Day5 of #BashBlazeChallenge

🚀 Automated Log Analysis Script! 🚀

In the fast-paced world of system administration, efficiently managing and monitoring server logs is crucial for ensuring the health and security of your network. To streamline this process, I took on the #BashBlazeChallenge and developed a Bash script that automates the analysis of daily log files, providing a comprehensive summary report.

The Challenge

As a system administrator, my task was to create a Bash script that takes the path to a log file as a command-line argument and performs the following tasks:

1. Error Count: Analyze the log file and count the number of error messages based on a specific keyword.

2. Critical Events: Identify lines containing the keyword "CRITICAL" and print them along with their line numbers.

3. Summary Report: Generate a summary report in a separate text file, including the date of analysis, log file name, total lines processed, total error count, and a list of critical events with line numbers.

I also created a script to create log file containing logs.

log generation script:

#!/bin/bash

log_file="log_file.log"

for ((i=1; i<=100; i++)); do
    timestamp=$(date "+%Y-%m-%d %H:%M:%S")
    rand=$((RANDOM % 4))

    case $rand in
        0)
            log_level="INFO"
            message="Application is running smoothly"
            ;;
        1)
            log_level="DEBUG"
            message="Debugging information: iteration $i"
            ;;
        2)
            log_level="ERROR"
            message="Error occurred at iteration $i"
            ;;
        3)
            log_level="CRITICAL"
            message="Critical issue detected at iteration $i"
            ;;
    esac

    echo "$timestamp $log_level: $message" >> "$log_file"
done

echo "Generated 100 logs in $log_file"

Log Analysis code:

#!/bin/bash

# Check if the log file exists
does_file_exists() {
    if [ ! -f "$1" ]; then
        echo "Error: Log file not found: $1"
        exit 1
    fi
}

# Check if the user provided the log file path as a command-line argument
if [ $# -ne 1 ]; then
    echo "Usage: $0 <path_to_logfile>, log file not provided."
    exit 1
fi

log_file="$1"

does_file_exists $log_file

# Count the total number of lines in the log file
total_line_count=$(wc -l < "$log_file")
# Count the number of error messages ( "ERROR" )
error_line_count=$( grep -c -i "ERROR" "$log_file")

# Search for critical events ( "CRITICAL" ) and store them in an array
mapfile -t critical_events < <(grep -n -i "CRITICAL" "$log_file")

# Generate the summary report in a separate file
summary_report="log_summary_$(date +%Y-%m-%d).txt"
{
    echo "Date of analysis: $(date)"
    echo "Log file: $log_file"
    echo "Total lines processed: $total_line_count"
    echo "Total error count: $error_line_count"
    echo -e "\nCritical events with line numbers:"
    for event in "${critical_events[@]}"; do
        echo "$event"
    done
} > "$summary_report"


echo "Summary report generated:"
echo $summary_report

Output :