Merge pull request #13153 from allisonlarson/docker_bridge_ip_update

Docker: Attempt using docker command for bridge ip

plugins/providers/docker/driver.rb

@@ -236,9 +236,22 @@ module VagrantPlugins
         execute('docker', 'ps', '-a', '-q', '--no-trunc').to_s.split
       end
 
+      # Attempts to first use the docker-cli tool to inspect the default bridge subnet
+      # Falls back to using /sbin/ip if that fails
+      #
       # @return [String] IP address of the docker bridge
       def docker_bridge_ip
-        output = execute('/sbin/ip', '-4', 'addr', 'show', 'scope', 'global', 'docker0')
+        bridge = inspect_network("bridge")&.first
+        if bridge 
+          bridge_ip = bridge.dig("IPAM", "Config", 0, "Gateway")
+        end
+        return bridge_ip if bridge_ip
+        @logger.debug("Failed to get bridge ip from docker, falling back to `ip`")
+        docker_bridge_ip_fallback
+      end
+
+      def docker_bridge_ip_fallback
+        output = execute('ip', '-4', 'addr', 'show', 'scope', 'global', 'docker0')
         if output =~ /^\s+inet ([0-9.]+)\/[0-9]+\s+/
           return $1.to_s
         else

test/unit/plugins/providers/docker/driver_compose_test.rb

@@ -339,9 +339,10 @@ describe VagrantPlugins::DockerProvider::Driver::Compose do
   describe '#docker_bridge_ip' do
     let(:stdout) { " inet 123.456.789.012/16 " }
 
-    it 'returns an array of all known containers' do
+    it 'returns the bridge ip' do
       expect(subject.docker_bridge_ip).to eq('123.456.789.012')
-      expect(cmd_executed.first).to eq("/sbin/ip -4 addr show scope global docker0")
+      expect(cmd_executed.first).to eq("docker network inspect bridge")
+      expect(cmd_executed.last).to eq("ip -4 addr show scope global docker0")
     end
   end
 end

test/unit/plugins/providers/docker/driver_test.rb

@@ -552,11 +552,65 @@ describe VagrantPlugins::DockerProvider::Driver do
   end
 
   describe '#docker_bridge_ip' do
-    let(:stdout) { " inet 123.456.789.012/16 " }
+    context 'from docker network command' do 
+    let(:network_struct) {
+    [{
+        "Name": "bridge",
+        "Id": "ae74f6cc18bbcde86326937797070b814cc71bfc4a6d8e3e8cf3b2cc5c7f4a7d",
+        "Created": "2019-03-20T14:10:06.313314662-07:00",
+        "Scope": "local",
+        "Driver": "bridge",
+        "EnableIPv6": false,
+        "IPAM": {
+            "Driver": "default",
+            "Options": nil,
+            "Config": [
+                {
+                    "Subnet": "172.17.0.0/16",
+                    "Gateway": "172.17.0.1"
+                }
+            ]
+        },
+        "Internal": false,
+        "Attachable": false,
+        "Ingress": false,
+        "ConfigFrom": {
+            "Network": ""
+        },
+        "ConfigOnly": false,
+        "Containers": {
+            "a1ee9b12bcea8268495b1f43e8d1285df1925b7174a695075f6140adb9415d87": {
+                "Name": "vagrant-sandbox_docker-1_1553116237",
+                "EndpointID": "fc1b0ed6e4f700cf88bb26a98a0722655191542e90df3e3492461f4d1f3c0cae",
+                "MacAddress": "02:42:ac:11:00:02",
+                "IPv4Address": "172.17.0.2/16",
+                "IPv6Address": ""
+            }
+        },
+        "Options": {
+            "com.docker.network.bridge.default_bridge": "true",
+            "com.docker.network.bridge.enable_icc": "true",
+            "com.docker.network.bridge.enable_ip_masquerade": "true",
+            "com.docker.network.bridge.host_binding_ipv4": "0.0.0.0",
+            "com.docker.network.bridge.name": "docker0",
+            "com.docker.network.driver.mtu": "1500"
+        },
+        "Labels": {}
+    }].to_json
+    }
+      it "returns the bridge gateway ip" do
+        allow(subject).to receive(:inspect_network).and_return(JSON.load(network_struct))
+        expect(subject.docker_bridge_ip).to eq('172.17.0.1')
+      end
+    end
 
-    it 'returns an array of all known containers' do
-      expect(subject.docker_bridge_ip).to eq('123.456.789.012')
-      expect(cmd_executed).to eq("/sbin/ip -4 addr show scope global docker0")
+    context 'when falling back to ip' do
+      let(:stdout) { " inet 123.456.789.012/16 " }
+
+      it 'returns the bridge ip' do
+        expect(subject.docker_bridge_ip).to eq('123.456.789.012')
+        expect(cmd_executed).to eq("ip -4 addr show scope global docker0")
+      end
     end
   end