G5k-checks

Description

Overview

• g5k-checks is expected to be integrated into the standard environment of the Grid'5000 computational nodes. It checks that a node meets several basic requirements before it declares itself as available to the OAR server.
• This lets the admins enable some checkers which may be very specific to the hardware of a cluster.

Architecture

G5kchecks is based on rspec test suite. Rspec is a little bit roundabout of it first mission: test a program. We use rspec to test all node characteristics. The first step is to retrieve node informatation with ohai. By default ohai provides a large set of characteristics of the machine. Added to this, we have developed some plugins to complete missing information (particularly for the disk, the cpu and the network). The second step is to compare those characteristics with the grid5000 Reference_Repository. To do that, g5kchecks takes each value of the API and compares them with the values given by ohai. If those values don't match, then an error is thrown via the rspec process.

OAR

• The oar-node flavour of OAR installation /etc/default/oar-node is started at at boot time. It launches /usr/lib/oar/oarnodecheckrun, which then runs the executable file /etc/oar/check.d/start_g5kchecks. The OAR server periodically invokes remotely /usr/bin/oarnodecheckquery. This command returns with status 1 if /var/lib/oar/check.d/ is not empty, 0 otherwise. So if /etc/oar/check.d/start_g5kchecks finds something wrong, it simply has to create a log file in that directory.
• If oarnodecheckquery fails, then the node is not ready to start, and it loops on running those scripts until either oarnodecheckquery returns 0 or a timeout is reached. If the timeout is reached, then it does not attempt to declare the node as "Alive".

This summarizes when g5kchecks is run:

• At service start with /etc/default/oar-node
• Between (non-deploy) jobs with remote execution of oarnodecheckrun and oarnodecheckquery (In case of deploy jobs, the first type of execution takes place)
• Launched by user manually (for now, never happens)

G5kchecks is never run during users jobs.

Checks Overview

The following values are checked by g5k-checks:

# Generated by g5k-checks (g5k-checks -m api)
---
genepi-9:
  architecture:
    nb_cores: 8
    nb_procs: 2
    nb_threads: 8
    platform_type: x86_64
  bios:
    release_date: 04/30/2008
    vendor: Phoenix Technologies LTD
    version: 1.1a
  chassis:
    manufacturer: Bull SAS
    name: Novascale Universal
    serial: XAN-SM5P-00187
  main_memory:
    ram_size: 8589934592
  network_adapters:
    bmc:
      ip: 172.17.16.9
      mac: 00:30:48:96:d4:8e
      management: true
    eth0:
      driver: e1000e
      firmware_version: 2.1-12
      interface: Ethernet
      mac: 00:30:48:7f:3e:ea
      management: false
      model: 80003ES2LAN Gigabit Ethernet Controller (Copper)
      name: enp5s0f0
      rate: 0
      vendor: Intel
    eth1:
      driver: e1000e
      firmware_version: 2.1-12
      interface: Ethernet
      ip: 172.16.16.9
      mac: 00:30:48:7f:3e:eb
      management: false
      model: 80003ES2LAN Gigabit Ethernet Controller (Copper)
      name: enp5s0f1
      rate: 1000000000
      vendor: Intel
    ib0:
      driver: mlx4_core
      guid: 20:00:55:00:41:80:00:00:00:00:00:00:00:02:c9:03:00:01:5b:15
      interface: InfiniBand
      ip: 172.18.16.9
      management: false
      model: MT26418 [ConnectX VPI PCIe 2.0 5GT/s - IB DDR / 10GigE]
      rate: 20000000000
      vendor: Mellanox Technologies
    ib1:
      driver: mlx4_core
      guid: 20:00:55:00:41:80:00:00:00:00:00:00:00:02:c9:03:00:01:5b:16
      interface: InfiniBand
      management: false
      model: MT26418 [ConnectX VPI PCIe 2.0 5GT/s - IB DDR / 10GigE]
      rate: 10000000000
      vendor: Mellanox Technologies
  operating_system:
    cstate_driver: none
    cstate_governor: menu
    cstate_max_id: 
    ht_enabled: false
    kernel: 3.16.0-4-amd64
    name: debian
    pstate_driver: acpi-cpufreq
    pstate_governor: performance
    turboboost_enabled: false
    version: 8.9
  processor:
    cache_l1d: 32768
    cache_l1i: 32768
    cache_l2: 6291456
    cache_l3: 0
    clock_speed: 2500000000
    ht_capable: true
    instruction_set: x86-64
    model: Intel Xeon
    other_description: Intel(R) Xeon(R) CPU           E5420  @ 2.50GHz
    vendor: Intel
    version: E5420
  storage_devices:
    sda:
      by_id: "/dev/disk/by-id/wwn-0x50014ee100951626"
      firmware_version: 20.06C06
      model: WDC WD1600YS-01S
      size: 164696555520
      vendor: Western Digital
  supported_job_types:
    virtual: ivt

This is an example of output file in API mode (g5k-checks launched with -m api option).

