add integration tests for DNS proxy

Signed-off-by: Bohan Chen <bochen@pivotal.io>
Co-authored-by: Taylor Silva <tsilva@pivotal.io>

integration/worker/dns_test.go

@@ -0,0 +1,47 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/concourse/concourse/integration/internal/dctest"
+	"github.com/concourse/concourse/integration/internal/flytest"
+)
+
+func TestDNSProxyyEnabled(t *testing.T) {
+	t.Parallel()
+
+	dc := dctest.Init(t, "../docker-compose.yml", "overrides/enable_dns_proxy.yml")
+
+	t.Run("deploy with DNS proxy enabled", func(t *testing.T) {
+		dc.Run(t, "up", "-d")
+	})
+
+	fly := flytest.Init(t, dc)
+	fly.WithEnv("EXPECTED_EXIT_CODE=0").Run(t, "execute", "-c", "tasks/assert_web_is_reachable.yml")
+}
+
+func TestDNSProxyyDisabled(t *testing.T) {
+	t.Parallel()
+
+	dc := dctest.Init(t, "../docker-compose.yml", "overrides/disable_dns_proxy.yml")
+
+	t.Run("deploy with DNS proxy disabled", func(t *testing.T) {
+		dc.Run(t, "up", "-d")
+	})
+
+	fly := flytest.Init(t, dc)
+	fly.WithEnv("EXPECTED_EXIT_CODE=1").Run(t, "execute", "-c", "tasks/assert_web_is_reachable.yml")
+}
+
+func TestExtraDNSServersAreAdded(t *testing.T) {
+	t.Parallel()
+
+	dc := dctest.Init(t, "../docker-compose.yml", "overrides/add_extra_dns_servers.yml")
+
+	t.Run("deploy with extra DNS servers", func(t *testing.T) {
+		dc.Run(t, "up", "-d")
+	})
+
+	fly := flytest.Init(t, dc)
+	fly.WithEnv("EXTRA_SERVER=1.1.1.1").Run(t, "execute", "-c", "tasks/assert_extra_dns_servers.yml")
+}

integration/worker/overrides/add_extra_dns_servers.yml

@@ -0,0 +1,6 @@
+version: '3'
+
+services:
+  worker:
+    environment:
+      CONCOURSE_CONTAINERD_DNS_SERVER: "1.1.1.1"

integration/worker/overrides/disable_dns_proxy.yml

@@ -0,0 +1,6 @@
+version: '3'
+
+services:
+  worker:
+    environment:
+      CONCOURSE_CONTAINERD_DNS_PROXY_ENABLE: "false"

integration/worker/overrides/enable_dns_proxy.yml

@@ -0,0 +1,6 @@
+version: '3'
+
+services:
+  worker:
+    environment:
+      CONCOURSE_CONTAINERD_DNS_PROXY_ENABLE: "true"

integration/worker/tasks/assert_extra_dns_servers.yml

@@ -0,0 +1,17 @@
+platform: linux
+
+image_resource:
+  type: mock
+  source: {mirror_self: true}
+
+params:
+  EXTRA_SERVER:
+
+run:
+  path: sh
+  args:
+  - -c
+  - |
+    set -ex
+
+    grep $EXTRA_SERVER /etc/resolv.conf

integration/worker/tasks/assert_web_is_reachable.yml

@@ -0,0 +1,20 @@
+platform: linux
+
+image_resource:
+  type: mock
+  source: {mirror_self: true}
+
+params:
+  EXPECTED_EXIT_CODE:
+
+run:
+  path: sh
+  args:
+  - -c
+  - |
+    set -x
+
+    nslookup web
+    if [ $? -ne $EXPECTED_EXIT_CODE ]; then
+      exit 1
+    fi