Archive for the 'Technology' Category

HOWTO: Back up your Android device with native rsync

Android
Recently, one of my Android devices stopped reading the memory card. Opening the device, the microSD card was so hot I couldn’t hold it in my hand. The battery on that corner of the device had started to swell slightly. I’ve used this device every day for 3+ years without any issues. Until this week.

I also use TitaniumBackup to back up my Android to this external memory card, but since the device can’t read the card, I can’t back it up to the card.

The card is fine, and works in my other devices, as well as being seen from the desktop. Other, blank microSD card can’t be read in the device and similarly overheat within seconds. It’s bad.

Enter rsync, the Swiss-Army Knife of power, to back up my Android device!

Here’s how:

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HOWTO: Purge Amazon Echo History with iMacros

Amazon Echo IoT Companion

This one is quick and easy… Have you ever wanted to go back into your Amazon Echo device and delete the history of all commands you asked Alexa to do for you? All the searches? All the weather requests?

Well, you can… manually from the mobile app, or from the Amazon Alexa Configuration page, but that can take hours, because each card you wan to remove is a minimum of two taps or clicks.

But there’s an even easier way… iMacros!

Load up the iMacros browser extension (Chrome version) (Firefox version) and create a new macro. You can edit it ‘raw’, if you wish, but you want only these lines in your macro:

VERSION BUILD=8970419 RECORDER=FX
TAB T=1
URL GOTO=http://alexa.amazon.com/spa/index.html#cards
TAG POS=1 TYPE=BUTTON ATTR=TXT:More
TAG POS=1 TYPE=SPAN ATTR=TXT:Removecard

Now when you load up the Amazon Alexa Configuration page, you can just launch your macro from iMacros and play it in a loop to progressively delete each and every one of those cards in seconds.

I personally wiped out over 5,000 cards in under 2 minutes with this approach. It works great!

Comment below if you have any luck with it, or modify it in a way that becomes more useful to others.

HOWTO: Run multiple Zwift sessions on the same PC (Windows only)

Zwift LogoMany people have asked me to write this up and I’m happy to be the first person to push Zwift this far with multiple, simultaneous sessions.

I can say with confidence that up to this point, I’m actually the only person who has this working correctly without overwriting or clobbering critical logs and data files. Others have tried some hacky methods, but they all result in instability and data loss (see “What does NOT work, and why” below).

I started this quest because I am working on a product design (“Secret Sauce” to be withheld in this HOWTO) that involves running multiple Zwift sessions on a single, 100% wireless PC, with the only wire being the single power cable to the wall. No USB cables, no video cables, no HDMI cables, no network cables.

Let’s get some general housekeeping out of the way first…

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HOWTO: Fully automated Zwift login on Mac OS X

Zwift LogoQuite a few riders on the Facebook Zwift Riders group have expressed an interest in this, so I decided to take a couple of hours, learn AppleScript and knock this out. Done! (if you’re on Windows, you want this other HOWTO instead)

What this code does, is allows you to create a single icon that will log you into Zwift, with no human interaction needed. It will put in your email, password, click the “Start Ride” button and away you go!

This also leverages the OS X Keychain to store your Zwift email address and password, so it’s secure, not leaked into the filesystem and is able to be called on by any other apps that might need it (ahem, like… Zwift itself!) :D

So here’s how to get it working…

First, we need to create a separate keychain to store the Zwift credentials. You could store them in the main keychain, but I’m a fan of credential separation, so let’s use that.

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HOWTO: Enable Docker API through firewalld on CentOS 7.x (el7)

centos-dockerPlaying more and more with Docker across multiple Linux distributions has taught me that not all Linux distributions are treated the same.

There’s a discord right now in the Linux community about systemd vs. SysV init. In our example, CentOS 7.x uses systemd, where all system services are spawned and started.

I am using this version of Linux to set up my own Docker lab host for tire-kicking, but it needs some tweaks.

I also wanted to see if I could use the Docker API from my Android phone, using DockerDroid, which (after configuring this) works famously!