In addition, not all tests are exporting data in this file. The following values are also checked:

• Grid5000 standard environment version
• Grid5000 post-install scripts version
• Usage of sudo-g5k (failed if used, could be destructive to other parts of the system)
• Correct mode of /tmp/
• Fstab partitions mounted and valids
• All partitions have expected size, position, offset, mount options, ...
• Correct KVM driver

Simple usage

Installation

G5kchecks is has been tested for jessie, debian stretch is work in progress but should be available soon. On grid5000 debian repository, just add on /etc/apt/sources.list

deb http://apt.grid5000.fr/debian sid main

node:

apt-get update

Install it:

node:

apt-get install g5kchecks

Get sources

git clone https://github.com/grid5000/g5k-checks.git

Run g5k-checks

If you want to check your node just run:

node:

g5k-checks -v

The output should highlight tests in error in red. Also, if some error occured, g5k-checks puts file in /var/lib/g5kchecks/. For instance:

 root@adonis-3:~# g5k-checks
 root@adonis-3:~# ls /var/lib/oar/checklogs/
 OAR_Architecture_should_have_the_correct_number_of_thread

You can see the detail of the values checked this way:

 root@adonis-3:~# cat /var/lib/oar/checklogs/OAR_Architecture_should_have_the_correct_number_of_thread

Get node description

G5k-checks has a double utility. It can check a node description against our reference API and detect errors. But it can also generate the data to populate this reference API.

If you want a exact node description you can run:

node:

g5k-checks -m api

(If launched with -v verbose mode, you can see that almost all tests are failing and it is normal as empty values are checked instead of real ones)

Then g5k-checks put a json and a yaml file in /tmp/

 root@adonis-3:~# g5k-checks -m api
 root@adonis-3:~# ls /tmp/
 adonis-3.grenoble.grid5000.fr.json  adonis-3.grenoble.grid5000.fr.yaml

Write your own checks/description

G5k-checks internal

G5k-checks is written in ruby on top of the rspec test framework. It gathers informations from ohai program and compare them with grid'5000 reference API data. Rspec is simple to read and write, so you can copy easily other checks and adapt them to your needs.

File tree is:

 ├── ohai # Ohai plugins, those informations are use by g5k-checks after
 ├── rspec # Add Rspec formatter (store informations in different way)
 ├── spec # Checks directory
 └── utils # some useful class

Play with ohai

Ohai is a small program who retrieve information from different files/other program on the host. It offers an easy to parse output in Json. We can add information to Json just by writing plugins. For instance if we want to add the version of bash in the description, you can create a small file /usr/lib/ruby/vendor_ruby/g5kchecks/ohai/package_version.rb with:

Ohai.plugin(:Packages) do

  provides "packages"

  collect_data do
      packages Mash.new
      packages[:bash] = `dpkg -l | grep bash | awk '{print $3}'`
      packages
  end
end

Play with Rspec

Rspec is a framework for testing ruby programs. G5k-checks use Rspec, not to test a ruby program, but to test host. Rspec is simple to read and write. For instance if we want to ensure that bash version is the good one, you can create a file /usr/lib/ruby/vendor_ruby/g5kchecks/spec/packages/packages_spec.rb with :

 describe "Packages" do
                                                                                                                                           
   before(:all) do                                                                                                                         
     @system = RSpec.configuration.node.ohai_description
   end
   
   it "bash should should have the good version" do                                                                                        
     puts @system[:packages][:bash].to_yaml
     bash_version = @system[:packages][:bash].strip                                                                                        
     bash_version.should eql("4.2+dfsg-0.1"), "#{bash_version}, 4.2+dfsg-0.1, packages, bash"                                              
   end
       
 end

Add checks

Example: I want to check if flag "acpi" is available on the processor:

Add to /usr/lib/ruby/vendor_ruby/g5kchecks/spec/processor/processor_spec.rb:

 it "should have apci" do
   acpi_ohai = @system[:cpu][:'0'][:flags].include?('acpi')
   acpi_ohai.should_not be_false, "#{acpi_ohai}, is not acpi, processor, acpi"
 end

Add informations in description

Example: I want to add bogomips of node:

First we should add information in ohai description. To do this we add in the file ohai/cpu.rb after line 80:

    if line =~ /^BogoMIPS/
      cpu[:Bogo] = line.chomp.split(": ").last.lstrip
    end

