[POC] add a wasm krm function implement with wasip1

kyaml/fn/runtime/runtimeutil/functiontypes.go

@@ -134,8 +134,12 @@ type FunctionSpec struct {
 
 	// ExecSpec is the spec for running a function as an executable
 	Exec ExecSpec `json:"exec,omitempty" yaml:"exec,omitempty"`
+
+	// Wasip1Spec is the spec for running a function as an wasm with wasm preview 1
+	Wasip1 Wasip1Spec `json:"wasip1,omitempty" yaml:"exec,omitempty"`
 }
 
+// ExecSpec defines a spec for running a function as an executable
 type ExecSpec struct {
 	Path string `json:"path,omitempty" yaml:"path,omitempty"`
 }
@@ -155,6 +159,13 @@ type ContainerSpec struct {
 	Env []string `json:"envs,omitempty" yaml:"envs,omitempty"`
 }
 
+// Wasip1Spec defines a spec for running a function as a wasm with wasm preview 1
+type Wasip1Spec struct {
+	File string `json:"file,omitempty" yaml:"file,omitempty"`
+
+	Image string `json:"image,omitempty" yaml:"image,omitempty"`
+}
+
 // StorageMount represents a container's mounted storage option(s)
 type StorageMount struct {
 	// Type of mount e.g. bind mount, local volume, etc.

kyaml/fn/runtime/wasip1/wasip1.go

@@ -0,0 +1,64 @@
+package wasip1
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+
+	"sigs.k8s.io/kustomize/kyaml/fn/runtime/runtimeutil"
+	"sigs.k8s.io/kustomize/kyaml/kio"
+	"sigs.k8s.io/kustomize/kyaml/yaml"
+
+	"github.com/tetratelabs/wazero"
+	"github.com/tetratelabs/wazero/imports/wasi_snapshot_preview1"
+)
+
+var _ kio.Filter = &Filter{}
+
+type Filter struct {
+	runtimeutil.Wasip1Spec `json:",inline" yaml:",inline"`
+
+	WorkingDir string `yaml:"workingDir,omitempty"`
+
+	runtimeutil.FunctionFilter
+}
+
+func (c *Filter) Filter(nodes []*yaml.RNode) ([]*yaml.RNode, error) {
+	c.FunctionFilter.Run = c.Run
+	return c.FunctionFilter.Filter(nodes) //nolint:wrapcheck
+}
+
+func (c *Filter) Run(reader io.Reader, writer io.Writer) error {
+	// Create a new runtime
+	ctx := context.Background()
+	r := wazero.NewRuntime(ctx)
+	defer r.Close(ctx)
+
+	// Import the WASI snapshot preview1 module
+	wasi_snapshot_preview1.MustInstantiate(ctx, r)
+
+	// Load the WASI binary from the filesystem
+	wasmBytes, err := os.ReadFile(filepath.Join(c.WorkingDir, c.File))
+	if err != nil {
+		return fmt.Errorf("failed to read wasi binary(path: '%s'): %w", c.File, err)
+	}
+
+	// Create a new module config with stdin and stdout
+	config := wazero.NewModuleConfig().WithStdin(reader).WithStdout(writer)
+
+	// It will not work unless program name (arg[0]) is set.
+	module, err := r.InstantiateWithConfig(ctx, wasmBytes, config.WithArgs("krm"))
+	if err != nil {
+		return fmt.Errorf("failed to wasip1 instantiate module: %w", err)
+	}
+	defer module.Close(ctx)
+
+	return nil
+}
+
+// NewWasmFilter returns a new wasm filter
+func NewWasmFilter(spec runtimeutil.Wasip1Spec) *Filter {
+	return &Filter{Wasip1Spec: spec}
+}

kyaml/go.mod

@@ -11,6 +11,7 @@ require (
 	github.com/sergi/go-diff v1.2.0
 	github.com/spf13/cobra v1.8.0
 	github.com/stretchr/testify v1.9.0
+	github.com/tetratelabs/wazero v1.8.1
 	github.com/xlab/treeprint v1.2.0
 	golang.org/x/sys v0.21.0
 	google.golang.org/protobuf v1.33.0

