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conflict

Docker, an advanced chroot utility


Chasm—just like a Docker creates a chasm between two sets of software

SECURITY WARNING

Before installing Docker and containers with services on your Linux system, make sure to read and understand the risks as mentioned on this Docker and iptables page. Especially, Docker will make all your containers visible to the entire world through your Internet connection. This is great if you want to indeed share that service with the rest of the world, it's very dangerous if you are working on that container service since it could have security issues that need patching and such. Docker documents a way to prevent that behavior by adding the following rule to your firewall:

iptables -I DOCKER-USER -i eth0 ! -s 192.168.1.0/24 -j DROP

This means that unless the IP address matches 192.168.1.0/24, the access is refused. The `eth0` interface name should be replaced with the interface name you use as the external ethernet connection. During development, you should always have such a rule.

That has not worked at all for me because my local network includes many other computers on my LAN and this rule blocks them all. So really not a useful idea.

Instead, I created my own entries based on some other characteristics. That includes the following lines in my firewall file:

*filter
:DOCKER-USER - [0:0]

-A DOCKER-USER -j early_forward
-A DOCKER-USER -i eno1 -p tcp -m conntrack --ctorigdstport 80 --ctdir ORIGINAL -j DROP
-A DOCKER-USER -i eno1 -p tcp -m conntrack --ctorigdstport 8080 --ctdir ORIGINAL -j DROP
-A DOCKER-USER -i eno1 -p tcp -m conntrack --ctorigdstport 8081 --ctdir ORIGINAL -j DROP

My early_forward allows my LAN to continue to work. These are my firewall rules that allow my LAN computers to have their traffic forwarded as expected.

Then I have three rules that block port 80, 8080, and 8081 from Docker.

Docker will add new rules that will appear after (albeit not within the DOCKER-USER list) and will open ports for whatever necessary service you install in your Dockers.

Note that the only ports you have to block are ports that Docker will share and that you have otherwise open on your main server. If Docker opens port 5000 and your firewall does not allow connections to port 5000 from the outside, then you're already safe. On my end I have Apache running so as a result I block quite usual HTTP ports from Docker.

Docker

As we are helping various customers, we encounter new technologies.

In the old days, we used chroot to create a separate environment where you could have your own installation and prevent the software from within that environment access to everything on your computer. This is particularly useful for publicly facing services liek Apache, Bind, etc.

SMS From Me Service

SMS From Me Logo SMS From Me is a service offered by Made to Order Software Corporation that allows registered users to automatically send SMS whenever they receive a lead in their funnel.

This solution lets you sends SMS message from your phone, which means that you start a conversation with your prospect.

Discuss This! module Known Issues

The module works and is secure, however, there are problems difficult to circumvent. The following lists them. If you can help fixing some them, you'll be more than welcome!

Reordering the Comments on your Node

It is possible to reorder the node fields using the CCK module. If the Discuss This! comments do not appear exactly where you'd expect them to be, try using the the CCK module:

  1. Download the CCK module
  2. Install the CCK module
  3. Go to Administer » Content management » Content types
  4. Click on Manage content fields next to the node type you are ...

PostgreSQL and Drupal conflict

We have been running Drupal for some time now and we have noticed that it generates a very large amount of warnings in our log files.

The warning is in link with improperly formatted strings. PostgreSQL tries to follow the SQL specification to the letter and that means you cannot use the backslash character to escape special character sequences (such as \n for a newline character.)

I knew that in most cases the error was generated because of the function saving a full page or some other content in the cache. In that case, the system includes the characters: \012 and \015 (\n and \r.) That ...

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This Agreement ("Agreement") is by and between Made to Order Software Corporation ("m2osw") a Californian Corporation and You, your heirs, your agents, successors and assigns ("You" and "Your"), and is made effective as of the date of electronic execution, which is when you register for an electronic account to use the Web site of m2osw. This Agreement sets forth the terms and conditions of Your use of the Online Services ...