closingtags </> – Page 4 – web development and then some
Categories
Automation Javascript Server

Node + MongoDB development environment w/Docker Compose

I’ve recently done some work on a personal project that I have put off for far too long. The project itself is a chat bot for moderating Telegram chat groups but this post isn’t about that project. Instead, it will focus on how I simplified setup of the development environment using Docker Compose.
I don’t have much experience with Docker or Docker Compose because in the past, I’ve used Vagrant for creating my environments. And Vagrant has been great, but over the years, I’ve run into a few issues:

virtual machines can take up to a minute to start, sometimes longer
new boxes (images) are slow to download
software versions fall out of sync with production environments
unexpected power outages have led to corrupted VMs

These issues are likely addressable in each configuration but between custom shell scripts and having so little experience with Ruby (Vagrantfiles are written in Ruby), managing it can quickly become unwieldy. Plus, Docker has become a de facto industry standard so it’s about time I learned something about it.
Ideally, this project would have a single file that makes spinning up a consistent development environment quick and painless, which is where Docker Compose comes in. A docker-compose.yml file; located in the root directory of the project, will make starting the environment as simple as running a single command; docker-compose up -d. The “-d” flag runs the containers in detached mode (the background) which frees up your terminal.
MongoDB
My first goal was to get MongoDB working with the project. This was relatively easy since the docker community maintains an official MongoDB image with an example docker-compose.yml:
# Use root/example as user/password credentials
version: ‘3.1’

services:

mongo:
image: mongo
restart: always
environment:
MONGO_INITDB_ROOT_USERNAME: root
MONGO_INITDB_ROOT_PASSWORD: example

mongo-express:
image: mongo-express
restart: always
ports:
– 8081:8081
environment:
ME_CONFIG_MONGODB_ADMINUSERNAME: root
ME_CONFIG_MONGODB_ADMINPASSWORD: example
ME_CONFIG_MONGODB_URL: mongodb://root:example@mongo:27017/
Since I wanted to start simple, I ran Node locally and connected to the MongoDB container as if it were another machine. To do that, ports needed to be exposed to the host machine. I also needed a database setup and for that same database to persist. I decided to keep the Mongo Express container as it creates a useful web interface for checking data.
version: ‘3.1’
services:
mongo:
container_name: toximongo
image: mongo
restart: always
environment:
MONGO_INITDB_ROOT_USERNAME: root
MONGO_INITDB_ROOT_PASSWORD: toxipass
MONGO_INITDB_DATABASE: toxichatdb
ports:
– 27017:27017
volumes:
– ./init-mongo.js:/docker-entrypoint-initdb.d/init-mongo.js:ro
– ./mongo-volume:/data/db
mongo-express:
container_name: toximongo-express
image: mongo-express
restart: always
ports:
– 8081:8081
environment:
ME_CONFIG_MONGODB_ADMINUSERNAME: root
ME_CONFIG_MONGODB_ADMINPASSWORD: toxipass
ME_CONFIG_MONGODB_URL: mongodb://root:toxipass@mongo:27017/toxichatdb
Some of the changes to take note of:

name containers to make them easy to differentiate and access
usernames + passwords set
expose MongoDB to local machine on port 27017
create a persistent volume at ./mongo-volume/ in the root of the project
run /docker-entrypoint-initdb.d/init-mongo.js to create a user and initialize the database

init-mongo.js is a very simple script that runs when the container is started for the first time.
db.createUser({
user: ‘root’,
pwd: ‘toxipass’,
roles: [
{
role: ‘readWrite’,
db: ‘toxichatdb’,
},
],
});
Node
After getting access to a database, the next step was to include Node. Since Node versions change frequently, its great to ensure that all developers are supporting the same version. It also simplifies getting started working on the project if a developer isn’t expected to have to install something else. This was also straightforward since there is an official image supplied by the Node JS Docker team with extensive documentation.
version: ‘3.1’

services:
node:
container_name: toxinode
image: “node:16”
user: “node”
working_dir: /home/node/app
environment:
– NODE_ENV=development
volumes:
– ./:/home/node/app
expose:
– “8080”
command: [sh, -c, “yarn && yarn start”]

mongo:
container_name: toximongo
image: mongo
restart: always
environment:
MONGO_INITDB_ROOT_USERNAME: root
MONGO_INITDB_ROOT_PASSWORD: toxipass
MONGO_INITDB_DATABASE: toxichatdb
ports:
– 27017:27017
volumes:
– ./init-mongo.js:/docker-entrypoint-initdb.d/init-mongo.js:ro
– ./mongo-volume:/data/db

mongo-express:
container_name: toximongo-express
image: mongo-express
restart: always
ports:
– 8081:8081
environment:
ME_CONFIG_MONGODB_ADMINUSERNAME: root
ME_CONFIG_MONGODB_ADMINPASSWORD: toxipass
ME_CONFIG_MONGODB_URL: mongodb://root:toxipass@toximongo:27017/toxichatdb

Again, I’ve given the container a custom name. There isn’t much else changed except for the command which issues a shell inside the container, calls Yarn to install dependencies, and then starts the application.
Summary
Since incorporating Docker Compose with this project, I’ve been impressed at the speed with which my development environment can start. This setup doesn’t include a Dockerfile but because it isn’t building custom images, I didn’t think that was necessary to include. I’m certain there are ways to improve it and I’ve got lots to learn, especially if I’d like to incorporate deploying this to production environments. If you’ve got tips or suggestions, let me know!

