Fedora Flock - 2016 - Day 1

So this is my first +Fedora Project Flock conference. I arrived in Krakow yesterday from Austin Texas.  The folks who put Flock together did a great job with this event.  I have never been to Krakow before, and they clearly communicated how you get around, which buses / trains to take, how to buy tickets, everything.  Kudos to that team.  I had a few reasons to come to Flock, I wanted to put some faces to names that I have been working with over the years.  I wanted to meet with the members of the Fedora Cloud group that I have been participating in, and I wanted to attend technical sessions and see what's coming up in the distro.

My schedule is listed here.  I'll blog each day that I'm here to share the experience.  Hopefully you will find it interesting enough to attend the next one if you ddn't get a chance to come to this Flock event.  I'll give an overview of each session that I attend.  I know I won't capture all the details from each session that I attend, but it's a taste.  The sessions are recoreded and will be posted to the Fedora youtube channel.

Day 1. 

Introduction from Joe B. to thank sponsors: Red Hat, Unix Stickers, SuSE, The Linux Foundation, stickermule.  Thanks sponsors!  Keep in mind though, Flock is a confernece that is run and led by contributors - for contributors.  I can tell there was a ton of work done behind the scenes to make this event happen.

Then the keynote by +Matthew Miller.  Matt covered some of the numbers that show Fedora is gaining steam in the cloud and developer space, among many others.  He also talked about a few of the major goals for 2016.  It's cool to see that the +Fedora Project has some big plans to continue moving forward in the cloud space.  Think items like Fedora Atomic, OpenShift and Flatpak.

OpenShift Origin on Fedora 24 on AWS - Wow.

So, this all started because I was just doing a little Friday tinkering and wanted to see how easy it is to get OpenShift Origin installed on Fedora... on AWS.  Well, it turns out, it's really, really easy.  So easy, in fact, that I decided to write it down here and share it with you. This will be the first of a few blog posts about running OpenShift Origin on Fedora.  This post details how to get OpenShift Origin running on a single instance of Fedora 24. This is also a manual configuration.  In future blog posts, I'll talk about how to set up a highly available OpenShift Origin install on Fedora.  In addition, I'll talk about how to consume AWS resources like ELBs, IAM, S3, route53, ec2 instances, etc...  Just maybe, I'll go into how to automate the deployments with the AWS CLI.  Feel free to leave some comments on just how far you want to go here.  I promise, it will be fun.

 I learned quite a bit during this process, namely:

• You can easily find and use Fedora images in the AWS community AMIs.
• OpenShift Origin has been packaged for Fedora 24 - who doesn't like new?
• It's easy to install the OpenShift Origin PaaS and get started.

The goal was to get Origin running on AWS, launch an application, and hit that app from my browser.  There's no real pre-requisites to get started here other than an AWS account with the proper permissions.  I do happen to have a DNS name managed by AWS route53 which helps a bit.  I also have some prior knowledge of how AWS works.

Let's chat a bit about what I'm using, what I had set up before this, and what I had to do to meet my goal.  I am using:

• Fedora AMI with the ID of ami-0a09e667 (Fedora-Cloud-Base-24-20160512.n.0.x86_64-us-east-1-HVM-standard-0). 
• For my testing, I'm using a m4.2xlarge instance of that AMI.
• I had an existing VPC that I launched the Fedora 24 instance into.  The only things to know about that is that I have DNS hostnames enabled on that VPC.
• I have an existing subnet in that VPC that I launched this into.
• I have an existing route table in that VPC with an internet gateway defined so my instance can get out.
• I created a new security group on instance launch for testing this.

I do need to prep AWS a bit before moving on.  I'll use the AWS CLI to do this.  I do have an AWS CLI cheat sheet that may help if you have questions about querying resources, launching resources, describing, etc.. Have a look.  To move forward, I need to know what OpenShift Origin needs.  I found that the OpenShift Origin documentation is great. Please have a look if you have any questions.  That's what I did. I went to the docs | installing | prerequisites and started there.  I'll just walk through the prerequisites here and share what I did.

