notbrain's questions

I'm running a couple scripts to drive a dot matrix display on boot of a Pi 3 B. A nodejs script just writes an image file to a path. The python script calls Adafruit_RGBmatrix to send the image to the display. The nodejs runs fine at boot. The python script can crash the entire pi when run at boot, but it runs fine when started manually with systemctl.

python: dashboard.py

import Image
import time
from rgbmatrix import Adafruit_RGBmatrix

# Rows and chain length are both required parameters:
matrix = Adafruit_RGBmatrix(32, 2)

matrix.SetWriteCycles(16)

while True:
  try:
    image = Image.open("/home/pi/dashboard.png")
    image.load()
    matrix.SetImage(image.im.id, 0, 0)
    time.sleep(10)
    matrix.Clear()
  except:
    print("Dashboard image could not be opened!")
    time.sleep(5)

systemd dashboard_display.service

[Unit]
Description=Dashboard Display Driver
#Requires=dashboard_png.service?
After=multi-user.target

[Service]
Type=simple
ExecStart=/usr/bin/python /home/pi/src/drive-display/dashboard.py
Restart=on-failure
RestartSec=10

[Install]
WantedBy=multi-user.target

When I run the dashboard_display.service using systemctl start dashboard_display.service it runs for days. Running it at boot after enable, it crashes the pi somewhow.

I've tried to set up some delays on reboot and have tried various After and Require values. Also wrapped the python script in a try/except to allow it to sleep and retry.

I don't get logs but it seems like it's failing extremely fast too many times and the pi crashes.

Is there a better way to ensure these services get started when everything is available? And the python service won't start until the nodejs service is done?

Looking for help on what extra configuration I can set to allow my ubuntu virtualbox vm to write into the NFS synced project directory on my OSX host. I've set the explicit sudoers for vagrant in macOS so it shouldn't have any issues modifying the host if needed.

End goal is to be able to operate the app's build and dev runtime within ubuntu, while editing the files on the macOS host and the ubuntu box will detect changes and rebuild with gulp as appropriate.

Currently getting an error on npm install for bcrypt when it tries to preserve permissions, but I'm also not sure if this is the root cuase of the full fail.

Cross posted: https://groups.google.com/forum/#!topic/vagrant-up/LS_eFJhZAwQ

Vagrantfile:

Vagrant.configure(2) do |config|
  config.vm.box = "ubuntu/xenial64"
  config.vm.provider "virtualbox" do |v|
    v.memory = "3072"
    v.customize ["setextradata", :id, "VBoxInternal2/SharedFoldersEnableSymlinksCreate/v-root", "1"]
  end

  config.vm.define "dev", primary: true do |dev|
    dev.vm.hostname = "proteus.dev"
    dev.vm.network "private_network", ip: "192.168.10.10"
    dev.vm.synced_folder '.', '/home/ubuntu/src/proteus', nfs: true, mount_options:['nolock,vers=3,udp,noatime,actimeo=1']
    # also tried 'rw' and other linux__mount_options
  end
end

Error output:

$ npm install bcrypt

> [email protected] install /home/ubuntu/src/proteus/node_modules/bcrypt
> node-pre-gyp install --fallback-to-build