Categories
Linux Programming

The Hacker Hotkey

I had plans to do an in-depth post about web application security this month but some major changes in my life made it difficult to finish the required research. Instead, I’m going to share something a little different.
Presenting, the Hacker Hotkey, the badge for Kernelcon 2021!
Hacker Hotkey on the left in a 3D printed case that a friend gave to me. Notice the custom sticker that perfectly fit the key caps.
Since Kernelcon 2021 was virtual again this year, the organizers wanted to do something different so they hosted a live hacking competition where viewers could vote on the challenges contestants were issued. The Hacker Hotkey came pre-programmed to open links to the event stream, the Discord chat, and cast votes. They’re currently still available for sale so grab one while you can and get yourself a handy-dandy stream deck!
As always, the organizers of Kernelcon knocked it out of the park but I’d be lying if I said I didn’t spend most of the time tinkering with my Hacker Hotkey. I thought I’d share my code and configuration here.
Edit (5/7/21): In order to get better support for media keys and contribute to the kernelcon/hacker-hotkey project, I’ve removed the old repository and updated it with one that no longer has my custom keybindings. Stay tuned, as this could be interesting!
All I really did was fork the official Kernelcon git repo and add in my own commands and keyboard shortcuts. I don’t do any streaming (for now) so my tweaks were meant to be simpler. For instance:

key 1 opens up a link to my personal cloud
key 2 starts OBS with the replay buffer running
key 3 is supposed to save the replay buffer to a file but I couldn’t get that to happen without setting a keyboard shortcut in OBS Studio (Ctrl + F8). I ran into a strange issue where the Hacker Hotkey will send those exact keystrokes to the system, but OBS Studio doesn’t recognize it unless OBS has focus. Loads of good that does me when I want to save a replay while I’m gaming! But weirdly enough, it works just fine when using the actual keystrokes on my keyboard. I’ll keep tinkering at it and hopefully get something better working.
key 4 uses gnome-screenshot to take a screenshot of the window that’s in focus and save that to my ~/Pictures directory

I wanted to set one key to toggle mute on my microphone, one to toggle my camera, another to pause/play music, and the last to move to the next song, but to get that working, I ended up having to set keyboard shortcuts within GNOME. That’s fine, but I can just use those keyboard shortcuts instead of the Hacker Hotkey so it’s doesn’t make a lot of sense. I also wanted the hotkey to be portable so that I could plug it into another system and keep that functionality and this way does not achieve that.
If you have any ideas about how I can fix this, or get my keyboard shortcuts to at least be portable via my dotfiles, leave a comment. I’m a little out of my depth with Arduino development but hey, it’s a fun learning opportunity
Edit (5/14/21): My repository now has support for media keys which makes toggling the play/pause of your system audio much simpler. This was achieved by swapping out the standard keyboard library with the NicoHood/HID library. See my pull request for more information.
My new keybindings follow like so:

key1 – open link to my cloud
key2 – start OBS with replaybuffer running
key3 – key binding set in OBS to save replay buffer (still not working unless OBS has focus)
key4 – take a screenshot using gnome-screenshot -w
key5 – print an emoticon and hit return
key6 – mic mute commands
key7 – MEDIA_PLAY_PAUSE
key8 – MEDIA_NEXT

Categories
Linux Programming

.dotfiles

Purchasing a new computer is all fun and games until you have to set it up. You’ve just opened up your brand spanking new machine and you want to play with it, but you can’t do that until you get everything you need installed. What do you do if you’ve just installed your favorite GNU/Linux distribution when a shiny, new one comes along? You were finally getting comfortable and the last thing you want to do is fight through the hassle of setting up your environment again.
Instead of sloshing through the installation of all those dependencies, you can take a little bit of time to setup a .dotfiles repository. What are .dotfiles? They’re those hidden files in your home folder that manage your profile configuration. You don’t need all of them, but a few can go a long ways. Take a look at mine. Whenever I’m setting up a new machine, the first thing I do is install git. From there, I can pull down my version controlled configuration, and be up and running in minutes. Let’s do a breakdown of each file.
.bash_aliases
# shortcuts
alias lh=’ls -lha’
alias plz=’sudo $(history -p \!\!)’
alias codecept=”php vendor/bin/codecept”

# Change directories aliases
alias cdot=’cd ~/.dotfiles’;
alias cdtox=’cd ~/Dev/projects/mine/tox’;
alias cdhack=’cd ~/Dev/vvv/www/hack/public_html/wp-content’
alias cdintra=’cd ~/Dev/projects/kalix’;
alias cdvvv=’cd ~/Dev/vvv’;
alias cdans=’cd ~/Dev/ans’;

# Apps
alias postman=’/usr/bin/PostmanCanary’

# Compress JPGs into directory
alias compress=’mkdir compressed;for photos in *.jpg;do convert -verbose “$photos” -quality 85% -resize 1920×1080 ./compressed/”$photos”; done’

As you can see, keeping useful comments in your .dotfiles can make maintenance easier. You’ll notice a few aliases that I have for frequently used commands, followed by a few more aliases that take me to frequently accessed directories. Lastly, you’ll notice a familiar command I use when compressing images.
.bashrc
# ~/.bashrc: executed by bash(1) for non-login shells.
# see /usr/share/doc/bash/examples/startup-files (in the package bash-doc)
# for examples

