Present Perfect

Every new year is a time of cleaning. After getting back to Inbox 0, my next target is my mailing list subscriptions.

It must be something psychological, but I cannot bring myself to unsubscribe from some of these mailing lists. I don't check on them daily, but once in a while it's darn useful to search through my local copy of mails on, say, selinux, and find solutions for a problem I'm having.

However, all this mailing list mail brings me a lot of headache. My email client is slow, and I would want it to be fast for the real mail I'm getting (from actual people, needing actual work). It's hard to track the mails that matter - all my list mail gets put into folders automatically with some procmail magic, but it also means that some of the things I should be paying more attention to are just another bold folder in Evolution somewhere down the mail tree. And lastly, the server where I host my mail shared with friends gets too much traffic, and syncing 3 different evolutions over IMAP with it is a big part of the burden.

I vastly prefered the newsreader model of old, and I think the de facto standard of mailing lists really is a mistake. But I'm not sure what to replace it with.

What I want:

1. have selected mailing list archives be available on my machines, locally
2. have them synced/updated automatically
3. have them out of the way of my normal mail usage unless when I need them

I've been considering getting a separate email account just for email lists for this purpose, although I don't look forward much to having to change all my subscriptions, and would first like to hear from other people how this approach works out for them.

There used to be a push towards web-based mailing list subscriptions, but I don't know if anyone is really seriously using that, and I would like to have the option of reading these mailing list archives offline.

How do you separate your 'real' mail from your mailing list mail? How do you handle them?

Every new year is a time of cleaning. After getting back to Inbox 0, my next target is my mailing list subscriptions. It must be something psychological, but I cannot...

Every few weeks I have to spend an hour figuring out exactly the same non-googleable thing I've already needed to figure out. So this time it's going on my blog.

The problem is simple: given an input file listing paths, one per line, which probably contain spaces - how do I run a shell command that converts each line to a single shell argument ?

Today, my particular case was a file /tmp/dirs on my NAS which lists all directories in one of my dirvish vaults that contains files bigger than a GB. For some reason not everything is properly hardlinked, but running hardlink on the vault blows up because there are so many files in there.

Let's see if wordpress manages to not mangle the following shell line.

perl -p -e 's@\n@\000@g' /tmp/dirs | xargs -0 /root/hardlink.py -f -p -t -c --dry-run

Every few weeks I have to spend an hour figuring out exactly the same non-googleable thing I've already needed to figure out. So this time it's going on my blog....

I don't want to simply be complaining about Nokia's sad Linux story ending.

It's obvious that things aren't going to get better though for Maemo device owners.

Here are two things that caused me trouble over the last few months, and the fix that did it for me, in case you were suffering from the same problems.

The Facebook photo sharing functionality just stopped working for me. It would upload the file, then give me an error without specifying any reason. I had simply assumed the Facebook API had changed, and since afaik this plugin is sadly closed-source (what on earth possessed Nokia to make a social media sharing component closed to begin with is beyond me - what kind of IP secrets could you possibly have in there?) I thought I would have to do without for now. And it really is a hassle to manually copy photos off then share them from the desktop.

Turns out that I simply had to re-authenticate the Sharing Account in Settings. No idea why - maybe Facebook changed some authentication system in the last few months ? Now it works again.

(As a side note, this plugin's behaviour is really annoying when it comes to uploading photos. It will always try to upload as soon as you connect to a network, although usually all you get is access to some web page on which you have to authenticate, usually by paying, to get on to the net. The sharing plugin already blasts photos at facebook, then fails, gives you a non-useful error message, and then sits there forever without any option to retry. All you can do is cancel the transfer, in which case you will have to re-upload the photos from your library. After some time I figured out that a reboot caused it to retry all pending uploads on the next network connect, and then after that I figured out a kill of a sharing manager process did the same thing. But really, Nokia engineers - a simple 'retry' button was too hard ?)

For the last two weeks my GPS stopped getting a lock completely. This wreaked havoc on my barriosquare/foursquare checkins as well, which simply don't register without a GPS lock (yes I still have a half-done port of bsq to the new foursquare API, but last time I tried I was still stuck on the simply terrible browser coming with the device that seems to be unable to properly complete SSL requests in emulator mode).

I stumbled across this page and simply changed the AGPS server to google's. Worked like a charm on the next connect. Nokia, I don't know what you did to your AGPS server - surely other phones you have are using it too, not just the Maemo ones ?

I swore I wasn't going to buy an N9 because there's no point in buying an EOL'd phone if I plan to develop for it. The reviews when it actually came out almost persuaded me to get it, and the five minutes I got to play with Luis de Bethencourt's phone got me really close. I've even seen plans in Belgium offering this phone! But really, there isn't much point if Nokia isn't going to support this phone any more and services are just going to get worse, and important parts of the stack remain closed and thus unfixable down the road.

