bake: multi ips support for extra hosts

Signed-off-by: CrazyMax <1951866+crazy-max@users.noreply.github.com>

tests/bake.go

@@ -2167,11 +2167,14 @@ func testBakeExtraHosts(t *testing.T, sb integration.Sandbox) {
 	dockerfile := []byte(`
 FROM busybox
 RUN cat /etc/hosts | grep myhost | grep 1.2.3.4
+RUN cat /etc/hosts | grep myhostmulti | grep 162.242.195.81
+RUN cat /etc/hosts | grep myhostmulti | grep 162.242.195.82
 	`)
 	bakefile := []byte(`
 target "default" {
   extra-hosts = {
     myhost = "1.2.3.4"
+    myhostmulti = "162.242.195.81,162.242.195.82"
   }
 }
 `)

tests/build.go

@@ -77,6 +77,7 @@ var buildTests = []func(t *testing.T, sb integration.Sandbox){
 	testBuildDefaultLoad,
 	testBuildCall,
 	testCheckCallOutput,
+	testBuildExtraHosts,
 }
 
 func testBuild(t *testing.T, sb integration.Sandbox) {
@@ -1322,6 +1323,24 @@ cOpy Dockerfile .
 	})
 }
 
+func testBuildExtraHosts(t *testing.T, sb integration.Sandbox) {
+	dockerfile := []byte(`
+FROM busybox
+RUN cat /etc/hosts | grep myhost | grep 1.2.3.4
+RUN cat /etc/hosts | grep myhostmulti | grep 162.242.195.81
+RUN cat /etc/hosts | grep myhostmulti | grep 162.242.195.82
+`)
+	dir := tmpdir(t, fstest.CreateFile("Dockerfile", dockerfile, 0600))
+	cmd := buildxCmd(sb, withArgs("build",
+		"--add-host=myhost=1.2.3.4",
+		"--add-host=myhostmulti=162.242.195.81",
+		"--add-host=myhostmulti=162.242.195.82",
+		"--output=type=cacheonly", dir),
+	)
+	out, err := cmd.CombinedOutput()
+	require.NoError(t, err, string(out))
+}
+
 func createTestProject(t *testing.T) string {
 	dockerfile := []byte(`
 FROM busybox:latest AS base