Support BUILDKIT_CACHE_MOUNT_NS for persistent caches

cache.go

@@ -18,7 +18,6 @@ const (
 	cacheMountUnset   = ""
 
 	BazelDefaultSocketID = "bazel-default" // Default ID for bazel socket
-
 )
 
 // getSccacheSource returns a Source for downloading and verifying sccache using SourceHTTP
@@ -73,13 +72,15 @@ type CacheConfig struct {
 }
 
 type CacheInfo struct {
+	Namespace   string
 	DirInfo     CacheDirInfo
 	GoBuild     GoBuildCacheInfo
 	RustSCCache SCCacheInfo
 	Bazel       BazelCacheInfo
 }
 
 type CacheDirInfo struct {
+	Namespace string
 	// Platform sets the platform used to generate part of the cache key when
 	// CacheDir.NoAutoNamespace is set to false.
 	Platform *ocispecs.Platform
@@ -105,6 +106,12 @@ func (f CacheDirOptionFunc) SetCacheDirOption(info *CacheDirInfo) {
 	f(info)
 }
 
+func WithCacheNamespace(namespace string) CacheConfigOption {
+	return CacheConfigOptionFunc(func(info *CacheInfo) {
+		info.Namespace = namespace
+	})
+}
+
 func WithCacheDirConstraints(opts ...llb.ConstraintsOpt) CacheConfigOption {
 	return CacheConfigOptionFunc(func(info *CacheInfo) {
 		var c llb.Constraints
@@ -115,44 +122,48 @@ func WithCacheDirConstraints(opts ...llb.ConstraintsOpt) CacheConfigOption {
 	})
 }
 
-func (c *CacheConfig) ToRunOption(worker llb.State, distroKey string, opts ...CacheConfigOption) llb.RunOption {
+func (c *CacheConfig) ToRunOption(worker llb.State, cacheIdentity string, opts ...CacheConfigOption) llb.RunOption {
 	if c.Dir != nil {
-		return c.Dir.ToRunOption(distroKey, CacheDirOptionFunc(func(info *CacheDirInfo) {
+		return c.Dir.ToRunOption(cacheIdentity, CacheDirOptionFunc(func(info *CacheDirInfo) {
 			var cacheInfo CacheInfo
 			for _, opt := range opts {
 				opt.SetCacheConfigOption(&cacheInfo)
 			}
 			*info = cacheInfo.DirInfo
+			info.Namespace = cacheInfo.Namespace
 		}))
 	}
 
 	if c.GoBuild != nil {
-		return c.GoBuild.ToRunOption(distroKey, GoBuildCacheOptionFunc(func(info *GoBuildCacheInfo) {
+		return c.GoBuild.ToRunOption(cacheIdentity, GoBuildCacheOptionFunc(func(info *GoBuildCacheInfo) {
 			var cacheInfo CacheInfo
 			for _, opt := range opts {
 				opt.SetCacheConfigOption(&cacheInfo)
 			}
 			*info = cacheInfo.GoBuild
+			info.Namespace = cacheInfo.Namespace
 		}))
 	}
 
 	if c.RustSCCache != nil {
-		return c.RustSCCache.ToRunOption(distroKey, SCCacheOptionFunc(func(info *SCCacheInfo) {
+		return c.RustSCCache.ToRunOption(cacheIdentity, SCCacheOptionFunc(func(info *SCCacheInfo) {
 			var cacheInfo CacheInfo
 			for _, opt := range opts {
 				opt.SetCacheConfigOption(&cacheInfo)
 			}
 			*info = cacheInfo.RustSCCache
+			info.Namespace = cacheInfo.Namespace
 		}))
 	}
 
 	if c.Bazel != nil {
-		return c.Bazel.ToRunOption(worker, distroKey, BazelCacheOptionFunc(func(info *BazelCacheInfo) {
+		return c.Bazel.ToRunOption(worker, cacheIdentity, BazelCacheOptionFunc(func(info *BazelCacheInfo) {
 			var cacheInfo CacheInfo
 			for _, opt := range opts {
 				opt.SetCacheConfigOption(&cacheInfo)
 			}
 			*info = cacheInfo.Bazel
+			info.Namespace = cacheInfo.Namespace
 		}))
 	}
 
@@ -227,12 +238,13 @@ type CacheDir struct {
 	Sharing string `json:"sharing" yaml:"sharing" jsonschema:"enum=shared,enum=locked,enum=private"`
 
 	// NoAutoNamespace disables the automatic prefixing of the cache key with the
-	// target specific information such as distro and CPU architecture, which may
-	// be auto-injected to prevent common issues that would cause an invalid cache.
+	// build environment identity and CPU architecture, which may be auto-injected
+	// to prevent common issues that would cause an invalid cache.
+	// It does not disable the global BUILDKIT_CACHE_MOUNT_NS prefix.
 	NoAutoNamespace bool `json:"no_auto_namespace" yaml:"no_auto_namespace"`
 }
 