Here’s what you need to do:

  1. Log into your CentOS machine and update to the most-current Docker version. The version shipped with CentOS 7 in the repo as I write this post, is “docker-1.3.2-4.el7.centos.x86_64”. You want to be using something more current, and 1.4 is the latest. To fetch that (and preserve your existing version), run the following:
    $ su -
    # cd /bin && mv /bin/docker /bin/docker.el7
    # wget https://get.docker.com/builds/Linux/x86_64/docker-latest -O docker
    # systemctl restart docker
    # exit
    $ 
    

    Now you should have a working Docker with the right version (current). You can verify that:

    $ sudo docker version
    Client version: 1.4.1
    Client API version: 1.16
    Go version (client): go1.3.3
    Git commit (client): 5bc2ff8
    OS/Arch (client): linux/amd64
    Server version: 1.4.1
    Server API version: 1.16
    Go version (server): go1.3.3
    Git commit (server): 5bc2ff8
  2. So far, so good! Now we need to make sure firewalld has a rule to permit this port to be exposed for external connections:
    $ sudo firewall-cmd --zone=public --add-port=4243/tcp --permanent
    $ sudo firewall-cmd --reload
    success
    

    You can verify that this new rule was added, by looking at /etc/firewalld/zones/public.xml, which should now have a line that looks like this:

    <port protocol="tcp" port="4243"/>
  3. Now let’s reconfigure Docker to expose the API to external client connections, by making sure the OPTIONS line in /etc/sysconfig/docker looks like this (note the portion in bold):
    OPTIONS=--selinux-enabled -H fd:// -H tcp://0.0.0.0:4243
    
  4. Restart the Docker service to enact the API on that port (if successful, you will not see any output):
    sudo systemctl restart docker
  5. To test the port locally, install telnet and then try telnet’ing to the port on localhost:
    $ sudo telnet localhost 4243
    Trying ::1...
    Connected to localhost.
    Escape character is '^]'.
    
    HTTP/1.1 400 Bad Request
    
    Connection closed by foreign host.

    All looks good so far!

  6. Lastly, install DockerDroid and configure it to talk to your server on this port:

    DockerDroid connecting to CentOS via API

  7. Now you should be able to use DockerDroid to navigate your Images, Containers and API.

    Good luck!

Tuesday Tip: rsync Command to Include Only Specific Files

I find myself using rsync a lot, both for moving data around, for creating backups using rsnapshot (yes, even on Windows!) and for mirroring public Open Source projects and repositories.

I used to create all sorts of filters and scripts to make sure I was getting only the files I wanted and needed, but I found a better way, and it wasn’t exactly intuitive.

--include="*/" --include="*.iso" --exclude="*"

In order for this to work as intended, the “include” patterns have to come before the “excludes”. This is because the very first pattern that matches is the one that gets evaluated. If your intended filename matches the specified exclude pattern first, it gets excluded from the scope.

When dealing with a very large, possibly unknown remote directory structure, you either have to include all of the remote subdirectories individually like this:

--include="/opt" --include="/var" --include="/home"

Or you can use the following syntax to include all directories (not files) in the scope:

--include="*/"

Once you’ve included every directory below your target scope, you can pass the filespec you’re interested in (in this case, I wanted every bootable ISO file from a remote CentOS mirror), and then you exclude everything else that doesn’t match that filespec. It looks like this:

1.) Include every directory:

--include="*/"

2.) Include *.iso as your intended matching scope

--include="*.iso"

3.) Exclude everything else

--exclude="*"

That’s the magic sauce.

Some of these options and the order they appear in may seem very non-intuitive, so please read the rsync documentation carefully paying specific attention to the “EXCLUDE PATTERNS” section of the docs.

When in doubt, always use “–dry-run –stats” to check your work before copying or modifying any data.

Measure twice, cut once.

HOWTO: Run boot2docker in VMware Fusion and ESXi with Shipyard to Manage Your Containers

fbbb494a7eef5f9278c6967b6072ca3eThis took me awhile to piece together, and I had to go direct to the maintainers of several of these components to get clarity on why some things worked, while others did not, even following the explicit instructions. Here, I present the 100% working HOWTO:

I started with a post I found written by someone on the boot2docker project page, describing how to get this working in VMware. But he missed some crucial steps, and the syntax is wrong. Also, Shipyard has gone to a new version, and the method of starting the containers is very different from the steps posted.

Creating the boot2docker VM Instance

First, we need to create a VM inside VMware Fusion and/or ESXi. If you’re using VMware Workstation, the steps are roughly the same, but the screenshots may differ slightly.

You’ll create a new VM, and add two NICs and a single IDE HDD to the VM. Something like 10GB should be fine to hold all of your containers, build scripts and any other persistent data you might need. Follow the screenshots below for some specifics and details. There are a few subtle tweaks you’ll need to maximize your boot2docker VM.

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HOWTO: Remove the “Year in Review” Posts from your Facebook Wall

It’s annoying. It’s Facebook. We all learn to either love or hate it, but there are ways to make the annoying parts of it go away.

