Merge pull request #908 from crazy-max/inline-buildattrs

build: inline buildinfo attrs

build/build.go

@@ -505,6 +505,12 @@ func toSolveOpt(ctx context.Context, d driver.Driver, multiDriver bool, opt Opti
 				}
 			}
 		}
+		if e.Type == "docker" || e.Type == "image" || e.Type == "oci" {
+			// inline buildinfo attrs from build arg
+			if v, ok := opt.BuildArgs["BUILDKIT_INLINE_BUILDINFO_ATTRS"]; ok {
+				e.Attrs["buildinfo-attrs"] = v
+			}
+		}
 	}
 
 	so.Exports = opt.Exports

docs/reference/buildx_build.md

@@ -56,6 +56,18 @@ For documentation on most of these flags, refer to the [`docker build`
 documentation](https://docs.docker.com/engine/reference/commandline/build/). In
 here we’ll document a subset of the new flags.
 
+### Built-in build args
+
+* `BUILDKIT_INLINE_BUILDINFO_ATTRS=<bool>` inline build info attributes in image config or not
+* `BUILDKIT_INLINE_CACHE=<bool>` inline cache metadata to image config or not
+* `BUILDKIT_MULTI_PLATFORM=<bool>` opt into determnistic output regardless of multi-platform output or not
+
+```shell
+docker buildx build --build-arg BUILDKIT_MULTI_PLATFORM=1 .
+```
+
+Other useful built-in args can be found in [dockerfile frontend docs](https://github.com/moby/buildkit/blob/master/frontend/dockerfile/docs/syntax.md#built-in-build-args).
+
 ## Examples
 
 ### <a name="allow"></a> Allow extra privileged entitlement (--allow)