Cloud-init NoCloud with URL for meta-data and user-data

 Recently I wrote an article on how to get cloud-init working locally http://www.whiteboardcoder.com/2016/04/install-cloud-init-on-ubuntu-and-use.html [1]

The basic idea was install cloud-init on a non-cloud install of Ubuntu.  Then to create a meta-data and user-data file at /var/lib/cloud/seed/nocloud-net then reboot.   The user-data file is the cloud-config file and the meta-data file is some presetting that I got to work partially.

Why would I do all of this?  I am used to using the AWS cloud or OpenStack, both of which support cloud-init.   I am planning on building an OpenStack box at home… someday… but I keep getting delayed with life.  

In the meantime I do have an ESXi box built out and running at home.  It works great.  But boy do I wish I had a simple nice interface or command line tool that would allow me to tell it to build a box of X size and run this cloud-init file. 

Running cloud-init locally I can kind of get that working well enough. 

1. Create a very base image with cloud-init installed
2. Copy my meta-data and user-data (cloud-init) files to /var/lib/cloud/seed/nocloud-net
3. Reboot (and let cloud-init do its thing)
4. Move VM over to my ESXi server

But I think I can one up it.  From what I have been reading I think I can set cloud-init to grab the meta-data and user-data files from a URL.   If I can get that working I can put all my meta-data and user-data files in a git repo, for tracking, then put the repo files on an internal nginx server I can link to.  Then I just have to edit a cloud-init config file to point in the right direction and I am good to go.

First a simple example (No URL)

First I want to show how to get a local simple cloud-init working on a fresh Ubuntu 14.04 install.

Install cloud-init

> sudo apt-get install cloud-init

Create the /var/lib/cloud/seed/nocloud-net/ folder

> sudo mkdir -p /var/lib/cloud/seed/nocloud-net

Make a very simple meta-data file

> sudo vi  /var/lib/cloud/seed/nocloud-net/meta-data

local-hostname: my-servername

(This will change the servers name to my-servername)

Use write_files to create a new /etc/network/interfaces file.

> sudo vi  /var/lib/cloud/seed/nocloud-net/user-data

#cloud-config # #################### ################################################## # # Install packages # ################################################## packages:  - htop  - tree ################################################## # # Reboot the machine when done. # This is done to make sure the mount script is # working # ################################################## power_state:  delay: "now"  mode: reboot  message: First Reboot!  timeout: 30 ################################################## # # Create groups # ################################################## groups:  - patman ################################################## # # Create users. #    * set their prefered shell #    * Set their group membership #    * give them admin permissions #    * Set their password (copied from ecnrypted version @ /etc/shadow) #    * Input Public SSH keys to allow access # ################################################## users:  - default  - name: patman    shell: /bin/bash    sudo: [ "ALL=(ALL) ALL" ]    primary-group: patman    passwd: $6$C5Hpbc-NOTREALKEY    ssh-authorized-keys:      - ssh-rsa AAAAB3NzaC-NOTREALKEY ################################################## # # runcmd: #    List of commands to execute #    If a command has a verbose setting, it's a #    good idea to use it.  Just in case you #    Need to debug later. #    Output is logged to #      /var/log/cloud-init-output.log # ################################################## runcmd: ################################################## # # passwd <username> -u #   When a user is created and their password # set... their password is locked in /etc/shadow # (it has a '!' in front of their encrypted # password, hard to see and a pain) # This command unlocks it # ##################################################  - 'passwd patman -u' ################################################## # # This fixes the hostname in /etc/hosts # which removes annoying messages when you # are trying to run commands using sudo # ##################################################  - 'echo 127.0.0.1 `hostname` >> /etc/hosts' ################################################## # # write_files: #    Files to write out. # ################################################## write_files: ################################################## # # Set static IP address (would rather do this in meta-data but it is no # working at the moment) #   @ /etc/network/interfaces # ##################################################  - path: /etc/network/interfaces    permissions: '0644'    owner: root:root    content: |       auto lo       iface lo inet loopback       #       #       auto eth0       iface eth0 inet static             address 192.168.0.75             netmask 255.255.255.0             broadcast 192.168.1.255             gateway 192.168.0.1             dns-nameservers 8.8.8.8

What will this cloud-init file do?  Let me go piece by piece

packages

################################################## # # Install packages # ################################################## packages:  - htop  - tree

This section tells it to install htop and tree

power_state (reboot)

################################################## # # Reboot the machine when done. # This is done to make sure the mount script is # working # ################################################## power_state:  delay: "now"  mode: reboot  message: First Reboot!  timeout: 30

This section tells it to reboot after cloud-init is done.

 groups

################################################## # # Create groups # ################################################## groups:  - patman

This section is creates groups.  I am creating a group for my user that has the same name as my user.