node-pre-gyp ERR! Tried to download(404): https://github.com/kelektiv/node.bcrypt.js/releases/download/v1.0.2/bcrypt_lib-v1.0.2-node-v48-linux-x64.tar.gz
node-pre-gyp ERR! Pre-built binaries not found for [email protected] and [email protected] (node-v48 ABI) (falling back to source compile with node-gyp)
make: Entering directory '/home/ubuntu/src/proteus/node_modules/bcrypt/build'
  CXX(target) Release/obj.target/bcrypt_lib/src/blowfish.o
  CXX(target) Release/obj.target/bcrypt_lib/src/bcrypt.o
  CXX(target) Release/obj.target/bcrypt_lib/src/bcrypt_node.o
  SOLINK_MODULE(target) Release/obj.target/bcrypt_lib.node
  COPY Release/bcrypt_lib.node
cp: preserving permissions for ‘Release/bcrypt_lib.node’: Operation not permitted
bcrypt_lib.target.mk:134: recipe for target 'Release/bcrypt_lib.node' failed
make: *** [Release/bcrypt_lib.node] Error 1
make: Leaving directory '/home/ubuntu/src/proteus/node_modules/bcrypt/build'
gyp ERR! build error
gyp ERR! stack Error: `make` failed with exit code: 2
gyp ERR! stack     at ChildProcess.onExit (/usr/lib/node_modules/node-gyp/lib/build.js:258:23)
gyp ERR! stack     at emitTwo (events.js:106:13)
gyp ERR! stack     at ChildProcess.emit (events.js:191:7)
gyp ERR! stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:215:12)
gyp ERR! System Linux 4.4.0-83-generic
gyp ERR! command "/usr/bin/nodejs" "/usr/lib/node_modules/node-gyp/bin/node-gyp.js" "build" "--fallback-to-build" "--module=/home/ubuntu/src/proteus/node_modules/bcrypt/lib/binding/bcrypt_lib.node" "--module_name=bcrypt_lib" "--module_path=/home/ubuntu/src/proteus/node_modules/bcrypt/lib/binding"
gyp ERR! cwd /home/ubuntu/src/proteus/node_modules/bcrypt
gyp ERR! node -v v6.11.0
gyp ERR! node-gyp -v v3.6.2
gyp ERR! not ok
node-pre-gyp ERR! build error
node-pre-gyp ERR! stack Error: Failed to execute '/usr/bin/nodejs /usr/lib/node_modules/node-gyp/bin/node-gyp.js build --fallback-to-build --module=/home/ubuntu/src/proteus/node_modules/bcrypt/lib/binding/bcrypt_lib.node --module_name=bcrypt_lib --module_path=/home/ubuntu/src/proteus/node_modules/bcrypt/lib/binding' (1)
node-pre-gyp ERR! stack     at ChildProcess.<anonymous> (/home/ubuntu/src/proteus/node_modules/node-pre-gyp/lib/util/compile.js:83:29)
node-pre-gyp ERR! stack     at emitTwo (events.js:106:13)
node-pre-gyp ERR! stack     at ChildProcess.emit (events.js:191:7)
node-pre-gyp ERR! stack     at maybeClose (internal/child_process.js:891:16)
node-pre-gyp ERR! stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:226:5)
node-pre-gyp ERR! System Linux 4.4.0-83-generic
node-pre-gyp ERR! command "/usr/bin/nodejs" "/home/ubuntu/src/proteus/node_modules/.bin/node-pre-gyp" "install" "--fallback-to-build"
node-pre-gyp ERR! cwd /home/ubuntu/src/proteus/node_modules/bcrypt
node-pre-gyp ERR! node -v v6.11.0
node-pre-gyp ERR! node-pre-gyp -v v0.6.32
node-pre-gyp ERR! not ok
Failed to execute '/usr/bin/nodejs /usr/lib/node_modules/node-gyp/bin/node-gyp.js build --fallback-to-build --module=/home/ubuntu/src/proteus/node_modules/bcrypt/lib/binding/bcrypt_lib.node --module_name=bcrypt_lib --module_path=/home/ubuntu/src/proteus/node_modules/bcrypt/lib/binding' (1)
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@^1.0.0 (node_modules/chokidar/node_modules/fsevents):
npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for [email protected]: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"x64"})
npm ERR! Linux 4.4.0-83-generic
npm ERR! argv "/usr/bin/nodejs" "/usr/bin/npm" "install" "bcrypt"
npm ERR! node v6.11.0
npm ERR! npm  v3.10.10
npm ERR! code ELIFECYCLE

I have a nginx config with about 10 vhosts, and I want to have them all share custom 404 and 50x and maintenance error pages. The nginx is a reverse proxy serving angular index.html and I'm a bit confused on how to get the error_page 404 /oops/root directive to pick up the font and image assets in a different directory than the website itself (can't point to the website dir if the site root is returning a 404).

If for any reason the root of the app results in a 404, I'd like to show a custom index.html inside the /usr/share/nginx/html/oops directory, and be able to point to oops/fonts/* and oops/image.svg and pngs.

