trjhtr

At my office we have an internal monitoring tool we use on customer systems to monitor various vitals and notify us via Slack. Our Lead Dev and Chief Architect are very paranoid about Git, and outright refuse to put it on customer systems, however they still like the idea of using it for development.

So I created an autoupdater script for our monitoring tool that allows us to push changes to git, and have the tool auto-update from the repo without having to put git on systems.

It's written in PHP as this is the primary language in use at the office (specifically 5.3.3, although one of our devs is currently writing a technical specification for updating to 5.6), and it uses GitLab's api on our own internal gitlab host.

I've also spoofed a few details for privacy reasons, for example the config file is not called config.conf, and the service is not called tool.

<?php
//Until config can be loaded, assume _LOC is the directory of this script
$_LOC = realpath(dirname(__FILE__)).'/';

//Look for config file
echo "Searching for ".$_LOC."config/config.confn";
if (!file_exists($_LOC.'config/config.conf')) 
 echo "Searching for ".$_LOC."config/config.template.confn";
 if (!file_exists($_LOC.'config/config.template.conf')) 
 exit('Config file does not exist and template was not found!');
 

 //Create config from template
 echo "Template exists, creating config filen";
 copy($_LOC.'config/config.template.conf', $_LOC.'config/config.conf');


//Imports
require($_LOC.'lib/functions.php');
require($_LOC.'config/config.conf');
require('/etc/casper/defaults.conf');

if ($_DEBUG) echo "Starting update checkn";

if ($_DEBUG) echo "Fetching commitsn";
//Fetch all commits for set branch, default sorted by newest first
$commitsjson = gitlab_fetch("projects/$_GIT_ID/repository/commits", array('ref' => $_GIT_BRANCH));
$commits = json_decode($commitsjson);
$lastcommit = $commits[0];
$lastcommit = $lastcommit->id;

if ($_DEBUG) echo "Latest commit is ".$lastcommit."n";
if ($lastcommit !== $_UPDATE_SHA) 
 if ($_DEBUG) echo "But current update is ".$_UPDATE_SHA."nUpdating...";
 //Fetch recursive tree of all files and directories
 $filejson = gitlab_fetch("projects/$_GIT_ID/repository/tree", array('recursive' => 'true', 'ref' => $_GIT_BRANCH));
 $fileinfo = json_decode($filejson);

 //Create backup directory
 $bakdate = date('Ymd');
 $bakloc = $_LOC.'bak'.$bakdate.'/';
 mkdir($bakloc);

 $files = array();
 $dirs = array();
 //Format each file to url to fetch file contents and filter directories to separate array
 foreach($fileinfo as $file) 
 if ($file->type == "blob")
 $files[$file->path] = "projects/$_GIT_ID/repository/files/".$file->path;
 else if ($file->type == "tree")
 $dirs = $file->path;
 
 //Create directories
 foreach($dirs as $dir) 
 if ($_DEBUG) echo "Creating directory $dirn";
 if (!file_exists($_LOC.$dir)) mkdir($_LOC.$dir);
 else mkdir($bakloc.$dir);
 
 //Fetch files
 foreach($files as $path => $fileapi) 
 if ($_DEBUG) echo "Fetching $pathn";
 //Fetch json
 $fileraw = gitlab_fetch($fileapi, array('ref' => $_GIT_BRANCH));
 $fileobj = json_decode($fileraw);
 //If content is set, file was successfully pulled
 if (isset($fileobj->content)) 
 //content is provided in base64, need to decode
 $filecontent = base64_decode($fileobj->content);
 if ($_DEBUG) echo "Fetched ".strlen($fileobj->content)." bytes, decoded into ".strlen($filecontent)." bytesn";
 //Backup file if it already exists
 if (file_exists($_LOC.$path)) 
 if ($_DEBUG) echo "Backing up $_LOC$path to $bakloc$pathn";
 copy($_LOC.$path, $bakloc.$path);
 
 if ($_DEBUG) echo "Overwriting $_LOC$pathn";
 file_put_contents($_LOC.$path, $filecontent);
 if ($_DEBUG) echo "Donen";
 //If message is set, an error was returned
 else if (isset($fileobj->message)) 
 //Output the error
 if ($_DEBUG) echo "Failed to download $path with response ".$fileobj->message."n";
 
 

 //Update the commit hash
 if ($_DEBUG) echo "Updating commit hashn";
 file_put_contents($_LOC.'config/update-hash', $lastcommit);
 if ($_DEBUG) echo "Restarting tool...n";
 //Log restart in slack, and restart service
 slack_pretty_log('Tool Updated', "Tool $_VERSION has updated! Restarting...", 'good');
 $output = shell_exec('sudo /etc/init.d/tool restart 2>&1');
 if ($_DEBUG) echo $output;
 //End
 else 
 if ($_DEBUG) echo "No new updatesn";

Functions such as slack_pretty_log and gitlab_fetch are defined externally and use the respective APIs, and any variables beginning with underscores (such as $_DEBUG and $_GIT_BRANCH) are defined in the config file.

I'm mainly interested in feedback on the flow of the logic itself, as well as naming conventions (which I admittedly didn't do a great job of adhering to) and comments.

This is a standalone script designed to run once per day on a cronjob, which is why it has a lot of logic outside of any functions or classes.

Why have you repeated if ($_DEBUG) echo a zillion times? That is begging to be embedded in a debug() function.

Every time you have a comment with a chunk of logic underneath it, that should be a method (named what the comment says).