Testing out AWS ssm

I was poking around the AWS CLI and testing out different features / functionality.  Amazons ssm caught my eye.  I decided to have a look at the remote functionality offered by this tool.  I'm consolidating all the notes I found in different resources here, to do a simple test.  Here's a high level overview of what it took me to get this configured and working properly:

1. Create a role and policy and assign that to an EC2 instance at launch time. You can't assign it to a running instance. The policy I assigned to the role that I attached to the instance is called: AmazonEC2RoleforSSM

2. Assign permissions to the user that will be executing the commands. The name of the policy is: AmazonSSMFullAccess

Of course, for your environment, make sure you adhere to your security requirements.  There are better ways to restrict this.

3. Deploy the instance and install the ssm agent.  You can either install the agent by passing  user-data or manually afterwards.  It's a a simple rpm package.

4. Create a policy document, mine was:

       
{
     "schemaVersion": "1.2",
     "description": "Check ip configuration of a Linux instance.",
     "parameters": {
     },
     "runtimeConfig": {
       "aws:runShellScript": {
       "properties": [
       {
       "id": "0.aws:runShellScript",
       "runCommand": 
    }
   ]
  }
 }
}

From the examples here: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/create-ssm-doc.html

Amazon Web Services Command Line Interface (AWS CLI) - Cheat Sheet

I have been standing up quite a bit of infrastructure in AWS lately using the AWS CLI.  Here are some commands that I found helpful in a cheat sheet format. I'll show you how to create resources, query resources for information and how to update resources. Hopefully this will get you started quickly. The cheat sheet covers the following topics:

• Setting up your environment.
• Working with Virtual Private Clouds (VPC).
• Working with Identity and Access Management (IAM).
• Working with Route53.
• Working with Elastic Load Balancers (ELB).
• Working with SSH.
• Working with DHCP.
• Working with Elastic Compute Cloud (EC2).
• Utilizing queries to gather information.

You can download the AWS CLI cheat sheet here.

You can preview the AWS CLI cheat sheet by clicking below (hover mouse over upper right corner):

You can test all these commands with Fedora images which can be launched here: https://getfedora.org/cloud/download/.

If you have any questions about any of the commands in particular, please drop a comment below and I'll try to help.  Much credit goes to Ryan Cook for frontloading a lot of this.

Grabbing a list of VMs from RHEV and Sorting

Simple post, but I thought it'd be worth sharing since I burned a day on it.  The goal was to find out which VMs on our RHEV environment were old and unused.  So I decided to use the RHEV-M API to grab the list, and sort it.  The only thing you need is the CA Cert for your RHEV-M environment.

https://gist.github.com/scollier/890159751cf04cee67c815d29284dc2b

Script here:

      
#!/bin/bash

# Set the variables for date, and argument
DATE=$(date +"%m_%d_%Y-%M")
INPUT="$1"

# Grab the password for RHEV-M, don't report it to std out.
echo
echo "Please provide the RHEVM password, password is not echoed out to stdout, enter password and press Enter."
read -p "Enter Password:" -s RHEVM_PASSWORD
echo

# Grab the xml report of all the VMs
curl -s -X GET -H "Accept: application/xml" -u "admin@internal:$RHEVM_PASSWORD" --cacert rhevm.cer https://your.domain.here.com/api/vms > vm-output-$DATE.xml

# Parse the xml output and look for the name of the VM, and the stop time of the VM, put it in a separate file.
xpath vm-output-$DATE.xml '/vms/vm/name | /vms/vm/stop_time' > vm-output-$DATE-formatted.xml 2> /dev/null


# Clean up the file here.  joherr helped out with this.  Place line breaks after each </stop_time> xml tag, and format it so it's readable in two columns.
sed -e 's/<\/name><stop_time>/ /g' \
-e 's/<\/stop_time><name>/\n/g' \
-e 's/<name>//g' \
-e 's/<\/stop_time>//g' vm-output-$DATE-formatted.xml | \
    sort -k 2 | \
    awk 'BEGIN { format = "%-60s %s\n"
            printf format, "VMs", "Date Stopped"
            printf format, "----------", "----------" }
        { printf format, $1, $2 }' > rhevm-vms-$DATE

