Knowledge Base for IT Professionals, Teachers and Astronauts
If you have already installed Chef Client on a Windows box and want to upgrade to the latest version
choco upgrade chef-clientIf you work in the AWS environment and launch and terminate servers frequently the same IP is reused many times. When you try to connect to a new server with SSH and the IP address is already in the known_hosts file you will get the following error message.
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
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IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
The fingerprint for the ECDSA key sent by the remote host is
SHA256:...
Please contact your system administrator.
Add correct host key in /c/Users/.../.ssh/known_hosts to get rid of this message.
Offending ECDSA key in /c/Users/.../.ssh/known_hosts:13
ECDSA host key for ... has changed and you have requested strict checking.
Host key verification failed.
The solution is to delete the line from the “c:/Users/YOUR_USER_NAME/.ssh/known_hosts” file that has the same IP address as the new server.
When you install a new version of ChefDK and try to run Test Kitchen converge you may get the following error message
>>>>>> ------Exception-------
>>>>>> Class: Kitchen::ActionFailed
>>>>>> Message: Failed to complete #create action: [SSL_connect returned=1 errno=0 state=SSLv3 read server certificate B: certificate verify failed
To solve the problem add the following to the Windows environment variables and open a new Command or Bash window for the change to take effect:
SSL_CERT_FILE=C:\opscode\chefdk\embedded\ssl\certs\cacert.pem
When you install the new version of ChefDK you may get the following error message when you try to run Test Kitchen
!!!!!! The `winrm` gem is missing and must be installed or cannot be properly activated. Run `gem install winrm --version '["~> 1.6"]'` or add the following to your Gemfile if you are using Bundler: `gem 'winrm ', '["~> 1.6"]'`.
To install Winrm for the correct Ruby version execute
gem install winrm
gem install winrm-fs
When you install a new version of ChefDK and try to run Test Kitchen the following error message may appear
!!!!!! The `berkshelf' gem is missing and must be installed or cannot be properly activated. Run `gem install berkshelf` or add the following to your Gemfile if you are using Bundler: `gem 'berkshelf'`.
To reinstall Brekshelf in the correct version of Ruby execute
gem install berkshelf
After installing a new version of ChefDK you may get the following error message when you try to run Test Kitchen:
Message: Could not load the 'ec2' driver from the load path. Please ensure that your driver is installed as a gem or included in your Gemfile if using Bundler.
To install the EC2 driver in the correct Ruby version execute
gem install kitchen-ec2
You may get the following error when you try to run Test Kitchen after installing the latest version of ChefDK:
$ kitchen
C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require': cannot load such file -- dl/import (LoadError)
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/authentication/pageant.rb:1:in `<top (required)>'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/authentication/agent/socket.rb:5:in `<top (required)>'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/authentication/agent.rb:22:in `<top (required)>'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/authentication/key_manager.rb:4:in `<top (required)>'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh/authentication/session.rb:4:in `<top (required)>'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/gems/2.2.0/gems/net-ssh-2.9.2/lib/net/ssh.rb:11:in `<top (required)>'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/gems/2.2.0/gems/test-kitchen-1.7.3/lib/kitchen/ssh.rb:20:in `<top (required)>'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/gems/2.2.0/gems/test-kitchen-1.7.3/lib/kitchen.rb:46:in `<top (required)>'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/gems/2.2.0/gems/test-kitchen-1.7.3/lib/kitchen/cli.rb:21:in `<top (required)>'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from C:/Ruby22/lib/ruby/gems/2.2.0/gems/test-kitchen-1.7.3/bin/kitchen:10:in `<top (required)>'
from C:/Ruby22/bin/kitchen:23:in `load'
from C:/Ruby22/bin/kitchen:23:in `<main>'
To make Test Kitchen work again execute the following:
gem install net-ssh -v 2.9.3.beta1
When you are interviewing candidates for a DevOps position this collection of resources can help to ask the right questions.
Wide variety of questions on the broad spectrum of tasks needed for the DevOps work.
https://github.com/spikenode/DevOps-Interview-Questions
Chef uses Ruby as the scripting language. If you need to extract data out from a JSON string you can use the following script
# Save the JSON values
instance_data_drive_config = '{"size":"500","type":"io1","iops":"15000"}'
# Parse the JSON to a hash
data = JSON.parse(instance_data_drive_config)
# Declare the variables
size = ''
type = ''
iops = ''
# Iterate through the hash
data.each do |child|
case child[0]
when 'size'
size = child[1]
when 'type'
type = child[1]
when 'iops'
iops = child[1]
end
end
# Display the result
puts "size=#{size}"
puts "type=#{type}"
puts "iops=#{iops}"
The output is
size=500
type=io1
iops=15000
When I update the DJI Phantom 4 firmware with DJI Assistant 2 most of the times the update stops at 92%.
If I turn off the DJI Phantom 4 and turn it on again the rear lights blink fast yellow (or fast white), and the DJI Assistant 2 application cannot recognize the DJI Phantom 4 anymore through the USB cable.
I have not found a graceful way to finish the update, but the following steps make the Phantom work again.