Everything is working fine except the assets. The 404 page shows up, but the images and fonts do not have the proper path. Can't seem to see in nginx debug level logs how to get them to show up.

upstream notbrain-api {
  server 192.168.1.2:3000;
}

server {

  access_log /var/log/nginx/access.log human_json;
  error_log /var/log/nginx/error.log debug;

  listen       443 ssl;
  server_name  notbrain.com;
  include /etc/nginx/ssl/shared_ssl.nginx;

  # font cache fix
  location ~* \.(?:woff|eot|ttf|otf) {
    root "/usr/local/apps/notbrain.com/dist";
    proxy_cache            STATIC;
    proxy_cache_valid      200  7d;
    add_header Vary Accept-Encoding;
    add_header Cache-Control public;
  }

  # proxy to upstream api host
  location /api {
    proxy_connect_timeout        60;
    proxy_send_timeout          300;
    proxy_read_timeout          300;
    send_timeout                300;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    expires -1;
    add_header Cache-Control "no-store";
    proxy_pass http://notbrain-api;
  }

  location / {
    root "/usr/local/apps/notbrain.com/dist";
    index index.html;
    try_files $uri $uri/ /index.html =404;
    expires -1;
    add_header Cache-Control "no-store";
  }

  location ~ \.(aspx|php|jsp|cgi|do|rb)$ {
    return 410;
  }

  # currently working for 404.html, but can't figure out how to point assets to snafu/
  # would like to avoid having to explicitly rewrite all images and fonts
  # 
  error_page 404 /snafu/404.html;
  location /snafu/ {
    # index and assets are inside /usr/share/nginx/html/snafu/[fonts/, images/]
    root "/usr/share/nginx/html/";
  }

 }

Was having some trouble as chronicled here - https://stackoverflow.com/questions/22570550/play-2-2-1-simpleresult-4xx-response-body-possible-via-cors-xhr

But I didn't focus on nginx since the 200 OK happy path was working as expected. It was 400 level http errors that weren't working as expected. I wasn't receiving a body or able to get the status code inside browser XHR objects.

4xx http errors worked as expected via XHR (readyState=3 experienced) only when I was passing Access-Control-Allow-Origin from the application server, but I don't want this embedded in the code.

Is the only way to pass content and status headers for 4xx responses is to compile with HeadersMoreNginxModule? Not ideal, but doable.

package controllers

import play.api._
import play.api.mvc._
import play.api.libs.iteratee.Enumerator

object Application extends Controller {

  def index = Action {
    Ok(views.html.index("Your new application is ready."))
  }

  def goodResponse = Action { implicit request =>
    // Ok("Hello world!")
    SimpleResult(
      header = ResponseHeader(200, Map(CONTENT_TYPE -> "application/json")),
      body = Enumerator("Hello world!".getBytes())
    )
  }

  def badResponse = Action { implicit request =>
    // BadRequest(
    //   """{"error":"bad request"}"""
    // )
    SimpleResult(
      header = ResponseHeader(
        400, 
        Map(
          CONTENT_TYPE -> "application/json",
          ACCESS_CONTROL_ALLOW_ORIGIN -> "*"     // FIXME: move to nginx?
        )
      ),
      body = Enumerator("""{"error":"bad request"}""".getBytes())
    )
  }

}

My nginx.conf uses a proxy_pass to the play server on port 9000:

http {

  # ...snipped...

  upstream api {
    server localhost:9000;
  }

  server {
    #listen   80; ## listen for ipv4; this line is default and implied
    #listen   [::]:80 default ipv6only=on; ## listen for ipv6
    listen 80;
    listen 443 default_server ssl;
    ssl_certificate      /usr/local/etc/nginx/ssl/api.crt;
    ssl_certificate_key  /usr/local/etc/nginx/ssl/nginx.key;

    root /usr/share/nginx/www;
    index index.html index.htm;

    # Make site accessible from https://api/
    server_name api;

    location / {
      # See http://enable-cors.org/server_nginx.html
      # Modified to set 'Access-Control-Allow-Origin' "$http_origin"
      include nginx_cors.conf;

      proxy_pass http://api;

    }

  }
}

Machine 1: Centos 5.6 AMI Machine 2: Amazon Linux AMI Beta

I changed resolv.conf on both to get around an apparent DNS hiccup/lag last week, by appending 'nameserver 8.8.8.8' to the file.

The CentOS box picked it up and ran with it. Amzn Linux wouldn't take it unless I also commented out the original proper nameserver.

