hlzhang

Source: http://willandorla.com/will/2011/01/convert-folder-into-git-submodule/

1. Clone new repository

$ git clone --no-hardlinks original-repo copied-repo

2. Filter out the files you want to keep and remove the others

hlzhang

Routing tips for VPNs on OS X

When VPNs Just Work™, they're a fantastic way of allowing access to a private network from remote locations. When they don't work it can be an experience in frustration. I've had situations where I can connect to a VPN from my Mac, but various networking situations cause routing conflicts. Here are a couple of cases and how I've been able to get around them.

Specific cases

Case 1: conflicting additional routes.

In this example the VPN we are connecting to has a subnet that does not conflict with our local IP, but has additional routes that conflict in some way with our local network's routing. In my example the remote subnet is 10.0.x.0/24, my local subnet is 10.0.y.0/24, and the conflicting route is 10.0.0.0/8. Without the later route, I can't access all hosts on the VPN without manually adding the route after connecting to the VPN:

hlzhang

Build Linaro for Mac

1. Prepare env

---

Abe requires Bash version 4+.

brew install bash autogen dejagnu coreutils gcc gawk #binutils
#brew install libmpc gmp mpf

hlzhang

set -x

function fix_content_root() {
    local in_directory="$1"
    local targets=($(grep -E -l --include \*.iml '<content url="file://\$MODULE_DIR\$/(\.\./)+src/main/resources"' -r ${in_directory} | grep -v 'fixContentRoot.sh'))
    for target in ${targets[@]}; do
        echo ${target};
        sed -Ei 's#<content url="file://\$MODULE_DIR\$/(\.\./)+src/main/resources" />##g' ${target};
        sed -i '/<content url="file:\/\/$MODULE_DIR$\/..\/src\/main\/resources">/{:a;N;/<\/content>/!ba};/<sourceFolder url="file:\/\/$MODULE_DIR$\/..\/src\/main\/resources" type="java-resource" \/>/d' ${target};
        sed -i '/<content url="file:\/\/$MODULE_DIR$\/..\/..\/src\/main\/resources">/{:a;N;/<\/content>/!ba};/<sourceFolder url="file:\/\/$MODULE_DIR$\/..\/..\/src\/main\/resources" type="java-resource" \/>/d' ${target};

hlzhang

/*
 * shared_mutex: Mutex in mmap memory shared between processes.
 *
 * Ben Cohen, July 2017.
 *
 * Compile using:
 *    gcc -o shared_mutex shared_mutex.c -ggdb -Wall -std=c99 -pthread
 *
 * Two processes are created with an mmap shared memory region
 * containing an array of chars and a mutex.  The mutex is created with

hlzhang

docker run \
    --name={{.Name}} \
    {{range $e := .Config.Env}}--env={{printf "%q" $e}} \
    {{end}}{{range $p, $conf := .NetworkSettings.Ports}}{{with $conf}}-p {{(index $conf 0).HostIp}}:{{(index $conf 0).HostPort}}:{{$p}} \
    {{end}}{{end}}{{range $n, $conf := .NetworkSettings.Networks}}{{with $conf}}--network {{printf "%q" $n}} \
    {{range $conf.Aliases}}--network-alias {{printf "%q" .}} {{end}} \
    {{end}}{{end}}{{range $v := .HostConfig.VolumesFrom}}--volumes-from={{printf "%q" .}} \
    {{end}}{{range $v := .HostConfig.Binds}}--volume={{printf "%q" .}} \
    {{end}}{{range $l, $v := .Config.Labels}}--label {{printf "%q" $l}}={{printf "%q" $v}} \
    {{end}}{{range $v := .HostConfig.CapAdd}}--cap-add {{printf "%q" .}} \

hlzhang

2018 Update: Easiest option is Justin's repo and image

Just run this from your Mac terminal and it'll drop you in a container with full permissions on the Moby VM. This also works for Docker for Windows for getting in Moby Linux VM (doesn't work for Windows Containers).

docker run -it --rm --privileged --pid=host justincormack/nsenter1

more info: https://github.com/justincormack/nsenter1

---

hlzhang

// jshell -v --add-modules=java.net.http http_request.jsh

import java.net.*;
import java.net.http.*;

HttpClient httpClient = HttpClient.newHttpClient();
HttpRequest httpRequest = HttpRequest.newBuilder().uri(new URI("https://graph.facebook.com/v2.9/me?fields=id,email,cover,first_name,gender,last_name,link,locale,name,timezone,updated_time,verified,friends&access_token=change_it&appsecret_proof=change_it&method=get&format=json")).GET().build();
HttpResponse<String> httpResponse = httpClient.send(httpRequest, HttpResponse.BodyHandlers.ofString());
System.out.println(httpResponse.statusCode());
System.out.println(httpResponse.body());

hlzhang

Moved to git repository: https://github.com/denji/nginx-tuning

NGINX Tuning For Best Performance

For this configuration you can use web server you like, i decided, because i work mostly with it to use nginx.

Generally, properly configured nginx can handle up to 400K to 500K requests per second (clustered), most what i saw is 50K to 80K (non-clustered) requests per second and 30% CPU load, course, this was 2 x Intel Xeon with HyperThreading enabled, but it can work without problem on slower machines.

You must understand that this config is used in testing environment and not in production so you will need to find a way to implement most of those features best possible for your servers.

hlzhang

1. screen ~/Library/Containers/com.docker.docker/Data/com.docker.driver.amd64-linux/tty
2. when done use CTRL-A CTRL-\ and then y (for yes) to exit

Alternative method: 

1. docker run -it --privileged --pid=host debian nsenter -t 1 -m -u -n -i sh