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+---
+title: Custom Music Syncing on Android
+layout: post
+---
+
+I have an HTC One, with CyanogenMod installed. I usually use Spotify, but I've been wanting to move away from it for a while.
+The biggest thing keeping me there was the ease of syncing up with my phone - I added music on my PC and it just showed up
+on my phone.
+
+So, I finally decided to make it work on my phone without Spotify. You might have success if you aren't using CyanogenMod,
+but you definitely need to be rooted and you need to access a root shell on your phone. I was using `adb shell` to start with,
+but it has poor terminal emulation. Instead, I ended up installing an SSH daemon on the phone and just using that. Easier to
+use vim in such an enviornment.
+
+The end result is that a cronjob kicks off each hour on my phone and runs a script that uses rsync to sync up my phone's music
+with my desktop's music. That's another thing - a prerequisite of this working is that you have to expose your music to the
+outside world on an SSH server somewhere.
+
+I'll tell you how I got it working, then you can see if it works for you. It might take some effort on your part to tweak
+these instructions to fit your requirements.
+
+## Sanity checks
+
+Get into your phone's shell and make sure you have basic things installed. You'll need to make sure you have:
+
+* bash
+* cron
+* ssh
+* rsync
+
+If you don't have them, you can probably get them by installing busybox.
+
+## Setting up SSH
+
+We need to generate a key. I tried using ssh-keygen before, but it had problems with rsync on Android. Instead, we use
+dropbearkey. Generate your key with `dropbearkey -t rsa -f /data/.ssh/id_rsa`. You'll see the public key echoed to stdout.
+It's not saved anywhere for you, so grab it out of your shell and put it somewhere - namely, in the authorized_keys file
+on the SSH server you plan to pull music from.
+
+At this point, you can probably SSH into the server you want to pull from. Run `ssh -i /data/.ssh/id_rsa <your server here>`
+to double check. Note that this isn't just for fun - you need to do this to get your server into known_hosts, so we can
+non-interactively access it.
+
+## Making Android more sane
+
+Now that this is working, we need to clean up a little before cron will run right. Android is only a "Linux" system in the
+sense that `uname` outputs "Linux". It grossly ignores the FHS and you need to fix it a little. Figure out how to do a
+nice init.d script on your phone. For my CyanogenMod install, I can add scripts to `/data/local/userlocal.d/` and they'll
+be run at boot. Here's my little script for making Android a little more sane:
+
+{% highlight bash %}
+#!/system/bin/sh
+# Making /system rw isn't strictly needed
+mount -o remount,rw /system
+mount -o remount,rw /
+ln -s /data/var /var
+ln -s /system/bin /bin
+ln -s /data/.ssh /.ssh
+crond
+{% endhighlight %}
+
+## Update script and initial import
+
+The following is the script we'll use to update your phone's music library.
+
+{% highlight bash %}
+#!/system/xbin/bash
+# Syncs music between a remote computer and this phone
+RHOST=<remote hostname>
+EHOST=<fallback, I use this for connecting from outside my LAN>
+RPORT=22
+RUSER=<username>
+ID=/data/.ssh/id_rsa
+RPATH=/path/to/your/remote/music
+# Omit the final directory. On my setup, this goes to /sdcard/Music, and my remote is /home/sircmpwn/Music
+LPATH=/sdcard
+
+echo $(date) >> /var/log/update-music.log
+
+rsync -ruvL --delete --rsh="ssh -p $RPORT -i $ID" $RUSER@$RHOST:$RPATH $LPATH >> /var/log/update-music-rsync-so.log 2>&1
+if [[ $? != 0 ]]; then
+    rsync -ruvL --delete --rsh="ssh -p $RPORT -i $ID" $RUSER@$EHOST:$RPATH $LPATH >> /var/log/update-music-rsync-so.log 2>&1
+fi
+{% endhighlight %}
+
+Save this script to `/data/updateMusic`, make it executable with `chmod +x /data/updateMusic`, then run the initial import
+with `/data/updateMusic`. After a while, you'll have all your computer's music on your phone. Now, we just need to make it
+update automatically.
+
+Note: I set up a couple of logs for you. `/var/log/update-music.log` has the timestamp of every time it did an update. Also,
+`/var/log/update-music-rsync-so.log` has the output of rsync from each run.
+
+## Cron
+
+Finally, we need to set up a cronjob. If you followed the instructions so far (and if you're lucky), you should have everything
+ready for cron. The biggest pain in my ass was getting cron to coorperate, but the init script earlier should take care of
+that. Run `crontab -e` and write your crontab:
+
+    0 * * * * /data/updateMusic
+
+Nice and simple. Your phone will now sync up your music every hour, on the hour, with your home computer. Here are some
+possible points for improvement:
+
+* Check wlan0 and only sync if it's up
+* Log cron somewhere
+* Alter the update script to do a little bit better about the "fallback"
+* Sync more than just music
+
+After all of this, I now have a nice setup that syncs music to my phone so I can listen to it with Apollo. I might switch
+away from Apollo, though, it's pretty buggy. [Let me know](mailto:sir@cmpwn.com) if you can suggest an alternative music
+player, or if you get stuck working through this procedure yourself.