# By default, output the number of VMs that are listed.
echo
echo "There are $(cat rhevm-vms-$DATE | wc -l) VMs now."
echo

# If it's run with a -p, ouput the entire list and sort by oldest first.
case $INPUT in
    -p|--print)
    cat rhevm-vms-$DATE
    shift # past argument
    ;;

esac
shift # past argument or value

Output here:

       
VMs                                                          Date Stopped
----------                                                   ----------
dh-ose-node2                                                 2014-10-23T16:42:27.045-05:00
ospceph-sft                                                  2014-11-10T21:01:23.524-06:00
dh-ose-broker                                                2014-11-11T16:32:59.985-06:00
ks-sft-test1                                                 2014-11-13T21:00:02.828-06:00
dh-ose-node1                                                 2014-11-24T19:02:53.995-06:00
collier-atomic-pxe                                           2014-12-18T15:01:45.325-06:00
sat6-pxe-rhel7                                               2015-03-05T10:54:13.907-06:00
sat6-pxe-rhel6                                               2015-03-05T10:54:14.401-06:00
rhel-atomic-7.1-GA-mjenner                                   2015-03-05T10:54:14.489-06:00
workstation-goern-1                                          2015-04-16T07:59:47.704-05:00
RHEL-Atomic-Test-Sat6                                        2015-05-29T11:42:58.093-05:00
hk-nfv                                                       2015-09-29T16:36:00.975-05:00
ks-back                                                      2015-09-29T16:36:01.851-05:00
rhel-atomic-mjenner                                          2015-09-29T16:36:02.026-05:00
dellaccess                                                   2015-09-29T16:36:02.785-05:00
collier-atomic-pxe-1                                         2015-09-29T16:36:03.663-05:00
....<snip>....

Now I have a decent idea of what VMs are out there, which ones haven't been powered on for months, and are candidates for deletion. Hope this helps.

Configure a Highly Available Kubernetes / etcd Cluster with Pacemaker on Fedora

I'm going to share some of the great work that Matt Farrellee, Rob Rati and Tim St. Clair have done with regards to figuring out $TOPIC - they get full credit for the technical details here.  It's really interesting work and I thought I'd share it with the upstream community.  Not to mention it gives me an opportunity to learn how this is all set up and configured.

In this configuration I will set up 5 virtual machines and one VIP:

fed-master1.example.com 192.168.123.100
fed-master2.example.com 192.168.123.101
fed-master3.example.com 192.168.123.102
fed-node1.example.com 192.168.123.103
fed-node2.example.com 192.168.123.104
fed-vip.example.com 192.168.123.105

If you are wondering how I set up this environment quickly and repetitively, check out omv from Purpleidea.  He's a clever guy with a great dev workflow.  In particular, have a look at the work he has done to put his great code into a package to make distribution easier.

In summary here, I used Vagrant, KVM and omv to build and destroy this environment.  I won't go into to many details about how that all works, but feel free to ask questions in the comments if needed.  My omv.yaml file is located here, this might help you get up and running quickly.  Just make sure you have a Fedora 22 Vagrant box that matches the name in the file.  Yup, I run it all on my laptop.

Global configuration:

• Configure /etc/hosts on all nodes so that name resolution works (omv can help here)
• Share SSH key from master to all other nodes

Running Kubernetes in Offline Mode

Here I'll talk about how to run kubernetes on a flight that doesn't have wifi... or, Red Hat Summit hands on lab that is completely disconnected.  In either case, to set some context, this is useful for me while I'm running on a single host kubernetes configuration for a lab or development where network access is limited or non-existent.

The issue is that K8s tries to pull the pause container whenever it launches a pod.  As such, it tries to connect to gcr.io and make a connection to download the pause image. The gcr.io is the Google Container Registry.  When you are in a disconnected environment this will cause the pod to enter a state of pending until it can pull down the pause container. 

Here's what you can do to bypass that - at least the only thing I know you can do: pull the pause container ahead of time.  It helps if you know you'll be in an environment with limited access ahead of time. 

