[FIXED] How to enable docker API to access via http

Issue

I'm trying to manage docker via PHP curl requests. (Using Ubuntu 15.10)

I have followed API documentation but it bit confusing and also followed a few online tutorials but no luck.

This is what I have done so far, stopped docker daemon and added

script
    /usr/bin/docker -H tcp://127.0.0.1:4243 -d
end script

to

/etc/init/docker.conf

Docker daemon started

This is My PHP script

function post_to_url($url, $data, $headers) {
    $ch = curl_init();

    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);

    curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 10);
    curl_setopt($ch, CURLOPT_TIMEOUT, 10); //timeout in seconds

    curl_setopt($ch, CURLOPT_URL, $url);
    if ($headers != '') {
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
    }
    curl_setopt($ch, CURLOPT_POST, 1);
    if ($data != '') {
        curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($data));
    }

    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

    $return = curl_exec($ch);
    if ($return == '') {
        return curl_getinfo($ch, CURLINFO_HTTP_CODE);
    } else {
        return $return;
    }
    curl_close($ch);
}
//Sample API request
echo post_to_url('http://127.0.0.1:4243/containers/json', '', '');

But I did not able to get any output via CURL request?

What I'm missing here?

Solution

Finally I was able to figure that out.

In /etc/defaults/docker I put

DOCKER_OPTS='-H tcp://127.0.0.1:4243 -H unix:///var/run/docker.sock'

(Use 0.0.0.0 instead of 127.0.0.1 to access API via any host)

My PHP function in the question is not compatible with REST API,

So I have used following function (Source - This)

// Method: POST, PUT, GET etc
// Data: array("param" => "value") ==> index.php?param=value

function CallAPI($method, $url, $data = false)
{
    $curl = curl_init();

    switch ($method)
    {
        case "POST":
            curl_setopt($curl, CURLOPT_POST, 1);

            if ($data)
                curl_setopt($curl, CURLOPT_POSTFIELDS, $data);
            break;
        case "PUT":
            curl_setopt($curl, CURLOPT_PUT, 1);
            break;
        default:
            if ($data)
                $url = sprintf("%s?%s", $url, http_build_query($data));
    }

    // Optional Authentication:
    curl_setopt($curl, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
    curl_setopt($curl, CURLOPT_USERPWD, "username:password");

    curl_setopt($curl, CURLOPT_URL, $url);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);

    $result = curl_exec($curl);

    curl_close($curl);

    return $result;
}

And called above function:

echo CallAPI('GET', 'http://127.0.0.1:4243/images/json', $data = false)

and it worked!

Opening up Docker API to the public is a major security risk, so I have used IP address 127.0.0.1 instead of 0.0.0.0, so my PHP script can still access it.

Answered By - M_R_K

Answer Checked By - David Marino (PHPFixing Volunteer)