Mr. Buzz Aldrin, everyone!

Just had the privilege of meeting Mr Buzz Aldrin, the second man to ever set foot on the Moon! :o))

How to access a django python rest service that uses a login page for authentication

Today we bumped into a little challenge at work where we had to document a REST API in the portal we're developing.

The main problem was that this REST API did not authenticate with http auth. Instead, it relied on authenticating against the portal's (html based) login page, getting the cookie and consuming the REST API from there.

Here's how we solved the problem:
step 1- check the login page's html to see what the username and password form fields are called
(in our  case, they were called uName and pwd)

step2- customize the following bash script with your username, password and form fields

[root@userportal ~]# cat templates.sh

LOGIN_URL=http://localhost:8081/login/

YOUR_USER='username'

YOUR_PASS='password'

COOKIES=cookies.txt

CURL_BIN="curl -s -c $COOKIES -b $COOKIES -e $LOGIN_URL"

echo "Django Auth: get csrftoken ..."

$CURL_BIN $LOGIN_URL > /dev/null

DJANGO_TOKEN="csrfmiddlewaretoken=$(grep cid $COOKIES | sed 's/^.*cid\s*//')"

echo "DJANGO TOKEN is $DJANGO_TOKEN"

echo "######################################################"

echo "Performing login..."

$CURL_BIN \

    -d "$DJANGO_TOKEN&uName=$YOUR_USER&pwd=$YOUR_PASS" \

    -X POST $LOGIN_URL

echo "######################################################"

echo "Getting all templates..."

$CURL_BIN \

    -d "$DJANGO_TOKEN&..." \

    -X GET http://localhost:8081/api/templates/ | python -m json.tool

rm $COOKIES

[root@userportal ~]#

What this script basically does is:

- it connects to the login page and saves its cookies into cookies.txt

- then it reads that file and extracts cookie "cid" to get the value of the "csrfmiddlewaretoken" 

- and authenticates against the login page passing your username, password and the csrfmiddlewaretoken variables

At this point you'll be authenticated and the session will be saved in cookies.txt so all there's left to do is call out your REST web service! :o)

Hope this can be of help to someone else!

CRIU, a project to implement checkpoint/restore functionality for Linux in userspace

Just bumped into this really cool project called CRIU.

Basically, CRIU lets you checkpoint / restore processes in Linux (from the userspace).


"Checkpoint/Restore In Userspace, or CRIU (pronounced kree-oo, IPA: /krɪʊ/, Russian: криу), is a software tool for Linux operating system. Using this tool, you can freeze a running application (or part of it) and checkpoint it to a hard drive as a collection of files. You can then use the files to restore and run the application from the point it was frozen at. The distinctive feature of the CRIU project is that it is mainly implemented in user space."

I did a small test with a perl application and it worked like a charm. Here's what I did:

Step 1- run a test perl script that writes to a temporary file every second

root@docker:~/docker_tests# cat test.pl

#!/usr/bin/perl

use IO::Handle;

my $filename = '/tmp/report.txt';

open(my $fh, '>', $filename) or die "Could not open file '$filename' $!";

for (my $i=1; $i <= 300; $i++) {

        print $fh "i is $i\n";

        $fh->flush();

        sleep 1;

}

close $fh;

root@docker:~/docker_tests# ./test.pl &

[1] 14969

root@docker:~/docker_tests# tail /tmp/report.txt

i is 1

i is 2

i is 3

i is 4

i is 5

i is 6

i is 7

root@docker:~/docker_tests# 

Step 2 - checkpoint the process id (14969) to a folder called "checkpoint"

root@docker:~/docker_tests# mkdir checkpoint

root@docker:~/docker_tests# criu-1.6/criu dump --shell-job  -D checkpoint -t 14969