# If not running interactively, don’t do anything
case $- in
*i*) ;;
*) return;;
esac

# don’t put duplicate lines or lines starting with space in the history.
# See bash(1) for more options
HISTCONTROL=ignoreboth

# append to the history file, don’t overwrite it
shopt -s histappend

# for setting history length see HISTSIZE and HISTFILESIZE in bash(1)
HISTSIZE=1000
HISTFILESIZE=2000

# check the window size after each command and, if necessary,
# update the values of LINES and COLUMNS.
shopt -s checkwinsize

# If set, the pattern “**” used in a pathname expansion context will
# match all files and zero or more directories and subdirectories.
#shopt -s globstar

# make less more friendly for non-text input files, see lesspipe(1)
[ -x /usr/bin/lesspipe ] && eval “$(SHELL=/bin/sh lesspipe)”

# set variable identifying the chroot you work in (used in the prompt below)
if [ -z “${debian_chroot:-}” ] && [ -r /etc/debian_chroot ]; then
debian_chroot=$(cat /etc/debian_chroot)
fi

# set a fancy prompt (non-color, unless we know we “want” color)
case “$TERM” in
xterm-color|*-256color) color_prompt=yes;;
esac

# uncomment for a colored prompt, if the terminal has the capability; turned
# off by default to not distract the user: the focus in a terminal window
# should be on the output of commands, not on the prompt
#force_color_prompt=yes

if [ -n “$force_color_prompt” ]; then
if [ -x /usr/bin/tput ] && tput setaf 1 >&/dev/null; then
# We have color support; assume it’s compliant with Ecma-48
# (ISO/IEC-6429). (Lack of such support is extremely rare, and such
# a case would tend to support setf rather than setaf.)
color_prompt=yes
else
color_prompt=
fi
fi

# Add git branch if its present to PS1
parse_git_branch() {
git branch 2> /dev/null | sed -e ‘/^[^*]/d’ -e ‘s/* \(.*\)/(\1)/’
}
if [ “$color_prompt” = yes ]; then
PS1=’${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[01;31m\] $(parse_git_branch)\[\033[00m\]\$ ‘
else
PS1=’${debian_chroot:+($debian_chroot)}\u@\h:\w $(parse_git_branch)\$ ‘
fi

# If this is an xterm set the title to user@host:dir
case “$TERM” in
xterm*|rxvt*)
PS1=”\[\e]0;${debian_chroot:+($debian_chroot)}\u@\h: \w\a\]$PS1″
;;
*)
;;
esac

# enable vi shortcuts
set -o vi

# enable color support of ls and also add handy aliases
if [ -x /usr/bin/dircolors ]; then
test -r ~/.dircolors && eval “$(dircolors -b ~/.dircolors)” || eval “$(dircolors -b)”
alias ls=’ls –color=auto’
#alias dir=’dir –color=auto’
#alias vdir=’vdir –color=auto’

alias grep=’grep –color=auto’
alias fgrep=’fgrep –color=auto’
alias egrep=’egrep –color=auto’
fi

# colored GCC warnings and errors
#export GCC_COLORS=’error=01;31:warning=01;35:note=01;36:caret=01;32:locus=01:quote=01′

# some more ls aliases
alias ll=’ls -alF’
alias la=’ls -A’
alias l=’ls -CF’

# Add an “alert” alias for long running commands. Use like so:
# sleep 10; alert
alias alert=’notify-send –urgency=low -i “$([ $? = 0 ] && echo terminal || echo error)” “$(history|tail -n1|sed -e ‘\”s/^\s*[0-9]\+\s*//;s/[;&|]\s*alert$//’\”)”‘

# Alias definitions.
# You may want to put all your additions into a separate file like
# ~/.bash_aliases, instead of adding them here directly.
# See /usr/share/doc/bash-doc/examples in the bash-doc package.

if [ -f ~/.bash_aliases ]; then
. ~/.bash_aliases
fi

# enable programmable completion features (you don’t need to enable
# this, if it’s already enabled in /etc/bash.bashrc and /etc/profile
# sources /etc/bash.bashrc).
if ! shopt -oq posix; then
if [ -f /usr/share/bash-completion/bash_completion ]; then
. /usr/share/bash-completion/bash_completion
elif [ -f /etc/bash_completion ]; then
. /etc/bash_completion
fi
fi

# disable Software Flow Control
stty -ixon

For the most part, this is a standard .bashrc file. The part that I find most helpful is the portion that shows me whatever git branch I’m on in the current directory (provided there is a git repo in the directory).

