Convert certificate from DER to PEM format
Sometimes you get a CA certificate in DER format and some application requires it in a PEM format. OpenSSL to the rescue: # openssl x509 -inform der -in myCA.der -out myCA.pem
Blog Links: Project management: A surefire way to kill your software product
One of the best articles about project management and software development Project management: A surefire way to kill your software product. As a software developer I have to agree with almost everything stated there and I can confirm most of it as true. You cannot treat creative people as resources and think that inspiration and… Read More »
#DRBD Growing online a replicated resource in a complex enterprise environment
At some point an increase in size of the replicated resource is needed. This can be caused by an increase in data retention times or an increase of transaction numbers affecting that resource. If the backing block devices can be grown while in operation (online), it is also possible to increase the size of a… Read More »
Set up automatic #Oracle database back-up using #RMAN
There is a very easy method of setting up on Linux an automatic back-up for Oracle by using database procedures, RMAN and scripts. STEP 1: Define a back-up script Create in /home/oracle/backup.sh a script file with the content: #!/bin/bash export ORACLE_HOME=/home/oracle/app/oracle/product/11.2.0/dbhome_1 export PATH=$PATH:$ORACLE_HOME/bin export ORACLE_SID=prod rman target / CMDFILE=/home/oracle/bin/backup.rman LOG /data/oradata/backuplogs/rman-`date -I`.log exit 0 Where… Read More »
#DRBD investigate and solve a sudden Diskless issue
Even when you think that you know something well enough you discover that there are some corner cases you never encountered. This is the main reason I like IT system administration tasks, you never get bored. This post is about one of this corner cases in a DRBD setup described in post #DRBD based disk… Read More »
#Docker images cleanup
CASE 1: If you use multi-stage docker builds you will end up with lots of un-tagged images. The proper way to clean the intermediary leftover images is: docker rmi $(docker images -f “dangling=true” -q) CASE 2: If you want to clean up all the old images for which you no longer have any instantiated container… Read More »
#Edgerouter: Force restart a PPPOE connection.
One of my internet service providers uses PPPOE for the internet connection. Sometimes if the physical connection is down for a long time the pppoe0 interface is no longer reconnecting or is stuck (looks like connected but no traffic passes through it). I found out that the problem is solved by force reconnecting it through… Read More »
Portable #RaspberryPI #Docker #Swarm – Static IP, Ethernet based, #Portainer
As I discussed in post Portable #Docker #Swarm made of #RaspberryPI – Updated hardware there were several hardware updates done to the swarm. One of the updates was adding a switch and connecting all the Raspberry PIs to the switch. First version of the Docker Swarm was done using the wifi connections of the PIs.… Read More »
Setup #Eclipse as #go IDE in Linux
I like Eclipse and I used it for many years on Linux for Java developement. I wanted to test how go(golang) works but I did not like all the suggested IDEs, you know the “cool” ones. I wanted to be able to use Eclipse. By default eclipse is not go oriented but with some small… Read More »
Portable #Docker #Swarm made of #RaspberryPI – Updated hardware
I wanted to update my hardware setup for the Docker Swarm cluster from post Portable #Docker #Swarm made of #RaspberryPI. The idea was to make it more portable, more reliable and a bit faster. The following steps were done: Add ethernet support The original setup used a small Edimax router with the Raspberry Pi nodes… Read More »