Warn  (arch/x86/crtools.c:132): Will restore 14969 with interrupted system call

root@docker:~/docker_tests#

[1]+  Killed                  ./test.pl

root@docker:~/docker_tests# ls -l checkpoint/

total 1416

-rw-r--r-- 1 root root     561 Jul 14 16:53 cgroup.img

-rw-r--r-- 1 root root     822 Jul 14 16:53 core-14969.img

-rw-r--r-- 1 root root      60 Jul 14 16:53 creds-14969.img

-rw-r--r-- 1 root root      56 Jul 14 16:53 fdinfo-2.img

-rw-r--r-- 1 root root      18 Jul 14 16:53 fs-14969.img

-rw-r--r-- 1 root root      32 Jul 14 16:53 ids-14969.img

-rw-r--r-- 1 root root      38 Jul 14 16:53 inventory.img

-rw-r--r-- 1 root root    1717 Jul 14 16:53 mm-14969.img

-rw-r--r-- 1 root root     241 Jul 14 16:53 pagemap-14969.img

-rw-r--r-- 1 root root 1388544 Jul 14 16:53 pages-1.img

-rw-r--r-- 1 root root      26 Jul 14 16:53 pstree.img

-rw-r--r-- 1 root root     751 Jul 14 16:53 reg-files.img

-rw-r--r-- 1 root root     794 Jul 14 16:53 sigacts-14969.img

-rw-r--r-- 1 root root      35 Jul 14 16:53 stats-dump

-rw-r--r-- 1 root root      32 Jul 14 16:53 tty.img

-rw-r--r-- 1 root root     169 Jul 14 16:53 tty-info.img

root@docker:~/docker_tests#

Step 3 - verify that the process is no longer running

root@docker:~/docker_tests# ps axuw | grep test.pl

root     14994  0.0  0.0  11748  2208 pts/3    S+   16:54   0:00 grep --color=auto test.pl

root@docker:~/docker_tests# tail /tmp/report.txt

i is 62

i is 63

i is 64

i is 65

i is 66

i is 67

i is 68

i is 69

i is 70

i is 71

root@docker:~/docker_tests#

Step 4 - restore the process and confirm it picked up exactly where it left off :o)

root@docker:~/docker_tests# criu-1.6/criu restore -d --shell-job -D checkpoint

root@docker:~/docker_tests# ps axuw | grep test.pl

root     14969  0.0  0.0  23548  1348 pts/3    S    16:55   0:00 /usr/bin/perl ./test.pl

root     14974  0.0  0.0  11748  2280 pts/3    S+   16:56   0:00 grep --color=auto test.pl

root@docker:~/docker_tests# tail /tmp/report.txt

i is 74

i is 75

i is 76

i is 77

i is 78

i is 79

i is 80

i is 81

i is 82

i is 83

root@docker:~/docker_tests#

ASUS RT-AC68U internal port forwarding issue

Just wanted to share the solution to a problem I was having with my new wifi router (an ASUS RT-AC68U)...

Basically, I have a few port forwarding rules set up and, when I would connect to the external ip address from my internal network, the port forwarding did not work.

I sniffed the network and noticed that the first few packets would be forwarded correctly (between the external ip and the local ip) but, then, the router would start NATing some packets with the router's internal ip address instead of its public one.

Anyway, the fix is pretty easy, you just have to disable NAT Acceleration under NAT \ Switch Control.

I hope this information can help someone else :o)

UPDATE: although disabling NAT Acceleration fixed my problem, it caused some heavy performance issues (my home connection dropped from 900Mbps+ to 300Mbps+). Fortunately, I was still able to solve the problem by simply updating to the latest available firmware (3.0.0.4.378_6975-g1f406a7) - they identified this problem as "NAT Loopback problem". The device said I was already using the latest firmware but it turned out that was a lie :oP.

Low Carb High Fat Sweet Pizza Crust

Last weekend I did the awesome low carb high fat pizza I posted about several months ago and my wife had a great idea: "what if we didn't add the powdered garlic to the crust and did a sweet pizza with the same crust?"

So today I decided to try it and here's the result:

The idea is to use these small pieces and add a syrup on top (like chocolate or strawberry), as well as a couple of pieces of fruit (e.g. strawberry, blackberries or raspberries).