This month's Android course at work at least got me familiar developing for the phone and I was actually impressed by Eclipse this time around, and while Java still seems like a bitch to program in, the whole emulator setup is easy to use... Who knows, my next phone may in fact be an Android.

In the meantime, it's nice to see that some of my fixes go noticed. That motivates me to possibly fix that other annoyance in erminig-ng - all-day events triggering an alarm at midnight and waking me up :)

I don't want to simply be complaining about Nokia's sad Linux story ending. It's obvious that things aren't going to get better though for Maemo device owners. Here are two...

I haven't been too good this year at removing friction from my workflow. Today I wanted to change that. And the random friction thrown my way today has to do with ssh.

You see, somewhere along the line I read that it is a good idea to create separate keys for separate identities. So I have an identity for all work-related stuff (which I consider 'ring 1': it's unlikely to change but everyone can get fired or change jobs), one for personal stuff on machines I actually control ('ring 0': they'd have to pry it out of my dead hands), another for my 'public online default' identity ('ring 2': I can always pull a whytheluckystiff and pull myself of the net and reinvent myself), and then per-project identities ('ring 3': I may lose interest in being a fedora or gstreamer contributor without massive changes in my personality).

I started splitting ring 3 per project when it made sense - for example, Fedora recently enforced a key change even if your account wasn't compromised and even if you already have a strong passphrase on your key (like I had), and of course a massive flamefest ensued. I shrugged and decided to split off a new key and set that on all my machines.

But the problem is, this whole tower of ssh doesn't really work well in practice. I chose a long passphrase for the new fedora keys, but obviously I do not want to type that every time I clone a package or commit changes. So I use ssh-agent. In theory, ssh-agent adds your keys and asks you for the passphrase once, and is then able to offer those identities to the other side.

The problem is a lot of ssh servers out there only give you a few tries. So your ssh agent will offer identity by identity until it gets refused. If my fedora identity was added as the fourth identity I lose - I can't clone a package.

Specifying IdentityFile in the ssh config is useless. It is poorly documented, but IdentityFile files actually come after your ssh-agent identities. So your agent blasts all the wrong keys at the host first, and you get denied.

So you can specify IdentityOnly to make sure that only the identity file you want is being used. Sadly in that case it will not use the ssh-agent at all, so it will ask you for the password to your key file - the whole reason you want agents to be used in the first place.

Now obviously ssh has all the pieces it needs to Do The Right Thing. If my config says to use this identity and this identity only, ssh should be able to request ssh-agent to present that identity, and that identity only, and make the login happen without any password.

Surely I must be missing something obvious. Surely one of you uberhackers out there has set up the same thing as me. Why don't you comment about it here and help the rest of us?

I haven't been too good this year at removing friction from my workflow. Today I wanted to change that. And the random friction thrown my way today has to do...

A new Fedora, a new decision on which machines to upgrade. Usually I try to stagger the three machines I use most - my work desktop, my home desktop, and my laptop. I had updated work machine and laptop to F-15 when it came out, and kept my home desktop at F-14.

I actually have two or three root partitions on each of those machines, and I typically do a fresh install on a separate root, so I can try things, poke around, and make sure everything I will need works. When I do the install, I don't mount my /home partition, because I don't want to have the new version upgrade things for me on my user config.

I have a pretty long checklist by now that I go through on each install/upgrade, installing the packages I use a lot, setting up specific configuration, copy over ssh keys, ...

I actually liked F-15 a lot, and though GNOME 3 has its issues (which I still want to document in a separate post), I overall enjoyed the experience. At home, I noticed myself using the windows key or moving my mouse to the top left corner expecting something to happen.

That is how you know you really are ready for GNOME3.

So I thought, what the heck, let's get to upgrading all of them. I started with my laptop, as usual. That mostly went fine, except for hurdle number one. My laptop actually has /home encrypted. And I did not add it to my custom layout in anaconda. So, the system dropped me in a rescue shell after booting. It took me quite a while to figure out that I had to copy over /etc/crypttab from the old system. After that, things worked again.

Arguably, hurdle #1 may not be Fedora's fault. Maybe normal users don't encrypt home drives, or use custom partitioning like I do (although on a few fedora upgrades this saved my bacon when it turned out certain things I needed didn't work in the new Fedora, like VMWare)

And yes, GNOME 3.2 is a slight improvement. Enough to make a difference at least. All the usual applications seem to work, so I can now mount my old /home directory.