The most-recent annoyance is Facebook’s compulsion to add the “Year in Review” posts from people to your Facebook wall.

Thankfully I’ve never been asked to fill mine out, but I do see hundreds of these from other “Friends” of mine. It looks like this:

2014-12-26 Facebook - Year In Review

Here’s how to get rid of them:

  1. Log into Facebook and go to this page:

    https://www.facebook.com/settings?tab=blocking

  2. Once you get there, you’ll see a section near the bottom labeled “Block Pages”. Put “YearInReview” into that form and hit Enter.

  3. If you’ve done it right, you should see something like this:

    2014-12-26 Facebook- Manage Blocking

That’s it, you’re done!

If you want to get rid of more Facebook garbage, ads and other annoyances, you can install the “Social Fixer” browser extension in your browser of choice. There are versions for Safari, Chrome, Firefox and Microsoft Internet Explorer. Works great!

Updating Legacy Fedora Linux Distributions to Use Archive Repositories

Fedora LinuxI run a VMware ESXi server here that hosts ~500 separate VMs, clones, templates and test builds of operating systems for testing, development, personal playground and other roles.

Some of these VMs are older Fedora, Ubuntu, Debian and various other Linux distributions. Since those distributions are no longer active, maintained by the community, the update URLs to install packages have gone away, or been moved to new locations.

Here’s how to update and fix those older versions of Fedora Linux so you can continue to install packages on them, past their “community expiration” date. I’ll post another entry for the same work for Ubuntu and Debian as well.

In your /etc/yum.repos.d/ directory are a number of configuration files specific to yum and repositories. It’s contents may look something like this:

[root@fedora-fc4 / yum.repos.d]# ls -lart
total 72
drwxr-xr-x  116 root root 12288 Nov 23 22:57 ..
-rw-r--r--    1 root root   344 Nov 24 14:42 fedora-updates-testing.repo
-rw-r--r--    1 root root   336 Nov 24 14:42 fedora-updates.repo
-rw-r--r--    1 root root   305 Nov 24 14:42 fedora-extras.repo
-rw-r--r--    1 root root   319 Nov 24 14:42 fedora-extras-devel.repo
-rw-r--r--    1 root root  1130 Nov 24 14:42 fedora-devel.repo
-rw-r--r--    1 root root   300 Nov 24 14:43 fedora.repo
drwxr-xr-x    2 root root  4096 Nov 24 14:43 .

In the case of Fedora Linux, you’ll want to change each of these so they reflect the new archive site, vs. the original download site, which no longer resolves and does not exist.

The original URL looks like this:

baseurl=http://download.fedora.redhat.com/pub/fedora/linux/core/$releasever/$basearch/os/

You’ll want to edit that to point to the following new URL (highlighted in red below):

baseurl=http://archive.fedoraproject.org/pub/archive/fedora/linux/core/$releasever/$basearch/os/

Once you make these edits to all of the repository files, you can run ‘yum update’ again and fetch all of the legacy update packages, install, remove and keep them as current as those distributions were at that time.

$ sudo yum install git-core
Setting up Install Process
Setting up repositories
updates-released          100% |=========================|  951 B    00:00
extras                    100% |=========================| 1.1 kB    00:00
base                      100% |=========================| 1.1 kB    00:00
Reading repository metadata in from local files
Parsing package install arguments
Resolving Dependencies
--> Populating transaction set with selected packages. Please wait.
---> Downloading header for git-core to pack into transaction set.
git-core-1.4.4.2-2.fc4.x8 100% |=========================|  67 kB    00:00
---> Package git-core.x86_64 0:1.4.4.2-2.fc4 set to be updated
--> Running transaction check

Dependencies Resolved

=============================================================================
 Package                 Arch       Version          Repository        Size
=============================================================================
Installing:
 git-core                x86_64     1.4.4.2-2.fc4    extras            2.9 M

Transaction Summary
=============================================================================
Install      1 Package(s)
Update       0 Package(s)
Remove       0 Package(s)
Total download size: 2.9 M
Is this ok [y/N]: y
Downloading Packages:
(1/1): git-core-1.4.4.2-2 100% |=========================| 2.9 MB    00:05
warning: rpmts_HdrFromFdno: Header V3 DSA signature: NOKEY, key ID 1ac70ce6
public key not available for git-core-1.4.4.2-2.fc4.x86_64.rpm
Retrieving GPG key from file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-extras
Importing GPG key 0x1AC70CE6 "Fedora Pre Extras Release "
Is this ok [y/N]: y
Key imported successfully
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
  Installing: git-core                     ######################### [1/1]

Installed: git-core.x86_64 0:1.4.4.2-2.fc4
Complete!

