Networking between 2 Devcontainer setups

[AchimGrolimund]

Hello everyone

I have a question regarding networking.

I have 2 projects:
A: Go + PostgreSQL
B: NodeJs + JavaScript

Now I need to get from the frontend to the API in project A. Unfortunately I can't get this done.
Is there a solution how to get 2 DevContainers projects into the same network?

Here are my configs:

Projekt A:

// For format details, see https://aka.ms/devcontainer.json. For config options, see the
// README at: https://github.com/devcontainers/templates/tree/main/src/go-postgres
{
	"name": "Go & PostgreSQL",
	"dockerComposeFile": "docker-compose.yml",
	"service": "app",
	"workspaceFolder": "/workspaces/${localWorkspaceFolderBasename}",
	"features": {
		"ghcr.io/devcontainers/features/git:1": {},
		"ghcr.io/devcontainers/features/github-cli:1": {},
		"ghcr.io/devcontainers-extra/features/curl-apt-get:1": {}
	},

	// Features to add to the dev container. More info: https://containers.dev/features.
	// "features": {},

	// Configure tool-specific properties.
	"customizations": {
		"vscode": {
			"extensions": [
				"dbaeumer.vscode-eslint",
				"EditorConfig.EditorConfig",
				"esbenp.prettier-vscode",
				"christian-kohler.path-intellisense",
				"saoudrizwan.claude-dev",
				"rooveterinaryinc.roo-cline"
			]
		}
	},

	// Use 'forwardPorts' to make a list of ports inside the container available locally.
	"forwardPorts": [5432, 8000],

	// Use 'postCreateCommand' to run commands after the container is created.
	"postCreateCommand": "go mod tidy"
	
	// Uncomment to connect as root instead. More info: https://aka.ms/dev-containers-non-root.
	// "remoteUser": "root"
}

Projekt B:

// For format details, see https://aka.ms/devcontainer.json. For config options, see the
// README at: https://github.com/devcontainers/templates/tree/main/src/javascript-node
{
	"name": "Node.js",
	// Or use a Dockerfile or Docker Compose file. More info: https://containers.dev/guide/dockerfile
	"image": "mcr.microsoft.com/devcontainers/javascript-node:1-22-bookworm",
	"features": {
		"ghcr.io/devcontainers/features/git:1": {}
	},

	// Features to add to the dev container. More info: https://containers.dev/features.
	// "features": {},

	// Use 'forwardPorts' to make a list of ports inside the container available locally.
	"forwardPorts": [4173, 5173],

	// Use 'postCreateCommand' to run commands after the container is created.
	"postCreateCommand": "npm install",
	
	// Network from Projekt A (Autocreated by Docker Compose)
	"runArgs": [ "--network=printstash-api_devcontainer_default" ], 

	// Configure tool-specific properties.
	"customizations": {
		"vscode": {
			"extensions": [
				"Vue.volar",
				"dbaeumer.vscode-eslint",
				"EditorConfig.EditorConfig",
				"esbenp.prettier-vscode",
				"christian-kohler.path-intellisense",
				"rooveterinaryinc.roo-cline"
			]
		}
	}

	// Uncomment to connect as root instead. More info: https://aka.ms/dev-containers-non-root.
	// "remoteUser": "root"
}

Best Achim