That's when I ran into hurdle number 2: the default uid/gid numbering change. My thomas user now was 1000:1000 as opposed to 500:500 on all my machines before Fedora 16.

In this day and age, I still have to shell it up to fix things like that:

find / -uid 500 -exec chown 1000 {} \;
find / -gid 500 -exec chown :1000 {} \;

If I had less shame I'd tell you how embarassing it is if you do this for a few users on your system, and start thinking "let's put this in a for loop", and because it's already 1 AM you start doing things like

for a in 0 1 3; do find / -uid 50$a -exec chown 10$a {} \; ; find / -gid 50$a -exec chown 100$a {} \; done

Note how I got the number of 0's wrong in the first find, and how I actually forgot the : in the second. You can imagine how amusing it is to fix the effect of those commands.

But I'm a shameful person so I won't tell you about this bit. Instead, suffice it to say that this took a long time.

Ok, so now /home is mounted on the laptop, and for the most part things worked fine.

On comes the weekend, so I turn to the home machine. I tend to keep the work machine for last, because I don't want to spend work time on fixing distro problems. And I usually take a whole weekend to upgrade at home. The home machine turned out to be more of a problem. I ran headlong into hurdle number three. You see, there is this new thing called GPT for your partition table, and it is now the default, and it means that fdisk will no longer work, and now you should use gdisk (which sadly is not installed on the rescue bit of the install DVD, boo!), and this is all so we can have grub2, which is supposed to be better or something.

I'm sure one day I will be thankful. But on my home machine, I didn't know any of this, and just had anaconda tell me something about the boot image being too large and there was no space for it and my system may not boot. (I am not sure why I did not run into this problem on my laptop - presumably, looking at the disk layout now, because I kept the original install, which includes Windows, and just shrunk that and added linux - so it's probably the windows thing doing the booting). And sure enough, the Fedora 16 install did not boot. It dropped me into my friend, the shell.

So here's the thing. This new way of doing things needs more space than your average MBR, so you actually need to create a primary partition for this, and it needs to be in the first 2 TiB. So you know what time it is now. It's resize-o-clock time - I get to learn the joys and mysteries of shrinking ext4-on-software-raid so I can make space for this new partition, which doesn't need to be big, apparently 5 MB is more than enough. Aren't I happy now that I stubbornly stuck to having a /boot partition as the primary one on my machines, so I can just shrink that a little?

So shrinking an ext partition I already had down pat. I learnt about shrinking software raid partitions, and again I got into the land of not understanding which of the many types of numbers (sectors ? blocks ? bytes ? cilinders ? Mebi vs Mega ?) are understood the same way by the tools, or not understanding how much of those numbers you need to count extra because of the layer of indirection being added (encryption on logical volume on LVM on software RAID anyone ?). So to be safe I end up shrinking 10% on each layer of the onion as I go deeper - then let the tools handle growing to the maximum space again, since that's the one thing they're usually decent at.

But you know, if I've done all this, I want to get it right. I don't want a stinking BIOS boot partition sitting after my /boot partitions. That's not how F16 sets it up by default. But I have never actually moved a partition. So, download gparted, look at it, figure out how it can let me do that, make sure I ask it to count by cylinders so it doesn't leave gaps, be puzzled at why it doesn't let me fractions for MiB sizes of partitions, and work around it in some other way. And so I finally have those two software raid /boot-wearing partitions where I want them - sitting right behind this new BIOS partition.

I create a new partition in fdisk (which is what I'm used to), but I can't actually set the partition type to EF02, which has four characters where I expect two. But really that is what BIOS BOOT should be.

And now the internet tells me I need to set some flag on it using a tool called parted - some flag called bios_grub. Except when I type that magical command that sets the flag, it tells me it can't exist:

[root@otto ~]# parted /dev/sda set 6 bios_grub
parted: invalid token: bios_grub
Flag to Invert?


Isn't this tool nicely written for only the writer of the tool instead of for human beings? Of course I don't know this when it barfs this at me, but at the end of this story I figured a bunch of things out that this tool could have told me.

You see, invalid token just means that it doesn't accept the flag named bios_grub. I know this because I'm a programmer so I know the programmer used a token parser - a thing normal people shouldn't have to know about. What's that you're asking? Flag to Invert? How about the Belgian flag, I would quite like to see the colors go in the opposite direction. No, that's a prompt to choose a different flag to invert than bios_grub. Apparently bios_grub is a flag, not a setting, and I'm trying to invert it, instead of setting it. Can you tell me what flags you do know about, dear parted ?


