Posts on Avinash Ramana

IDEA Legacy SSE MCP ... :)

Sat, 21 Mar 2026 10:18:22 -0400

IDEA Legacy SSE MCP …

SSE is deprecated in favor of WebSockets, but it is still supported by most browsers and can be used for simple real-time applications. SSE is a simple and efficient way to push updates from the server to the client.

May have to exploit this for my purpose - here’s a good starting point.

Enable MCP in IDEA: https://www.jetbrains.com/help/idea/mcp.html

Connect to IDEA

You’ll establish SSE socket and wait

TCP Proxy

Thu, 01 Jan 2026 00:00:00 +0000

TCP Proxy in Java

I’ve been using this for general purpose spying when I need to do formatting and it’s too cumbersome with Wireshark/Ethereal

package com.gent00.proxy;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.nio.charset.StandardCharsets;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class TcpProxy implements AutoCloseable {
private static final DateTimeFormatter TS = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS");

    private final String targetHost;
    private final int targetPort;
    private final int listenPort;

    private final ExecutorService executor = Executors.newCachedThreadPool();
    private volatile boolean running;
    private ServerSocket serverSocket;

    public TcpProxy(int listenPort, String targetHost, int targetPort) {
        this.listenPort = listenPort;
        this.targetHost = targetHost;
        this.targetPort = targetPort;
    }

    public void start() throws IOException {
        if (running) {
            return;
        }

        serverSocket = new ServerSocket();
        serverSocket.bind(new InetSocketAddress(listenPort));
        running = true;
        log("Listening on port %d, forwarding to %s:%d", listenPort, targetHost, targetPort);

        while (running) {
            try {
                Socket client = serverSocket.accept();
                log("Accepted client %s", client.getRemoteSocketAddress());
                executor.submit(() -> handleClient(client));
            } catch (IOException e) {
                if (running) {
                    throw e;
                }
            }
        }
    }

    private void handleClient(Socket client) {
        String clientAddress = String.valueOf(client.getRemoteSocketAddress());
        try (client;
             Socket target = new Socket(targetHost, targetPort)) {

            log("Connected %s -> %s:%d", clientAddress, targetHost, targetPort);

            executor.submit(() -> pipe(client, target, "client->target", clientAddress));
            pipe(target, client, "target->client", clientAddress);

        } catch (IOException e) {
            log("Connection failed for %s: %s", clientAddress, e.getMessage());
        } finally {
            log("Closed connection for %s", clientAddress);
        }
    }

    private void pipe(Socket from, Socket to, String direction, String clientAddress) {
        try (InputStream in = from.getInputStream();
             OutputStream out = to.getOutputStream()) {

            byte[] buffer = new byte[8192];
            int read;
            while ((read = in.read(buffer)) != -1 && running) {
                out.write(buffer, 0, read);
                out.flush();
                log("%s %s bytes for %s", direction, read, clientAddress);
                String payload = new String(buffer, 0, read, StandardCharsets.UTF_8);
                log("%s payload: %s", direction, payload);
            }
        } catch (IOException e) {
            log("%s ended for %s: %s", direction, clientAddress, e.getMessage());
        } finally {
            try {
                to.shutdownOutput();
            } catch (IOException ignored) {
                // Ignore shutdown issues.
            }
        }
    }

    private void log(String format, Object... args) {
        System.out.printf("[%s] %s%n", LocalDateTime.now().format(TS), String.format(format, args));
    }

    public void stop() {
        running = false;
        try {
            if (serverSocket != null && !serverSocket.isClosed()) {
                serverSocket.close();
            }
        } catch (IOException ignored) {
            // Ignore shutdown issues.
        }
        executor.shutdownNow();
        log("Proxy stopped");
    }

    @Override
    public void close() {
        stop();
    }

    public static void main(String[] args) throws Exception {
        if (args.length != 3) {
            System.out.println("Usage: java TcpProxy <listenPort> <targetHost> <targetPort>");
            return;
        }

        int listenPort = Integer.parseInt(args[0]);
        String targetHost = args[1];
        int targetPort = Integer.parseInt(args[2]);

        try (TcpProxy proxy = new TcpProxy(listenPort, targetHost, targetPort)) {
            proxy.start();
        }
    }
}

Thorntail Fraction Loading

Mon, 16 Mar 2020 00:00:00 +0000

Thorntail Fraction Loading

What is a Fraction?

Here’s what thorntail says about it…

Thorntail is defined by an unbounded set of capabilities. Each piece of functionality is called a fraction. Some fractions provide only access to APIs, such as JAX-RS or CDI; other fractions provide higher-level capabilities, such as integration with RHSSO (Keycloak).

I guess I can do anything, after all, it’s unbounded

Source code

Start it up in debug mode - ~/apps/apache-maven-3.6.3/bin/mvn thorntail:run -Dthorntail.debug.port=5005 -Dswarm.logging=DEBUG -Dthorntail.logging=DEBUG

LXC and LXD Cheat Sheet

Sat, 01 Feb 2020 00:00:00 +0000

LXD Commands

Profile

List profiles

Add a network profile

root@trs2:/snap# lxc network attach-profile lxdbr0 storage-nas
root@trs2:/snap# lxc profile show storage-nas
config: {}
description: ""
devices:
  lxdbr0:
    nictype: bridged
    parent: lxdbr0
    type: nic
  root:
    path: /
    pool: codesnap
    type: disk
name: storage-nas
used_by:
- /1.0/instances/tough-dinosaur

