Make bind address configurable for app dev server #6396

lmcrean · 2025-09-14T07:48:19Z

Adds configurable bind address support to the shopify app dev command to enable Docker container development workflows.

Problem

Fixes [Feature]: Make bind address configurable for local servers #6355
Recent CLI versions hardcode localhost binding for app dev servers for security
Docker containers require 0.0.0.0 binding to accept connections from host machine
Theme dev server already supports --host flag, but app dev server does not
Breaks containerized development setups (working version was 3.83.3)

Solution

Add --host flag to shopify app dev command with SHOPIFY_FLAG_HOST env var support
Update proxy server setup to use configurable host instead of hardcoded 'localhost'
Maintain secure default (127.0.0.1) while enabling Docker flexibility
Match existing theme dev server pattern for consistency

Changes Made

1. Added host flag to app dev command

File: packages/app/src/cli/commands/app/dev.ts
Added --host flag with environment variable support
Default: 127.0.0.1 (maintains security)
Override: 0.0.0.0 (enables Docker containers)

2. Updated proxy server to use configurable host

File: packages/app/src/cli/services/dev/processes/setup-dev-processes.ts
Changed hardcoded 'localhost' to use passed host parameter
Added host parameter to proxy server setup function

Usage Examples

For Docker containers:

SHOPIFY_FLAG_HOST=0.0.0.0 shopify app dev
# or
shopify app dev --host=0.0.0.0

For normal development (default):

shopify app dev  # Still binds to localhost by default

Testing

Unit Tests

Added comprehensive unit test coverage in packages/app/src/cli/services/dev/processes/setup-dev-processes.test.ts:

New Test: `proxy server process includes host parameter when configured for Docker`

Purpose: Verifies that the proxy server correctly uses the host parameter when set to 0.0.0.0 for Docker compatibility
Test setup: Creates a dev configuration with host: '0.0.0.0' simulating Docker usage
Verification: Confirms the proxy server process options include the correct host value
Location: Lines 85-150 in the test file

Updated Existing Tests

All existing tests were updated to include the required host: 'localhost' parameter in commandOptions to satisfy TypeScripts' requirements for the Devoptions interface. Users get localhost by default so no action needed.

Test Commands

# Run unit tests for the setup-dev-processes module
pnpm test packages/app/src/cli/services/dev/processes/setup-dev-processes.test.ts

Manual Testing

Verify default behavior unchanged (binds to localhost)
Verify --host=0.0.0.0 enables external connections
Verify SHOPIFY_FLAG_HOST environment variable works
Test Docker container setup with port forwarding
Ensure backwards compatibility

No Breaking Changes

This is a feature addition that maintains 100% backward compatibility. Users who don't need Docker support will see zero changes in behavior. Only users who specifically want to bind to a different network interface need to use the new --host flag.

- Introduced a new `host` flag in the dev command to specify the network interface for the web server, defaulting to 'localhost'. - Updated the `DevOptions` interface to include the `host` property. - Modified the setup of proxy server processes to utilize the new `host` option. - Renamed `startProxyServer` to `proxyService` for clarity in the proxy server function.

…onfiguration

…rocesses test

- Add missing directory and update properties to DevOptions test objects - Add missing config property to TestAppWithConfigOptions calls - Add missing partnerUrlsUpdated property to DevConfig setupDevProcesses calls - Update CLI documentation and manifest for --host flag

theo-styles-radiant · 2025-10-15T13:13:20Z

any eta when this will be looked at? It's blocking me working on an app that uses docker

github-actions · 2025-11-15T03:44:20Z

This PR seems inactive. If it's still relevant, please add a comment saying so. Otherwise, take no action.
→ If there's no activity within a week, then a bot will automatically close this.
Thanks for helping to improve Shopify's dev tooling and experience.

lmcrean · 2025-11-15T10:17:01Z

can someone review this PR please?

karreiro

Thank you very much for this PR, @lmcrean!

I've made just one suggestion to ensure the flags are consistent. :)

Additionally, could you please run pnpm changeset add? This will allow us to include a changeset for this feature.

Thanks again for your contribution! 🚀

packages/app/src/cli/commands/app/dev.ts

lmcrean · 2025-11-26T13:18:45Z

Thank you for the professional notes @karreiro @isaacroldan

Just confirming that this is in my pipeline, it appears to be nearly there, I'll be engaging with it during end of December/ early Jan

github-actions · 2025-12-27T03:50:19Z

This PR seems inactive. If it's still relevant, please add a comment saying so. Otherwise, take no action.
→ If there's no activity within a week, then a bot will automatically close this.
Thanks for helping to improve Shopify's dev tooling and experience.

lmcrean · 2025-12-27T11:57:12Z

still relevant -- looking at it now actually

…documentation. This change ensures consistency across the application and improves clarity for users regarding the network interface settings.

…opment

…eters in setPortsAndAddProxyProcess call

…tion

…est to enhance readability and maintain consistency in configuration formatting.

lmcrean · 2025-12-27T17:04:08Z

Ready for review!

Kept --host per @isaacroldan's point about it affecting all extensions, and changed the default to 127.0.0.1 for consistency with shopify theme dev.

Also fixed the lint errors and added a changeset.

lmcrean added 4 commits September 8, 2025 21:00

Merge branch 'main' of https://github.com/Shopify/cli into lmcrean-6355

42a0f92

Update setupDevProcesses to include commandOptions in proxy process c…

0275c2e

…onfiguration

Add host parameter to proxy server process configuration in setupDevP…

d863faa

…rocesses test

lmcrean marked this pull request as ready for review September 14, 2025 08:41

lmcrean requested a review from a team as a code owner September 14, 2025 08:41

Merge branch 'Shopify:main' into lmcrean-6355

700021a

lmcrean requested a review from a team as a code owner September 20, 2025 13:54

lmcrean force-pushed the lmcrean-6355 branch from c885c87 to c5fae9c Compare September 20, 2025 13:58

dnovikov mentioned this pull request Nov 12, 2025

[Feature]: Make bind address configurable for local servers #6355

Open

github-actions bot added the no-pr-activity label Nov 15, 2025

github-actions bot removed the no-pr-activity label Nov 16, 2025

karreiro reviewed Nov 18, 2025

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packages/app/src/cli/commands/app/dev.ts Show resolved Hide resolved

karreiro requested a review from isaacroldan November 18, 2025 07:12

karreiro mentioned this pull request Nov 18, 2025

CI for #6396 #6633

Closed

github-actions bot added the no-pr-activity label Dec 27, 2025

lmcrean added 5 commits December 27, 2025 16:22

Update default host value from 'localhost' to '127.0.0.1' in CLI and …

5f5b9d8

…documentation. This change ensures consistency across the application and improves clarity for users regarding the network interface settings.

Add --host flag to shopify app dev command for Docker container devel…

68d1a0a

…opment

Refactor setupDevProcesses to improve readability by formatting param…

449b96a

…eters in setPortsAndAddProxyProcess call

Add '--host <value>' option to appdev interface for network configura…

7a399d6

…tion

Refactor test setup for proxy server process in setup-dev-processes t…

1ee8cbd

…est to enhance readability and maintain consistency in configuration formatting.

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Problem

Solution

Changes Made

1. Added host flag to app dev command

2. Updated proxy server to use configurable host

Usage Examples

For Docker containers:

For normal development (default):

Testing

Unit Tests

New Test: proxy server process includes host parameter when configured for Docker

Updated Existing Tests

Test Commands

Manual Testing

No Breaking Changes

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lmcrean commented Sep 14, 2025 •

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New Test: `proxy server process includes host parameter when configured for Docker`