Friday, June 10, 2016

haproxy on Centos 7 with SELinux

Setting up haproxy and varnish with reference to the configuration from these sites: http://sharadchhetri.com/2014/12/20/how-to-install-varnish-4-version-on-centos-7-rhel-7/ https://www.upcloud.com/support/haproxy-load-balancer-centos/ And finally can access plone on the server. But when I check the haproxy status, only client1 can be accessed. All other clients were down with general socket error, permission denied. Googling a bit I finally found out it was due to SELinux. Refer to this page: http://stackoverflow.com/questions/26420729/haproxy-health-check-permission-denied With the solution from that page, I installed policycoreutils-python and tried to run the command given:
semanage port --add --type http_port_t --proto tcp 8081
But that command failed with the error that the port was already defined. When I looked it up using:
semanage port -l | grep 8081
It belonged to some other type (transproxy_port_t). When I tried to delete the type using:
semanage port -d -t transproxy_port_t -p tcp 8081
Got the error that it belongs in the policy and cannot be deleted. After much frustation and further googling finally found out I can modify the port
semanage port -m -t http_port_t -p tcp 8081
And finally haproxy was able to use the other clients. Finally.....

Thursday, June 9, 2016

Installing Centos 7 on HP G7 Server

When I first initially tried it, the installer cannot detect any local hard disk to install to. After much googling found out that it was because a certain driver for the Smart Array Controller is no longer available on Centos 7. To allow for use of the new driver on old hardware, you need to enable the option. Once the DVD has booted and on the first menu screen, highlight the first option and then press tab which would bring you to a command line where you can add additional parameters to boot. Add the following parameters:
hpsa.hpsa_allow_any=1 hpsa.hpsa_simple_mode=1
And then press enter to boot. You should now be able to install as you wish. After installation, on the first boot, make sure at the menu, press 'e' to edit the parameters and add them again. Then once booted, go to /boot/grub2/grub.cfg to permanently add the parameters to the menu. Refer to http://serverfault.com/questions/611182/centos-7-x64-and-hp-proliant-dl360-g5-scsi-controller-compatibility and it's comments for the explaination.

Is Blogging No Longer a Thing?

As I embark on my new journey to learn the Rust programming language, I find myself pondering—where have all the blogs gone? In search of pr...