The recipe is very similar to the one I use for the crust of the low carb high fat pizza.

Crust Ingredients

• 3 cups shredded cheese (a mixture of mozzarella and cheddar is best)
• 16 oz of cream cheese
• 4 large eggs
• 2 cups of almond meal flour
• 2 cups of artificial sweetener

Melt the shreeded cheese and the cream cheese in the microwave for 1 minute and then just mix everything together in a blender (or by hand) and put it in the oven at 425F for about 10 minutes (if I use my electric convect oven, I need about 10 minutes, but on the gas oven it took about 15 minutes) - just keep an eye on the oven to make sure you don't over cook it!

And that's about it! Enjoy! :o) 

iotop

Ah, I just learned a new awesome Linux command: iotop :oP
Should I feel ashamed that I only found out about it today?

Low Carb Cheese Danish

My wife just found out this recipe for a low carb cheese danish.
I haven't personally tried it but wanted to record it here so I can refer back to it in the future :oP

"Dough

1. 1 1/4 cup 2% mozzarella shredded cheese (140 grams)
2. 6 tbsp Almond Flour (42 grams)
3. 3 tbsp Coconut Flour (21 grams)
4. 4 tbsp sugar equivalent (I used 5 tsp Truvia)
5. 1/2 tsp baking powder
6. 1/2 tsp vanilla
7. 4 tbsp butter (omit if you are using a higher fat cheese but I implore you to use the 2% or part skim mozzarella cheese!)
8. 1 egg

Filling

1. 6 oz cream cheese
2. 1 tsp lemon juice
3. 1/2 tsp vanilla extract
4. 1/4 cup sugar equivalent
5. 1 egg yolk

Frosting

1. 3 tbsp powdered sweetener (3 tbsp truvia in a coffee grinder for 30 secs and then measure out 3 tbsp of the powdered.)
2. 2 tbsp heavy cream
3. 2 oz cream cheese
4. 1/4 tsp vanilla extract

Instructions

1. Preheat oven to 400 degrees.

Filling

1. Soften cream cheese and combine with lemon juice, vanilla, and sweetener and egg yolk using a whisk or electric mixer. Set aside in the fridge until you are ready with the dough.

Dough

1. Measure out almond flour, coconut flour, and baking powder. Combine well with a whisk.
2. Melt 4 tbsp butter and add vanilla and sweetener. Stir.
3. Melt 1 1/4 cup shredded mozzarella cheese in the microwave (30% power for 2 minutes with a 1200 watt microwave).
4. Combine all the ingredients and add an egg.
5. Stir until batter is combined and the cheese and dough are completely mixed. Use your hands or a spatula to press and fold the cheese and the batter together. Reheat for 10 seconds in the microwave. Press and fold some more until 99% of the dough is all one color. (Tip-this gets sticky and if you wet your hands a little it helps tremendously. The water from your hands will stop the stickiness on the outside of the dough making it very easy to roll out.)
6. Reheat dough for 10 seconds and roll out into a square the approximate length of a rolling pin and slice into four quarters with a pizza slicer.
7. Fold the corners into the center repeating with all four squares.
8. Pipe filling (or spoon it on top!) into the center of each danish.
9. Bake for 10-12 minutes. (Check on this at 10 minutes and make sure to remove it from the oven as soon as it has a deep golden brown color! Just slightly past 13 minutes and 2 of mine did get burnt. Definitely keep an eye on it.)

Frosting

1. Soften cream cheese in the microwave and add powdered sweetener, heavy cream and vanilla. Mix well with a whisk and pour into a ziploc bag. Cut a tiny hole in the corner and pipe onto each danish.

Notes

1. Serves 4
2. per serving 429 Calories; 41g Fat; 9g Protein; 8g Carbohydrate; 3g Dietary Fiber; 5 net carbs each!"

Anybody want to try it and share their experiences? :o)