(parted) help set
set NUMBER FLAG STATE change the FLAG on partition NUMBER

NUMBER is the partition number used by Linux. On MS-DOS disk labels,
the primary partitions number from 1 to 4, logical partitions from 5
onwards.
FLAG is one of: boot, root, swap, hidden, raid, lvm, lba, hp-service,
palo, prep, msftres, bios_grub, atvrecv, diag, legacy_boot
STATE is one of: on, off


Wait, what ? You do know about bios_grub ? But you don't let me set it ?

I seriously spent 30 minutes on trying to figure that one out.

In the end, it's because a) I should run gdisk b) parted won't let you set that flag on a normal MBR drive c) gdisk should convert to using GPT and d) the messages gdisk prints by default are SUPER scary and the docs say that this is intentional to keep away stupid Windows users (I am not making this shit up). Well, that's why I use software RAID, isn't it ? How about we take our chances, dive in deep, and let this gdisk thing do the conversion to GPT on the first disk. Gulp.

OK, I got lucky. That actually worked. I can now create this partition, with the proper flag set. While I'm at it, why don't we try this 'sort partitions' option in gdisk so that this new partition, which is now at the start, but listed as number 4 out of 4, shows up as number 1. Sure, it will renumber all other partitions, but let's just hope that most things use UUID's and labels and what not by now, and if not I should be able to figure things out.

In what feels like Day 5 in a two-day weekend, the system now boots! I actually see a new grub (wait, why is that text-mode only again ? Fedora guys, you spent years to make everything look graphical, because that was some huge important feature that mostly got in my way when it took longer than it was supposed to and I had no way to see why except reboot and remove quiet and rhgb from the options) and now you suddenly let grub2 take that back from you? Show us some spine, please), and the system shows me plymouth again. Until it doesn't anymore, and drops me into a terminal screen.

Hurdle number four. Can you guess what it is ? Go on, take a stab. If you've updated your system, I'm sure you know the answer. I'll give you some whitespace to think about it...

SELinux. Riding in to relabel my file system to save it from the evil people out there. And sure, it warns me. This may take a long time. And then it proceeds to throw asterisks in my face. Lots of asterisks. It's not the first time this happens. But every time it does, I cannot help but wonder one thing.

Who thought it was a great idea to throw asterisks at the user? How many asterisks am I supposed to expect? Never mind that you can't actually count them unless you glue your eyeball at the screen, because there are so many they actually scroll off at the top. You know, if you squint hard enough, you can see the maniacally laughing face of the programmer who thought this was a nice way of showing progress. Never mind that tools like fsck can show a progress bar that actually means something (if you trick it into sending data to file descriptor 0) in a sensible way - one line on the console, and visible progress towards an end goal of 100%.

If only I could guess what a long time is going to end up being. Is it a 'get a drink' amount of time? Or 'watch some dexter'. Or nookie time? Or, get the hell out of the house and do all the shopping for the next three hours because there's no way you'll be doing anything useful with this system for that long?

So I do all of those things, twice, and one even four times times (I won't tell you which but I ended up having to pee a lot), and I come back, and the system has rebooted, and there's actually a GUI asking me to log in.

You know, this Fedora 16 better be frigging spectacular after this six day weekend.

I log in, follow my standard upgrade checklist, try out some of my tools. Media keys don't seem to work as before for my prototype music player (it flashes a nasty forbidden sign at me), and even though I set up to have nothing happen on inserting audio CD's (because my LEGO robot is inserting CD's into an external drive about fifty times a day), Rhythmbox craps on and FORCES me to select which of the many CD's with exactly the same name that audio CD might be. So, par for the course so far.

Maybe a reboot will fix that, it may not know about those settings until I have everything installed and upgraded. And if I reboot, I'd better convert my second drive to GPT and fix my /boot and set that flag and all that. So I do. And for some reason I can't figure out how to tell software raid that sda2 and sdb2 (which are both still perfectly mountable as ext file systems and were part of the previous RAID-1 /boot array before I resized them) really are a software raid. So there's this point where I've wasted more time on trying that then it would have taken me to actually manually type every byte on that /boot partition, and I just give up and recreate a software raid on those two partitions and copy stuff over.

And then I reboot. And won't you know it. Effing goddamn selinux relabel all over again. In fact, this way too long entry was typed completely in less than half the time selinux took to complete some work it had already done an hour ago.

I better have a working system after this last relabel finishes. Now excuse me while I go make some comfort food, potatoes and beans and runny eggs with butter sauce. I'm going to eat it while my good friend Dexter comes back from a long holiday. It's the only thing that is going to get me out of this weekend funk. And you know who I will be thinking about every time my friend Dexter tells me of a problem he solved...

A new Fedora, a new decision on which machines to upgrade. Usually I try to stagger the three machines I use most - my work desktop, my home desktop, and...