mindscratch

Setting up a CentOS 7 server to run a VNC server and connect to a VPN.

The basic steps:

• install and start vnc server
• install openconnect
• connect to vpn
• create ssh tunnel from desktop to server
• use vnc viewer to connect to vnc server

Setup VNC Server

mindscratch

Unfortunately, the Cisco AnyConnect client for Mac conflicts with Pow. And by "conflicts", I mean it causes a grey-screen-of-death kernel panic anytime you connect to the VPN and Pow is installed.

As an alternative, there is OpenConnect, a command-line client for Cisco's AnyConnect SSL VPN.

Here's how to get it set up on Mac OS X:

1. OpenConnect can be installed via homebrew:

    brew update
   

brew install openconnect

mindscratch

import "github.com/julienschmidt/httprouter"
import "net/http"
 
func doRequest(method, uri string, body *bytes.Buffer, handle httprouter.Handle) (*httptest.ResponseRecorder, error) {
  resp := httptest.NewRecorder()
  req, err := http.NewRequest(method, uri, body)
  if err != nil {
    return nil, err
  }

mindscratch

package main

import "testing"
import "time"
import "fmt"

func TestBar(t *testing.T) {
  fmt.Println("FOO sleeping")
  time.Sleep(time.Second)
  fmt.Println("FOO done")

mindscratch

Build Aurora 0.7.1-SNAPSHOT on CentOS 6.5

I created a CentOS 6.5 Droplet on Digital Ocean with 8GB RAM (you'll need at least 4 for the Java portion of the build), feel free to use any other CentOS 6.5 environment that you can have root on.

Prepare the Environment

First, Mesos 0.21.0+ requires subversion 1.8+ devel package which is not available by default by yum. Add a repo that has subversion-devel 1.8 available, i.e:

Add new repo /etc/yum.repos.d/wandisco-svn.repo, with:

mindscratch

mindscratch: now that some people are here, here's an earlier question: hen performing a rolling update (https://github.com/GoogleCloudPlatform/kubernet...) ...how does kubernetes know which image to update if a pod has multiple containers with different images 2:23 PM

jbeda: mindscratch: Right now, it is run client side and is kind of a little too simple. 2:24 PM It captures the list of pods and just kills them one by one. It assumes there is a replication controller that will 'heal' them with the new version 2:24 PM

jbeda: Ideally, the 'upgrader' would make sure that the new pods come up okay, do some health checking, etc.

mindscratch

import (
  "bytes"
  "io"
  "os"
)

// not thread safe
func captureStdout(f func()) string {
  old := os.Stdout
  r, w, _ := os.Pipe()

mindscratch

From "Lessons Learned Optimizing NSQ"

• https://speakerd.s3.amazonaws.com/presentations/a67a65808c9301319a381659f8c2cbb1/nsq_2014-03-06.pdf

Reducing GC Pressure

• avoid []byte to string conversions
• re-use buffers or objects (use sync.Pool in Go 1.3)
• pre-allocate slices make([]byte, 0, 1024)
• explicitly specify number/size of items on the wire
• leave nothing unbounded

mindscratch

package main

import (
    "encoding/base64"
    "net/http"
    "strings"
)

type handler func(w http.ResponseWriter, r *http.Request)

mindscratch

docker run --rm -it centos:centos6 /bin/bash
yum install -y wget tar
wget https://github.com/GoogleCloudPlatform/kubernetes/releases/download/v0.5.4/kubernetes.tar.gz
wget https://github.com/coreos/etcd/releases/download/v0.4.6/etcd-v0.4.6-linux-amd64.tar.gz

# untar kubernetes and add binaries to path
tar -xf kubernetes.tar.gz
cd kubernetes/server
tar -xf kubernetes-server-linux-amd64.tar.gz
cd kubernetes/server/bin