From 31fb4aea3cd90063df79902603311567811bc145 Mon Sep 17 00:00:00 2001
From: Juergen Kunz <juergen@foss.global>
Date: Fri, 6 Feb 2026 15:05:46 +0000
Subject: [PATCH] feat(classes.dockerfile): support using a local base image as
 a build context in buildx commands

---
 changelog.md             |  7 +++++++
 ts/00_commitinfo_data.ts |  2 +-
 ts/classes.dockerfile.ts | 12 ++++++++++--
 3 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/changelog.md b/changelog.md
index e4ad49d..40f011a 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,5 +1,12 @@
 # Changelog
 
+## 2026-02-06 - 1.10.0 - feat(classes.dockerfile)
+support using a local base image as a build context in buildx commands
+
+- Adds --build-context flag mapping base image to docker-image://<localTag> when localBaseImageDependent && localBaseDockerfile are set
+- Appends the build context flag to both single-platform and multi-platform docker buildx commands
+- Logs an info message indicating the local build context mapping
+
 ## 2026-02-06 - 1.9.0 - feat(build)
 add verbose build output, progress logging, and timing for builds/tests
 
diff --git a/ts/00_commitinfo_data.ts b/ts/00_commitinfo_data.ts
index b4c5a27..e0c0437 100644
--- a/ts/00_commitinfo_data.ts
+++ b/ts/00_commitinfo_data.ts
@@ -3,6 +3,6 @@
  */
 export const commitinfo = {
   name: '@git.zone/tsdocker',
-  version: '1.9.0',
+  version: '1.10.0',
   description: 'develop npm modules cross platform with docker'
 }
diff --git a/ts/classes.dockerfile.ts b/ts/classes.dockerfile.ts
index 0559da7..8e66de1 100644
--- a/ts/classes.dockerfile.ts
+++ b/ts/classes.dockerfile.ts
@@ -409,15 +409,23 @@ export class Dockerfile {
     const noCacheFlag = options?.noCache ? ' --no-cache' : '';
     const verbose = options?.verbose ?? false;
 
+    let buildContextFlag = '';
+    if (this.localBaseImageDependent && this.localBaseDockerfile) {
+      const fromImage = this.baseImage;
+      const localTag = this.localBaseDockerfile.buildTag;
+      buildContextFlag = ` --build-context "${fromImage}=docker-image://${localTag}"`;
+      logger.log('info', `Using local build context: ${fromImage} -> docker-image://${localTag}`);
+    }
+
     let buildCommand: string;
 
     if (platformOverride) {
       // Single platform override via buildx
-      buildCommand = `docker buildx build --platform ${platformOverride}${noCacheFlag} --load -t ${this.buildTag} -f ${this.filePath} ${buildArgsString} .`;
+      buildCommand = `docker buildx build --platform ${platformOverride}${noCacheFlag}${buildContextFlag} --load -t ${this.buildTag} -f ${this.filePath} ${buildArgsString} .`;
     } else if (config.platforms && config.platforms.length > 1) {
       // Multi-platform build using buildx
       const platformString = config.platforms.join(',');
-      buildCommand = `docker buildx build --platform ${platformString}${noCacheFlag} -t ${this.buildTag} -f ${this.filePath} ${buildArgsString} .`;
+      buildCommand = `docker buildx build --platform ${platformString}${noCacheFlag}${buildContextFlag} -t ${this.buildTag} -f ${this.filePath} ${buildArgsString} .`;
 
       if (config.push) {
         buildCommand += ' --push';