What would be the proper way to get the Amzn instance to acknowledge the new nameserver and ignore the first entry?

Following the instructions here: http://www.mongodb.org/display/DOCS/CentOS+and+Fedora+Packages

Can't really decipher what I should be doing...broke down and just got the linux binary but I want yum control...

$ cat /etc/yum.repos.d/10gen-mongodb.repo

[10gen]
name=10gen Repository
baseurl=http://downloads.mongodb.org/distros/centos/5.4/os/x86_64/
gpgcheck=0

$ sudo yum install mongo-stable mongo-stable-server

Loaded plugins: fastestmirror, security
Loading mirror speeds from cached hostfile
Setting up Install Process
No package mongo-stable available.
No package mongo-stable-server available.

Also tried:

baseurl=http://downloads-distro.mongodb.org/repo/redhat/os/x86_64

Are these packages just no longer available at these locations? Not sure if it's a technicality wrt redhat vs centos. Thanks!

I've got an Amazon EC2 instance with the 64bit Linux AMI. I changed my shell to tcsh and then set up .tcshrc with

PATH = ".:/usr/local/lib/play-1.1:$PATH"

After a

$ source ~/.tcshrc
$ echo $PATH
/usr/local/lib/play-1.1:/usr/local/bin:/bin:/usr/bin:/usr/X11R6/bin

I can't put anything into my path and have it get picked up for some reason.

I also tried an alias:

$ ln -s /usr/local/lib/play-1.1/play /usr/local/bin/play
$ play
play: command not found

with the same result, it doesn't get picked up in my path. Am I ignorant of some global config? My experience is with CentOS so this is strange to me.

/home/notbrain
notbrain@aws-dev1: echo $PATH
.:/usr/local/lib/play-1.1:/usr/local/bin:/bin:/usr/bin:/usr/X11R6/bin

/home/notbrain
notbrain@aws-dev1: ls /usr/local/bin
total 8.0K
4.0K drwxr-xr-x  2 root 4.0K Jan 28 05:41 ./
4.0K drwxr-xr-x 13 root 4.0K Jan 11 21:44 ../
   0 lrwxrwxrwx  1 root   28 Jan 28 05:41 play -> /usr/local/lib/play-1.1/play*

/home/notbrain
notbrain@aws-dev1: play
play: Command not found.

/home/notbrain
notbrain@aws-dev1: sudo play
sudo: play: command not found

/home/notbrain
notbrain@aws-dev1: /usr/local/bin/play
~        _            _
~  _ __ | | __ _ _  _| |
~ | '_ \| |/ _' | || |_|
~ |  __/|_|\____|\__ (_)
~ |_|            |__/
~
~ play! 1.1, http://www.playframework.org
~
~ Usage: play cmd [app_path] [--options]
~
~ with,  new      Create a new application
~        run      Run the application in the current shell
~        help     Show play help
~

/home/notbrain
notbrain@aws-dev1:

Thanks,

Brian

Does anyone know of a Heroku-like service for PHP (read: Symfony 1.4, PHP 5.3+) where I can use git(hub) to manage deployment?

On my MacBook Pro, I have iTerm and use the (black background) Pastel color set. World writable directories show up with a yellow background behind grey text. This I can live with, since the grey is dark enough to still be visible when surrounded by the muted yellow color.

But when I connect to my company's Slackware servers (via ssh and tcsh as my shell on the remote side), 777 directories show up as solid blocks of light green, as both bg and text color are identical (or close enough to make the text impossible to read).

How do I change the color used for the backgrounds of world-readable (777) directories?

Thanks!

-Brian

I currently have a perm_redirects.conf file that gets included into my apache config stack where I have lines in the format

RedirectPermanent /old/url/path /new/url/path

It looks like I'm required to use an absolute URL for the new path, e.g.: http://example.com/new/url/path. In the logs I'm getting "incomplete redirect target /new/url/path was corrected to http://example.com/new/url/path." (paraphrased).

In the 2.2 docs for RewriteRule, at the bottom they show the following as being a valid redirect, with only the url-paths instead of an abs URL for the right hand side of the redirect:

RewriteRule ^/old/url/path(.*) /new/url/path$1 [R]

But I can't seem to get that format to work to replicate the functionality of the RedirectPermanent version. Is this possible?