node-installer: initialize

go.work

@@ -3,4 +3,5 @@ go 1.21
 use (
 	.
 	./service-mesh
+	./node-installer
 )

node-installer/README.md

@@ -0,0 +1,44 @@
+# Contrast node installer
+
+This program runs as a daemonset on every CC-enabled node of a Kubernetes cluster.
+It expects the host filesystem of the node to be mounted under `/host`.
+On start, it will read a configuration file under `$CONFIG_DIR/contrast-node-install.json` and install binary artifacts on the host filesystem according to the configuration.
+After installing binary artifacts, it installs and patches configuration files for the Contrast runtime class `contrast-cc-isolation` and restarts containerd.
+
+## Configuration
+
+By default, the installer ships with a config file under `/config/contrast-node-install.json`, which takes binary artifacts from the container image.
+If desired, you can replace the configuration using a Kubernetes configmap by mounting it into the container.
+
+- `files`: List of files to be installed.
+- `files[*].url`: Source of the file's content. Use `http://` or `https://` to download it or `file://` to copy a file from the container image.
+- `files[*].path`: Target location of the file on the host filesystem.
+- `files[*].integrity`: Expected Subresource Integrity (SRI) digest of the file. Only required if url starts with `http://` or `https://`.
+
+Consider the following example:
+
+```json
+{
+    "files": [
+        {
+            "url": "https://cdn.confidential.cloud/contrast/node-components/2024-03-13/kata-containers.img",
+            "path": "/opt/edgeless/share/kata-containers.img",
+            "integrity": "sha256-EdFywKAU+xD0BXmmfbjV4cB6Gqbq9R9AnMWoZFCM3A0="
+        },
+        {
+            "url": "https://cdn.confidential.cloud/contrast/node-components/2024-03-13/kata-containers-igvm.img",
+            "path": "/opt/edgeless/share/kata-containers-igvm.img",
+            "integrity": "sha256-E9Ttx6f9QYwKlQonO/fl1bF2MNBoU4XG3/HHvt9Zv30="
+        },
+        {
+            "url": "https://cdn.confidential.cloud/contrast/node-components/2024-03-13/cloud-hypervisor-cvm",
+            "path": "/opt/edgeless/bin/cloud-hypervisor-snp",
+            "integrity": "sha256-coTHzd5/QLjlPQfrp9d2TJTIXKNuANTN7aNmpa8PRXo="
+        },
+        {
+            "url": "file:///opt/edgeless/bin/containerd-shim-contrast-cc-v2",
+            "path": "/opt/edgeless/bin/containerd-shim-contrast-cc-v2",
+        }
+    ]
+}
+```

node-installer/go.mod

@@ -0,0 +1,8 @@
+module github.com/edgelesssys/contrast/node-installer
+
+go 1.21
+
+require (
+	github.com/pelletier/go-toml v1.9.5
+	golang.org/x/sys v0.18.0
+)

node-installer/go.sum

@@ -0,0 +1,4 @@
+github.com/pelletier/go-toml v1.9.5 h1:4yBQzkHv+7BHq2PQUZF3Mx0IYxG7LsP222s7Agd3ve8=
+github.com/pelletier/go-toml v1.9.5/go.mod h1:u1nR/EPcESfeI/szUZKdtJ0xRNbUoANCkoOuaOx1Y+c=
+golang.org/x/sys v0.18.0 h1:DBdB3niSjOA/O0blCZBqDefyWNYveAYMNF1Wum0DYQ4=
+golang.org/x/sys v0.18.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=

