white paint warning
Monday, September 8 2014
After over a year of development, my client is getting close to beta-launching that Lightroom-interfacing webapp. Among the many things the webapp does in its complex data choreography is FTPing thumbnails of images from Lightroom up to a web server so that things can be done with the images there, beyond the numerous constraints that Lightroom imposes on its plugins. Up until today, I'd had trouble with server permissions and had actually hardcoded the credentials of a very powerful user into the Lua code so that it could do the FTPing without any guff about what it could or could not do. But with a release imminent, I realized I couldn't let that code go into general circulation. So today, after playfully experimenting with obfuscating the password algorithmically (in a way that any actual programmer would have no problem untangling), I went through the ordeal of making the permissions happen they way that they need to. The Lua code would only be given access to an FTP dropbox (ideally with write-only access, though in practice this didn't work), and once uploaded, the PHP would process of a text-file data manifest and transfer the images to their permanent home (and ultimately delete them from the dropbox). I've complained about this before and I'll complain about it again: every Linux server is different, and there's no fixed place where configuration files will be found or even what species of dæmon is handling what responsibilities. On this particular server, for example, the FTP dæmon was PureFTP. Not only did I have to acquaint myself with commands like chgrp and gpasswd, but I also learned that changes made to PureFTP users do not manifest until you issue a pure-pwd mkdb. That last one alone ate up at least an hour of my day. But it was satisfying to finally get the application handling its FTP duties in a reasonably-secure fashion.
Its telling that the Putty window where I was issuing these commands was not the only one I had going during this time. Simultaneously with that work, I was fixing a database synchronization script on that Los Angeles movie site I've recently started working on. Due to the tiny 8 gigabyte size of that server's "hard drive" (I use quotes because it's all virtual), I'd been having trouble finding space to place the database dumps (which can be over a gigabyte in size). And all of this is just to get a lousy development site up and running without incurring a huge unexpected expense. The takeaway I'm learning from working with Amazon Web Services is that it's not a very good deal and (as with health care), it's hard to predict in advance how much the taking of certain actions is going to cost. If you find yourself needing to spin up a database instance to fix some problem, you can get hit with a multi-hundred-dollar shock (as happened to the movie website after that database fiasco I accidentally triggered a few weeks back).
Down in the greenhouse, I drilled three more holes and installed three large bolts (salvaged from the scrapped Honda Civic) into the rock face where I plan to install the cantilevered support for the north end of the floor girder. I also used "the fucked saw" to cut some grooves into the rock face so there would be a nice rough attachment surface for the concrete I will eventually pour. Yesterday I'd used two triangular and one rectangular pieces of plywood to make a three-sided mold that will allow me to create the base for a girder support shaped like half of an upside-down pyramid. Using a number of four-foot-long sticks of lumber, I was able to wedge this mold tightly against the rock face around all that metal hardware bristling from it. Now all I needed was some fresh concrete.
In cat news, Phoebe has mostly remained in the upstairs bathroom, though we've let her roam freely into the bedroom occasionally (while keeping its door to the rest of the house closed). Celeste was more tolerant of her today, and she Phoebe genuinely seems to like Ramona (when the latter is not too preoccupied with her butthole). The big surprise today was Phoebe's interaction with Clarence, a cat to whom she hadn't really been introduced. When he came into the bathroom, she marched right up to him and stuck her nose against his. Clarence was a little taken aback, but he didn't hiss. He even tolerated a second intrusion into his personal space when she followed him up to the food dish on the large wooden cabinet beneath the window.
Gretchen had me cook dinner tonight, and so I made rice pasta with red sauce, chick peas, and vegan sausage and a side of kale straight from the garden flavored with hot peppers and garlic (also from the garden) as well as a few leaves from a Velvetleaf weed (because I'd read they eat it is stir-fried in China and Malta).
When the mail had come today, I'd received a cheap Chinese LCD display with an HDMI input, and so this evening I excitedly tried hooking it up to a Raspberry Pi. But all it did was make a surprisingly-loud hissing sound from its electronics; its display never was anything but black. So then I tried a different wall wart, and then a different one (always between 5 and 12 volts supplying one amp). At some point I smelled a bad smell and realized that a power supply chip on the electronics board was rapidly overheating. Later I figured out why: that last wall wart had delivered 12 volts AC not DC. Oops! From then on, the LCD display didn't even make that hissing noise any more. It had apparently died completely. But it had never really worked to begin with, so I'll have to see if I can claw my $38 back from the eBay vendor.
The screwup with the wall wart underscored the problem I have of reading the tiny print that gives those devices' specifications. My eyes just aren't as good as they used to be when it comes to reading tiny print. Clearly, I needed a way to see at a glance whether or not a wall wart provided AC (at the very minimum). So I rooted through my box of wall warts and painted white the plugs of the two AC devices I found. I also labeled the sides of the wall wart itself with big ugly blobs of white finger paint spelling out the letters "AC."
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