.vimrc
set nocompatible ” be iMproved, required
filetype off ” required
set number
set tabstop=4
set softtabstop=0 noexpandtab
set shiftwidth=4
set autochdir
set wildignore+=vendor/**,mail/**,runtime/**
let $BASH_ENV = “~/.bash_aliases”

syntax on
” set the runtime path to include Vundle and initialize
set rtp+=~/.vim/bundle/Vundle.vim
call vundle#begin()
” alternatively, pass a path where Vundle should install plugins
“call vundle#begin(‘~/some/path/here’)

” let Vundle manage Vundle, required
Plugin ‘VundleVim/Vundle.vim’

” Color scheme
Plugin ‘morhetz/gruvbox’

” File Tree
Plugin ‘scrooloose/nerdtree’

” Search files
Plugin ‘ctrlpvim/ctrlp.vim’
” Install ripgrep as well (https://github.com/BurntSushi/ripgrep)
Plugin ‘dyng/ctrlsf.vim’

” Multi-cursor support
Plugin ‘terryma/vim-multiple-cursors’

” Surrounding tags
Plugin ‘tpope/vim-surround’

” Upgraded status line
Plugin ‘itchyny/lightline.vim’

” Syntax checks
Plugin ‘vim-syntastic/syntastic’

” Git
Plugin ‘tpope/vim-fugitive’

” auto-complete
Plugin ‘Valloric/YouCompleteMe’

” All of your Plugins must be added before the following line
call vundle#end() ” required
filetype plugin indent on ” required
” To ignore plugin indent changes, instead use:
“filetype plugin on
”
” Brief help
” :PluginList – lists configured plugins
” :PluginInstall – installs plugins; append `!` to update or just :PluginUpdate
” :PluginSearch foo – searches for foo; append `!` to refresh local cache
” :PluginClean – confirms removal of unused plugins; append `!` to auto-approve removal
”
” see :h vundle for more details or wiki for FAQ
” Put your non-Plugin stuff after this line

colorscheme gruvbox
set background=dark

” Python path (required for autocomplete plugin)
” let g:python3_host_prog = ‘c:\\Users\\dylan\\AppData\\Local\\Programs\\Python\\Python37-32\\python.exe’
set encoding=utf-8

” Auto start NERDtree
autocmd vimenter * NERDTree
map <C-k> :NERDTreeToggle<CR>
autocmd BufEnter * if (winnr(“$”) == 1 && exists(“b:NERDTree”) && b:NERDTree.isTabTree()) | q | endif
let g:NERDTreeNodeDelimiter = “\u00a0″
let g:NERDTreeShowHidden = 1

” search settings
let g:ctrlsf_default_root = ‘project’
let g:ctrlsf_position = ‘bottom’
let g:ctrlsf_default_view_mode = ‘compact’
let g:ctrlp_custom_ignore = {
\ ‘dir’: ‘vendor\|.git\$’
\}

” code quality
set statusline+=%#warningmsg#
set statusline+=%{SyntasticStatuslineFlag()}
set statusline+=%*

let g:syntastic_always_populate_loc_list = 1
let g:syntastic_auto_loc_list = 1
let g:syntastic_check_on_open = 1
let g:syntastic_check_on_wq = 1

” status line config
set noshowmode
let g:lightline = {
\ ‘active’: {
\ ‘left’: [ [ ‘mode’, ‘paste’ ],
\ [ ‘gitbranch’, ‘readonly’, ‘filename’, ‘modified’ ] ],
\ ‘right’: [ [ ‘lineinfo’ ], [’absolutepath’] ]
\ },
\ ‘component_function’: {
\ ‘gitbranch’: ‘fugitive#head’
\ },
\ }

” YouCompleteMe Options
let g:ycm_disable_for_files_larger_than_kb = 1000
” autoinsert closing brackets
“inoremap ” “”<left>
“inoremap ‘ ”<left>
“inoremap ( ()<left>
“inoremap [ []<left>
inoremap { {}<left>
inoremap {<CR> {<CR>}<ESC>O
inoremap {;<CR> {<CR>};<ESC>O

” nvim terminal options
” To map <Esc> to exit terminal-mode: >
:tnoremap <Esc> <C-\><C-n>
” To use `ALT+{h,j,k,l}` to navigate windows from any mode: >
:tnoremap <A-h> <C-\><C-N><C-w>h
:tnoremap <A-j> <C-\><C-N><C-w>j
:tnoremap <A-k> <C-\><C-N><C-w>k
:tnoremap <A-l> <C-\><C-N><C-w>l
:inoremap <A-h> <C-\><C-N><C-w>h
:inoremap <A-j> <C-\><C-N><C-w>j
:inoremap <A-k> <C-\><C-N><C-w>k
:inoremap <A-l> <C-\><C-N><C-w>l
:nnoremap <A-h> <C-w>h
:nnoremap <A-j> <C-w>j
:nnoremap <A-k> <C-w>k
:nnoremap <A-l> <C-w>l
” don’t show warning on terminal exit
set nomodified

This file is the entire reason I started tracking my .dotfiles. Being able to effortlessly pull down my programming environment makes switching to a new computer so much simpler. Most of this file concerns the installation of various Vim plugins using Vundle but there are a few keyboard shortcuts as well. I’ll save preaching about Vim for another post.
Vim in action
install.sh
#!/bin/bash

ln -sf ~/.dotfiles/.bashrc ~/.bashrc
ln -sf ~/.dotfiles/.vimrc ~/.vimrc
ln -sf ~/.dotfiles/.bash_aliases ~/.bash_aliases

# php
sudo add-apt-repository ppa:ondrej/php
sudo add-apt-repository ppa:jtaylor/keepass

sudo apt-get update
sudo apt-get install -y python3 curl wget software-properties-common ansible vim vim-gtk3 git ripgrep build-essential cmake wireguard php7.4 php7.4-curl php7.4-gd php7.4-json php7.4-mbstring php7.4-xml keepass2 imagemagick neovim vim-nox python3-dev

