Send AuditLog via new middleware fn for admin APIs (#17632)

A new middleware function is added for admin handlers, including options
for modifying certain behaviors. This admin middleware:

- sets the handler context via reflection in the request and sends AuditLog
- checks for object API availability (skipping it if a flag is passed)
- enables gzip compression (skipping it if a flag is passed)
- enables header tracing (adding body tracing if a flag is passed)

While the new function is a middleware, due to the flags used for
conditional behavior modification, which is used in each route registration
call.

To try to ensure that no regressions are introduced, the following
changes were done mechanically mostly with `sed` and regexp:

- Remove defer logger.AuditLog in admin handlers
- Replace newContext() calls with r.Context()
- Update admin routes registration calls

Bonus: remove unused NetSpeedtestHandler

Since the new adminMiddleware function checks for object layer presence
by default, we need to pass the `noObjLayerFlag` explicitly to admin
handlers that should work even when it is not available. The following
admin handlers do not require it:

- ServerInfoHandler
- StartProfilingHandler
- DownloadProfilingHandler
- ProfileHandler
- SiteReplicationDevNull
- SiteReplicationNetPerf
- TraceHandler

For these handlers adminMiddleware does not check for the object layer
presence (disabled by passing the `noObjLayerFlag`), and for all other
handlers, the pre-check ensures that the handler is not called when the
object layer is not available - the client would get a
ErrServerNotInitialized and can retry later.

This `noObjLayerFlag` is added based on existing behavior for these
handlers only.

cmd/admin-bucket-handlers.go

@@ -56,9 +56,7 @@ const (
 // specified in the quota configuration will be applied by default
 // to enforce total quota for the specified bucket.
 func (a adminAPIHandlers) PutBucketQuotaConfigHandler(w http.ResponseWriter, r *http.Request) {
-	ctx := newContext(r, w, "PutBucketQuotaConfig")
-
-	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))
+	ctx := r.Context()
 
 	objectAPI, _ := validateAdminReq(ctx, w, r, iampolicy.SetBucketQuotaAdminAction)
 	if objectAPI == nil {
@@ -110,9 +108,7 @@ func (a adminAPIHandlers) PutBucketQuotaConfigHandler(w http.ResponseWriter, r *
 
 // GetBucketQuotaConfigHandler - gets bucket quota configuration
 func (a adminAPIHandlers) GetBucketQuotaConfigHandler(w http.ResponseWriter, r *http.Request) {
-	ctx := newContext(r, w, "GetBucketQuotaConfig")
-
-	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))
+	ctx := r.Context()
 
 	objectAPI, _ := validateAdminReq(ctx, w, r, iampolicy.GetBucketQuotaAdminAction)
 	if objectAPI == nil {
@@ -145,9 +141,8 @@ func (a adminAPIHandlers) GetBucketQuotaConfigHandler(w http.ResponseWriter, r *
 
 // SetRemoteTargetHandler - sets a remote target for bucket
 func (a adminAPIHandlers) SetRemoteTargetHandler(w http.ResponseWriter, r *http.Request) {
-	ctx := newContext(r, w, "SetBucketTarget")
+	ctx := r.Context()
 
-	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))
 	vars := mux.Vars(r)
 	bucket := pathClean(vars["bucket"])
 	update := r.Form.Get("update") == "true"
@@ -289,9 +284,8 @@ func (a adminAPIHandlers) SetRemoteTargetHandler(w http.ResponseWriter, r *http.
 // ListRemoteTargetsHandler - lists remote target(s) for a bucket or gets a target
 // for a particular ARN type
 func (a adminAPIHandlers) ListRemoteTargetsHandler(w http.ResponseWriter, r *http.Request) {
-	ctx := newContext(r, w, "ListBucketTargets")
+	ctx := r.Context()
 
-	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))
 	vars := mux.Vars(r)
 	bucket := pathClean(vars["bucket"])
 	arnType := vars["type"]
@@ -324,9 +318,8 @@ func (a adminAPIHandlers) ListRemoteTargetsHandler(w http.ResponseWriter, r *htt
 
 // RemoveRemoteTargetHandler - removes a remote target for bucket with specified ARN
 func (a adminAPIHandlers) RemoveRemoteTargetHandler(w http.ResponseWriter, r *http.Request) {
-	ctx := newContext(r, w, "RemoveBucketTarget")
+	ctx := r.Context()
 
-	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))
 	vars := mux.Vars(r)
 	bucket := pathClean(vars["bucket"])
 	arn := vars["arn"]
@@ -368,8 +361,7 @@ func (a adminAPIHandlers) RemoveRemoteTargetHandler(w http.ResponseWriter, r *ht
 
 // ExportBucketMetadataHandler - exports all bucket metadata as a zipped file
 func (a adminAPIHandlers) ExportBucketMetadataHandler(w http.ResponseWriter, r *http.Request) {
-	ctx := newContext(r, w, "ExportBucketMetadata")
-	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))
+	ctx := r.Context()
 
 	bucket := pathClean(r.Form.Get("bucket"))
 	// Get current object layer instance.
@@ -652,9 +644,7 @@ func (i *importMetaReport) SetStatus(bucket, fname string, err error) {
 // 2. Replication config - is omitted from import as remote target credentials are not available from exported data for security reasons.
 // 3. lifecycle config - if transition rules are present, tier name needs to have been defined.
 func (a adminAPIHandlers) ImportBucketMetadataHandler(w http.ResponseWriter, r *http.Request) {
-	ctx := newContext(r, w, "ImportBucketMetadata")
-
-	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))
+	ctx := r.Context()
 
 	// Get current object layer instance.
 	objectAPI, _ := validateAdminReq(ctx, w, r, iampolicy.ImportBucketMetadataAction)
@@ -1069,8 +1059,7 @@ func (a adminAPIHandlers) ImportBucketMetadataHandler(w http.ResponseWriter, r *
 // ReplicationDiffHandler - POST returns info on unreplicated versions for a remote target ARN
 // to the connected HTTP client.
 func (a adminAPIHandlers) ReplicationDiffHandler(w http.ResponseWriter, r *http.Request) {
-	ctx := newContext(r, w, "ReplicationDiff")
-	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))
+	ctx := r.Context()
 
 	vars := mux.Vars(r)
 	bucket := vars["bucket"]
@@ -1132,8 +1121,7 @@ func (a adminAPIHandlers) ReplicationDiffHandler(w http.ResponseWriter, r *http.
 
 // ReplicationMRFHandler - POST returns info on entries in the MRF backlog for a node or all nodes
 func (a adminAPIHandlers) ReplicationMRFHandler(w http.ResponseWriter, r *http.Request) {
-	ctx := newContext(r, w, "ReplicationMRF")
-	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))
+	ctx := r.Context()
 
 	vars := mux.Vars(r)
 	bucket := vars["bucket"]