Increase docker pool size by changing storage driver

Configure Docker with the devicemapper storage driver

NOTE: This is for Docker CE & Docker EE

Issue:

By default you will notice that docker storage device is "brtfs" i.e. default storage, which is limited to 20GB of data storage.

Usually you will find this storage as too limited to use. As most of the times we have to install multiple images that too of high storage like 4/8/10GB. And with this default storage you will be end up getting frustrated.

Solution:

Configure Docker with "devicemapper" storage driver.

How to do this:

1) Stop Docker

$ sudo systemctl stop docker 

2) Edit /etc/docker/daemon.json. If it does not yet exist, create it. Assuming that the file was empty, add the following contents.

{
  "storage-driver": "devicemapper"
}

Note: Docker will not start if the daemon.json file contains badly-formed JSON

3) Start Docker

$ sudo systemctl start docker

4) Verify that the daemon is using the devicemapper storage driver. Use the docker info command and look for Storage Driver

Note: This host is running in loop-lvm node, which is not supported on production systems. This is indicated by the fact that the Data loop file and a Metadata loop file are on files under /var/lib/docker/devicemapper/devicemapper.

Useful link: Use device mapper storage driver

Hope this helps :-)
Enjoy :-)

Enable SSL in between OHS & Outbound Applications

Enabling SSL in between OHS & OutBound Applications

Prerequisites:

1. OHS SSL is enabled.
2. Outbound App SSL is enabled like OAM, Weblogic, OIM etc.

What we are aiming is to setup SSL in b/w OHS & outbound apps

Eg: Consider you want to proxy your OAM server via OHS as a load balancer/proxy call it any. This is a very normal usecase where you have your OAM servers sitting in your data-center & you don't want it's hostname/IP to be exposed. So what you usually do is proxy OAM via OHS.

• Consider your OHS server name is https://abc.com. So if admin needs to access the oamconsole. Admin will fire the url as https://abc.com/oamconsole
• To enable this usecase, /oamconsole is to be added in ssl.conf/mod_wl_ohs.conf file(usual way).
• But the catch is that our OHS & OAM are in SSL mode.
• This means that they will do handshake before starting to talk to each other.
• As we all know that while doing handshake, server sends its user certificate, now this cert is verified by client i.e. here mod_wl_proxy of OHS. So the wallet used by it has to have the trusted certificate entry in it.

Steps you need to follow for this are as;

• Import the certificate used by Outbound app such as Oracle WebLogic Server into the Oracle HTTP Server wallet as a trusted certificate.
• To add trusted certificate you can use orapki utility or any of your choice.
• <MW_HOME>/oracle_common/bin/orapki wallet add -wallet ./ -trusted_cert -cert cacert.pem -auto_login_only 
• Note: './' is used as we consider that you are running this command from the directory where your cwallet.sso is present. You can substitute it with directory path of cwallet.sso as well.
•  Now you need to add 2 tags in ssl.conf or mod_wl_proxy.conf:

• SecureProxy On

  WlSSLWallet "<wallet location>" 

Complete Eg:

<Location /console>
SetHandler weblogic-handler
WebLogicHost xyz.us.domain.com
WebLogicPort 7001

SecureProxy ON
WlSSLWallet "/MW_HOME/keystores/newwallet"
</Location>

Now start your OHS server, and try to access the proxied url, you should be able to make a successful connection. You can also confirm the same by capturing wireshark traces. 

Hope this helps... :-)

Useful links:

https://docs.oracle.com/cd/E23943_01/core.1111/e10105/sslconfig.htm#ASADM10286

http://middlewaretimes.blogspot.sg/2014/03/configuring-modwlohs-to-use-ssl-between.html

Enjoy :-)