Update BuildKit endpoint configuration to use port input and adjust related documentation

Author: dash14

.github/workflows/example-audit.yml

@@ -18,7 +18,7 @@ jobs:
         uses: docker/setup-buildx-action@v3
         with:
           driver: remote
-          endpoint: ${{ steps.buildcage.outputs.endpoint }}
+          endpoint: tcp://localhost:${{ steps.buildcage.outputs.port }}
 
       - name: Create test Dockerfile
         run: |

.github/workflows/example-restrict.yml

@@ -19,7 +19,7 @@ jobs:
         uses: docker/setup-buildx-action@v3
         with:
           driver: remote
-          endpoint: ${{ steps.buildcage.outputs.endpoint }}
+          endpoint: tcp://localhost:${{ steps.buildcage.outputs.port }}
 
       - name: Create test Dockerfile
         run: |

README.md

@@ -116,12 +116,13 @@ The internal proxy server inspects the SNI field (for HTTPS) or the Host header
 | `proxy_mode` | No | `restrict` | Operation mode (`audit` / `restrict`) |
 | `allowed_http_domains` | No | empty | Allowed HTTP domains (comma-separated) |
 | `allowed_https_domains` | No | empty | Allowed HTTPS domains (comma-separated) |
+| `port` | No | `1234` | BuildKit endpoint port on localhost |
 
 **Output:**
 
 | Name | Description |
 |------|-------------|
-| `endpoint` | BuildKit endpoint to pass to `docker buildx create --driver remote` |
+| `port` | BuildKit endpoint port |
 
 ### Report
 
@@ -154,7 +155,7 @@ jobs:
         uses: docker/setup-buildx-action@v3
         with:
           driver: remote
-          endpoint: ${{ steps.buildcage.outputs.endpoint }}
+          endpoint: tcp://localhost:${{ steps.buildcage.outputs.port }}
 
       - name: Build
         uses: docker/build-push-action@v6

setup/action.yml

@@ -22,10 +22,14 @@ inputs:
     description: "Comma-separated allowed HTTPS domains"
     required: false
     default: ''
+  port:
+    description: "BuildKit endpoint port on localhost"
+    required: false
+    default: '1234'
 
 outputs:
-  endpoint:
-    description: "BuildKit endpoint for docker buildx create --driver remote"
+  port:
+    description: "BuildKit endpoint port"
 
 runs:
   using: node24

setup/compose.yml

@@ -3,7 +3,7 @@ services:
     image: ${BUILDCAGE_IMAGE:-ghcr.io/dash14/buildcage}:${BUILDCAGE_VERSION:-latest}
     privileged: true
     ports:
-      - "1234:1234"
+      - "${PORT:-1234}:1234"
     environment:
       - PROXY_MODE=${PROXY_MODE:-restrict}
       - ALLOWED_HTTP_DOMAINS=${ALLOWED_HTTP_DOMAINS:-}

setup/main.mjs

@@ -21,9 +21,11 @@ execFileSync(
       ALLOWED_HTTPS_DOMAINS: process.env.INPUT_ALLOWED_HTTPS_DOMAINS || "",
       BUILDCAGE_IMAGE: process.env.INPUT_BUILDCAGE_IMAGE || "ghcr.io/dash14/buildcage",
       BUILDCAGE_VERSION: process.env.INPUT_BUILDCAGE_VERSION || "latest",
+      PORT: process.env.INPUT_PORT || "1234",
     },
   }
 );
 
 // Set action output
-appendFileSync(process.env.GITHUB_OUTPUT, "endpoint=tcp://localhost:1234\n");
+const port = process.env.INPUT_PORT || "1234";
+appendFileSync(process.env.GITHUB_OUTPUT, `port=${port}\n`);