I wanted to upload files directly into the Wordpress from my bash script and did not want to sit around tinkering with PHP to achieve it. So what I ended up doing is setting up FTP, making life much more simpler.

Installating vsftpd

vsftpd is a FTP server program. Install it on your remote machine with,

$ sudo apt-get install vsftpd

Configuring vsftpd

To configure vsftpd, open up the /etc/vsftpd.conf file in your text-editor:

$ sudo vi /etc/vsftpd.conf

The default options are good enough, but if you want to modify them, they are well commented, so you shouldn't find a problem modifying it to your preferences. I didn't modify anything on mine except for the ftpd_banner.

Additionally, replace the line that says pam_service_name=vsftpd with

pam_service_name=ftp

Why? Read the error section to know about it.

And remember to restart the FTP server after you're done editing the file.

$ sudo service vsftpd restart

Creating a local user to make the uploads.

Next, we add a local user on the machine and set his HOME directory to the directory we want them to be able to upload to (in my case /var/www/html/wordpress/wp-content/uploads/)

$ sudo useradd -d /var/www/html/wordpress/wp-content/uploads/ uploader

We then set a password for this user,

$ sudo passwd uploader

Testing it out:

We should be able to upload files using FTP and the new user we created, so from the local machine,

$ curl -T viEditorCheatSheet.pdf ftp://192.168.56.101 --user uploader:pass

$ curl -I http://192.168.56.101/wordpress/wp-content/uploads/viEditorCheatSheet.pdf
HTTP/1.1 200 OK
Date: Thu, 15 Jan 2015 09:21:55 GMT
Server: Apache/2.4.7 (Ubuntu)
Last-Modified: Thu, 15 Jan 2015 06:47:42 GMT
ETag: "435bd-50cab3b985df0"
Accept-Ranges: bytes
Content-Length: 275901
Content-Type: application/pdf

And that's it! You're all set champ! ;)

The error:

Before I changed the pam_service_name=vsftpd to pam_service_name=ftp in the config file, I got this error:

$ curl -T viEditorCheatSheet.pdf ftp://192.168.56.101 --user uploader:pass
ftp://192.168.56.101 --user uploader:pass
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:--  0:00:03 --:--:--     0
curl: (67) Access denied: 530

To see what was happening, I tried logging into the FTP server in the debugging mode.

$ ftp -dv 192.168.56.101
Connected to 192.168.56.101.
220 Welcome to blah FTP service.
ftp: setsockopt: Bad file descriptor
Name (192.168.56.101:nitin): uploader
---> USER uploader
331 Please specify the password.
Password:
---> PASS XXXX
530 Login incorrect.
Login failed.
---> SYST
530 Please login with USER and PASS.

I knew that my login credentials were correct, but something was amiss.

After some digging around, I found that you needed to an edit the configuration. So, going back to /etc/vsftpd.conf

$ sudo vi /etc/vsftpd.conf

Hunt for the line that says pam_service_name=vsftpd and change it to

pam_service_name=ftp

And, restart the FTP server,

$ sudo service vsftpd restart

And, voila! FTP-ing works!

$ curl -T viEditorCheatSheet.pdf ftp://192.168.56.101 --user uploader:pass
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  269k    0     0  100  269k      0   957k --:--:-- --:--:-- --:--:--  958k

$ curl -I http://192.168.56.101/wordpress/wp-content/uploads/viEditorCheatSheet.pdf
HTTP/1.1 200 OK
Date: Thu, 15 Jan 2015 09:21:55 GMT
Server: Apache/2.4.7 (Ubuntu)
Last-Modified: Thu, 15 Jan 2015 06:47:42 GMT
ETag: "435bd-50cab3b985df0"
Accept-Ranges: bytes
Content-Length: 275901
Content-Type: application/pdf