From f472cb193f5dfcfa4e40e4afc11055070fa5608b Mon Sep 17 00:00:00 2001
From: Tonis Tiigi <tonistiigi@gmail.com>
Date: Wed, 27 Feb 2019 14:53:52 -0800
Subject: [PATCH] exec: fix platform value in cache key

Use vertex platform instead of the current system one. This shouldn't break any cache unless qemu was used. Even when qemu was used the issue would not cause any cache collisions because the base images for run were scoped by platform, but better to stop using invalid data for cache key calculation.

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
---
 solver/llbsolver/ops/exec.go | 34 ++++++++++++++++++++++++----------
 worker/base/worker.go        |  2 +-
 2 files changed, 25 insertions(+), 11 deletions(-)

diff --git a/solver/llbsolver/ops/exec.go b/solver/llbsolver/ops/exec.go
index 0e2e8a8f4..078aa8b7b 100644
--- a/solver/llbsolver/ops/exec.go
+++ b/solver/llbsolver/ops/exec.go
@@ -10,13 +10,13 @@ import (
 	"os"
 	"path"
 	"path/filepath"
-	"runtime"
 	"sort"
 	"strings"
 	"sync"
 	"time"
 
 	"github.com/containerd/containerd/mount"
+	"github.com/containerd/containerd/platforms"
 	"github.com/docker/docker/pkg/locker"
 	"github.com/moby/buildkit/cache"
 	"github.com/moby/buildkit/cache/metadata"
@@ -34,6 +34,7 @@ import (
 	utilsystem "github.com/moby/buildkit/util/system"
 	"github.com/moby/buildkit/worker"
 	digest "github.com/opencontainers/go-digest"
+	specs "github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/opencontainers/runc/libcontainer/system"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
@@ -51,12 +52,13 @@ type execOp struct {
 	md        *metadata.Store
 	exec      executor.Executor
 	w         worker.Worker
+	platform  *pb.Platform
 	numInputs int
 
 	cacheMounts map[string]*cacheRefShare
 }
 
-func NewExecOp(v solver.Vertex, op *pb.Op_Exec, cm cache.Manager, sm *session.Manager, md *metadata.Store, exec executor.Executor, w worker.Worker) (solver.Op, error) {
+func NewExecOp(v solver.Vertex, op *pb.Op_Exec, platform *pb.Platform, cm cache.Manager, sm *session.Manager, md *metadata.Store, exec executor.Executor, w worker.Worker) (solver.Op, error) {
 	return &execOp{
 		op:          op.Exec,
 		cm:          cm,
@@ -65,6 +67,7 @@ func NewExecOp(v solver.Vertex, op *pb.Op_Exec, cm cache.Manager, sm *session.Ma
 		exec:        exec,
 		numInputs:   len(v.Inputs()),
 		w:           w,
+		platform:    platform,
 		cacheMounts: map[string]*cacheRefShare{},
 	}, nil
 }
@@ -98,16 +101,27 @@ func (e *execOp) CacheMap(ctx context.Context, index int) (*solver.CacheMap, boo
 	}
 	op.Meta.ProxyEnv = nil
 
+	p := platforms.DefaultSpec()
+	if e.platform != nil {
+		p = specs.Platform{
+			OS:           e.platform.OS,
+			Architecture: e.platform.Architecture,
+			Variant:      e.platform.Variant,
+		}
+	}
+
 	dt, err := json.Marshal(struct {
-		Type string
-		Exec *pb.ExecOp
-		OS   string
-		Arch string
+		Type    string
+		Exec    *pb.ExecOp
+		OS      string
+		Arch    string
+		Variant string `json:",omitempty"`
 	}{
-		Type: execCacheType,
-		Exec: &op,
-		OS:   runtime.GOOS,
-		Arch: runtime.GOARCH,
+		Type:    execCacheType,
+		Exec:    &op,
+		OS:      p.OS,
+		Arch:    p.Architecture,
+		Variant: p.Variant,
 	})
 	if err != nil {
 		return nil, false, err
diff --git a/worker/base/worker.go b/worker/base/worker.go
index 1926d50f7..fe7c64fb8 100644
--- a/worker/base/worker.go
+++ b/worker/base/worker.go
@@ -197,7 +197,7 @@ func (w *Worker) ResolveOp(v solver.Vertex, s frontend.FrontendLLBBridge, sm *se
 		case *pb.Op_Source:
 			return ops.NewSourceOp(v, op, baseOp.Platform, w.SourceManager, sm, w)
 		case *pb.Op_Exec:
-			return ops.NewExecOp(v, op, w.CacheManager, sm, w.MetadataStore, w.Executor, w)
+			return ops.NewExecOp(v, op, baseOp.Platform, w.CacheManager, sm, w.MetadataStore, w.Executor, w)
 		case *pb.Op_Build:
 			return ops.NewBuildOp(v, op, s, w)
 		}