Firstly confirm you have the appropriate hardware version (there are two for the BCM4360!)
lspci -vnn | grep Net
The 'wl' module only supports the '14e4:43a0' version.
The RPM fusion repository have kindly already packaged it up for us - so let's firstly add the repo:
sudo dnf install -y https://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-26.noarch.rpm https://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-26.noarch.rpm
sudo dnf install -y broadcom-wl kernel-develsudo akmods --force --kernel `uname -r` --akmod...
Monday, 31 July 2017
Thursday, 27 July 2017
curl: 8 Command Line Examples
curl is a great addition to any scripter's arsenal and I tend to use it quite a lot - so I thought I would demonstrate some of its features in this post.
Post data (as parameters) to url
curl -d _username="admin" -d password="<password>" https://127.0.0.1/login.php
Ensure curl follows redirects
curl -L google.com
Limit download bandwidth (2 MB per second)
curl --limit-rate 2M -O http://speedtest.newark.linode.com/100MB-newark.bin
Perform basic authentication
curl -u username:password https://localhost/restrictedarea
Enabling...
Wednesday, 26 July 2017
Windows Containers / Docker Networking: Inbound Communication
When working with Windows Containers I got a really bad headache trying to work out how to setup inbound communication to the container from external hosts.
To summerize my findings:
In order to allow inbound communication you will either need to use the '--expose' or '--expose' a long with '--ports' switch - each of them do slightly different things.
'--expose': When specifying this Docker will expose (make accessible) a port that is available to other containers only.
'--ports': When used in conjunction...
Tuesday, 25 July 2017
git: Removing sensitive information from a repository
While you can use the 'filter-branch' switch to effectively erase all trace of a file from a repository - there is a much quicker way to do this using BFG Repo-Cleaner.
Firstly grab an up to date copy of the repo with:
git pull https://github.com/user123/project.git master
Remove the file from the current branch:
git rm 'dirtyfile.txt'
Commit the changes to the local repo:
git commit -m "removal"
Push changes to the remote repo:
git push origin master
Download and execute BFG Repo-Cleaner:
cd /tmp
yum install jre-headless
wget http://repo1.maven.org/maven2/com/madgag/bfg/1.12.15/bfg-1.12.15.jar
cd...
Friday, 21 July 2017
Querying a PostgreSQL database
Firstly ensure your user has the adequate permissions to connect to the postgres server in pg_hba.conf.
For the purposes of this tutorial I will be using the postgres user:
sudo su - postgres
psql
\list
\connect snorby
or
psql snorby
For help we can issue:
\?
to list the databases:
\l
and to view the tables:
\dt
to get a description of the table we issue:
\d+ <table-name>
we can then query the table e.g.:
select * from <table> where <column-name> between '2017-07-19 15:31:09.444' and '2017-07-21 15:31:09.444';
and...
Thursday, 20 July 2017
Resolved: wkhtmltopdf: cannot connect to X server
Unfortunately the latest versions of wkhtmltopdf are not headless and as a result you will need to download wkhtmltopdf version 0.12.2 in order to get it running in a CLI environment. I haven't had any luck with any other versions - but please let me know if there are any other versions confirmed working.
The other alternative is to fake an X server - however (personally) I prefer to avoid this approach.
You can download version 0.12.2 from here:
cd /tmp
wget https://github.com/wkhtmltopdf/wkhtmltopdf/releases/download/0.12.2/wkhtmltox-0.12.2_linux-centos7-amd64.rpm
rpm...
Tuesday, 18 July 2017
Exporting MSSQL Databases (schema and data) from Azure
Because Microsoft have disabled the ability to perform backups / exports of MSSQL databases from Azure directly from the SQL Management Studio (why?!) we now have to perform this from the Azure Portal.
A new format introduced as a 'bacpac' file allows you to store both the database schema and data within a single (compressed) file.
Open up the Resource Group in the Azure Portal, select the relevant database >> Overview >> and then select...
Friday, 14 July 2017
A crash course on Bash / Shell scripting concepts
if statement
if [[ $1 == "123" ]]
then echo "Argument 1 equals to 123"
else
echo "Argument 1 does not equal to 123"
fi
inverted if statement
if ! [[ $1 == "123" ]]
then echo "Argument 1 does not equal to 123"
fi
regular expression (checking for number)
regex='^[0-9]+$'
if [[ $num =~ regex ]]
then echo "This is a valid number!"
fi
while loop
NUMBER=1
while [[ $NUMBER -le "20" ]]
do echo "The number ($NUMBER) is less than 20"
NUMBER=$((NUMBER + 1))
done
awk (separate by char)
LINE=this,is,a,test
echo "$LINE" | awk -F ',' '{print...
Setting up Octopus Tentacle on Windows Server 2012/2016 Core
For this tutorial I will be setting up Octopus Tentacle in a container running Server 2016 Core.
Let's firstly create our container with:
docker run -it --cpus 2 --memory 4G --network=<network-id> --name windowscore -h <your-hostname> microsoft/windowsservercore cmd.exe
Ensure that your computer name is correct and setup in DNS - so both Octopus and the server running the Tentacle can communicate with each other.
and for the purposes of this tutorial we will use a static IP and also join to to our domain with Powershell:
Get-NetIPInterface...
Thursday, 13 July 2017
Script to remove bad characters from a set of files
The need for this script was prompted by a series of files being uploaded to Sharepoint which had special characters within their filenames such as an astrix or tilde.
Although there are many ways to achieve this I chose for a simplistic approach using cp and sed.
