From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 64491CD37B0 for ; Mon, 18 Sep 2023 15:06:20 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qiFob-000234-3Q; Mon, 18 Sep 2023 11:05:34 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qiFoW-0001yO-7Y for qemu-devel@nongnu.org; Mon, 18 Sep 2023 11:05:28 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qiFoT-0007Wf-L7 for qemu-devel@nongnu.org; Mon, 18 Sep 2023 11:05:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1695049524; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=hyQYA7IIeCzdPkW4Ca2xXB9ZVoHu7kA9b3a5ereaXB4=; b=c6Xkco5Tlvo0aH9qC3Xgao0n94rbF+2cgYllWlCXWbk8Zq/Lc/Rk5ISsGoq7nBtAACrUV3 jcc0kMQpGd6+pgvDQsHtNjHQRfBgL9IoVtCGUOVqda3SQ9kdOerTwXBzGm02G8RkIo9wkp inNPuwksjMPoqKZ6PRoSYLS2MHrWA2Q= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-135-ss7Gj89nMoqc3YVwzhwKuA-1; Mon, 18 Sep 2023 11:05:19 -0400 X-MC-Unique: ss7Gj89nMoqc3YVwzhwKuA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id E3D7829ABA21; Mon, 18 Sep 2023 15:05:04 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.192.127]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AB749C158BA; Mon, 18 Sep 2023 15:05:04 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id B5E7821E6900; Mon, 18 Sep 2023 17:05:03 +0200 (CEST) From: Markus Armbruster To: Daniel Xu Cc: kkostiuk@redhat.com, michael.roth@amd.com, berrange@redhat.com, qemu-devel@nongnu.org, hmodi@aviatrix.com Subject: Re: [PATCH 2/3] qga: Add optional stream-output argument to guest-exec References: <604ef5fd5bda8acdb837b5d28ec405e9fb0332a3.1695034158.git.dxu@dxuuu.xyz> Date: Mon, 18 Sep 2023 17:05:03 +0200 In-Reply-To: <604ef5fd5bda8acdb837b5d28ec405e9fb0332a3.1695034158.git.dxu@dxuuu.xyz> (Daniel Xu's message of "Mon, 18 Sep 2023 04:54:22 -0600") Message-ID: <87il87bjz4.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Received-SPF: pass client-ip=170.10.129.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Daniel Xu writes: > Currently, commands run through guest-exec are "silent" until they > finish running. This is fine for short lived commands. But for commands > that take a while, this is a bad user experience. > > Usually long running programs know that they will run for a while. To > improve user experience, they will typically print some kind of status > to output at a regular interval. So that the user knows that their > command isn't just hanging. > > This commit adds support for an optional stream-output parameter to > guest-exec. This causes subsequent calls to guest-exec-status to return > all buffered output. This allows downstream applications to be able to > relay "status" to the end user. > > If stream-output is requested, it is up to the guest-exec-status caller > to keep track of the last seen output position and slice the returned > output appropriately. This is fairly trivial for a client to do. And it > is a more reliable design than having QGA internally keep track of > position -- for the cases that the caller "loses" a response. > > Signed-off-by: Daniel Xu > --- [...] > diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json > index b720dd4379..0a76e35082 100644 > --- a/qga/qapi-schema.json > +++ b/qga/qapi-schema.json > @@ -1315,13 +1315,18 @@ > # @capture-output: bool flag to enable capture of stdout/stderr of > # running process. defaults to false. > # > +# @stream-output: causes future guest-exec-status calls to always > +# return current captured output rather than waiting to return > +# it all when the command exits. defaults to false. (since: 8.2) So guest-exec-status normally returns no captured output until the process terminates, right? Its documentation (shown below for convenience) did not make me expect this! > +# > # Returns: PID on success. > # > # Since: 2.5 > ## > { 'command': 'guest-exec', > 'data': { 'path': 'str', '*arg': ['str'], '*env': ['str'], > - '*input-data': 'str', '*capture-output': 'GuestExecCaptureOutput' }, > + '*input-data': 'str', '*capture-output': 'GuestExecCaptureOutput', > + '*stream-output': 'bool' }, > 'returns': 'GuestExec' } ## # @GuestExecStatus: # # @exited: true if process has already terminated. # # @exitcode: process exit code if it was normally terminated. # # @signal: signal number (linux) or unhandled exception code (windows) # if the process was abnormally terminated. # # @out-data: base64-encoded stdout of the process # # @err-data: base64-encoded stderr of the process Note: @out-data and # @err-data are present only if 'capture-output' was specified for # 'guest-exec' # # @out-truncated: true if stdout was not fully captured due to size # limitation. # # @err-truncated: true if stderr was not fully captured due to size # limitation. # # Since: 2.5 ## { 'struct': 'GuestExecStatus', 'data': { 'exited': 'bool', '*exitcode': 'int', '*signal': 'int', '*out-data': 'str', '*err-data': 'str', '*out-truncated': 'bool', '*err-truncated': 'bool' }} ## # @guest-exec-status: # # Check status of process associated with PID retrieved via # guest-exec. Reap the process and associated metadata if it has # exited. # # @pid: pid returned from guest-exec # # Returns: GuestExecStatus on success. # # Since: 2.5 ## { 'command': 'guest-exec-status', 'data': { 'pid': 'int' }, 'returns': 'GuestExecStatus' } Could you throw in a patch to clarify what exactly is returned while the process is still running, and what only after it terminated? It should go first.