Ensure you have a good profile for disk/io

I have created a special profile that uses a codesnap disk array. This is backed by 32x12g SAS drives. We will still have to bind mount the NVMe for later…

iscsi in Linux for VMWare ESXi

Thu, 02 Jan 2020 00:00:00 +0000

Provision Disks

I’m going to grab all the empty SATA drives. ST2**

 1root@trs2:/home/avinash# lsblk -o NAME,SIZE,TYPE,MODEL
 2NAME                        SIZE TYPE  MODEL
 3loop0                      89.1M loop  
 4loop1                      89.1M loop  
 5loop2                      64.5M loop  
 6loop3                      64.5M loop  
 7sda                         1.8T disk  ST2000NM0055-1V4
 8sdb                         1.8T disk  ST2000NM0055-1V4
 9sdc                         1.8T disk  ST2000NM0055-1V4
10sdd                         1.8T disk  ST2000NM0055-1V4
11sde                         1.8T disk  ST2000NM0055-1V4
12sdf                         1.8T disk  ST2000NM0055-1V4
13sdg                         1.8T disk  ST2000NM0055-1V4
14sdh                         1.8T disk  ST2000NM0055-1V4
15sdi                         1.8T disk  WDC_WD20EARX-00P
16└─sdi1                      1.8T part  
17  └─md0                     1.8T raid1 
18    ├─cluster-Xq            1.5T lvm   
19    ├─cluster-Xq            100G lvm   
20    └─cluster-Xq            200G lvm   
21sdj                         1.8T disk  WDC_WD20EARX-00P
22└─sdj1                      1.8T part  
23  └─md0                     1.8T raid1 
24    ├─cluster-Xq            1.5T lvm   
25    ├─cluster-Xq            100G lvm   
26    └─cluster-Xq            200G lvm   
27sdk                       232.9G disk  Samsung_SSD_850
28sdl                       232.9G disk  Samsung_SSD_850
29sdm                        55.9G disk  OCZ-AGILITY3
30├─sdm1                        1M part  
31├─sdm2                        1G part  
32└─sdm3                     54.9G part  
33  └─ubuntu--vg-ubuntu--lv    24G lvm   
34nvme0n1                     477G disk  Samsung SSD 960 PRO 512GB
35└─md127                     1.9T raid0 
36nvme1n1                     477G disk  Samsung SSD 960 PRO 512GB
37└─md127                     1.9T raid0 
38nvme3n1                     477G disk  Samsung SSD 960 PRO 512GB
39└─md127                     1.9T raid0 
40nvme2n1                     477G disk  Samsung SSD 960 PRO 512GB
41└─md127                     1.9T raid0

Identify the drives to provision

We can re-use this var for later. Saves us some typing, but verify these drives are correct!

NVMe Performance on Zen TR4 Architecture

Tue, 02 Apr 2019 00:00:00 +0000

The original objective was to observe and understand performance characteristics of nvme within early Linux kernels. We’ll be investigating the new polling mechanism , as opposed to the interrupt model.

TLDR;

4 x NVMe Random Write 4K - Samsung Pro

1.4 million IOPS @ sub-millisecond latency

1 x NVMe Sequential Write 4K - Samsung Pro

1.2 GB/s with 4K record size

12/01/2019

I couldn’t even get that far. My priorities recently were fixing some KVM and LXC issues that would allow us to get off of early Xen architecture on SPARC. Unfortunately, will have to get back to this in a Part 2, to explain the changes required to the kernel to get NVMe devices to stop driving up the sys due to MSI-X interrupting.

PCIE Theoretical Bandwidth

Tue, 02 Apr 2019 00:00:00 +0000

How to calculate PCIe throughput

 gigatransfer bits bits.per.xfer GB.s       enc   enc.GB.s
 1            8    1    8000000000    1 0.9846154  0.9846154
 2            8    2   16000000000    2 0.9846154  1.9692308
 3            8    4   32000000000    4 0.9846154  3.9384615
 4            8    8   64000000000    8 0.9846154  7.8769231
 5            8   16  128000000000   16 0.9846154 15.7538462
 6            8   32  256000000000   32 0.9846154 31.5076923

options(scipen=999)
df=data.frame(gigatransfer=rep(c(8),times=6),bits=2^c(0:5))
df$bits.per.xfer=(df$gigatransfer*10^9)*df$bits
df$GB.s=df$bits.per.xfer/8/1000/1000/1000
df$enc=(128/130)
df$enc.GB.s=df$GB.s*df$enc
print(df)

Forked docker-hugo

Sun, 02 Apr 2017 00:00:00 +0000

Docker bind mount permission or USER someguy

As part of a root-escalation defect, hugo needs to support a non-root user. There’s some “official” documentation from Docker ala Docker - Security Conclusions.

Docker concludes…

Docker containers are, by default, quite secure; especially if you take care of running your processes inside the containers as non-privileged users (i.e., non-root).

You can add an extra layer of safety by enabling AppArmor, SELinux, GRSEC, or your favorite hardening solution.

Dell DRAC5 HakPak

Sun, 01 Jan 2017 00:00:00 +0000

Hack DRAC5

Overview

DRAC uses deprecated SSL procotols and also tries to execute unsigned code from Dell. I’m going to run it straight with Java instead of WebStart, because we can bypass many issues and get debugging turned on as well.

Running iDRAC5 in Standalone

Pre-requisites

32-bit JVM
Modify Java’s security files to enable disabled cipher suites
Download your DRAC instance’s connection JAR and native lib.
Ensure you have all dependencies for your OS (Linux, or Windows)

Running DRAC Console

If you want to run things directly, try this script. You’ll need to grab the JARs right off your DRAC instance and stash them somewhere locally.