From: Max Reitz <mreitz@redhat.com>
To: "Daniel P. Berrangé" <berrange@redhat.com>,
"Markus Armbruster" <armbru@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>, John Snow <jsnow@redhat.com>,
qemu-devel@nongnu.org, qemu-block@nongnu.org,
Maxim Levitsky <mlevitsk@redhat.com>
Subject: Re: [PATCH 02/13] qcrypto-luks: implement encryption key management
Date: Thu, 6 Feb 2020 15:20:41 +0100 [thread overview]
Message-ID: <f5f7380d-d5b3-65ce-96c9-5fb3c75d050a@redhat.com> (raw)
In-Reply-To: <20200206134918.GM2391707@redhat.com>
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On 06.02.20 14:49, Daniel P. Berrangé wrote:
> On Thu, Feb 06, 2020 at 02:44:45PM +0100, Markus Armbruster wrote:
>> Markus Armbruster <armbru@redhat.com> writes:
>>
>>> Kevin Wolf <kwolf@redhat.com> writes:
>>>
>>>> Am 05.02.2020 um 11:03 hat Markus Armbruster geschrieben:
>>>>> Kevin Wolf <kwolf@redhat.com> writes:
>> [...]
>>>>>> Adding a key gets more complicated with your proposed interface because
>>>>>> state must be set explicitly now whereas before it was derived
>>>>>> automatically from the fact that if you give a key, only active makes
>>>>>> sense.
>>>>>
>>>>> The explicitness could be viewed as an improvement :)
>>>>
>>>> Not really. I mean, I really know to appreciate the advantages of
>>>> -blockdev where needed, but usually I don't want to type all that stuff
>>>> for the most common tasks. qemu-img amend is similar.
>>>>
>>>> For deleting, I might actually agree that explicitness is an
>>>> improvement, but for creating it's just unnecessary verbosity.
>>>>
>>>>> If you'd prefer implicit here: Max has patches for making union tags
>>>>> optional with a default. They'd let you default active to true.
>>>>
>>>> I guess this would improve the usability in this case.
>>
>> Thinking and writing in the "Making QEMU easier for management tools and
>> applications" monster thread have made me realize we're mixing up two
>> aspects that ought to be kept separate: machine-friendly QMP and
>> human-friendly CLI.
>>
>> You argue that
>>
>> $ qemu-img amend -o encrypt.keys.0.new-secret=sec0 test.qcow2
>>
>> is nicer than
>>
>> $ qemu-img amend -o encrypt.keys.0.state=active,encrypt.keys.0.secret=sec0 test.qcow2
>>
>> and you do have a point: humans want their CLI terse. Redundancy is
>> unwanted, except perhaps to protect users from dangerous accidents. In
>> this example, state=active is redundant when a secret is given, because
>> anything else would be an error.
>>
>> In QMP, however, we like things simple and explicit, and we eschew
>> magic.
>>
>> This particular magic might just be simple enough to be acceptable in
>> QMP. We'd "merely" have to support explicit defaults in the schema (a
>> clear improvement if you ask me), and optional union tags (tolerable as
>> long as the default comes from the schema, I guess).
>>
>> My point is: QAPI schema design *must* focus on QMP and nothing else.
>> If we try to serve both QMP and human-friendly CLI, we'll likely botch
>> both.
>>
>> I believe a truly human-friendly CLI requires more than just
>> human-friendly concrete syntax for QMP. Same as HMP, really.
>
> A human-friendly approach to this problem would never even
> have the generic "amend" design IMHO. Friendly would be to
> have a CLI that is approx the same as "cryptsetup" provides
> eg
>
> $ qemu-img add-key /path/to/disk
> enter key>..
> re-enter key>...
>
> or
>
> qemu-img add-key --keyfile /some/file.txt /path/to/disk
I have only scanned through the discussion up until this point, but I
agree that amend doesn’t need to be human-friendly at all cost.
If we really want a human-friendly keyslot modification interface, we
can always add a specific qemu-img subcommand that provides high-level
succinct operations based on a low-level and more verbose amend interface.
(Or just a script that isn’t even built into qemu-img, because I suppose
such a operation “translation” would be easier to implement in a
scripting language. Maybe qemu-img could be extended to invoke external
scripts for specific subcommands? But anyway, those would all be ideas
for the future.)