users

################################################## # # Create users. #    * set their prefered shell #    * Set their group membership #    * give them admin permissions #    * Set their password (copied from ecnrypted version @ /etc/shadow) #    * Input Public SSH keys to allow access # ################################################## users:  - default  - name: patman    shell: /bin/bash    sudo: [ "ALL=(ALL) ALL" ]    primary-group: patman    passwd: $6$C5Hpbc-NOTREALKEY    ssh-authorized-keys:      - ssh-rsa AAAAB3NzaC-NOTREALKEY

In this section you can add your user and get them set up the way you want.   I've set up the default shell, my primary group, my password (as taken from /etc/shadow), and my ssh public keys.  

runcmd

################################################## # # runcmd: #    List of commands to execute #    If a command has a verbose setting, it's a #    good idea to use it.  Just in case you #    Need to debug later. #    Output is logged to #      /var/log/cloud-init-output.log # ################################################## runcmd: ################################################## # # passwd <username> -u #   When a user is created and their password # set... their password is locked in /etc/shadow # (it has a '!' in front of their encrypted # password, hard to see and a pain) # This command unlocks it # ##################################################  - 'passwd patman -u' ################################################## # # This fixes the hostname in /etc/hosts # which removes annoying messages when you # are trying to run commands using sudo # ##################################################  - 'echo 127.0.0.1 `hostname` >> /etc/hosts'

Runcmd basically defines a bash script to run.  This is useful to do some setup that otherwise can't be done in other cloud-init modules.

This particular runcmd would result in this bash file being created and run.

#!/bin/sh passwd patman -u echo 127.0.0.1 `hostname` >> /etc/hosts

These command unlock the user patman (who is created in a locked state).  It also updates the /etc/hosts file to add the new hostname to it so you don't get that annoying warning when running sudo commands in Ubuntu.

write_files

################################################## # # write_files: #    Files to write out. # ################################################## write_files: ################################################## # # Set static IP address (would rather do this in meta-data but it is no # working at the moment) #   @ /etc/network/interfaces # ##################################################  - path: /etc/network/interfaces    permissions: '0644'    owner: root:root    content: |       auto lo       iface lo inet loopback       #       #       auto eth0       iface eth0 inet static             address 192.168.0.75             netmask 255.255.255.0             broadcast 192.168.1.255             gateway 192.168.0.1             dns-nameservers 8.8.8.8

This section creates a new /etc/network/interfaces file.  In my case it will set a static IP address to 192.168.0.75 on a reboot.

Then reboot it

> sudo reboot now

Now, I should also be able to login as patman at the static IP address.

> ssh patman@192.168.0.75

And tree and htop should be installed.

OK that is all working… Now to figure out how to move it to a URL and get cloud-init to use that URL.

Create a URL

You can come up with your own idea on where to store stuff but here is my method.

I happen to have an nginx server running on one of my local machines.  I am going to make a directory there and set It up to listen on port 8888  (which in my case is not available outside my network).

> sudo vi /etc/nginx/nginx.conf

I added this section to it.

server {     listen 8888;     location / {        root /nginx/cloud-init/;     }   }

Let me make the folder

> sudo mkdir /nginx/cloud-init    > sudo chown www-data:www-data /nginx/cloud-init

And restart nginx

> sudo service nginx restart

Within /nginx/cloud-init I think I will eventually create some folder structure that makes sense for me and my servers.  But for now I will just make a test folder there.

> cd /nginx/cloud-init    > sudo mkdir test

Meta-data file/url

Create the meta-data file

> sudo vi test/meta-data

And place the following in it.

local-hostname: my-servername

User-data file/url

Create the user-data file

> sudo vi test/user-data

And place the following in it.

#cloud-config # #################### ################################################## # # Install packages # ################################################## packages:  - htop  - tree ################################################## # # Reboot the machine when done. # This is done to make sure the mount script is # working # ################################################## power_state:  delay: "now"  mode: reboot  message: First Reboot!  timeout: 30 ################################################## # # Create groups # ################################################## groups:  - patman ################################################## # # Create users. #    * set their prefered shell #    * Set their group membership #    * give them admin permissions #    * Set their password (copied from ecnrypted version @ /etc/shadow) #    * Input Public SSH keys to allow access # ################################################## users:  - default  - name: patman    shell: /bin/bash    sudo: [ "ALL=(ALL) ALL" ]    primary-group: patman    passwd: $6$C5Hpbc-NOTREALKEY    ssh-authorized-keys:      - ssh-rsa AAAAB3NzaC-NOTREALKEY ################################################## # # runcmd: #    List of commands to execute #    If a command has a verbose setting, it's a #    good idea to use it.  Just in case you #    Need to debug later. #    Output is logged to #      /var/log/cloud-init-output.log # ################################################## runcmd: ################################################## # # passwd <username> -u #   When a user is created and their password # set... their password is locked in /etc/shadow # (it has a '!' in front of their encrypted # password, hard to see and a pain) # This command unlocks it # ##################################################  - 'passwd patman -u' ################################################## # # This fixes the hostname in /etc/hosts # which removes annoying messages when you # are trying to run commands using sudo # ##################################################  - 'echo 127.0.0.1 `hostname` >> /etc/hosts' ################################################## # # write_files: #    Files to write out. # ################################################## write_files: ################################################## # # Set static IP address (would rather do this in meta-data but it is no # working at the moment) #   @ /etc/network/interfaces # ##################################################  - path: /etc/network/interfaces    permissions: '0644'    owner: root:root    content: |       auto lo       iface lo inet loopback       #       #       auto eth0       iface eth0 inet static             address 192.168.0.75             netmask 255.255.255.0             broadcast 192.168.1.255             gateway 192.168.0.1             dns-nameservers 8.8.8.8

