MINOR: reg-tests: add a way to add service dependency

I was looking at writing a simple first test for prometheus but I
realised there is no proper way to exclude it if haproxy was not built
with prometheus plugin.

Today we have `REQUIRE_OPTIONS` in reg-tests which is based on `Feature
list` from `haproxy -vv`. Those options are coming from the Makefile
itself.

A plugin is build this way:
  EXTRA_OBJS="contrib/prometheus-exporter/service-prometheus.o"

It does register service actions through `service_keywords_register`.
Those are listed through `list_services` in `haproxy -vv`.
To facilitate parsing, I slightly changed the output to a single line
and integrate it in regtests shell script so that we can now specify a
dependency while writing a reg-test for prometheus, e.g:

  #REQUIRE_SERVICE=prometheus-exporter
  #REQUIRE_SERVICES=prometheus-exporter,foo

There might be other ways to handle this, but that's the cleanest I
found; I understand people might be concerned by this output change in
`haproxy -vv` which goes from:

  Available services :
          foo
          bar

to:

  Available services : foo bar

Signed-off-by: William Dauchy <wdauchy@gmail.com>

scripts/run-regtests.sh

@@ -56,9 +56,11 @@ _help()
 
     # Below option is required to complete this test successfully
     #REQUIRE_OPTION=OPENSSL, this test needs OPENSSL compiled in.
-
     #REQUIRE_OPTIONS=ZLIB|SLZ,OPENSSL,LUA
 
+    #REQUIRE_SERVICE=prometheus-exporter
+    #REQUIRE_SERVICES=prometheus-exporter,foo
+
     # To define a range of versions that a test can run with:
     #REQUIRE_VERSION=0.0
     #REQUIRE_VERSION_BELOW=99.9
@@ -133,6 +135,7 @@ _findtests() {
     require_version="$(sed -ne 's/^#REQUIRE_VERSION=//p' "$i")"
     require_version_below="$(sed -ne 's/^#REQUIRE_VERSION_BELOW=//p' "$i")"
     require_options="$(sed -ne 's/^#REQUIRE_OPTIONS=//p' "$i" | sed  -e 's/,/ /g')"
+    require_services="$(sed -ne 's/^#REQUIRE_SERVICES=//p' "$i" | sed  -e 's/,/ /g')"
     exclude_targets="$(sed -ne 's/^#EXCLUDE_TARGETS=//p' "$i" | sed  -e 's/,/ /g')"
     require_binaries="$(sed -ne 's/^#REQUIRE_BINARIES=//p' "$i" | sed  -e 's/,/ /g')"
     if [ $any_test -ne 1 ] ; then
@@ -151,6 +154,11 @@ _findtests() {
       require_options="$require_options $requiredoption"
     fi
 
+    requiredservice="$(sed -ne 's/^#REQUIRE_SERVICE=//p' "$i" | sed  -e 's/,.*//')"
+    if [ -n "$requiredservice" ]; then
+      require_services="$require_services $requiredservice"
+    fi
+
     excludedtarget="$(sed -ne 's/^#EXCLUDE_TARGET=//p' "$i" | sed  -e 's/,.*//')"
     if [ -n "$excludedtarget" ]; then
       exclude_targets="$exclude_targets $excludedtarget"
@@ -192,6 +200,20 @@ _findtests() {
       fi
     done
 
+    for requiredservice in $require_services; do
+      alternatives=$(echo "$requiredservice" | sed -e 's/|/ /g')
+      found=
+      for alt in $alternatives; do
+        if echo "$SERVICES" | grep -qw "\+$alt"; then
+          found=1;
+	fi
+      done
+      if [ -z $found ]; then
+        echo "  Skip $i because haproxy is not compiled with the required service $requiredservice"
+        skiptest=1
+      fi
+    done
+
     for requiredbin in $require_binaries; do
       if ! command -v $requiredbin >/dev/null 2>&1
       then
@@ -322,8 +344,8 @@ if [ $preparefailed ]; then
   exit 1
 fi
 
-{ read HAPROXY_VERSION; read TARGET; read FEATURES; } << EOF
-$($HAPROXY_PROGRAM $HAPROXY_ARGS -vv |grep 'HA-Proxy version\|TARGET.*=\|^Feature' | sed 's/.* [:=] //')
+{ read HAPROXY_VERSION; read TARGET; read FEATURES; read SERVICES; } << EOF
+$($HAPROXY_PROGRAM $HAPROXY_ARGS -vv | grep 'HA-Proxy version\|TARGET.*=\|^Feature\|^Available services' | sed 's/.* [:=] //')
 EOF
 
 HAPROXY_VERSION=$(echo $HAPROXY_VERSION | cut -d " " -f 3)
@@ -342,6 +364,7 @@ fi
 
 echo "Target : $TARGET"
 echo "Options : $FEATURES"
+echo "Services : $SERVICES"
 
 echo "########################## Gathering tests to run ##########################"
 # if htx is enable, but HAProxy version is lower to 1.9, disable it

src/stream.c

@@ -2791,10 +2791,8 @@ void list_services(FILE *out)
 	fprintf(out, "Available services :");
 	list_for_each_entry(kw_list, &service_keywords, list) {
 		for (i = 0; kw_list->kw[i].kw != NULL; i++) {
-			if (!found)
-				fputc('\n', out);
 			found = 1;
-			fprintf(out, "\t%s\n", kw_list->kw[i].kw);
+			fprintf(out, " %s", kw_list->kw[i].kw);
 		}
 	}
 	if (!found)