node-installer/internal/asset/fetcher.go

@@ -0,0 +1,103 @@
+package asset
+
+import (
+	"context"
+	"crypto/sha256"
+	"crypto/sha512"
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"hash"
+	"net/url"
+	"sync"
+)
+
+// Fetcher can retrieve assets from various sources.
+// It works by delegating to a handler for the scheme of the source URI.
+type Fetcher struct {
+	handlers map[string]handler
+	mux      sync.RWMutex
+}
+
+// NewDefaultFetcher creates a new fetcher with default handlers.
+func NewDefaultFetcher() *Fetcher {
+	fetcher := NewFetcher()
+	fetcher.RegisterHandler("file", NewFileFetcher())
+	fetcher.RegisterHandler("http", NewHTTPFetcher())
+	fetcher.RegisterHandler("https", NewHTTPFetcher())
+	return fetcher
+}
+
+// NewFetcher creates a new fetcher.
+func NewFetcher() *Fetcher {
+	return &Fetcher{
+		handlers: make(map[string]handler),
+	}
+}
+
+// Fetch retrieves a file from a source URI.
+func (f *Fetcher) Fetch(ctx context.Context, sourceURI, destination, integrity string) (changed bool, retErr error) {
+	uri, err := url.Parse(sourceURI)
+	if err != nil {
+		return false, err
+	}
+	hasher, expectedSum, err := hashFromIntegrity(integrity)
+	if err != nil {
+		return false, err
+	}
+	schemeFetcher := f.getHandler(uri.Scheme)
+	if schemeFetcher == nil {
+		return false, fmt.Errorf("no handler for scheme %s", uri.Scheme)
+	}
+	return schemeFetcher.Fetch(ctx, uri, destination, expectedSum, hasher)
+}
+
+// FetchUnchecked retrieves a file from a source URI without verifying its integrity.
+func (f *Fetcher) FetchUnchecked(ctx context.Context, sourceURI, destination string) error {
+	uri, err := url.Parse(sourceURI)
+	if err != nil {
+		return err
+	}
+	schemeFetcher := f.getHandler(uri.Scheme)
+	if schemeFetcher == nil {
+		return errors.New("no handler for scheme " + uri.Scheme)
+	}
+	return schemeFetcher.FetchUnchecked(ctx, uri, destination)
+}
+
+// RegisterHandler registers a handler for a scheme.
+func (f *Fetcher) RegisterHandler(scheme string, h handler) {
+	f.mux.Lock()
+	defer f.mux.Unlock()
+	f.handlers[scheme] = h
+}
+
+func (f *Fetcher) getHandler(scheme string) handler {
+	f.mux.RLock()
+	defer f.mux.RUnlock()
+	return f.handlers[scheme]
+}
+
+type handler interface {
+	Fetch(ctx context.Context, uri *url.URL, destination string, expectedSum []byte, hasher hash.Hash) (bool, error)
+	FetchUnchecked(ctx context.Context, uri *url.URL, destination string) error
+}
+
+func hashFromIntegrity(integrity string) (hash.Hash, []byte, error) {
+	var hash hash.Hash
+	switch integrity[:7] {
+	case "sha256-":
+		hash = sha256.New()
+	case "sha384-":
+		hash = sha512.New384()
+	case "sha512-":
+		hash = sha512.New()
+	default:
+		return nil, nil, fmt.Errorf("unsupported hash algorithm: %s", integrity[:7])
+	}
+	expectedSum, err := base64.StdEncoding.DecodeString(integrity[7:])
+	if err != nil {
+		return nil, nil, fmt.Errorf("decoding integrity value: %w", err)
+	}
+	return hash, expectedSum, nil
+}

node-installer/internal/asset/file.go

@@ -0,0 +1,65 @@
+package asset
+
+import (
+	"context"
+	"fmt"
+	"hash"
+	"io"
+	"net/url"
+	"os"
+	"slices"
+
+	"github.com/edgelesssys/contrast/node-installer/internal/fileop"
+)
+
+// FileFetcher is a Fetcher that retrieves assets from a file.
+// It handles the "file" scheme.
+type FileFetcher struct {
+	copier copier
+}
+
+// NewFileFetcher creates a new file fetcher.
+func NewFileFetcher() *FileFetcher {
+	return &FileFetcher{copier: fileop.NewDefault()}
+}
+
+// Fetch retrieves a file from the local filesystem.
+func (f *FileFetcher) Fetch(_ context.Context, uri *url.URL, destination string, expectedSum []byte, hasher hash.Hash) (bool, error) {
+	if uri.Scheme != "file" {
+		return false, fmt.Errorf("file fetcher does not support scheme %s", uri.Scheme)
+	}
+	sourceFile, err := os.Open(uri.Path)
+	if err != nil {
+		return false, fmt.Errorf("opening file: %w", err)
+	}
+	defer sourceFile.Close()
+
+	if _, err := io.Copy(hasher, sourceFile); err != nil {
+		return false, fmt.Errorf("hashing file: %w", err)
+	}
+	if err := sourceFile.Close(); err != nil {
+		return false, fmt.Errorf("closing file: %w", err)
+	}
+	actualSum := hasher.Sum(nil)
+	if !slices.Equal(actualSum, expectedSum) {
+		return false, fmt.Errorf("file hash mismatch: expected %x, got %x", expectedSum, actualSum)
+	}
+	changed, err := f.copier.CopyOnDiff(uri.Path, destination)
+	if err != nil {
+		return false, fmt.Errorf("copying file: %w", err)
+	}
+	return changed, nil
+}
+
+// FetchUnchecked retrieves a file from the local filesystem without verifying its integrity.
+func (f *FileFetcher) FetchUnchecked(_ context.Context, uri *url.URL, destination string) error {
+	if uri.Scheme != "file" {
+		return fmt.Errorf("file fetcher does not support scheme %s", uri.Scheme)
+	}
+	_, err := f.copier.CopyOnDiff(uri.Path, destination)
+	return err
+}
+
+type copier interface {
+	CopyOnDiff(src, dst string) (bool, error)
+}