Now, in my case I have a url for meta-data at

http://192.168.0.80:8888/test/meta-data

and a url for user-data at

http://192.168.0.80:8888/test/user-data

I think it should be ready now.

First Attempt (Failed miserably)

Now back to a very fresh install of Ubuntu 14.04.

First install cloud-init.

> sudo apt-get install cloud-init

Now test and make sure you can reach the urls from this server using wget.  (use your own URLS but here is my example)

> wget http://192.168.0.80:8888/test/meta-data    > wget http://192.168.0.80:8888/test/user-data

 

Looks like that is working just fine.

Tweak /etc/cloud/cloud.cfg

Here is where I am in some new territory, but I found this gist that may be of some help https://github.com/number5/cloud-init/blob/master/doc/examples/cloud-config-datasources.txt [2]

Looks like I can add a NoCloud section to the datasource section and point it to my URL.

Let me edit it.

> sudo vi /etc/cloud/cloud.cfg

Scrolling down a little I can see this datasource section that is commented out.

Here is what I updated mine to.

datasource:   NoCloud:     # default seedfrom is None     # if found, then it should contain a url with:     #    <url>/user-data and <url>/meta-data     # seedfrom: http://my.example.com/i-abcde     seedfrom: http://192.168.0.80:8888/test

Save it and reboot.

> sudo reboot now

OK that failed miserably… It took forever trying to get data from EC2 urls that were not there then finally got to here and kinda got into a wonky state that wiped my passwords so I could not get in.

SecondAttempt (Failed)

Now back to a very fresh install of Ubuntu 14.04.

First install cloud-init.

> sudo apt-get install cloud-init

I found something interesting.  If I look at /etc/cloud/cloud.cfg.d/90_dpkg.cfg

I can see that all the different datasources are listed.  Also I see a command I can run to change that.

Let me try it

> sudo dpkg-reconfigure cloud-init

Interesting I can set this here… But it looks like if I use NoCloud option it won't use the URLS?  Maybe the URL option for NoCloud is a version 0.7.7 cloud-init thing and 14.04 is running 0.7.5?

But at any rate I am going do deselect all but NoCLoud and hit OK.

Did  /etc/cloud/cloud.cfg.d/90_dpkg.cfg  change?

Yes it did!

I think if I ran this it would skip over checking EC2, etc for meta-data/user-data and instead just use NoCloud…. But that the NoCloud would only look into the directory /var/lib/cloud/seed

Let me edit it.

> sudo vi /etc/cloud/cloud.cfg

Add in the following again.

datasource:   NoCloud:     # default seedfrom is None     # if found, then it should contain a url with:     #    <url>/user-data and <url>/meta-data     # seedfrom: http://my.example.com/i-abcde     seedfrom: http://192.168.0.80:8888/test

> sudo reboot now

Reboot, but I have a feeling it will not work.

Failed!

I found the issue  !!

I think I found the issue!

 

I think the URL listed needs to end in with a '/'

datasource:   NoCloud:     # default seedfrom is None     # if found, then it should contain a url with:     #    <url>/user-data and <url>/meta-data     # seedfrom: http://my.example.com/i-abcde     seedfrom: http://192.168.0.80:8888/test/

Need to end the url with a '/'

Third Attempt (Total Success!!)

Now back to a very fresh install of Ubuntu 14.04.

First install cloud-init.

> sudo apt-get install cloud-init

Edit /etc/cloud/cloud.cfg

> sudo vi /etc/cloud/cloud.cfg

Add in the following again.  (With the ending in / )

datasource:   NoCloud:     # default seedfrom is None     # if found, then it should contain a url with:     #    <url>/user-data and <url>/meta-data     # seedfrom: http://my.example.com/i-abcde     seedfrom: http://192.168.0.80:8888/test/

Configure Cloud-init

> sudo dpkg-reconfigure cloud-init

 

Select NoCloud

 

And select None: Failsafe

> sudo reboot now

I should also be able to login as patman

> ssh patman@192.168.0.75

And tree and htop should be installed.

Working!

One tweak and it is working!

References

[1]        Install cloud-init on Ubuntu and use locally… NoCloud
http://www.whiteboardcoder.com/2016/04/install-cloud-init-on-ubuntu-and-use.html
Accessed 04/2016

[2]        cloud-config-datasources.txt
https://github.com/number5/cloud-init/blob/master/doc/examples/cloud-config-datasources.txt
Accessed 04/2016