WIP - Package Updates

[rossmcdonald]

Restructured the package's filesystem hierarchy:

• Binaries are now located at /usr/bin/
• Configuration is now located at /etc/telegraf

In addition:

• Added a build.py script to mirror InfluxDB and Kapacitor.
• A few fixes and updates to the init.sh script
• Minor update to the telegraf.service unit file to correct usage of variable
• Added a post-install.sh and pre-install.sh to handle upgrades and other housekeeping

[rossmcdonald]

@sparrc Can you review the CONFIGURATION.md file to make sure I merged it correctly? Apologies if I overwrote anything.

[sparrc]

Looks good 👍

[sparrc]

Should we get rid of scripts/package.sh?

[rossmcdonald]

Let's leave it in for now in case we run into any issues with the new script. I'd also like to go through and make sure that all functionality is covered in the future before we strip it out. I've done that for InfluxDB, but it looks like Telegraf's is slightly different.

[sparrc]

cool, LGTM, let me know when it's ready and I'll merge it with the 0.3.0 branch

[rossmcdonald]

@sparrc One caveat to the upgrade path (and this is the same with InfluxDB too) is that RHEL/CentOS users upgrading from 0.2 to 0.3 will probably have their configurations overwritten by the upgrade. There is a backup stored at /etc/telegraf/telegraf.conf.$(date +%s).backup, so all they have to do is restore the backup before restarting the service. It's probably not a huge deal since this release has some breaking changes in it anyways, but I wanted to make sure you are aware. This also only pertains to CentOS/RHEL, and not Debian/Ubuntu.

Other than that, I think this is ready to merge.

[sparrc]

thanks for the heads-up @rossmcdonald, I'll put a note about that in the changelog