       
# docker pull gcr.io/google_containers/pause
Trying to pull repository gcr.io/google_containers/pause ...
6c4579af347b: Download complete 
511136ea3c5a: Download complete 
e244e638e26e: Download complete 
Status: Downloaded newer image for gcr.io/google_containers/pause:latest




# docker images
REPOSITORY                       TAG                 IMAGE ID            CREATED             VIRTUAL SIZE
fedora/apache                    latest              1eff270e703a        7 days ago          649.7 MB
gcr.io/google_containers/pause   1.0                 6c4579af347b        11 months ago       239.8 kB
gcr.io/google_containers/pause   go                  6c4579af347b        11 months ago       239.8 kB
gcr.io/google_containers/pause   latest              6c4579af347b        11 months ago       239.8 kB

Extending Storage on an Fedora Atomic Host

I had to spend some time understanding how to use docker-storage-setup on an Atomic host. The tool docker-storage-setup comes by default and makes the configuration of storage on your Atomic host easier. I didn't read any of the provided documentation (although that probably would have helped) other than the script itself.  So, pardon me if this is a duplicate of other info out there.  It was a great way to learn more about it.  The goal here is to add more disk space to an Atomic host.  By default, the cloud image that you download has one device (vda) that is 6GB in size.  When I'm testing many, many docker builds and iterating through the Fedora-Dockerfiles repo, that's just not enough space.  So, I need to know how to expand it.

To provide some context about my environment, I'm using a local KVM environment to hack around in.  The first thing I'll do is go ahead and add a few extra disks to my environment so I can do some testing of docker-storage-setup.  Here is what we will be modifying on our running Atomic VM:

My VM is called: atomic1
New disk 1: vdb (logical name presented to VM)
New disk 2: vdc (logical name presented to VM)
New disk 3: vdd (logical name presented to VM)

As with anything you do regarding storage, make sure you have a backup.

Here is what it looks like on the Atomic VM before I add my disks:

       

# atomic host status
  TIMESTAMP (UTC)         VERSION   ID             OSNAME            REFSPEC                                                
* 2015-06-27 20:22:47     22.50     0eca6e0777     fedora-atomic     fedora-atomic:fedora-atomic/f22/x86_64/docker-host     
  2015-05-21 19:01:46     22.17     06a63ecfcf     fedora-atomic     fedora-atomic:fedora-atomic/f22/x86_64/docker-host     


# fdisk -l | grep vd
Disk /dev/vda: 6 GiB, 6442450944 bytes, 12582912 sectors
/dev/vda1  *      2048   616447   614400  300M 83 Linux
/dev/vda2       616448 12582911 11966464  5.7G 8e Linux LVM

How to Contribute to the "Container Best Practices Guide"

Hey there.  We are starting a new best practices guide for containers!  We'll cover tips and tricks for running containers on Fedora (rkt or Docker), CentOS, Red Hat Enterprise Linux and Atomic.  Some of the topics will cover items from how to build single app containers running on a single host to building containers with the intention of orchestrating them across multiple hosts with a higher level tool like OpenShift and or Kubernetes.

Right now we are just getting started with this consolidation of container knowledge effort.  Please feel free to have a look at the Github repo and contribute by submitting a pull request.  The guide will be written in asciidoc so it's going to be very easy to contribute to.  There are three ways to render the asciidoc files into PDF or HTML format:

• Install the appropriate packages (git asciidoc dockbook-xsl fop make) on your Fedora host
• Build your own container-best-practices (click the link to get the Dockerfile) image and do the processing inside the container
• Pull the trusted image from the Fedora account on the Docker registry by issuing a "docker pull fedora/container-best-practices"

Syntax highlighting for asciidoc

Cool tip to track here.

http://www.methods.co.nz/asciidoc/userguide.html#_vim_syntax_highlighter

To enable syntax highlighing:

• Put a Vim autocmd in your Vim configuration file (see the example vimrc file).
• or execute the Vim command :set syntax=asciidoc.
• or add the following line to the end of you AsciiDoc source files:

  // vim: set syntax=asciidoc: