Journal: Add message ids for emergency log messages

[1awesomeJ]

There's a need to provide more details and possible fixes for all our emergency log messages.
So we're adding a UUID to each existing message, and making an entry for each of them in the catalog using this UUID.
We'll also be modifying the log_emergency() and log_emergency_errno() functions to require a MESSAGE_ID going forward.

The ultimate goal is to help users find meaningful help when they encounter such emergency messages.

[1awesomeJ]

@bluca, @poettering
I'm starting with src/core/crash-handler.c
The file has 13 of our existing 23 log_emergency* calls.

Kindly pitch in or the error descriptions and the possible fixes in your spare minutes sirs.

Thank you.

[bluca]

Don't worry about the message text for now, focus on the implementation so that they can be used and displayed

[1awesomeJ]

Okay.
Good morning sir.

I did get 7 hours of sleep.
Just saying.

[1awesomeJ]

@bluca,
Good afternoon sir.
I just finished working on the log_emergency*() calls.
There are 30 of them total, I worked on 29 in all.
The last one is made in a Coccinelle file (SmPL) It's somewhat different.

I assigned a UUID to each of the 29 messages, and I added an entry for them with these UUIDs in the catalog.

[1awesomeJ]

Now I need to modify the log_emergency*() calls to take these UUIDs as MESSAGE_ID.

I found the functions are variadic, so they have room for the extra arg.

The issue I have is how the MESSAGE_ID will get used.

[1awesomeJ]

I traced the calls like so:
log_emergency(r, "emergency : %m") -> log_full(LOG_EMERG, r, "emergency: %m") (if PID =1),
then log_full_errno_zerook(LOG_EMERG, 0, r, "emergency: %m") then log_internal() then log_internalv() then log_dispatch_internal() then write_to_journal() then log_do_header(), log_do_context(), and sendmsg()

[1awesomeJ]

I haven't found where exactly the MESSAGE_ID should be used

Can you guide on that sir?

Thank you so so much.

[bluca]

Take a look at log_struct()

[1awesomeJ]

Take a look at log_struct()

Okay sir.

Please can I ask questions till 10pm tonight?

And maybe 2 questions tomorrow.

I'd like this to be ready for testing by Monday.

Thank you sir.

[1awesomeJ]

@bluca,
Good evening sir.
Did you have an amazing day?

I've looked at the log_struct(). Like the logging functions which eventually lead to log_internal(), log_struct() also funnels down to log_struct_internal()

So, I'll spend time tomorrow studying these two functions in details: log_struct_internal() and log_dispatch_internal

I didn't work on it again after we last communicated.

I decided to watch some TV for the first time in about 12 months since I started learning programming.

Thank you for being a great mentor.
You guys have made the journey awesome for me. "Thank you" to everyone too.

[1awesomeJ]

Before I go back to NFLX though,
Here's the current prototype of log_struct_internal():

int log_struct_internal(
                int level,
                int error,
                const char *file,
                int line,
                const char *func,
                const char *format, ...) _printf_(6,0) _sentinel_;

I'm thinking we should add a sd_id128 message_id field

[bluca]

that is not necessary, it is already possible to use it, check how MESSAGE_ID is used elsewhere in src/, it happens often

[1awesomeJ]

I realized that too.
After seeing that there was a call to sd_journal_add_match() with the filter "MESSAGE_ID="

[bluca]

I will be away for a week, but @poettering will be able to help you out

[1awesomeJ]

I will be away for a week, but @poettering will be able to help you out

Ohhh ..

1. I hope it's a vacation.
   Like boat rides and all.

2. I hope I'll get guidance from you still when you get back sir.

Thank you so much for all I've gotten these past months.
Have an amazing trip sir.
Thank you so much!!!

[1awesomeJ]

@poettering,
I'm considering changing the definitions of the log_emergency*() functions like so:

static inline int log_emergency(const char *id, const char *message) {
          return log_struct(LOG_EMERGENCY,
                                     LOG_MESSAGE(message),
                                     "MESSAGE_ID=" id);
}

However to accomodate the va_args, will this be better:

static inline int log_emergency(const char *id, const char *message, ...) {
          return log_struct(LOG_EMERGENCY,
                                     LOG_MESSAGE(message),
                                     "MESSAGE_ID=" id, ...);
}

what do you advise sir?

[1awesomeJ]

If that is okay,
I will have to manually update the 30 existing calls to log_emergency() and log_emergency_errno(),
and perhaps some docs?

[1awesomeJ]

@poettering,
Good morning sir.

[1awesomeJ]

We can the use then message id to fetch the entry from the catalog somehow,
Then we'll have a webpage for that entry, and its url will be passed to our print_qrcode() call.

[1awesomeJ]

I do appreciate your time on this sir.
Thank you!

[1awesomeJ]

On the fixes sir.

[1awesomeJ]

@bluca,
Good morning sir.
Please is there anything outstanding on this PR?
What are the next steps now that the IDs have been added?
Will those next steps be part of this PR?

[bluca]

@bluca, Good morning sir. Please is there anything outstanding on this PR? What are the next steps now that the IDs have been added? Will those next steps be part of this PR?

The catalog is published at https://cgit.freedesktop.org/systemd/systemd/plain/catalog/systemd.catalog
It is very crude for now, and just a single page, but a starting point would be to update the bsod tool to create a link to that page, and to print the message-id to look for.

The outreachy internship period is now over, so you are not expected to work anymore - you are of course welcome to keep contributing if you want to

[1awesomeJ]

@bluca, Good morning sir. Please is there anything outstanding on this PR? What are the next steps now that the IDs have been added? Will those next steps be part of this PR?

The catalog is published at https://cgit.freedesktop.org/systemd/systemd/plain/catalog/systemd.catalog It is very crude for now, and just a single page, but a starting point would be to update the bsod tool to create a link to that page, and to print the message-id to look for.

The outreachy internship period is now over, so you are not expected to work anymore - you are of course welcome to keep contributing if you want to

I'd love to keep contributing.
I hope you're able to still guide me in your spare time sir.

Thank you.

[1awesomeJ]

Now that the internship issue is closed,
Can I open a new issue with the subject "beginners seeking guidance" or so, so I can discuss with you there before I open PRs?
Sir?

[bluca]

Just open PRs directly, it's fine

[1awesomeJ]

Okay sir.
When it's something I don't have an idea on how to get started? I'll open an "empty" PR, tag you, and wait for when you find time to respond.

Thank you sir.

[bluca]

You can use the mailing list for generic questions/topics https://lists.freedesktop.org/mailman/listinfo/systemd-devel

[1awesomeJ]

You can use the mailing list for generic questions/topics https://lists.freedesktop.org/mailman/listinfo/systemd-devel

Alright sir.

Although I feel not everyone may have the time and patience to attend to my questions which may be crude, but I'll try, and I'll tag you in PRs too sir.