Redfish message registries, plus translation

Matt Spinler mspinler at
Fri Feb 21 06:48:45 AEDT 2020

On 2/19/2020 12:03 PM, James Feist wrote:
> On 2/19/20 9:07 AM, Joseph Reynolds wrote:
>> On 2/18/20 4:02 PM, James Feist wrote:
>>> On 2/18/20 11:25 AM, Bills, Jason M wrote:
>>>> On 2/17/2020 5:53 PM, Joseph Reynolds wrote:
>>>>> On 2/16/20 5:37 PM, Andrew Jeffery wrote:
>>>>>> On Sat, 15 Feb 2020, at 06:27, Matt Spinler wrote:
>>>>>>> Hi James,
>>>>>>> It's looking like in our future we will have to provide:
>>>>>>> 1) Redfish logs using multiple message registries that probably 
>>>>>>> can't be
>>>>>>>      hardcoded into hpp files and checked in.
>>>>>>>      - For example, a registry for our host firmware and 
>>>>>>> hypervisor errors,
>>>>>>>        as our BMC handles displaying logs for them, that we 
>>>>>>> would pick up
>>>>>>>        during our build process.
>>>>>>> and
>>>>>>> 2) Message registry text in multiple languages
>>>>>>> Those being my goals, I have a few questions:
>>>>>>> In general, is the multi-language strategy to just provide a 
>>>>>>> standalone
>>>>>>> registry array for each language which the code then selects 
>>>>>>> based on the
>>>>>>> Language property?
>>>>>>> To support both of the above, would you be open to having 
>>>>>>> functionality
>>>>>>> added
>>>>>>> to read in registries from data files, including based on 
>>>>>>> language? Or,
>>>>>>> would you
>>>>>>> have any other ideas for how to support these items?
>>>>>> Bit of a drive-by question, but shouldn't we be using GNU 
>>>>>> gettext[1] to
>>>>>> handle translation?
>>>>> Matt's proposal is for BMCWeb to have two languages:
>>>>> 1. The implementation language.  When BMCWeb writes internal log 
>>>>> entries, these will be in English.  The BMCWeb developers will use 
>>>>> these to understand what is going on,  and the BMC admin may be 
>>>>> able to read the, but they are not for BMC users.
>>>>> We can certainly use gettext to internationalize this. But it is 
>>>>> not what Matt is asking about.
>>>>> 2. The languages used for Redfish messages.  These message are 
>>>>> added to the HTTP response body.  These are meant to be read by 
>>>>> any BMC REST API user.  For example, messages from the Redfish 
>>>>> "Base" message registry Base.1.7.0.json within DSP8011.  BMCWeb 
>>>>> has a hard-coded version of a subset of these messages, for 
>>>>> example, the AccountModified message in 
>>>>> These messages are defined in English and meant to be translated. 
>>>>> That's what Matt is asking about.
>>>>> Here's my drive-by response.
>>>>> The current implementation is locked into English-only. BMCWeb 
>>>>> code sends messages like this:
>>>>> 1. #include 
>>>>> 2. Write code like: propertyValueModified(res, "myProperty", 
>>>>> myModifiedValue);
>>>>> This calls the function in error_messages.cpp which is hard-coded 
>>>>> English.
>>>>> Having hard-coded function calls and hard-coded implementations 
>>>>> helps with BMCWeb's goal for performance and startup times.
>>>>> However, IMHO, the development process to add new Redfish messages 
>>>>> to BMCWeb is cumbersome.  It should be as easy as copying 
>>>>> Redfish's new JSON file.
>>>> To ease this, there is a script in bmcweb that is designed to parse 
>>>> the JSON message registries into the header file. I just ran it and 
>>>> it has a couple minor bugs that were introduced when we changed the 
>>>> format to fix build warnings.  I'll push a fix.
>>>> One possible solution would be to adapt this script to run 
>>>> automatically at build time.  Then any JSON message registry files 
>>>> that get added either to bmcweb or as an append could be 
>>>> transparently converted to the header file.
>>> An added benefit of this is that it could verify JSON is in legal 
>>> format before it makes it to the BMC.
>> Agreed.  As an alternative, we could enhance the BMCWeb build to 
>> validate the JSON message registry files that are destined for use by 
>> BMCWeb.  That would catch most errors, but be weaker than converting 
>> them to header files: it leaves a window where those files could be 
>> modified after they are packaged into the image and before they are 
>> read into bmcweb.
> Also if someone uses a bbappend and patches in their own files after 
> the build completes (or using a different recipe entirely), they won't 
> be validated.
>>>>> IMHO, the easiest way to to support multiple languages (including 
>>>>> English) is to keep the prototypes in error_messages.hpp so all 
>>>>> the existing uses will continue to work.  Then change the 
>>>>> implementation to select a message from a JSON file based on the 
>>>>> hard-coded message name (example: AccountNotModified) and language 
>>>>> (en-us, zh-cn, or whatever).
>>> Is there any reason to have this update-able at runtime? Regardless 
>>> to limit the possibility of errors I'd like to avoid constant 
>>> pulling from JSON. I'd rather see the JSON being pulled at 
>>> application start, so we take any impact (timing or bugs/crashes) 
>>> early. However I'm not sure I know of a use-case to have this be 
>>> done at runtime.
>> I did not mean for the JSON files to be modifiable at runtime; I see 
>> no use case for that.  I imagined that BMCWeb would read any given 
>> JSON file exactly once and stay in bmcweb heap storage until the 
>> server terminates.  The simplest design is to read all of the JSON 
>> files from its message registry directory: all messages files (Base, 
>> Oem.Redfish, etc.) and all language versions (en-us, cn-zh, etc.). If 
>> the registry gets large because of many messages multiplied by many 
>> translated versions and memory consumption is a concern, then we can 
>> consider just-in-time reading JSON files for that language. (But 
>> let's not go there now.)
>> To be clear: I am also not advocating for the JSON message 
>> translation files to be updatable by any BMC interface.  As far as I 
>> am concerned, they can be baked into the image.  Doing it this way, 
>> the messages can be updated by a firmware update.
> Great, I was just wondering if there was some use case I missed.