Then we can retrieve information and add it to the description. To do this we add in /usr/lib/ruby/vendor_ruby/g5kchecks/spec/processor/processor_spec.rb:

    it "should have BogoMIPS" do
      bogo_ohai = @system[:cpu][:Bogo]
      #First value is system, second is from API, thirs is the YAML path in the created '/tmp/' file for -m api mode.
      #Last argument is false to export value in API mode, true to skip
      Utils.test(bogo_ohai, nil, 'processor/bogoMIPS', false) do |v_ohai, v_api, error_msg|
          expect(v_ohai).to eql(v_api), error_msg
      end
    end

Now you have the information in /tmp/mynode.mysite.grid5000.fr.yaml:

   root@graphene-100:/usr/lib/ruby/vendor_ruby/g5kchecks# g5k-checks -m api
   root@graphene-100:/usr/lib/ruby/vendor_ruby/g5kchecks# grep -C 3 bogo /tmp/graphene-100.nancy.grid5000.fr.yaml 
     ram_size: 16860348416
   processor:
     clock_speed: 2530000000
     bogoMIPS: 5053.74
     instruction_set: x86-64
     model: Intel Xeon
     version: X3440

Releasing and testing

Tests and reference-repository update

Before creating a new standard environment, g5k-checks can be tested on target environments using the jenkins test: https://intranet.grid5000.fr/jenkins/job/test_g5kchecks

This test can reserve all or the maximum possible nodes (targets cluster-ALL and cluster-BEST) on each cluster of Grid5000.

It will checkout a (configurable) branch of g5k-checks and test it against a (configurable) branch of the reference-api.

The test will fail if mandatory test fails (i.e. there are entries in /var/lib/oar/checklogs).

Also, the Yaml output of the "-m api" option of g5k-checks will be written to $HOME/g5k-checks-output directory of the ajenkins user on the target site.

Note: it is possible to change the branches of both reference-repository and g5k-checks for the test by configuring the jenkins test:

cd /srv/jenkins-scripts && ruby -Ilib -rg5kcheckstester -e "G5KChecksTester::new.test('$site_cluster', 'dev_feature', 'dev_feature_refrepo')"

For example, this will take the 'dev_feature' branch of g5kcheck and test it against the data present in the 'dev_feature_refrepo' branch of the reference-api.

Updating the reference-repository

Once the tests are finished on the desired clusters, generated Yaml files must be imported manually.

• In the reference repository, go in the generators/run-g5kchecks directory.
• Now get yaml files you want to include. For example: rsync -va "rennes.adm:/home/ajenkins/g5k-checks-output/paravance*.yaml" ./output/

The output directory hold the temporary files that will be included as input in the reference-repository.

• Run the post-processing script: 'ruby ./postprocessing.rb'
• Check modified properties of nodes in input

Release a new version

Once modifications are tested correct on a maximum of clusters, a new version can be released.

Rake tasks are provided to ease this process.

The first step is to increase the version number with those rake tasks: rake package:bump:*

Then the debian package can be created using this task:

rake package:build

And finally the debian package can be built and published on the Grid'5000 apt repository:

rake package:publish

Environment update

The version of g5k-checks included in standard environment is defined in the following file:

virtualbox/steps/data/puppet/modules/env/manifests/std/install_g5kchecks.pp

Once the environment is correct and its version updated, it can be generated with the automated jenkins job: https://intranet.grid5000.fr/jenkins/job/env_generate/

New environment release and reference-api update guidelines

The following procedure summarizes the steps taken to test and deploy a new environment with g5k-checks.

G5k-checks relies on the reference-api to check system data against it. Data from the reference-api must be up-to-date for tests to succeed but most of this data is generated by g5k-checks itself, creating a sort of 'circular dependency'. To avoid dead nodes, g5k-checks data from all nodes should be gathered before pushing a new environment.

• Do a reservation of all nodes of G5K, for example: oarsub -t placeholder=maintenance -l nodes=BEST,walltime=06:00 -q admin -n 'Maintenance' -r '2017-08-31 09:00:00'

The reservation should happen early enough to ensure most (ideally all) of the resources will be available at that time.

• Prepare and release a new debian package of g5k-checks (see #Release a new version)

• Prepare a new standard environment with this new g5k-checks version (see #Environment update)

• Now g5k-checks should be run on all reserved nodes in 'api' mode in order to retrieve the yaml description that will be used to update the reference-api.

This step might be the most tedious one but can be done before the actual deployment. See #Tests and reference-repository update

• Commit and push theses changes to master branch of the reference-repository

• Soon after, push new environment version to all sites using the automated jenkins job: https://intranet.grid5000.fr/jenkins/job/env_push/

The jenkins job does a oar reservation of type 'destructive' that will force the deployment of the new environment.