We can use the sed substitute function to replace any bad characters - we have the following directory we wish to 'cleanse':
ls /tmp/test
drwxrwxr-x. 2 limited limited 120 Jul 13 13:45 .
drwxrwxrwt. 40 root root 1280 Jul 13 13:43 ..
-rw-rw-r--....
Configuring NICs on Windows Server 2016 from the command line / Powershell
It seems that in Server 2016 they have removed some of the functionality in some older utilities such as netsh, netdom etc.
So in order to configure IP addresses from the command line it looks like we should put our trust solely in Powershell (*cringes*.)
In order to set a static IP address there are a few commands we need to run - firstly disabling the DHCP on the relevant NIC:
Get-NetIPInterface | FL # grab the relevant interface ID from here
Set-NetIPInterface -InterfaceIndex 22 -DHCP Disabled
*Note: We can also use the 'InterfaceAlias'...
Wednesday, 12 July 2017
Windows Containers / Docker - Creating a 'bridged' or 'transparent' network
By default Windows Containers (or Docker on Server 2016) uses WinNAT to provide NAT functionality to containers - however in some cases you will likely want to run a container in bridged mode - i.e. provide direct network access to the container.
We can do this fairly easily with:
docker network create -d transparent -o com.docker.network.windowsshim.interface="Ethernet0" TransparentNet
Confirm with:
docker network ls
We can also check the details of the network with the 'inspect' switch for example:
docker network inspect <network-id>
Static...
Snippet: Copying only modified files within X days
The following spinet allows you to copy only modified within the last 7 days (from the current date) to a predefined destination.
find /var/log -d -mtime -7 -exec cp {} /home/user/modified_logs \;
The -mtime command specifies the time (in days) of how far you wish to span back.
You can also check for files that have been accessed with the '-atime' switch and similarly the creation time with 'ctime'.
The '-exec' switch allows us to execute a custom command (in this case cp) and transplant the output of the find command into the custom cp command...
Sunday, 9 July 2017
CentOS / RHEL: Enabling automatic updates of critical security patches
While I certainty wouldn't recommend enabling automatic updates (even general security updates) on a production server I would however (in most cases) recommend enabling automatic updates for critical security patches.
We can do this with the yum-cron tool - which (as suggested) creates a cronjob to perform the updates:
sudo -y install yum-cron
We can then configure yum-cron - ensuring it only applies critical security updates:
vi /etc/yum/yum-cron.conf
and setup a mail host and destination - while ensuring that the update_cmd is set accordingly:
update_cmd minimal-security-severity:Critical
start...
Friday, 7 July 2017
Linux: Benchmarking disk I/O and determining block size
A quick command that can be used to benchmark the disk write speed:
time sh -c "dd if=/dev/zero of=ddfile bs=8k count=250000 && sync"; rm ddfile
and with a slightly larger block size:
time sh -c "dd if=/dev/zero of=ddfile bs=16M count=10 && sync"; rm ddfile
Note: Finding the appropriate block size when working with dd will be dependant on the hardware - the block size determines how how data is kept in memory during the copy - so you can imagine that if the block size is 2G in size you would need to ensure that you have at least...
RAM, CPU and I/O Throttling with Windows Server Containers / Docker
CPU
Docker provides several options for limiting CPU with containers - one of the more common switches is '--cpus' - which allows you to limit the number of CPU's a container can use - for example if I wanted to ensure a container only used 1 and a half processors I could issue:
docker run -it --name windowscorecapped --cpus 1.5 microsoft/windowsservercore cmd.exe
There is also a switch called '--cpu-shares' which allows you to delegate which containers would get priority (weighted) access to CPU cycles during (and only during) contention...
Installing / configuring Windows Server Containers (Docker) on Server 2016 Core
Docker and Microsoft formed an agreement back in 2014 to provide Docker technology to be integrated into Windows Server 2016.
Forenote: If you are running the host machine under ESXI you should ensure that you create a port group with promiscuous mode enabled in order to get Docker networking running in transparent mode!
Before enabling Docker we should ensure that the host system is up to date by running:
cmd.exe
sconfig
and select 'option 6'
or if you are on a non-core version:
wuauclt.exe /updatenow
restart the system and install...
Thursday, 6 July 2017
Creating and restoring a block level backup of a disk with dd and par2
Let's firstly take an image of the disk / partition we wish to backup by piping it into a gzip archive:
dd if=/dev/sda1 bs=64K | gzip -9 -c > /tmp/backup.img.gz; sync
For parity we need to ensure par2 is installed with:
sudo yum -y par2cmdline
cd /tmp
par2 create backup.img.gz
Which by default will provide 5% redundancy and a recovery block count of 100.
We could alternativley use a custom level with:
par2 create -s500000 -r10 backup.img.gz
Where the recovery is set at 10% with a block size of 500KB.
We can then restore the partition...
Tuesday, 4 July 2017
Snort: Installing and configuring pulledpork
Pulledpork is a utility written perl that provides automation of snort rule updates.
Let's firstly grab a copy of the latest version of pulledpork from official repo on Github:
cd /tmp
git clone https://github.com/shirkdog/pulledpork.git
cd pulledpork
cp pulledpork.pl /usr/local/bin/
chmod +x /usr/local/bin/pulledpork.pl
We'll also need to install perl and few of it's packages are installed:
sudo yum -y install perl cpan
sudo cpanm LWP ExtUtils::CBuilder Path::Class Crypt::SSLeay Sys::Syslog Archive::Tar
We can now copy all...