Containers

Revision as of 20:42, 18 August 2017 by B01 (talk | contribs) (Example with Transitional/Yunohost container and services)

We install containers to manage the transitional, finally LXE: https://wiki.debian.org/LXC

STEP 0 Install lxc

apt-get update apt-get install lxc

STEP 1 Create Let's create a 'Transitional' virtual machine, a container

lxc-create -n transitional -t debian


Start the container,deattach the container from the root terminal and change password of the container

START lxc-start -n transitional -d

OPEN lxc-console -n transitional

STOP lxc-stop -n transitional

LIST the containers and their IP lxc-ls -f



ERRORS along the way which got solved

Could not find writable mount point for cgroup hierarchy 8 while trying to create cgroup.

We imagine that if we upgrade to jessie 8.8, that the Cgroup issue (=a subsystem in the linux kernell, which allows process separation) will be a resolved. For now we add the mountpoint. and follow this manual [1]


STEP 2 How can a container access the network?

A container, has MAC adress, we need a bridge for networking, via dhcp, So the container get an ip, and give access to the server's internal network

Do we opt for static of dynamic ip's? the dhcp server can have static ip via host/ it is anyhow setup to give a unique ip to the MAC address of the container (guest). So the choice is obsolete.

/var/lib/lxc/<name>/config

   lxc.network.type = veth
   lxc.network.flags = up
   lxc.network.link = lxc-nat-bridge
   lxc.network.name = eth0
   lxc.network.ipv4 = 10.0.3.2
   lxc.network.ipv4.gateway = 10.0.3.1


Using /etc/network/interfaces, the bridge could be created simply:

iface lxc-nat-bridge inet static

   bridge_ports none
   bridge_fd 0
   address 10.0.3.1
   netmask 255.255.255.0


We will also add, /etc/network/interface, the iptable rules for your main 'out' interface (here eth0):

iface eth0 inet static

     ...
     up iptables -t nat -F POSTROUTING
     up iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE

or

     iptables -A FORWARD -i eth0 -o lxc-nat-bridge -j ACCEPT                                                                                       |
     iptables -A FORWARD -i lxc-nat-bridge -o eth0 -j ACCEPT



Restart network interface

service networking restart

WARNING deprecated!!!!


Enable IPv4 forwarding by putting this in /etc/sysctl.conf:

net.ipv4.ip_forward=1

and then applying it using:

sysctl -p

STEP 3 How can we access via the internet a container?

Setup routing / (reverse) proxy system for networking, so depending on the different services (Living data, Nekrocemetery, Transitional) we create subdomains which direct you to the correct container.

Example with Transitional/Yunohost container and services

Add the subdomain at Gandi

In need for a user/pwd !

Configure the hosts

Modify /etc/hosts on the root of the server

sudo nano /etc/hosts

Add :

10.0.3.2        ynh.anarchaserver.org

'Modify /etc/hosts on your computer to test before the domain is propagated

sudo nano /etc/hosts

Add :

209.51.163.19 ynh.anarchaserver.org

Create a HTTPS Certificate with let'sencrypt (certbot)

See the existings certificates :

sudo certbot certificates

Create the certificate for the domain with apache server

sudo certbot --apache -d ynh.anarchaserver.org

Please choose whether HTTPS access is required or optional.


1: Easy - Allow both HTTP and HTTPS access to these sites 2: Secure - Make all requests redirect to secure HTTPS access


Select the appropriate number [1-2] then [enter] (press 'c' to cancel): 2 That's it !

To check if the certificates needs to be renewed (and renew them)

sudo certbot renew


Configure Apache to proxy the subdomain

Create 2 files in /etc/apache2/sites-availables for http and https config :

sudo nano /etc/apache2/sites-available/yunohost.conf

<VirtualHost *:80>

       ServerAdmin webmaster@localhost
       ServerName ynh.anarchaserver.org
       ErrorLog ${APACHE_LOG_DIR}/ynh-error.log
       CustomLog ${APACHE_LOG_DIR}/ynh-access.log combined


       ProxyPreserveHost       On
       ProxyRequests           Off
       ProxyPass / https://10.0.3.2
       ProxyPassReverse https://10.0.3.2 /


       <Proxy *>
               Order deny,allow
               Allow from all
       </Proxy>
  1.  Uncomment and adapt if you want to swith automaticaly from http to https
  2. RewriteEngine on
  3. RewriteCond %{SERVER_NAME} =ynh.anarchaserver.org
  4. RewriteRule ^ https://%{SERVER_NAME}%{REQUEST_URI} [END,QSA,R=permanent]

</VirtualHost>

2ème fichier :

sudo nano /etc/apache2/sites-available/yunohost-le-ssl.conf

<IfModule mod_ssl.c> <VirtualHost *:443>

       ServerAdmin webmaster@localhost
       ServerName ynh.anarchaserver.org
       ErrorLog ${APACHE_LOG_DIR}/ynh-error.log
       CustomLog ${APACHE_LOG_DIR}/ynh-access.log combined
       ProxyPreserveHost       On
       ProxyRequests           Off
       <Proxy *>
               Order deny,allow
               Allow from all
       </Proxy>
       SSLEngine on
       SSLProxyEngine On
       ProxyPass /  https://ynh.anarchaserver.org/
       ProxyPassReverse / https://ynh.anarchaserver.org/

SSLCertificateFile /etc/letsencrypt/live/ynh.anarchaserver.org/fullchain.pem SSLCertificateKeyFile /etc/letsencrypt/live/ynh.anarchaserver.org/privkey.pem Include /etc/letsencrypt/options-ssl-apache.conf </VirtualHost> </IfModule>

Reload Apache2 (if there is a problem, Apache will keep its configuration)

sudo systemctl reload apache2.service

STEP 4 How can we administrate this container

Access the container

  • Log into anarchaserver and then type : (you need to be a user on this container to be able to login with ssh public key or root account)
sudo lxc-console -n transitional
  • To access the container without an account
sudo lxc-attach -n transitional

Install and update things in the container

Once logged :

sudo apt-get update
sudo apt-get upgrade
sudo apt-get iputils-ping