simplify dns tests

- use 'host' to lookup MX record. It's shorter
- use getent everywhere else for dns lookups, instead of dig; this
  tests more of the o/s name resolution machinery and is generally
  shorter.
- introduce assert_dns_record helper that performs forward and reverse
- lookup introduce some vars for holding constants, so we don't have
  to repeat them

test/200_dns_test.sh

@@ -4,6 +4,7 @@
 
 C1=10.2.0.78
 C2=10.2.0.34
+NAME=seetwo.weave.local
 
 start_suite "Resolve names on a single host"
 
@@ -13,13 +14,9 @@ weave_on $HOST1 launch-dns 10.2.254.1/24
 
 docker_on $HOST1 rm -f c1 c2 || true
 
-weave_on $HOST1 run $C2/24 -t --name=c2 -h seetwo.weave.local ubuntu
+weave_on $HOST1 run $C2/24 -t --name=c2 -h $NAME ubuntu
 weave_on $HOST1 run --with-dns $C1/24 -t --name=c1 aanand/docker-dnsutils /bin/sh
 
-ok=$(exec_on $HOST1 c1 dig +short seetwo.weave.local)
-assert "echo $ok" "$C2"
-
-ok=$(exec_on $HOST1 c1 dig +short -x $C2)
-assert "echo $ok" "seetwo.weave.local."
+assert_dns_record $HOST1 c1 $NAME $C2
 
 end_suite

test/210_dns_multicast_test.sh

@@ -4,6 +4,7 @@
 
 C1=10.2.3.78
 C2=10.2.3.34
+NAME=seetwo.weave.local
 
 start_suite "Resolve names across hosts"
 
@@ -19,16 +20,12 @@ weave_on $HOST2 launch $HOST1
 weave_on $HOST1 launch-dns 10.2.254.1/24 -debug
 weave_on $HOST2 launch-dns 10.2.254.2/24 -debug
 
-weave_on $HOST2 run $C2/24 -t --name=c2 -h seetwo.weave.local ubuntu
+weave_on $HOST2 run $C2/24 -t --name=c2 -h $NAME ubuntu
 weave_on $HOST1 run --with-dns $C1/24 --name=c1 -t aanand/docker-dnsutils /bin/sh
 
-ok=$(exec_on $HOST1 c1 dig +short seetwo.weave.local)
-assert "echo $ok" "$C2"
+assert_dns_record $HOST1 c1 $NAME $C2
 
-ok=$(exec_on $HOST1 c1 dig +short -x $C2)
-assert "echo $ok" "seetwo.weave.local."
-
-ok=$(exec_on $HOST1 c1 dig +short -x 8.8.8.8)
-assert "test -n \"$ok\" && echo pass" "pass"
+ok=$(exec_on $HOST1 c1 getent hosts 8.8.8.8)
+assert_raises "echo $ok | grep google"
 
 end_suite

test/220_dns_custom_test.sh

@@ -4,22 +4,20 @@
 
 C1=10.2.56.34
 C2=10.2.54.91
+DOMAIN=foo.bar
+NAME=seetwo.$DOMAIN
 
 start_suite "Resolve names in custom domain"
 
 weave_on $HOST1 stop || true
 weave_on $HOST1 stop-dns || true
-weave_on $HOST1 launch-dns 10.2.254.1/24 --domain foo.bar.
+weave_on $HOST1 launch-dns 10.2.254.1/24 --domain $DOMAIN.
 
 docker_on $HOST1 rm -f c1 c2 || true
 
-weave_on $HOST1 run $C2/24 -t --name=c2 -h seetwo.foo.bar ubuntu
+weave_on $HOST1 run $C2/24 -t --name=c2 -h $NAME ubuntu
 weave_on $HOST1 run --with-dns $C1/24 -t --name=c1 aanand/docker-dnsutils /bin/sh
 
-ok=$(exec_on $HOST1 c1 dig +short seetwo.foo.bar.)
-assert "echo $ok" "$C2"
-
-ok=$(exec_on $HOST1 c1 dig +short -x $C2)
-assert "echo $ok" "seetwo.foo.bar."
+assert_dns_record $HOST1 c1 $NAME $C2
 
 end_suite

test/300_fallback_dns_test.sh

@@ -10,10 +10,10 @@ docker_on $HOST1 rm -f c1 || true
 
 weave_on $HOST1 run --with-dns 10.2.1.5/24 --name=c1 -t aanand/docker-dnsutils /bin/sh
 
-ok=$(exec_on $HOST1 c1 dig +short -t MX weave.works)
-assert "test -n \"$ok\" && echo pass" "pass"
+ok=$(exec_on $HOST1 c1 host -t mx weave.works)
+assert_raises "echo $ok | grep google"
 
-ok=$(exec_on $HOST1 c1 dig +short -x 8.8.8.8)
-assert "test -n \"$ok\" && echo pass" "pass"
+ok=$(exec_on $HOST1 c1 getent hosts 8.8.8.8)
+assert_raises "echo $ok | grep google"
 
 end_suite

test/config.sh

@@ -88,6 +88,14 @@ exec_on() {
     docker -H tcp://$host:2375 exec $container "$@"
 }
 
+# assert_dns_record <host> <container> <name> <ip>
+assert_dns_record() {
+    ok=$(exec_on $1 $2 getent hosts $3)
+    assert "echo $ok" "$4 $3"
+    ok=$(exec_on $1 $2 getent hosts $4)
+    assert "echo $ok" "$4 $3"
+}
+
 start_suite() {
     whitely echo $@
 }