Thanks for all of the replies.

To address Andrew's earlier suggestion of gettext, that seems to only 
apply to hardcoded
strings in code, which wouldn't help if we were to pull in other message 
registry data files.

I think that for the sake of extensibility, being able to read in the 
message registries from JSON
files is a big plus, but is that a worse translation scheme?

Does anyone with translation experience have any thoughts on the 2 
different methods?

>> - Joseph
>>>>> All of the usual issues come up with approach:
>>>>> - Will BMCWeb pre-load or load-on-demand the JSON file would be 
>>>>> pre-loaded.  It certainly will not be loaded for every message.
>>>>> - Fallbacks.  For example, if the ja-jp message files does not 
>>>>> have the AccountNotModified message, format the en-us message 
>>>>> instead.
>>>>> - Need a default message.  For example, if BMCWeb tries to sent 
>>>>> the message "NotARealMessage" which is not defined in any message 
>>>>> file, it might be useful to send the raw data instead.
>>>> bmcweb currently provides the given MessageId with a blank Message 
>>>> field if it cannot be found in a registry.
>>>>> - We use the Redfish "Base" message registry, and I think we also 
>>>>> use an OpenBMC Oem message registry as well.  So BMCWeb will have 
>>>>> to load multiple message registries per language.
>>>>> More:
>>>>> - Will a initial set of supported languages be baked into the 
>>>>> firmware image (on the BMC's file system) in English or some other 
>>>>> languages?
>>>>> - Can the BMC admin add and remove supported languages (by adding 
>>>>> or deleting JSON message registry files)?
>>>>> - Will there be REST APIs for that?
>>>>> - Supported by the Redfish spec?
>>>>> So what the the requirements?
>>>>> - Joseph
>>>>> You can see one open source project's work here: 
>>>>>> [1]
>>>>>> Andrew

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