}.${CURRENT_LOG_TIME}.log ${SCREEN_LOGDIR}/screen-${1}.log
+
+ # TODO(dtroyer): Hack to get stdout from the Python interpreter for the logs.
+ export PYTHONUNBUFFERED=1
+ fi
+
+ exec /bin/bash -c "$command"
+ die "$service exec failure: $command"
+}
+
+
+# run_process() launches a child process that closes all file descriptors and
+# then exec's the passed in command. This is meant to duplicate the semantics
+# of screen_it() without screen. PIDs are written to
+# $SERVICE_DIR/$SCREEN_NAME/$service.pid
+# run_process service "command-line"
+function run_process() {
+ local service=$1
+ local command="$2"
+
+ # Spawn the child process
+ _run_process "$service" "$command" &
+ echo $!
+}
+
+
# Helper to launch a service in a named screen
# screen_it service "command-line"
function screen_it {
SCREEN_NAME=${SCREEN_NAME:-stack}
SERVICE_DIR=${SERVICE_DIR:-${DEST}/status}
- SCREEN_DEV=`trueorfalse True $SCREEN_DEV`
+ USE_SCREEN=$(trueorfalse True $USE_SCREEN)
if is_service_enabled $1; then
# Append the service to the screen rc file
screen_rc "$1" "$2"
- screen -S $SCREEN_NAME -X screen -t $1
+ if [[ "$USE_SCREEN" = "True" ]]; then
+ screen -S $SCREEN_NAME -X screen -t $1
- if [[ -n ${SCREEN_LOGDIR} ]]; then
- screen -S $SCREEN_NAME -p $1 -X logfile ${SCREEN_LOGDIR}/screen-${1}.${CURRENT_LOG_TIME}.log
- screen -S $SCREEN_NAME -p $1 -X log on
- ln -sf ${SCREEN_LOGDIR}/screen-${1}.${CURRENT_LOG_TIME}.log ${SCREEN_LOGDIR}/screen-${1}.log
- fi
+ if [[ -n ${SCREEN_LOGDIR} ]]; then
+ screen -S $SCREEN_NAME -p $1 -X logfile ${SCREEN_LOGDIR}/screen-${1}.${CURRENT_LOG_TIME}.log
+ screen -S $SCREEN_NAME -p $1 -X log on
+ ln -sf ${SCREEN_LOGDIR}/screen-${1}.${CURRENT_LOG_TIME}.log ${SCREEN_LOGDIR}/screen-${1}.log
+ fi
- if [[ "$SCREEN_DEV" = "True" ]]; then
# sleep to allow bash to be ready to be send the command - we are
# creating a new window in screen and then sends characters, so if
# bash isn't running by the time we send the command, nothing happens
@@ -763,7 +806,8 @@
NL=`echo -ne '\015'`
screen -S $SCREEN_NAME -p $1 -X stuff "$2 || touch \"$SERVICE_DIR/$SCREEN_NAME/$1.failure\"$NL"
else
- screen -S $SCREEN_NAME -p $1 -X exec /bin/bash -c "$2 || touch \"$SERVICE_DIR/$SCREEN_NAME/$1.failure\""
+ # Spawn directly without screen
+ run_process "$1" "$2" >$SERVICE_DIR/$SCREEN_NAME/$service.pid
fi
fi
}