add test d00012.vtc

src/tests/d00012.vtc

+varnishtest "Test a dynamic backend discard during a request"
+
+# vcl.discard testing inspired by v00006.vtc from commit e1f7207
+
+server s1 {
+	rxreq
+	expect req.url == "/foo"
+	sema r1 sync 2
+	txresp
+} -start
+
+varnish v1 -arg "-p thread_pools=1" -vcl {
+	import backend_dyn from "${vmod_topbuild}/src/.libs/libvmod_backend_dyn.so";
+
+	backend dummy { .host = "${bad_ip}"; }
+
+	sub vcl_init {
+		if (!backend_dyn.create(name="s1", host="${s1_addr}",
+		   		        	   port="${s1_port}")) {
+			return(fail);
+		}
+	}
+
+	sub vcl_recv {
+		set req.backend_hint = backend_dyn.by_name("s1");
+	}
+} -start
+
+client c1 {
+	txreq -url "/foo"
+	rxresp
+	expect resp.status == 200
+} -start
+
+varnish v1 -expect MAIN.n_backend == 2
+# expected: vcl1.dummy, vcl1.s1
+
+server s2 {
+	rxreq
+	expect req.url == "/bar"
+	txresp
+} -start
+
+varnish v1 -vcl {
+	import backend_dyn from "${vmod_topbuild}/src/.libs/libvmod_backend_dyn.so";
+
+	backend dummy { .host = "${bad_ip}"; }
+
+	sub vcl_init {
+		if (!backend_dyn.create(name="s2", host="${s2_addr}",
+		   		        	   port="${s2_port}")) {
+			return(fail);
+		}
+	}
+
+	sub vcl_recv {
+		set req.backend_hint = backend_dyn.by_name("s2");
+	}
+}
+
+varnish v1 -cli "vcl.discard vcl1"
+sema r1 sync 2
+
+client c1 -wait
+delay 2
+
+varnish v1 -expect MAIN.n_backend == 4
+# expected: vcl1.dummy, vcl1.s1, vcl2.dummy, vcl2.s2
+
+varnish v1 -expect n_vcl_avail == 1
+varnish v1 -expect n_vcl_discard == 1
+
+client c1 {
+	txreq -url "/bar"
+	rxresp
+	expect resp.status == 200
+} -run
+
+varnish v1 -cli "vcl.list"
+varnish v1 -expect MAIN.n_backend == 2
+# expected: vcl2.dummy, vcl2.s2
+varnish v1 -expect n_vcl_avail == 1
+varnish v1 -expect n_vcl_discard == 0