This article is one in a series showing how to use the REST API to produce sample output. This example rather than producing a CSV file will produce a HTML Table in a web browser.
Pre-requisites
- The script is written in PHP 7. It should work with any web server that supports PHP 7 (e.g. Apache, IIS, Nginx)
- The script relies on two optional modules php7-curl for web requests and php7-json
Step One - build the CURL connection to the Rest API host
As before, use your local values for the host name, username and password for the Rest API host.
// update these for your location
$rhost = "vm-mike-sql17";
$aname = "admin";
$psswd = "password";
/*
* Use curl to fetch the results from the REST API
*/
$ch = curl_init();
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_VERBOSE, 1);
curl_setopt($ch, CURLOPT_HEADER, 1);
curl_setopt($ch, CURLOPT_USERPWD, $aname . ":" . $psswd);
curl_setopt($ch, CURLOPT_URL, "http://" .$rhost ."/API/v1/devices");
$response = curl_exec($ch);
// We want to parse the headers to find X-fetch-count
$header_size = curl_getinfo($ch, CURLINFO_HEADER_SIZE);
$headers = substr($response, 0, $header_size);
// explode multiline response headers into an array of lines
$header = explode("\n",$headers);
foreach ($header as $line)
{
// find the two headers we're specifically interested in
list($key,$value) = explode(": ",$line);
if (strcasecmp($key,"X-fetch-count")==0) { $max = $value; } // total no of devices in database
if (strcasecmp($key,"X-fetch-current-size")==0) { $count = $value; }// count of devices returned in THIS query - will stop at 200 if there are more than 200 results
}
$body = substr($response, $header_size);
$jsondata = json_decode($body, true); // recursive associative array please
By default the REST API "/api/v1/devices" page will return 200 devices at a time. We can increase or decrease this using the "fetch_size" parameter in the URL. The X-fetch-count header contains the total number of devices in the dataset. The X-fetch-current-size header shows how many were returned in this batch of results.
The body of the result is coded in JSON. The php function json_decode will convert JSON into a PHP variable. Passing "True" as the second parameter means return the data as an associative array.
Step through the results
As a simple example, we're going to produce a HTML Table containing hostname, ram and CPU for each scanned device. The summary info returned in the first API call above contains the hostname and a link to the rest of the device details.
At this point we also prepare the start of the output.
$output = "<html><head><title>List of Devices</title></head>\n<body>\n";
$output = "<p>Details for " . $count . " devices.</p>\n";
$output .= "<table border='1' cellpadding='1'>\n<tr><td>Hostname</td><td>RAM</td><td>CPU</td></tr>\n";
echo "$output";
$ch2 = curl_init(); // move this out of the loop later
curl_setopt($ch2, CURLOPT_USERPWD, $aname . ":" . $psswd); // move this out of the loop later
curl_setopt($ch2, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch2, CURLOPT_VERBOSE, 1);
curl_setopt($ch2, CURLOPT_HEADER, 1);
$output = "";
$i=0;
while ($i != $count)
{
$hostname = $jsondata[$i]["host_name"] ?? "(no hostname)";
$self = $jsondata[$i]["self"];
// do something
$i++
}
With the $self url we need to do a second api call to get the remaining details and parse the resulting JSON. Therefore our "do something" expands out as follows:
curl_setopt($ch2, CURLOPT_URL, $self); $device_response = curl_exec($ch2); $header_size = curl_getinfo($ch2, CURLINFO_HEADER_SIZE); $devicedetails = substr($device_response, $header_size); $device = json_decode($devicedetails,true); $ram = $device['total_memory_mb'] ?? "(no ram info)"; $cpu = $device['cpu'][0]['cpu_model'] ?? "(no cpu info)" ; $output .= "<tr><td>$hostname</td><td>$ram</td><td>$cpu</tr>\n"; curl_close($ch2);
We call curl_close() to free up memory as we go through the loop - lets not crash the web server.
Completed Code
Related articles