# neovim
echo “set runtimepath^=~/.vim runtimepath+=~/.vim/after” >> ~/.config/nvim/init.vim
echo “let &packpath = &runtimepath” >> ~/.config/nvim/init.vim
echo “source ~/.vimrc” >> ~/.config/nvim/init.vim

# composer
# double check if hash has changed
php -r “copy(‘https://getcomposer.org/installer’, ‘composer-setup.php’);”
php -r “if (hash_file(‘sha384’, ‘composer-setup.php’) === ‘e5325b19b381bfd88ce90a5ddb7823406b2a38cff6bb704b0acc289a09c8128d4a8ce2bbafcd1fcbdc38666422fe2806’) { echo ‘Installer verified’; } else { echo ‘Installer corrupt’; unlink(‘composer-setup.php’); } echo PHP_EOL;”
php composer-setup.php
php -r “unlink(‘composer-setup.php’);”
sudo mv composer.phar /usr/local/bin/composer
sudo chown root:root /usr/local/bin/composer

While my .vimrc is what convinced me to start a .dotfiles repo, the install.sh is by far the most useful file in the entire project. When this file is run, the first thing it does is connect my .bashrc, .vimrc, and .bash_aliases to my profile. It will then add a couple of repositories, update the repositories, and install most everything I need to get up and running. Whenever I find myself installing another useful package on my machine, I try to remember to add it here as well so that I’ll have it in the future. After the installation of commonly used packages, I’ll setup Neovim and download composer for PHP dependency management. Interestingly enough, this process always breaks because I never have the correct hash to compare the updated composer.phar file to.
README
While this may not seem important, I can assure you that it’s the most important file in the entire repository. My README file tracks changes, documents proper installation techniques, and gives me a heads up about any quirks I might run into. You will always appreciate having documentation later so take the time to keep up with this one.
Conclusion
Managing a .dotfiles repository is by no means a one-off project. It’s an ever-changing entity that will follow you wherever you go and be whatever you need it to be. Use it as you need it, but if you take care of it, it will take care of you. You’ll thank yourself later on for putting in the work now. For more information, check out http://dotfiles.github.io/ or do some quick searching on the interwebs to find tons of other examples.

Categories
Linux Server

Backup containers w/Ansible

The one thing that you should absolutely be doing routinely is backing up your stuff. Yet you’ll notice in my previous post about using Ansible to automate my homelab, there is no mention of backing up the environment. If you’re wondering why that is, it’s because I am both lazy and forgetful.
Having been bitten one too many times by my fancy automated updates, I decided I’d had enough. I was spending too much time connecting to the Proxmox web GUI, starting a backup, then running updates so if (when) things broke, I’d have access to a more recent backup. I needed to be able to take backups within Ansible as well as run my updates.
This is the solution I came up with:
—
– hosts: host
remote_user: root

vars_prompt:
– name: ctid
prompt: ‘Specify container ID or leave blank for all’
private: no

tasks:
– name: Backup all containers.
command:
cmd: vzdump –all –maxfiles 5 –compress gzip
when: ctid == “”

– name: Backup specified container.
command:
cmd: vzdump {{ ctid }} –maxfiles 5 –compress gzip
when: ctid != “”

This playbook should be easy enough to understand without too much exlaining but I’ll sum it up: if a container ID is specified when run, use the Proxmox tool vzdump to backup that container; otherwise, backup all containers (compress those files and only keep the most recent 5). Please borrow, tweak, share, and critique.

Categories
PHP Programming

Generate thumbnails for PDFs

As I’ve noted a previous post, ImageMagick is an incredibly powerful tool for image manipulation. While it’s handy for image compression, it can also be used for so many more things, like processing uploaded files. Whether you want to crop all images to the same dimensions, or invert their orientation, Imagick can manage it. I’ve found it particularly useful for generating a thumbnail that can be used as a preview for PDFs uploaded to my application. Here’s some code that does just that:
// generates a jpg thumbnail for a PDF
// returns true on success
// returns false on failure
private function generateThumbnail($filePathNoExt = ”) {
try {
$img = new \Imagick($filePathNoExt . ‘.pdf[0]’);
$img->scaleImage(200, 0);
$img->setImageFormat(‘jpg’);
$img = $img->flattenImages();
$img->writeImage($filePathNoExt . ‘.jpg’);

$img->clear();
$img->destroy();
return true;
} catch (\ImagickException $e) {
// thumbnail generation failed
echo $e;
}
return false;
}

This code is pretty self-explanatory. After the PDF has been uploaded, this function is called with the path to the PDF provided as the parameter (minus the extension ‘.pdf’). A new Imagick object is instantiated and some settings are configured before writing the file. The flattenImages() method is used to merge all layers within the PDF for a consistent thumbnail. If you wished to have the thumbnail format as a PNG or with a different size, those parameters can be adjusted as need. At the end of it all, we return a true if the thumbnail was successfully written or a false if there was an error. The thumbnail can be found in the same directory as the PDF, with the same file name.
Then, show the thumbnail inside a link to your PDF like so:
<a href=”/path/to/file.pdf” title=”Open Attachment”>
<img src=”/path/to/file.jpg”>
</a>
For further reading, check out this article from BinaryTides that helped me along the way.

