Changed the requires file to take 'before' and 'after' parameters to declare forward and backward dependencies. Declaring 'before' will FORCE the listed module to be installed along with this one. See the docs.

balls/groups/requires

@@ -1 +1,2 @@
-entities
+after entities
+before users

balls/users/requires

@@ -1,2 +1 @@
-entities
+after entities
-groups

client/bin/disco

@@ -47,22 +47,39 @@ function dance() {
 	exit 1
     fi
 
-    # Create the toposort of all the modules
+    # Create the toposort of all the modules and fetch all their metadata
-    for module in $(disco-param keys $(hostname)/modules)
+    # This also includes fetching modules that aren't explicitly called out in
-    do
+    # our class list, but are required by 'before' statements in the requires files.
-	NOOP="true" disco-ball fetch $module
+    rm -f /tmp/$$.tsort
-	disco-ball requires $module >> /tmp/$$.tsort
+    disco-param keys $(hostname)/modules | tac > /tmp/$$.modules.prev
+    NEWBALLS=$(cat /tmp/$$.modules.prev)
+    while [ "$NEWBALLS" != "" ]; do
+	for module in $NEWBALLS
+	do
+	    NOOP="true" disco-ball fetch $module
+	    disco-ball requires $module >> /tmp/$$.tsort
+	    cat /tmp/$$.tsort | tsort | tac > /tmp/$$.modules.new
+	done
+	NEWBALLS=$(diff /tmp/$$.modules.prev /tmp/$$.modules.new | grep "^> " | cut -d " " -f 2-)
+	cp /tmp/$$.modules.new /tmp/$$.modules.prev
+	if [ "$NEWBALLS" != "" ]; then
+	    echo "info: Discovered dependency : ${module} : $(echo -n ${NEWBALLS} | sed s/' '/', '/g)"
+	fi
     done
 
-    for module in $(cat /tmp/$$.tsort | tsort | tac)
+    echo "info: Ready to dance :"
-    do
+    cat /tmp/$$.tsort | tsort | tac | sed s/"^"/"info:        "/g
-	disco-ball spin ${module}
+
-    done
+#    for module in $(cat /tmp/$$.tsort | tsort | tac)
+#    do
+#	disco-ball spin ${module}
+#    done
 
     if [ "$REPORT" != "" ]; then
 	report
     fi
 
+    #rm -f /tmp/$$.*
 }
 
 $1 "$2" "$3" "$4" "$5" "$6" "$7" "$8" "$9"

universe/bin/disco-ball

@@ -31,38 +31,86 @@ function fetch_params() {
     return $RETVAL
 }
 
+function params() {
+    if [ "$1" == "" ]; then
+	echo "Must pass a module name to fetch data for"
+	return 1
+    fi
+    mkdir -p ${DISCOROOT}/reports/$1
+    rm -f ${DISCOROOT}/reports/${1}/params
+    /usr/bin/time -f "$TIME" -o ${DISCOROOT}/reports/$1/params \
+	rsync -aWH ${STORAGE}/parameters/* ${DISCOROOT}/parameters/$(hostname)/
+    return $?
+}
+
 function fetch() {
     if [ "$1" == "" ]; then
-	echo "Must pass a module name to fetch"
+	echo "Must pass a module name to fetch data for"
 	return 1
     fi
+    SRC="${SERVERURI}::${1}"
+    if [ "$2" != "" ]; then
+	SRC="$2"
+    fi
     if [ "$NOOP" == "" ]; then
 	DEST=/var/disco/testfs/real/scratchfs
     else
 	DEST=/var/disco/testfs/noop/scratchfs
     fi
+
     rm -rf ${STORAGE}/${1}
     mkdir -p ${DISCOROOT}/reports/$1
     rm -f ${DISCOROOT}/reports/${1}/fetch
     # Sometimes there's some shell escaping voodoo and rsync doesn't like the command args some people will pass it straight on
     # the command line; so we wrap it in a little bash script, and everyone's happy.
-    echo ${RSYNC} ${SERVERURI}::${1}/files/* ${DEST} > /tmp/$$.sh
+    echo ${RSYNC} --delete ${SRC}/requires ${SRC}/scripts ${SRC}/parameters ${SRC}/templates ${STORAGE}/${1} > /tmp/$$.sh
-    echo ${RSYNC} --delete ${SERVERURI}::${1}/requires ${SERVERURI}::${1}/scripts ${SERVERURI}::${1}/parameters ${SERVERURI}::${1}/templates ${STORAGE}/${1} >> /tmp/$$.sh
     echo 'exit $?' >> /tmp/$$.sh
-    /usr/bin/time -f "$TIME" -o ${DISCOROOT}/reports/${1}/fetch /tmp/$$.sh 2>/tmp/$$.errors | sed s/"^"/"info: ${1}: "/g
+    /usr/bin/time -f "$TIME" -o ${DISCOROOT}/reports/${1}/fetch /bin/bash /tmp/$$.sh 2>/tmp/$$.errors | sed s/"^"/"info: ${1}: "/g
     cat /tmp/$$.errors | grep -v "some files/attrs were not transferred" | sed s/"^"/"error: ${1}: "/g
     RETVAL=$?
     rm -f /tmp/$$.sh
     return $RETVAL
 }
 
+function files() {
+    if [ "$1" == "" ]; then
+	echo "Must pass a module name to retrieve files for"
+	return 1
+    fi
+    SRC="${SERVERURI}::${1}"
+    if [ "$2" != "" ]; then
+	SRC="$2"
+    fi
+    if [ "$NOOP" == "" ]; then
+	DEST=/var/disco/testfs/real/scratchfs
+    else
+	DEST=/var/disco/testfs/noop/scratchfs
+    fi
+
+    mkdir -p ${DISCOROOT}/reports/$1
+    rm -f ${DISCOROOT}/reports/${1}/files
+    # Sometimes there's some shell escaping voodoo and rsync doesn't like the command args some people will pass it straight on
+    # the command line; so we wrap it in a little bash script, and everyone's happy.
+    echo ${RSYNC} ${SRC}/files/* ${DEST} > /tmp/$$.sh
+    echo 'exit $?' >> /tmp/$$.sh
+    /usr/bin/time -f "$TIME" -o ${DISCOROOT}/reports/${1}/files /bin/bash /tmp/$$.sh 2>/tmp/$$.errors | sed s/"^"/"info: ${1}: "/g
+    cat /tmp/$$.errors | grep -v "some files/attrs were not transferred" | sed s/"^"/"error: ${1}: "/g
+    RETVAL=$?
+    rm -f /tmp/$$.sh
+    return $RETVAL
+}
+
+
 function requires()
 {
     if [ "$1" == "" ]; then
 	echo "Must pass a module name for requirements"
 	return 1
     fi
-    cat ${STORAGE}/${1}/requires | sed s/"^"/"${1} "/g
+    cat ${STORAGE}/${1}/requires 2>/dev/null |\
+        grep -v "^#" |\
+        sed -e s/"^ *after"/"${1} "/g \
+            -e s/"^ *before *\([a-zA-Z0-9\-_\.]*\)"/"\1 ${1}"/g
 }
 
 function exec() {
@@ -117,6 +165,7 @@ function template() {
 function spin() {
     module=$1
     echo "info: Processing ${module}"
+    NOOP="true" files $module
     NOOP="true" template $module
     if [ "$NOOP" == "" ]; then
 	# We rsync all the configs and files into the 'real' scratchfs so that we can
@@ -146,4 +195,4 @@ function spin() {
     return $?
 }
 
-$1 $2
+$1 "$2" "$3" "$4" "$5" "$6" "$7" "$8"