feat: add docker login function

modules/docker/login.go

@@ -0,0 +1,30 @@
+package docker
+
+import (
+	"github.com/gruntwork-io/terratest/modules/logger"
+	"github.com/gruntwork-io/terratest/modules/shell"
+	"github.com/gruntwork-io/terratest/modules/testing"
+	"github.com/stretchr/testify/require"
+)
+
+type LoginOptions struct {
+	Registry string
+	Login    string
+	Password string
+}
+
+// Login runs the 'docker login' command to login the given registry. This will fail the test if there are any errors.
+// Do not use production password, only for testing purpose.
+func Login(t testing.TestingT, opt LoginOptions) {
+	require.NoError(t, login(t, opt))
+}
+
+// login runs the 'docker login' command to login the given registry.
+func login(t testing.TestingT, opt LoginOptions) error {
+	logger.Logf(t, "Running 'docker login' for user %s", opt.Login)
+	cmd := shell.Command{
+		Command: "docker",
+		Args:    []string{"login", opt.Registry, "-u", opt.Login, "-p", opt.Password},
+	}
+	return shell.RunCommandE(t, cmd)
+}