Categories
Linux

A Brief Introduction to the Lemur Pro by System76

I’ve been in the market for a new laptop since the battery died on my secondhand Samsung. Even the replacement (aftermarket) batteries I found for it would only give me 2 hours of usage for the first month and then drastically drop off to 45 minutes. Having to hunt for an outlet everywhere I took it was so much of a nuisance that I couldn’t comfortably use it in my own living room.
So when I saw that System76 announced they were releasing a new laptop that claimed 14 hours of battery life, my mind was made up. I was going to have that machine.
Which brings us to this post. I’ve taken a new approach in an effort to brag share my first impressions with the world by creating videos. I’m well aware that the video quality isn’t great and that’s because I don’t know the first thing about video recording, editing, sound, light, etc. Also, I’m lazy.

Unboxing

Disassembly
System76 is kind enough to provide repair manuals but it’s really simple to get inside and gain access to various components.

Keyboard + Trackpad
The backlit keyboard has 4 different brightness settings as well as the capability of being shut off. The only real complaint I’ve had about the keyboard is that the space bar is so soft that I sometimes wonder if I actually hit it. The arrow keys are quite close together but if you’re doing most of your writing in Vim (I am), it’s not that big of a deal. The trackpad took some getting used to since I’m so used to having physical clickers but the two-fingered tap for right click is has worked really well.
Display
Being such a small form factor with an HD screen, it’s actually quite difficult to read some text. It may just be that my glasses prescription needs to be updated (it desperately does) but I kept finding myself having to bring the device closer to me so I could read it. I’m probably just getting old. In any case, it was an easy fix in the Pop Shell/GNOME accessibility settings. I’ve also turned up the interface size to 125% on applications like Telegram and increased the font size in Firefox to make it easier to read at a comfortable distance.
Battery
Having only had the laptop for a day, there’s not really much that I can say about the battery life yet except that it’s a huge step up for me. I’ve put around 6 hours of actual usage onto and it still has 55% battery left with an estimated 7 hours. During that time, I’ve updated the firmware, the packages, installed around half of the tools needed to do my day-to-day work, streamed music, written this post, cloned my dotfiles repo, and just played around with it.
Update (5/23/20): After using the Lemur Pro for a couple of weeks now, I’ve been averaging a little over 12 hours of usage. That typically includes running a VM for web development, a chat client, email, a browser with multiple tabs, and Vim. Going from less than 10% battery back to 100% typically takes about 5 hours. The only gripe with charging is that the charging cable is the very short. Fortunately, its simple enough to purchase a longer length of cable to use with the charger.
Pop OS
Pop OS 20.04 really steals the show on this machine. I did not expect to be as excited about it as I currently am. Having tiling functionality baked into GNOME with Vim keybindings really gives you the best parts of window managers like i3-gaps and gnome-shell. It’s easy to move between windows and workspaces. I never really used workspaces in GNOME before because it was just so awkward to drag and drop windows to a new location and get them setup how I wanted them. But with tiling built into the Pop Shell, I can use my trackpad to select a workspace or Super + Ctrl + H, J, K, or L to cycle through them. I’m not sure I’m the best person to do an in depth review of Pop OS so if you’re curious about it, you should read everything System76 has done with it. It works really well. I’ve not tried Regolith Linux but that project seems to attempt to solve similar problems that the Pop Shell has.

All of the extensions that come pre-loaded displayed on the gnome shell extensions website via the gnome shell extensions browser add-on.

Competition
As I said earlier, I did some shopping around before settling on the Lemur Pro. The most obvious competitor is the Dell XPS 13 Developer Edition but when I selected a model with similar specifications to this particular Lemur Pro, I was surprised to find that the Lemur Pro was cheaper than the XPS 13.

Granted, the Dell XPS comes with a higher resolution display but the battery life isn’t nearly what the Lemur Pro is and it doesn’t allow for multiple storage devices. It was a no brainer for me, because I also got to support a smaller US based company that is promoting free software.
I never in a million years would buy a Macbook Pro, but I was curious about the difference in price point and, well, I wasn’t surprised that it clocked in at more than $1000 than the Lemur Pro.

Obviously, Apple devices come with an experience that is fine tuned to their environment but I don’t know if I could justify spending so much when other quality options are available.
I had also considered a Surface Pro but unsurprisingly, it was also prohibitively expensive.

3 month update
After using the Lemur Pro for about 3 months now, I have noticed a few issues. The first and most notable being the Page Up/Page Down keys on the keyboard. Because of how often I use those buttons (default keybinding in GNOME terminal tabs), I find it difficult to correctly get to even the arrow keys. If you’ve got fat fingers, this could be a deal breaker for you.
Secondly, the System76 logo on the laptop is just a sticker, which makes sense when you think in terms of the laptop being a rebranded Clevo device. While some people might think this is a downside, it’s also means you can peel the logo off with a tweezers and some GooGone to get a completely nondescript black laptop.
And finally, I’ve noticed some strange issues with WiFi cutting out after resuming from suspend. This has only happened recently which makes me think it was an update that introduced the problem. I try to keep my systems as up to date as possible, but there’s always a chance that something will break in doing so. Hopefull, System76 can address it soon as this seems to be my number one usability issue so far.

For more reading, checkout what these fine folks had to say:
Lemur Pro Review
Unboxing the Lemur Pro
Beyond The Specs: These 2 New Linux Laptops Aren’t Created Equal
If you have questions about the laptop or would like to add some thoughts, leave a comment or contact me and I’d be happy to chat with you about it.

