Amazon Server new articles

My new articles related to Amazon Server:
Copy EC2 EBS
Cleanup Amazon Linux
Access Amazon Linux via Far Manager

Amazon Server blog

I continue to write articles about Amazon Services and servers here: Amazon Server

Convert image to base64

It is extremely simple, and  without server-side:

<script>
    function convertToBase64(event) {
        var file = event.target.files[0];
        var reader = new FileReader();
        reader.onload = function (event) {
            document.getElementById('text').value = event.target.result;
            document.getElementById('text').select();
        };
        reader.readAsDataURL(file);
    }
</script>

<input id="file" type="file" onchange="convertToBase64(event)">
<textarea id="text"> </textarea>

You may use it at: ImageToBase64 or directly from here:


See this project on GitHub

Merge log files from multiple servers

If you have some similar servers (e.g. balanced EC2-instances) and need to analyze log files from them - it is possible to automatize downloading and merging all these files via shell script like this:

#!/bin/bash

LOG_DIR=log-`date +%Y.%m.%d_%H.%M.%S`

mkdir -p $LOG_DIR

scp -C ec2-user@node1.server.com:/log/file.log $LOG_DIR/file1.log
scp -C ec2-user@node2.server.com:/log/file.log $LOG_DIR/file2.log
scp -C ec2-user@node3.server.com:/log/file.log $LOG_DIR/file3.log

cat $LOG_DIR/*.log | sort >$LOG_DIR/files.log

Also it is a good idea to use ssh-agent to keep private keys.

Count string characters in Python

Simple code that calculates frequency of letters:
from collections import Counter

s = '''
She sells sea-shells on the sea-shore.
The shells she sells are sea-shells, I'm sure.
For if she sells sea-shells on the sea-shore
Then I'm sure she sells sea-shore shells.
'''

print Counter(s)


Result:
Counter({'s': 32, 'e': 29, ' ': 25, 'l': 18, 'h': 16, 'a': 7, 'r': 7, '-': 6, 'o': 6, '\n': 5, '.': 3, 'n': 3, "'": 2, 'I': 2, 'T': 2, ' m': 2, 'u': 2, 't': 2, ',': 1, 'F': 1, 'S': 1, 'f': 1, 'i': 1})