Now it works. Good luck!

How Many Java Versions is Enough for Mavericks, Apple?

Apple OSX Mavericks logoA lot of software outright fails to work on Apple OS X Mavericks.

It’s a disaster. Almost nothing works right.

Not only is the entire OS noticeably slower, by several orders of magnitude over the previous Lion (10.7.5) was running until a few days ago on my 11″ MacBook Air, but there are dozens and dozens of glaringly-obvious bugs that make me want to go back to my Linux laptop full-time.

Here are some obvious ones:

  • The trackpad randomly disables two-finger scrolling and the only way to get it back is to either log out and back in, or restart the machine entirely.
  • The direction of the trackpad scrolling was reversed after the upgrade. Dragging fingers down, used to pull the page down, now it pulls the page up. You can flip the toggle to reverse it, but why was it changed at all from the default?
  • The audio up/down buttons are about 1-2 seconds behind the actual button press, which is a bit disjointed when you’re trying to determine how far down or up to change the volume for a video or song.
  • USB Ethernet used to work plug-and-play, but now if your OS X machine is booted and you connect a USB Ethernet dongle, it will not be recognized, until you reboot the machine with the dongle plugged in. Every time. This feels like Windows to me. I never had to do this with Lion previously.
  • There’s a cut-off/echo with the voices in OS X Mavericks. When I have the clock set to announce the time every 15 minutes, instead of “It’s three-fifteen” or “It’s eleven o’clock”, I hear “…ee fifteen” or “…ven o’clock”, the first 1-2 syllables are completely missing, cut off.

There are dozens more that I’ve tripped on (and reported), but they still hamper productive use of the machine.

I also run several apps that depend on Java, including XCode, XMind, The Hit List and others. Most of these just flat-out fail to function. I was so frustrated at the amateurish quality of this major “greatest ever” OS update, that I started investigating myself.

Apple, a plea… how many Java versions, incorrect, non-current Java versions is enough? On this upgraded version of OS X (Lion -> Mavericks), I count 6+ distinct installs!

# OpenJDK Runtime Environment (build 1.7.0-internal-root_2012_07_25_17_59-b00)
./Applications/Xcode.app/Contents/Applications/Application Loader.app/Contents/MacOS/itms/java/bin/java

# Java(TM) SE Runtime Environment (build 1.7.0_45-b18)
./Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home/bin/java

# Java(TM) SE Runtime Environment (build 1.7.0_04-b21)
./Library/Java/JavaVirtualMachines/1.7.0.jdk/Contents/Home/bin/java

# Java(TM) SE Runtime Environment (build 1.7.0_04-b21)
./Library/Java/JavaVirtualMachines/1.7.0.jdk/Contents/Home/jre/bin/java

# Java(TM) SE Runtime Environment (build 1.7.0_04-b21)
./System/Library/Frameworks/JavaVM.framework/Versions/A/Commands/java

# Java(TM) SE Runtime Environment (build 1.6.0_65-b14-462-11M4609)
./System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/bin/java

[...]

The only one that is clean and current, is the one I installed:

# "./Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home/bin/java" -version
java version "1.7.0_45"
Java(TM) SE Runtime Environment (build 1.7.0_45-b18)
Java HotSpot(TM) 64-Bit Server VM (build 24.45-b08, mixed mode)

Of course, you don’t use it anywhere, no apps are referring to it, and instead you refer to the other versions which crash, break or fail to correctly launch any applications that use these Java interpreters.

Please, don’t tout your OS as being the “greatest work ever”, while providing a slow, buggy, de-evolved experience from the previous versions.

Fix it, or allow us to roll back to the previous version of the OS, which did work.

UPDATE: After much testing, I determined that the short-term “solution” was to rm the symlink to ‘java’ in ‘/usr/bin/’ and point it to the version of Java I installed from Oracle, as follows:

$ sudo ls -l /usr/bin/java
lrwxr-xr-x  1 root  wheel  74 Oct 27 15:55 /usr/bin/java -> /System/Library/Frameworks/JavaVM.framework/Versions/Current/Commands/java
$ sudo rm /usr/bin/java
$ sudo ln -s /Library/Internet\ Plug-Ins/JavaAppletPlugin.plugin/Contents/Home/bin/java /usr/bin/java

After doing this, my Java-based OS X apps started working as expected. This is not a fix, it’s a temporary hack and workaround, but it gets me back up and running on apps that were crashing and failing before.

Apple, please fix this.

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