Categories
Linux Programming

Bulk Image Compression via CLI

Occasionally, I like to share HD photos but they always end up tens of megabytes in size and large files can be a pain send to family and friends. To circumvent this, I make sure to do some image compression before ever sending the images. It’s also very helpful when posting images to a website as large files means longer load times for users (and users don’t like that). So when I wanted to add many photos to a blog post but didn’t want to resize and compress each file manually, I had to figure something else out. A quick search led me to this post that reminded me of the power of Imagick. I’ve used it in the past to generate thumbnails based on PDFs so I knew it had a command line interface but this trick takes it to a whole new level. You’ll need to install imagick (available from most package managers) but once done, the command looks like:
mkdir compressed;for photos in *.jpg;do convert -verbose “$photos” -quality 85% -resize 1920×1080 ./compressed/”$photos”; done
Running this command from the directory your images are located in will 1.) create a new sub-directory to add your compressed files to, 2.) run a for loop through all jpegs in the current director, 3.) create a new image file with the same name in the sub-directory with the dimensions of 1920×1080 pixels and compress it by 15%. This one command saved me so much time, I had time to write another post about it.

Categories
Linux Server Yii2

Starting Systemd Services with Vagrant machines

I recently ran into a minor inconvenience with a configuration on one of my Vagrant machines. You see, I’m implementing a queueing service on an application and I needed that service to be started whenever the machine starts up. Normally, this is quite simple and is done by creating a file named myservice@service in /etc/systemd/system with content like so:
[Unit]
Description=My Queue Worker %I
After=network.target
[Service]
User=www-data
Group=www-data
ExecStart=/usr/bin/php /var/www/my_project/my_script –verbose
Restart=on-failure
[Install]
WantedBy=multi-user.target
Then run systemctl daemon-reload and systemctl enable myservice@1 myservice@2 to start two workers on system boot. Reboot your system, run systemctl status myservice@* and you should see both of those services running.
The problem with doing this on Vagrant occurs when the file your service is attempting to run is located in the shared folder that doesn’t end up getting mounted until the system has already started all services. But Vagrant has that handy file for provisioning and it can do all sorts of neat things like run shell commands after provisioning. To get these very same services to start up in a Vagrant VM, you simply need to add this bit to your Vagrantfile:
Vagrant.configure(“2”) do | config|
config.vm.provision “shell”, run: “always”,
inline: “systemctl start myservice@1 myservice@2”
end
Because this is a change to the Vagrantfile, you’ll have to re-provision the VM with vagrant reload –provision. This will shutdown the currently running VM, and re-run all provisions. Normally, these provisions are only run during the provisioning stage of Vagrant but because we added the run: “always” flag, this snippet will be run every time the machine is started. Now, once you’ve booted your VM with vagrant up, ssh into it with vagrant ssh and you should be able to run systemctl status myservice@* to see all of your services running.

Categories
Linux Server

Automating Proxmox LXC Container Creation, Updates, and more with Ansible

I love tinkering with my homelab but there is always a fear in the back of my mind, that one of my servers is running an outdated package that is being actively exploited. I don’t want to spend my free time cleaning up a mess that some nefarious party has made of my servers and network; I want to tinker! I like to keep everything up to date to prevent that, but I hate having to navigate my way into each and every server to run the updates manually. I’m a fan of automating anything that I have to do more than a couple times so I started researching Ansible.
If you’re doing any sort of server management or application deployment, you really ought to be looking into using this tool. It’s simple to get setup with and once you put in the initial time investment, it will undoubtedly save you time. Now when I want to update all of my servers, I can run two commands from my terminal. But it doesn’t just stop at updating servers, oh no. If I want to create a new server, it’s a matter of copying/pasting an existing configuration from one of my “playbooks,” changing a couple variables, and running the playbook. Just like that, I’ve got a brand new server running on my network.
By now, you agreed that Ansible is great and you should be using it, so how can you get started? I’ve got a repo setup on Github where I’ve shared what I have so far. If you’re looking to start using Ansible to automate Proxmox, I’ve done some of the heavy lifting already. A lot of what I have there, is taken from Nathan Curry’s post on his website. Give that a read first, then come back to my repo where you can tweak to your heart’s desire.
 

Categories
Security

Kernelcon – An Epic Gathering of Hackers

Over the past weekend, I had the pleasure of attending Kernelcon 2019 in Omaha, Nebraska and this conference has become my new yearly pilgrimage. If I never go to any other conferences ever again and only went to this one, I’d be perfectly happy with that. What made it so great?
Organization

This conference was incredibly well organized. Not only was our parking paid for, but upon arrival we were greeted by these vinyl pillar wraps which made it immediately clear this conference had thought of everything. After registering, we were given our swag bags which were loaded with stickers, quality notebooks, pens, extra soft t-shirts in our size, our conference badges, and an assortment of goods from various sponsors.

Yes, I wore my WordCamp Omaha 18 shirt in hopes of shamelessly cross promoting a conference I helped organize.

