Tag Archives: Open Source

Static IP with NetworkManager

Couple of days ago I had to configure a static IP on the Orange PI wifi interface. Had to use cli, since it is running as a server and there’s no need for a graphical interface. Below is the bash script I made:


CONN="conn_name" # Enter connection name
SSID="myessid" # Define WIFI SSID
IP="" # Enter IP, example ""
GW="" # Enter gateway
DNS="," # Define DNS servers

nmcli dev wifi list
echo "Adding wifi ${CONN} to SSID ${SSID}."
nmcli connection add type wifi con-name ${CONN} ifname wlan0 ssid ${SSID}
echo "Configuring ${CONN} IP, GW and DNS."
nmcli connection modify ${CONN} ipv4.method manual ipv4.addresses ${IP} ipv4.gateway ${GW} ipv4.dns ${DNS}
echo "Configuring wifi security."
nmcli connection modify ${CONN} wifi-sec.key-mgmt wpa-psk
read -s -p "Enter wifi password: " PASSWORD
nmcli connection modify ${CONN} wifi-sec.psk  ${PASSWORD}
echo "Bringing up connection ${CONN}."
nmcli connection up ${CONN} 

Here are some resources I used:

Debian Wifi HowTo

Debian NetworkManager

networking with nmcli

OpenDKIM in Debian

Lately I’ve been playing with postfix and ways to validate my mail. That’s how I reached DKIM records. Something like ssh keys (a public and private key) but for mail. Installation in Debian GNU/Linux is pretty simple via apt-get as usual, we need to install opendkim and opendkim-tools.

dpkg -l | grep dkim
ii  libmail-dkim-perl              0.40-1                           all          cryptographically identify the sender of email - perl library
ii  libopendkim9                   2.9.2-2+deb8u1                   amd64        Library for signing and verifying DomainKeys Identified Mail signatures
ii  opendkim                       2.9.2-2+deb8u1                   amd64        Milter implementation of DomainKeys Identified Mail
ii  opendkim-tools                 2.9.2-2+deb8u1                   amd64        Set of command line tools for OpenDKIM

We need to open a port for opendkim (8891 in my case), we need to edit /etc/default/opendkim in order to do this as below.

grep -v "^#" /etc/default/opendkim 
SOCKET="inet:8891@localhost" # listen on loopback on port 8891

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Primitive way with Folium

So I discovered Folium about two months ago and decided to map the primitive way with it. Coordinates data is retrieved from Strava gpx files and cleaned up leaving only latitude and longitude as below.

head Camin_prim_stage1.csv

Below is the python file we will use to retrieve data and create the map with the routes.

import folium
from pyspark.sql import SparkSession
from pyspark.sql.functions import col
spark = SparkSession.builder.master("local").getOrCreate()

# Change Spark loglevel

# Load the rides and ride_routes data from local instead of HDFS
position1 = spark.read.load("/home/user/Camin_prim_stage1.csv", format="csv", sep=",", inferSchema="true", header="true")
position2 = spark.read.load("/home/user/Camin_prim_stage2.csv", format="csv", sep=",", inferSchema="true", header="true")
position3 = spark.read.load("/home/user/Camin_prim_stage3.csv", format="csv", sep=",", inferSchema="true", header="true")

position = [position1, position2, position3]

m = folium.Map()

# Check file was correctly loaded
for x in position:
# x.printSchema()
# x.show(2)

# Map position
coordinates = [[float(i.lat), float(i.lon)] for i in x.collect()]

# Make a Folium map
#m = folium.Map()
m.fit_bounds(coordinates, padding=(25, 25))
folium.PolyLine(locations=coordinates, weight=5, color=colArray[col]).add_to(m)
folium.Marker(coordinates[1], popup="Origin").add_to(m)
folium.Marker(coordinates[-1], popup="Destination").add_to(m)
col = col + 1
# Save to an html file

# Cleanup

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Fixing fail2ban

I had installed fail2ban but had noticed it wasn’t working blocking ssh brute force attacks. Attacks such as below.

grep sshd /var/log/auth.log | tail
Apr 29 08:06:17 sd-229337 sshd[20646]: pam_unix(sshd:auth): check pass; user unknown
Apr 29 08:06:17 sd-229337 sshd[20646]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=211-75-3-35.hinet-ip.hinet.net
Apr 29 08:06:18 sd-229337 sshd[20646]: Failed password for invalid user db2inst from port 52724 ssh2
Apr 29 08:06:19 sd-229337 sshd[20646]: Connection closed by [preauth]
Apr 29 08:18:21 sd-229337 sshd[20711]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=59-120-243-8.hinet-ip.hinet.net  user=root
Apr 29 08:18:25 sd-229337 sshd[20711]: Failed password for root from port 34312 ssh2
Apr 29 08:18:25 sd-229337 sshd[20711]: Connection closed by [preauth]
Apr 29 08:19:14 sd-229337 sshd[20713]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=195-154-136-62.rev.poneytelecom.eu  user=root
Apr 29 08:19:16 sd-229337 sshd[20713]: Failed password for root from port 24329 ssh2
Apr 29 08:19:16 sd-229337 sshd[20713]: Connection closed by [preauth]