kyaml/go.sum

@@ -70,6 +70,8 @@ github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO
 github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+github.com/tetratelabs/wazero v1.8.1 h1:NrcgVbWfkWvVc4UtT4LRLDf91PsOzDzefMdwhLfA550=
+github.com/tetratelabs/wazero v1.8.1/go.mod h1:yAI0XTsMBhREkM/YDAK/zNou3GoiAce1P6+rp/wQhjs=
 github.com/xlab/treeprint v1.2.0 h1:HzHnuAF1plUN2zGlAFHbSQP2qJ0ZAD3XF5XD7OesXRQ=
 github.com/xlab/treeprint v1.2.0/go.mod h1:gj5Gd3gPdKtR1ikdDK6fnFLdmIS0X30kTTuNd/WEJu0=
 golang.org/x/sys v0.21.0 h1:rF+pYz3DAGSQAxAu1CbC7catZg4ebC4UIeIhKxBZvws=

kyaml/runfn/runfn.go

@@ -19,6 +19,7 @@ import (
 	"sigs.k8s.io/kustomize/kyaml/fn/runtime/container"
 	"sigs.k8s.io/kustomize/kyaml/fn/runtime/exec"
 	"sigs.k8s.io/kustomize/kyaml/fn/runtime/runtimeutil"
+	"sigs.k8s.io/kustomize/kyaml/fn/runtime/wasip1"
 	"sigs.k8s.io/kustomize/kyaml/kio"
 	"sigs.k8s.io/kustomize/kyaml/kio/kioutil"
 	"sigs.k8s.io/kustomize/kyaml/yaml"
@@ -462,6 +463,21 @@ func (r *RunFns) ffp(spec runtimeutil.FunctionSpec, api *yaml.RNode, currentUser
 			"results-%v.yaml", r.resultsCount))
 		atomic.AddUint32(&r.resultsCount, 1)
 	}
+
+	// if the function is a wasip1 function, run it as a wasip1 function
+	if spec.Wasip1.Image != "" || spec.Wasip1.File != "" {
+		wf := wasip1.NewWasmFilter(spec.Wasip1)
+
+		wf.WorkingDir = r.WorkingDir
+
+		wf.FunctionConfig = api
+		wf.GlobalScope = r.GlobalScope
+		wf.ResultsFile = resultsFile
+		wf.DeferFailure = spec.DeferFailure
+		return wf, nil
+	}
+
+	// if the function is a container, run it as a container
 	if !r.DisableContainers && spec.Container.Image != "" {
 		// TODO: Add a test for this behavior
 		uidgid, err := getUIDGID(r.AsCurrentUser, currentUser)
@@ -491,6 +507,7 @@ func (r *RunFns) ffp(spec runtimeutil.FunctionSpec, api *yaml.RNode, currentUser
 		return cf, nil
 	}
 
+	// if the function is an exec function, run it as an exec function
 	if r.EnableExec && spec.Exec.Path != "" {
 		ef := &exec.Filter{
 			Path:       spec.Exec.Path,

plugin/builtin/prefixtransformer/go.mod

@@ -23,6 +23,7 @@ require (
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
 	github.com/stretchr/testify v1.9.0 // indirect
+	github.com/tetratelabs/wazero v1.8.1 // indirect
 	github.com/xlab/treeprint v1.2.0 // indirect
 	golang.org/x/sys v0.21.0 // indirect
 	google.golang.org/protobuf v1.33.0 // indirect

plugin/builtin/prefixtransformer/go.sum

@@ -60,6 +60,8 @@ github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO
 github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+github.com/tetratelabs/wazero v1.8.1 h1:NrcgVbWfkWvVc4UtT4LRLDf91PsOzDzefMdwhLfA550=
+github.com/tetratelabs/wazero v1.8.1/go.mod h1:yAI0XTsMBhREkM/YDAK/zNou3GoiAce1P6+rp/wQhjs=
 github.com/xlab/treeprint v1.2.0 h1:HzHnuAF1plUN2zGlAFHbSQP2qJ0ZAD3XF5XD7OesXRQ=
 github.com/xlab/treeprint v1.2.0/go.mod h1:gj5Gd3gPdKtR1ikdDK6fnFLdmIS0X30kTTuNd/WEJu0=
 go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=