fix: correct port binding for non-default ports

[anisaoshafi]

When configuring a non-default port (e.g. 4567), the Docker binding was 4567:4567 instead of 4567:4566, so the health check could not reach localstack and lstk would hang.

Fix port binding for non-default ports so the emulator actually becomes ready.

[coderabbitai]

📝 Walkthrough

Walkthrough

Added an integration test that starts the service with a non-default port via a generated TOML config and mock license server. The docker runtime was changed to bind a fixed container port ("4566/tcp") instead of deriving the container port from the configured host port.

Changes

Cohort / File(s)	Summary
Test Integration test/integration/start_test.go	Added TestStartCommandSucceedsWithNonDefaultPort which writes a temporary TOML config (port 4567), starts a mock license server, and runs lstk start --config to verify successful startup.
Docker Runtime internal/runtime/docker.go	Introduced emulatorContainerPort = nat.Port("4566/tcp") and updated Start to use this fixed container port for ExposedPorts and PortBindings instead of deriving from config.Port.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

🚥 Pre-merge checks | ✅ 2

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately summarizes the main change: correcting port binding for non-default ports in Docker configuration.
Description check	✅ Passed	The pull request description clearly explains the bug fix for Docker port binding when using non-default ports and how the changes resolve the issue.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch drg-611

📝 Coding Plan

• Generate coding plan for human review comments

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[coderabbitai]

🧹 Nitpick comments (1)

internal/container/start.go (1)

326-332: Consider extracting the default port to a constant to avoid duplication.

The string "4566" is hardcoded here, but the same default is also defined in internal/config/config.go:setDefaults(). If the default port changes in one place but not the other, non-default port detection will silently break.

♻️ Suggested approach

Define a constant in the config package and reference it from both locations:

// In internal/config/config.go
const DefaultPort = "4566"

func setDefaults() {
    viper.SetDefault("containers", []map[string]any{
        {
            "type": "aws",
            "tag":  "latest",
            "port": DefaultPort,
        },
    })
}

Then in needsGatewayListen:

 func needsGatewayListen(port string, env []string) bool {
-    return port != "4566" && !slices.ContainsFunc(env, func(e string) bool {
+    return port != config.DefaultPort && !slices.ContainsFunc(env, func(e string) bool {
         return strings.HasPrefix(e, "GATEWAY_LISTEN=")
     })
 }

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@internal/container/start.go` around lines 326 - 332, Extract the hardcoded
"4566" into a shared constant (e.g. DefaultPort string) in the config package
(add const DefaultPort = "4566" in internal/config/config.go and use it inside
setDefaults()), then replace the literal "4566" in needsGatewayListen with
config.DefaultPort and add the config import in internal/container/start.go;
ensure all references to the default port use config.DefaultPort so non-default
detection remains consistent.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Nitpick comments:
In `@internal/container/start.go`:
- Around line 326-332: Extract the hardcoded "4566" into a shared constant (e.g.
DefaultPort string) in the config package (add const DefaultPort = "4566" in
internal/config/config.go and use it inside setDefaults()), then replace the
literal "4566" in needsGatewayListen with config.DefaultPort and add the config
import in internal/container/start.go; ensure all references to the default port
use config.DefaultPort so non-default detection remains consistent.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Repository UI (base), Organization UI (inherited)

Review profile: CHILL

Plan: Pro

Run ID: 08836855-fa8f-4c4d-8368-99ea054603a3

📥 Commits

Reviewing files that changed from the base of the PR and between 2ce11ae and ce6eef2.

📒 Files selected for processing (2)

• internal/container/start.go
• test/integration/start_test.go