Max
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next prev parent reply other threads:[~2020-02-06 14:21 UTC|newest]
Thread overview: 84+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-14 19:33 [PATCH 00/13] LUKS: encryption slot management using amend interface Maxim Levitsky
2020-01-14 19:33 ` [PATCH 01/13] qcrypto: add generic infrastructure for crypto options amendment Maxim Levitsky
2020-01-28 16:59 ` Daniel P. Berrangé
2020-01-29 17:49 ` Maxim Levitsky
2020-01-14 19:33 ` [PATCH 02/13] qcrypto-luks: implement encryption key management Maxim Levitsky
2020-01-21 7:54 ` Markus Armbruster
2020-01-21 13:13 ` Maxim Levitsky
2020-01-28 17:11 ` Daniel P. Berrangé
2020-01-28 17:32 ` Daniel P. Berrangé
2020-01-29 17:54 ` Maxim Levitsky
2020-01-30 12:38 ` Kevin Wolf
2020-01-30 12:53 ` Daniel P. Berrangé
2020-01-30 14:23 ` Kevin Wolf
2020-01-30 14:30 ` Daniel P. Berrangé
2020-01-30 14:53 ` Markus Armbruster
2020-01-30 14:47 ` Markus Armbruster
2020-01-30 15:01 ` Daniel P. Berrangé
2020-01-30 16:37 ` Markus Armbruster
2020-02-05 8:24 ` Markus Armbruster
2020-02-05 9:30 ` Kevin Wolf
2020-02-05 10:03 ` Markus Armbruster
2020-02-05 11:02 ` Kevin Wolf
2020-02-05 14:31 ` Markus Armbruster
2020-02-06 13:44 ` Markus Armbruster
2020-02-06 13:49 ` Daniel P. Berrangé
2020-02-06 14:20 ` Max Reitz [this message]
2020-02-05 10:23 ` Daniel P. Berrangé
2020-02-05 14:31 ` Markus Armbruster
2020-02-06 13:20 ` Markus Armbruster
2020-02-06 13:36 ` Daniel P. Berrangé
2020-02-06 14:25 ` Kevin Wolf
2020-02-06 15:19 ` Markus Armbruster
2020-02-06 15:23 ` Maxim Levitsky
2020-01-30 15:45 ` Maxim Levitsky
2020-01-28 17:21 ` Daniel P. Berrangé
2020-01-30 12:58 ` Maxim Levitsky
2020-02-15 14:51 ` QAPI schema for desired state of LUKS keyslots (was: [PATCH 02/13] qcrypto-luks: implement encryption key management) Markus Armbruster
2020-02-16 8:05 ` Maxim Levitsky
2020-02-17 6:45 ` QAPI schema for desired state of LUKS keyslots Markus Armbruster
2020-02-17 8:19 ` Maxim Levitsky
2020-02-17 10:37 ` QAPI schema for desired state of LUKS keyslots (was: [PATCH 02/13] qcrypto-luks: implement encryption key management) Kevin Wolf
2020-02-17 11:07 ` Maxim Levitsky
2020-02-24 14:46 ` Daniel P. Berrangé
2020-02-24 14:50 ` Maxim Levitsky
2020-02-17 12:28 ` QAPI schema for desired state of LUKS keyslots Markus Armbruster
2020-02-17 12:44 ` Eric Blake
2020-02-24 14:43 ` Daniel P. Berrangé
2020-02-24 14:45 ` QAPI schema for desired state of LUKS keyslots (was: [PATCH 02/13] qcrypto-luks: implement encryption key management) Daniel P. Berrangé
2020-02-25 12:15 ` Max Reitz
2020-02-25 16:48 ` QAPI schema for desired state of LUKS keyslots Markus Armbruster
2020-02-25 17:00 ` Max Reitz
2020-02-26 7:28 ` Markus Armbruster
2020-02-26 9:18 ` Maxim Levitsky
2020-02-25 17:18 ` Daniel P. Berrangé
2020-03-03 9:18 ` QAPI schema for desired state of LUKS keyslots (was: [PATCH 02/13] qcrypto-luks: implement encryption key management) Maxim Levitsky
2020-03-05 12:15 ` Maxim Levitsky
2020-01-14 19:33 ` [PATCH 03/13] block: amend: add 'force' option Maxim Levitsky
2020-01-14 19:33 ` [PATCH 04/13] block: amend: separate amend and create options for qemu-img Maxim Levitsky
2020-01-28 17:23 ` Daniel P. Berrangé
2020-01-30 15:54 ` Maxim Levitsky
2020-01-14 19:33 ` [PATCH 05/13] block/crypto: rename two functions Maxim Levitsky
2020-01-14 19:33 ` [PATCH 06/13] block/crypto: implement the encryption key management Maxim Levitsky
2020-01-28 17:27 ` Daniel P. Berrangé
2020-01-30 16:08 ` Maxim Levitsky
2020-01-14 19:33 ` [PATCH 07/13] qcow2: extend qemu-img amend interface with crypto options Maxim Levitsky
2020-01-28 17:30 ` Daniel P. Berrangé
2020-01-30 16:09 ` Maxim Levitsky
2020-01-14 19:33 ` [PATCH 08/13] iotests: filter few more luks specific create options Maxim Levitsky
2020-01-28 17:36 ` Daniel P. Berrangé
2020-01-30 16:12 ` Maxim Levitsky
2020-01-14 19:33 ` [PATCH 09/13] qemu-iotests: qemu-img tests for luks key management Maxim Levitsky
2020-01-14 19:33 ` [PATCH 10/13] block: add generic infrastructure for x-blockdev-amend qmp command Maxim Levitsky
2020-01-21 7:59 ` Markus Armbruster
2020-01-21 13:58 ` Maxim Levitsky
2020-01-14 19:33 ` [PATCH 11/13] block/crypto: implement blockdev-amend Maxim Levitsky
2020-01-28 17:40 ` Daniel P. Berrangé
2020-01-30 16:24 ` Maxim Levitsky
2020-01-14 19:33 ` [PATCH 12/13] block/qcow2: " Maxim Levitsky
2020-01-28 17:41 ` Daniel P. Berrangé
2020-01-14 19:33 ` [PATCH 13/13] iotests: add tests for blockdev-amend Maxim Levitsky
2020-01-14 21:16 ` [PATCH 00/13] LUKS: encryption slot management using amend interface no-reply
2020-01-16 14:01 ` Maxim Levitsky
2020-01-14 21:17 ` no-reply
2020-01-16 14:19 ` Maxim Levitsky
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