AB#1915 Local PCR calculation (#243)

* Add QEMU cloud-logging

* Add QEMU metadata endpoints to collect logs during cluster boot

* Send PCRs to QEMU metadata if boot fails on Azure or GCP

Signed-off-by: Daniel Weiße <dw@edgeless.systems>

coordinator/cloudprovider/qemu/logger.go

@@ -0,0 +1,32 @@
+package qemu
+
+import (
+	"net/http"
+	"net/url"
+	"strings"
+)
+
+// Logger is a Cloud Logger for QEMU.
+type Logger struct{}
+
+// NewLogger creates a new Cloud Logger for QEMU.
+func NewLogger() *Logger {
+	return &Logger{}
+}
+
+// Disclose writes log information to QEMU's cloud log.
+// This is done by sending a POST request to the QEMU's metadata endpoint.
+func (l *Logger) Disclose(msg string) {
+	url := &url.URL{
+		Scheme: "http",
+		Host:   qemuMetadataEndpoint,
+		Path:   "/log",
+	}
+
+	_, _ = http.Post(url.String(), "application/json", strings.NewReader(msg))
+}
+
+// Close is a no-op.
+func (l *Logger) Close() error {
+	return nil
+}