Pelican notes

Extensions

• If Typogrify library is installed, typographical enhancements may be enabled in the settings file
• pygments for syntax highlightning
• Pelican also supports Markdown Extensions, which might have to be installed separately if they are not included in the default Markdown package and can be configured and loaded via the MD_EXTENSIONS setting
• pelican-plugins repository contains more additional plugin

Metadata
Note that, aside from the title, none of this article metadata is mandatory: if the date is not specified and DEFAULT_DATE is set to 'fs', Pelican will rely on the file’s “mtime” timestamp, and the category can be determined by the directory in which the file resides. A file located at python/foobar/myfoobar.rst will have a category of foobar. If you would like to organize your files in other ways where the name of the subfolder would not be a good category name, you can set the setting USE_FOLDER_AS_CATEGORY to False.

Caching
When experimenting with different settings (especially the metadata ones) caching may interfere and the changes may not be visible. In such cases disable caching with LOAD_CONTENT_CACHE = False or use the --ignore-cache command-line switch.

 

Prepare for an interview

Study

• horizontal vs vertical scaling
• sql vs nosql
• strace, gdb, profiling
• python basics
• multiprocessing & multithreading
• python datastructures internals: dicts 

Tune self

• дослушиваю до конца и задаваю вопрос
• структурирую проблему и разрабатываю основу ее решения
• думаю прежде, чем говорю
• акцентирую внимание на особо важных вопросах
• обсуждаю ход своих мыслей 

Ansible notes

Gather facts

ansible all -m setup

Pytest configuration

List fixtures for the given path

py.test --fuxtures [testpath]

Enable external pytest plugin
Add pytest_plugins variable to conftest.py

pytest_plugins = ['path.to.external.pytest.plugin']

Study npm

Change npm global prefix

npm config set prefix ~/.npm-global
export PATH=~/.npm-global/bin:$PATH

Install package locally (to node_modules/). Add -g to install globally.

npm install package

Update local packages

npm update

List outdated packages

npm outdated

Git one-liners

Remove stale remote branches

git remote prune <origin-name>

Configure Django application

Configure application

• To configure an application, subclass django.apps.AppConfig and put the dotted path to that subclass in INSTALLED_APPS.
• When INSTALLED_APPS simply contains the dotted path to an application module, Django checks for a default_app_config variable in that module.
• If it’s defined, it’s the dotted path to the AppConfig subclass for that application.
• If there is no default_app_config, Django uses the base AppConfig class.

Progression sums

Arithmetic progression sum

S(n, p) = sum(i**p for i in range(1, n)) = Theta(n ** (p + 1)), where p >= 1

Geometric progression sum

G(n, a) = sum(a ** i for i in range(1, n)) = a * (a ** (n+1) - 1) / (a - 1)

If n -> Infinity

G(n, a) = 1 / (1 - r)

Check OpenSSH Roaming vulnerability

This command should complete with no output

ssh -v -T git@github.com 2>&1 | grep Roaming 

Change MySQL user password

set password for 'user'@'host' = PASSWORD('password')

Manage GnuPG keys

Create GnuPG key pair

gpg --gen-key

List keys

gpg --list-keys
gpg --list-public-keys
gpg --list-secret-keys

Export keys

gpg --armor --output <keyid>-public.key --export <keyid>
gpg --armor --output <keyid>-secret.key --export-secret-keys <keyid>

Import keys

gpg --import  <keyid>-public.key
gpg --import  <keyid>-secret.key

 Delete keys

gpg --delete-secret-keys <keyid>
gpg --delete-keys <keyid>

Add some packages from PPA

dh-virtualenv

add-apt-repository ppa:spotify-jyrki/dh-virtualenv

ansible

apt-get install software-properties-common
apt-add-repository ppa:ansible/ansible

Run Celery task from command line

Run Celery task from command line

celery call --app <app.module.path> <task.module.path> --args '["argument"]'

--args parameter should be valid JSON