The badges were fully functioning circuit boards that came with 5 LED lights and programmed to allow attendees to changes colors and patterns. Not only was that fun, but they were hackable! People could take their badges to the Hardware Hacking Village in the conference to extend their badges and add even more blinking lights. Along with the actual badges, the conference had a thoughtful privacy policy communicated via two different colored lanyards; if you wore the provided yellow lanyard, it meant that you were not interested in having your picture taken whereas if you wore the black lanyard, it meant you didn’t have a preference. Reminders were posted all around the convention since this was a security conference and people interested in security also tend to be interested in privacy. For the most part, everyone I encountered was very respectful of this policy.

Experience
I didn’t get a chance to attend the morning keynote as the first day, the workshop I wanted to attend started right away in the morning. But I can’t complain all that much because the workshop was fantastic. In it, we assembled an ODROID-GO. Now, this may look like a simple gaming emulator but it’s so much more than that. After installing a few things like the Arduino IDE and some packages that integrate it nicely with the ODROID-GO, we got to tinkering. Click here for the workshop syllabus repository.

Fully assembled ODROID-GO

Some sample tetris code that I didn’t personally write, but could tinker with if I felt so inclined.

Photoresistor (light sensor) with code that prints out sensor reading to the LCD.

After wiring up the bread boards to work with some extra power, we added an ultrasonic sensor (sonar) to measure distance and print the results to the LCD.

Not only did we do these fun little projects, but we also wired up our boards to work with temperature sensors, connected them to a WiFi access point, and reported the temperature data to a server on the network. That’s right, this gameboy-looking device has WiFi on board, and can even connect to Bluetooth. There are so many possibilities!
Along with the workshops, there was a conference wide Capture The Flag (CTF) challenge where attendees could sign up as a team or individual, and score points for competing various challenges like “hacking” a server on the network, finding hidden WiFi access points, or picking locks. I wanted to participate, and even made some friends at the conference who also wanted to but we were so busy practicing lock picking, that we never got around to it.

In the lock picking village, instructors were setup with videos and directions teaching anyone who was interested in learning.

After practicing on beginner locks, I successfully picked my first real lock; a lock that happens to be one of the most common available to consumers.

I also learned how to shim handcuffs with nothing more than a bobby pin.

The second day, I brought my two year old to the conference who SUCCESSFULLY PICKED HIS FIRST LOCK. Granted, I held the tension wrench down for him but he raked the pins all by himself.

I’ve blurred out any potential PII so as to not violate the privacy of patients.

The conference didn’t have a shortage of hackers doing what they do. One attendee, setup his software defined radio (SDR) and tuned it to the frequency of pagers. What does this mean? It means that this person was able to see all things sent back and forth between these devices since they are broadcast over the air like how any wireless technology is. Unfortunately for some of the patients at local hospitals, their personally identifying information was captured and shown to the world. Let this be a reminder to everyone to take their privacy seriously.

This conference took an interesting approach by not providing food to conference attendees and instead, opted for a lunch break. I think most people could appreciate this as it left lunch plans up to attendees and drove economic incentives for Omaha by bringing business into the downtown area. However; supper and drinks were provided at the after party thanks to sponsors. Along with sustenance, the after party made for a great opportunity for attendees to socialize. Mini-games were held, as well as “Who’s Slide is it Anyways” where participants were assigned a presentation with pre-made slides (unseen by them until the presentation) that were on a wide variety of topics like the History of Bitcoin, Why Sloths are Awesome, and my favorite; Corn. Why was corn my favorite? Because it’s the presentation my co-worker and I ended up giving AND WINNING.

Giving a 10 minute presentation on corn is tough, but Jordon and I pulled it off.

As I mentioned before, I brought my two year old with the second day. Not only did he have a blast picking locks, but he also enjoyed some of the games that were available like the Jurrasic Park arcade game. He wanted to play in the Super Smash Bros. tournament, but we’re not quite ready to compete at the level that the hardcore players were.

We played this game together a lot and even made it in the official Kernelcon’s tweets.

He had to play a couple rounds with Jordon as well.

https://twitter.com/_kernelcon_/status/1114551537081225216

Speakers & Presentations
All this, and I haven’t even gone into the different talks by all the great speakers. I know a few wished they had more time, and so did attendees, but there was so much to cram into our two short days. If I had one complaint about the entire conference, it would be that I didn’t get to participate in nearly as many workshops or watch all the talks I wanted to. Decisions had to be made to make the most out of my time but I still managed to see plenty of security focused talks loaded with tips and information about how to become a better developer.

Wrap It Up
At the end of the conference, organizers surveyed attendees to find out what was good, what was not good, where there were hangups, and how people felt overall. I think it was very much appreciated by attendees as everyone who wanted to tell them thank you, was given that opportunity. Prizes for the the after-party games were awarded, along with CTF and the Smash Bros. tournament. Some of those prizes included the Wifi Pineapple (a $200 device), various Arduino boards, and Raspberry Pi’s (a favorite device for hackers). Winners of the CTF were awarded the most coveted prize of all: the Eternal Kernel, a badge that got them free admission to every future Kernelcon. Gasps could be heard throughout the crowd upon this announcement. I’m sure the competition will be ferocious next year.
This is getting to be a very long post so let me just close by saying that Kernelcon was an incredibly well done conference that I can’t wait to attend again. I met lots of interesting people, made some new friends, and learned so much. Big thanks to the volunteer organizers of Kernelcon for putting on one hell of a conference.

All the goodies I took home from the conference with cute pup tax.