In order to fix this we need to modify /etc/fail2ban/filter.d/common.local and modify bsd_syslog_verbose entry. Substitute __bsd_syslog_verbose = (<[^.]+\.[^.]+>) for __bsd_syslog_verbose = (<[^.]+ [^.]+>).

grep bsd_syslog_verbose /etc/fail2ban/filter.d/common.local
#__bsd_syslog_verbose = (<[^.]+\.[^.]+>)
__bsd_syslog_verbose = (<[^.]+ [^.]+>)
__prefix_line = \s*%(__bsd_syslog_verbose)s?\s*(?:%(__hostname)s )?(?:%(__kernel_prefix)s )?(?:@vserver_\S+ )?%(__daemon_combs_re)s?\s%(__daemon_extra_re)s?\s*

Restart fail2ban and you shall now see IPs performing brute force attacks being blocked as below.

tail -30 /var/log/fail2ban.log | grep actions
2018-04-29 18:43:19,835 fail2ban.actions[28271]: WARNING [ssh] Unban
2018-04-29 18:43:20,742 fail2ban.actions[28519]: INFO    Set banTime = 1800
2018-04-29 18:43:20,936 fail2ban.actions[28519]: INFO    Set banTime = 600
2018-04-29 18:43:59,119 fail2ban.actions[28519]: WARNING [ssh] Ban
2018-04-29 18:46:05,286 fail2ban.actions[28519]: WARNING [ssh] Ban
2018-04-29 19:13:59,938 fail2ban.actions[28519]: WARNING [ssh] Unban
2018-04-29 19:14:50,026 fail2ban.actions[28519]: WARNING [ssh] Ban
2018-04-29 19:15:35,102 fail2ban.actions[28519]: WARNING [ssh] Ban
2018-04-29 19:16:06,167 fail2ban.actions[28519]: WARNING [ssh] Unban
2018-04-29 19:44:50,740 fail2ban.actions[28519]: WARNING [ssh] Unban
2018-04-29 19:45:35,821 fail2ban.actions[28519]: WARNING [ssh] Unban
2018-04-29 19:45:38,858 fail2ban.actions[28519]: WARNING [ssh] Ban

But why is this happening? It is because of regular expressions. The way logs are being written it will never find a match with the original __bsd_syslog_verbose. Below script test both bsd_syslog_verbose settings. Originally we needed to have a ., but in reality we have a space in our logs, so we need to modify bsd_syslog_verbose.

#!/usr/bin/env python

import re

testline = 'May 13 06:24:36'

match = re.search('[^.]+\.[^.]+', testline)
if match:
    print 'Found:', match.group()
    print 'Not found for bsd_syslog_verbose=[^.]+\.[^.]+'

match = re.search('[^.]+ [^.]+', testline)
if match:
    print 'Found:', match.group()
    print 'Not found for bsd_syslog_verbose=[^.]+ [^.]+'

And we execute:

 python regex.py 
Not found for bsd_syslog_verbose=[^.]+\.[^.]+
Found: May 13 06:24:36

More info here and some instructive regex google doc.

Apache Flume to write web server logs to Hadoop

In this post we will use flume to dump Apache webserver logs into HDFS. We already have a web server running and flume installed, but we need to configure a target and a source.

We use the following file as target.

## configuration file location:  /etc/flume-ng/conf
## START Agent: flume-ng agent -c conf -f /etc/flume-ng/conf/flume-trg-agent.conf -n collector

collector.sources = AvroIn  
collector.sources.AvroIn.type = avro  
collector.sources.AvroIn.bind =  
collector.sources.AvroIn.port = 4545  
collector.sources.AvroIn.channels = mc1 mc2

## Channels ##
## Source writes to 2 channels, one for each sink
collector.channels = mc1 mc2


collector.channels.mc1.type = memory  
collector.channels.mc1.capacity = 100

collector.channels.mc2.type = memory  
collector.channels.mc2.capacity = 100

## Sinks ##
collector.sinks = LocalOut HadoopOut

## Write copy to Local Filesystem 
collector.sinks.LocalOut.type = file_roll  
collector.sinks.LocalOut.sink.directory = /var/log/flume-ng  
collector.sinks.LocalOut.sink.rollInterval = 0  
collector.sinks.LocalOut.channel = mc1

## Write to HDFS
collector.sinks.HadoopOut.type = hdfs  
collector.sinks.HadoopOut.channel = mc2  
collector.sinks.HadoopOut.hdfs.path = /user/training/flume/events/%{log_type}/%y%m%d  
collector.sinks.HadoopOut.hdfs.fileType = DataStream  
collector.sinks.HadoopOut.hdfs.writeFormat = Text  
collector.sinks.HadoopOut.hdfs.rollSize = 0  
collector.sinks.HadoopOut.hdfs.rollCount = 10000  
collector.sinks.HadoopOut.hdfs.rollInterval = 600

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