-func (c *CacheDir) ToRunOption(distroKey string, opts ...CacheDirOption) llb.RunOption {
+func (c *CacheDir) ToRunOption(cacheIdentity string, opts ...CacheDirOption) llb.RunOption {
 	return RunOptFunc(func(ei *llb.ExecInfo) {
 		var sharing llb.CacheMountSharingMode
 		switch c.Sharing {
@@ -259,18 +271,18 @@ func (c *CacheDir) ToRunOption(distroKey string, opts ...CacheDirOption) llb.Run
 			opt.SetCacheDirOption(&info)
 		}
 
-		if !c.NoAutoNamespace {
-			platform := ei.Platform
-
-			if platform == nil {
-				platform = info.Platform
-			}
-
-			if platform == nil {
-				p := platforms.DefaultSpec()
-				platform = &p
-			}
-			key = fmt.Sprintf("%s-%s-%s", distroKey, platforms.Format(*platform), key)
+		if c.NoAutoNamespace {
+			key = PersistentCacheID{
+				Namespace: info.Namespace,
+				Key:       key,
+			}.String()
+		} else {
+			key = PersistentCacheID{
+				Namespace:   info.Namespace,
+				Environment: cacheIdentity,
+				Platform:    execCacheIDPlatform(ei, info.Platform),
+				Key:         key,
+			}.String()
 		}
 
 		llb.AddMount(c.Dest, llb.Scratch(), llb.AsPersistentCacheDir(key, sharing)).SetRunOption(ei)
@@ -320,7 +332,8 @@ func (c *GoBuildCache) validate() error {
 }
 
 type GoBuildCacheInfo struct {
-	Platform *ocispecs.Platform
+	Namespace string
+	Platform  *ocispecs.Platform
 }
 
 type GoBuildCacheOption interface {
@@ -345,7 +358,7 @@ func WithGoCacheConstraints(opts ...llb.ConstraintsOpt) CacheConfigOption {
 
 const goBuildCacheDir = "/tmp/dalec/gobuild-cache"
 
-func (c *GoBuildCache) ToRunOption(distroKey string, opts ...GoBuildCacheOption) llb.RunOption {
+func (c *GoBuildCache) ToRunOption(cacheIdentity string, opts ...GoBuildCacheOption) llb.RunOption {
 	return RunOptFunc(func(ei *llb.ExecInfo) {
 		if c.Disabled {
 			return
@@ -356,20 +369,13 @@ func (c *GoBuildCache) ToRunOption(distroKey string, opts ...GoBuildCacheOption)
 			opt.SetGoBuildCacheOption(&info)
 		}
 
-		platform := ei.Platform
-
-		if platform == nil {
-			platform = info.Platform
-		}
-		if platform == nil {
-			p := platforms.DefaultSpec()
-			platform = &p
-		}
-
-		key := fmt.Sprintf("%s-%s-dalec-gobuildcache", distroKey, platforms.Format(*platform))
-		if c.Scope != "" {
-			key = fmt.Sprintf("%s-%s", key, c.Scope)
-		}
+		key := PersistentCacheID{
+			Namespace:   info.Namespace,
+			Environment: cacheIdentity,
+			Platform:    execCacheIDPlatform(ei, info.Platform),
+			Type:        cacheTypeGoBuild,
+			Key:         c.Scope,
+		}.String()
 		llb.AddMount(goBuildCacheDir, llb.Scratch(), llb.AsPersistentCacheDir(key, llb.CacheMountShared)).SetRunOption(ei)
 		llb.AddEnv("GOCACHE", goBuildCacheDir).SetRunOption(ei)
 	})
@@ -398,7 +404,8 @@ func (c *SCCache) validate() error {
 }
 
 type SCCacheInfo struct {
-	Platform *ocispecs.Platform
+	Namespace string
+	Platform  *ocispecs.Platform
 }
 
 type SCCacheOption interface {
@@ -416,7 +423,7 @@ const (
 	sccacheBinary   = "/tmp/internal/dalec/sccache/sccache"
 )
 
-func (c *SCCache) ToRunOption(distroKey string, opts ...SCCacheOption) llb.RunOption {
+func (c *SCCache) ToRunOption(cacheIdentity string, opts ...SCCacheOption) llb.RunOption {
 	// TODO: Future improvement - allow pulling sccache from build context instead of GitHub
 	// This would provide better security and flexibility by allowing users to:
 	// 1. Bring their own verified sccache binary
@@ -443,10 +450,13 @@ func (c *SCCache) ToRunOption(distroKey string, opts ...SCCacheOption) llb.RunOp
 			platform = &p
 		}
 
-		key := fmt.Sprintf("%s-%s-dalec-rustsccache", distroKey, platforms.Format(*platform))
-		if c.Scope != "" {
-			key = fmt.Sprintf("%s-%s", key, c.Scope)
-		}
+		key := PersistentCacheID{
+			Namespace:   info.Namespace,
+			Environment: cacheIdentity,
+			Platform:    FormatCacheIDPlatform(*platform),
+			Type:        cacheTypeRustSccache,
+			Key:         c.Scope,
+		}.String()
 