node-installer/internal/asset/http.go

@@ -0,0 +1,114 @@
+package asset
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"hash"
+	"io"
+	"net/http"
+	"net/url"
+	"os"
+
+	"github.com/edgelesssys/contrast/node-installer/internal/fileop"
+)
+
+// HTTPFetcher is a Fetcher that retrieves assets from http(s).
+// It handles the "http" and "https" schemes.
+type HTTPFetcher struct {
+	mover  mover
+	client *http.Client
+}
+
+// NewHTTPFetcher creates a new HTTP fetcher.
+func NewHTTPFetcher() *HTTPFetcher {
+	return &HTTPFetcher{mover: fileop.NewDefault(), client: http.DefaultClient}
+}
+
+// Fetch retrieves a file from an HTTP server.
+func (f *HTTPFetcher) Fetch(ctx context.Context, uri *url.URL, destination string, expectedSum []byte, hasher hash.Hash) (bool, error) {
+	if uri.Scheme != "http" && uri.Scheme != "https" {
+		return false, fmt.Errorf("http fetcher does not support scheme %s", uri.Scheme)
+	}
+
+	if existing, err := os.Open(destination); err == nil {
+		defer existing.Close()
+		if _, err := io.Copy(hasher, existing); err != nil {
+			return false, fmt.Errorf("hashing existing file %s: %w", destination, err)
+		}
+		if sum := hasher.Sum(nil); bytes.Equal(sum, expectedSum) {
+			// File already exists and has the correct hash
+			return false, nil
+		}
+		hasher.Reset()
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, uri.String(), nil)
+	if err != nil {
+		return false, fmt.Errorf("creating request: %w", err)
+	}
+	response, err := f.client.Do(req)
+	if err != nil {
+		return false, fmt.Errorf("fetching file: %w", err)
+	}
+	defer response.Body.Close()
+
+	tmpfile, err := os.CreateTemp("", "download")
+	if err != nil {
+		return false, err
+	}
+	defer tmpfile.Close()
+	defer os.Remove(tmpfile.Name())
+
+	reader := io.TeeReader(response.Body, hasher)
+
+	if _, err := io.Copy(tmpfile, reader); err != nil {
+		return false, fmt.Errorf("downloading file contents from %s: %w", uri.String(), err)
+	}
+
+	sum := hasher.Sum(nil)
+	if !bytes.Equal(sum, expectedSum) {
+		return false, fmt.Errorf("hash mismatch for %s: expected %x, got %x", uri.String(), expectedSum, sum)
+	}
+	if err := tmpfile.Sync(); err != nil {
+		return false, fmt.Errorf("syncing file %s: %w", tmpfile.Name(), err)
+	}
+	if err := f.mover.Move(tmpfile.Name(), destination); err != nil {
+		return false, fmt.Errorf("moving file: %w", err)
+	}
+
+	return true, nil
+}
+
+// FetchUnchecked retrieves a file from an HTTP server without verifying its integrity.
+func (f *HTTPFetcher) FetchUnchecked(ctx context.Context, uri *url.URL, destination string) error {
+	if uri.Scheme != "http" && uri.Scheme != "https" {
+		return fmt.Errorf("http fetcher does not support scheme %s", uri.Scheme)
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, uri.String(), nil)
+	if err != nil {
+		return fmt.Errorf("creating request: %w", err)
+	}
+	response, err := f.client.Do(req)
+	if err != nil {
+		return fmt.Errorf("fetching file: %w", err)
+	}
+	defer response.Body.Close()
+
+	dstFile, err := os.Create(destination)
+	if err != nil {
+		return err
+	}
+	defer dstFile.Close()
+
+	_, err = io.Copy(dstFile, response.Body)
+	if err != nil {
+		return fmt.Errorf("downloading file contents from %s: %w", uri.String(), err)
+	}
+	return nil
+}
+
+type mover interface {
+	Move(src, dst string) error
+}