Configuration To send mail from the command line in Ubuntu Precise sudo apt-get install mailutils If you mess up configuring or want to reconfigure dpkg-reconfigure mailutils Sending your test email Let’s send a test email! echo “test email body” |…
Problems I was facing two problems with my Logstash setup Logstash service constantly required manual restarts (no longer indexing, hanging process) Local log files were filling up my root partition Symptom Logstash failed to: Index events in the queue Trim…
Here’s my bash cheat sheet: Tests Combining [ condition ] && action; # action executes if condition is true. [ condition ] || action; # action executes if condition is false. Filesystem related tests We can test different filesystem related…
I recently ran in to trouble restarting neo4j over ssh here’s the fix: From machine calling neo4j host ssh -f $USER@$HOST ‘sh -c “( (nohup sudo restart 2>&1 >output.file </dev/null) & )”‘ Target Machine Sudoers Replace “someuser” with whatever…
Recently I needed to debug an issue by testing SSL chaining issues My old standby tools (curl and openssl were not reporting any errors) The exception javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path validation failed: java.security.cert.CertPathValidatorException: Path does not chain with any of…
How can we easily download a single file from Amazon S3? Install s3cmd apt-get install ipset Setup s3cmd s3cmd –configure List your buckets and files s3cmd ls Download your file s3cmd get s3://bucket-name//file-name
Goal: Whitelist an Entire Country with ipset For this article i’ll be referencing the github repository I set up at We have a few files there, specifically: * cidr_to_ipset.sh (a script to create an ipset ruleset) * Some example…
What to do when barnyard2 won’t log to the database…. Are you seeing something like this? [SignatureReferencePullDataStore()]: No Reference found in database … Full text: # /usr/local/bin/barnyard2 -c -d /var/log/snort -f snort.log -w Running in Continuous mode –==…
Objective Add two network interface in ubuntu 12.04 in aws and route traffic properly to either ip Scope: Amazon EC2 Attach Elastic Network Interface (VPC) Related Documentation Process Start AMI in VPC After boot attach…
Example to egrep valid ip address To egrep all valid ip addresses in current directory: egrep -r ‘[[:digit:]]{1,3}\.[[:digit:]]{1,3}\.[[:digit:]]{1,3}\.[[:digit:]]{1,3}’ . An Alternative: /bin/egrep ‘\b(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b’