 		// Set up cache mount for sccache compilation cache
 		llb.AddMount(sccacheCacheDir, llb.Scratch(), llb.AsPersistentCacheDir(key, llb.CacheMountShared)).SetRunOption(ei)
@@ -485,7 +495,9 @@ fi`),
 		// Set up RUSTC_WRAPPER to point at the absolute sccache binary path (no PATH update needed)
 		llb.AddEnv("RUSTC_WRAPPER", sccacheBinary).SetRunOption(ei)
 	})
-} // BazelCache sets up a cache for bazel builds.
+}
+
+// BazelCache sets up a cache for bazel builds.
 // Currently this only supports setting up a *local* bazel cache.
 //
 // BazelCache relies on the *system* bazelrc file to configure the default cache location.
@@ -506,6 +518,7 @@ func (c *BazelCache) validate() error {
 }
 
 type BazelCacheInfo struct {
+	Namespace   string
 	Platform    *ocispecs.Platform
 	constraints *llb.Constraints
 }
@@ -531,7 +544,7 @@ type BazelCacheOption interface {
 	SetBazelCacheOption(*BazelCacheInfo)
 }
 
-func (c *BazelCache) ToRunOption(worker llb.State, distroKey string, opts ...BazelCacheOption) llb.RunOption {
+func (c *BazelCache) ToRunOption(worker llb.State, cacheIdentity string, opts ...BazelCacheOption) llb.RunOption {
 	return RunOptFunc(func(ei *llb.ExecInfo) {
 		var info BazelCacheInfo
 
@@ -549,10 +562,13 @@ func (c *BazelCache) ToRunOption(worker llb.State, distroKey string, opts ...Baz
 			platform = &p
 		}
 
-		key := fmt.Sprintf("%s-%s-dalec-bazelcache", distroKey, platforms.Format(*platform))
-		if c.Scope != "" {
-			key = fmt.Sprintf("%s-%s", key, c.Scope)
-		}
+		key := PersistentCacheID{
+			Namespace:   info.Namespace,
+			Environment: cacheIdentity,
+			Platform:    FormatCacheIDPlatform(*platform),
+			Type:        cacheTypeBazel,
+			Key:         c.Scope,
+		}.String()
 
 		// See bazelrc https://bazel.build/run/bazelrc for more information on the bazelrc file
 

cache_id.go

@@ -0,0 +1,75 @@
+package dalec
+
+import (
+	"strings"
+
+	"github.com/containerd/platforms"
+	"github.com/moby/buildkit/client/llb"
+	ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
+)
+
+const (
+	cacheTypeGoBuild     = "dalec-gobuildcache"
+	cacheTypeRustSccache = "dalec-rustsccache"
+	cacheTypeBazel       = "dalec-bazelcache"
+)
+
+// PersistentCacheID describes a Dalec persistent BuildKit cache mount ID.
+type PersistentCacheID struct {
+	// Namespace is an optional global namespace prepended to the whole cache ID.
+	Namespace string
+	// Environment identifies the build environment that owns the cache.
+	Environment string
+	// Platform identifies the platform when a cache must be platform-scoped.
+	Platform string
+	// Type identifies the Dalec cache type.
+	Type string
+	// Key identifies user-provided cache key material, scope, or a sub-cache.
+	Key string
+}
+
+// String format the cache ID from its non-empty parts.
+func (id PersistentCacheID) String() string {
+	parts := make([]string, 0, 4)
+	for _, part := range []string{id.Environment, id.Platform, id.Type, id.Key} {
+		if part != "" {
+			parts = append(parts, part)
+		}
+	}
+
+	cacheID := strings.Join(parts, "-")
+	if id.Namespace == "" {
+		return cacheID
+	}
+
+	ns := strings.TrimRight(id.Namespace, "/")
+	if cacheID == "" {
+		return ns
+	}
+	return ns + "/" + cacheID
+}
+
+// FormatCacheIDPlatform formats a platform for use in cache IDs.
+func FormatCacheIDPlatform(p ocispecs.Platform) string {
+	return platforms.Format(p)
+}
+
+// FormatSafeCacheIDPlatform formats a platform without path separators.
+func FormatSafeCacheIDPlatform(p ocispecs.Platform) string {
+	return strings.NewReplacer("/", "_", ":", "_").Replace(FormatCacheIDPlatform(p))
+}
+
+func defaultedCacheIDPlatform(p *ocispecs.Platform) string {
+	if p == nil {
+		dp := platforms.DefaultSpec()
+		p = &dp
+	}
+	return FormatCacheIDPlatform(*p)
+}
+
+func execCacheIDPlatform(ei *llb.ExecInfo, fallback *ocispecs.Platform) string {
+	if ei.Platform != nil {
+		return defaultedCacheIDPlatform(ei.Platform)
+	}
+	return defaultedCacheIDPlatform(fallback)
+}