Place a medium pot over medium-high heat and add the water. Once water starts to simmer, add in the galangal, lemongrass, Kaffir lime leaves and shallot. Bring the soup to a boil.Once soup is boiling, add the zucchini noodles, shrimp, chili powder, salt, fish sauce, and mix together. Let shrimp cook for 3 minutes or until opaque and c-shaped. Then, add in the chilis and parsley. Stir well and add the lime juice. Remove the galangal and lemongrass before eating. Serve hot.