Ubuntu Manpage: chake - serverless configuration with chef

NAME

       chake - serverless configuration with chef

INTRODUCTION

       chake is a tool that helps you manage multiple hosts with, without the need for a chef
       server. Configuration is managed in a local directory, which should probably be under
       version control with git(1) or anything else. Configuration is usually deployed via rsync
       over SSH, and applied by invoking chef-solo(1) over SSH on each host.

CREATING THE REPOSITORY

           $ chake init
           [create] nodes.yaml
           [ mkdir] nodes.d/
           [create] config.rb
           [ mkdir] config/roles
           [ mkdir] cookbooks/basics/recipes/
           [create] cookbooks/basics/recipes/default.rb
           [create] Rakefile

       A brief explanation of the created files:

       •   nodes.yaml: where you will list the hosts you will be managing, and what recipes to
           apply to each of them.

       •   nodes.d: a directory with multiple files in the same format as nodes.yaml. All files
           matching *.yaml in it will be added to the list of nodes.

       •   config.rb: contains the chef-solo configuration. You can modify it, but usually you
           won’t need to.

       •   config/roles: directory is where you can put your role definitions.

       •   cookbooks: directory where you will store your cookbooks. A sample cookbook called
           "basics" is created, but feel free to remove it and add actual cookbooks.

       •   Rakefile: Contains just the require 'chake' line. You can augment it with other tasks
           specific to your intrastructure.

       After the repository is created, you can call either chake or rake, as they are completely
       equivalent.

MANAGING NODES

       Just after you created your repository, the contents of nodes.yaml is the following:

           host1.mycompany.com:
             run_list:
               - recipe[basics]

       You can list your hosts with rake nodes:

           $ rake nodes
           host1.mycompany.com                      ssh

       To add more nodes, just append to nodes.yaml:

           host1.mycompany.com:
             run_list:
               - recipe[basics]
           host2.mycompany.com:
             run_list:
               - recipes[basics]

       And chake now knows about your new node:

           $ rake nodes
           host1.mycompany.com                      ssh
           host2.mycompany.com                      ssh

PREPARINGS NODES TO BE MANAGED

       Nodes have very few initial requirements to be managed with chake:

       •   The node must be accessible via SSH.

       •   The user you connect to the node must either be root, or be allowed to run sudo (in
           which case sudo must be installed).

       A note on password prompts: every time chake calls ssh on a node, you may be required to
       type in your password; every time chake calls sudo on the node, you may be require to type
       in your password. For managing one or two nodes this is probably fine, but for larger
       numbers of nodes it is not practical. To avoid password prompts, you can:

       •   Configure SSH key-based authentication. This is more secure than using passwords.
           While you are at it, you also probably want disable password authentication
           completely, and only allow key-based authentication

       •   Configure passwordless sudo access for the user you use to connect to your nodes.

CHECKING CONNECTIVITY AND INITIAL HOST SETUP

       To check whether hosts are correcly configured, you can use the check task:

           $ rake check

       That will run the the sudo true command on each host. If that pass without you having to
       passwords, you are sure that

       •   you have SSH access to each host; and

       •   the user you are connecting as has password-less sudo correctly setup.

           $ rake check

APPLYING COOKBOOKS

       To apply the configuration to all nodes, run

           $ rake converge

       To apply the configuration to a single node, run

           $ rake converge:$NODE

       To apply a single recipe on all nodes, run

           $ rake apply[myrecipe]

       To apply a single recipe on a specific node, run

           $ rake apply:$NODE[myrecipe]

       If you don’t inform a recipe in the command line, you will be prompted for one.

       To run a shell command on all nodes, run

           $ rake run[command]

       If the command you want to run contains spaces, or other characters that are special do
       the shell, you have to quote them.

       To run a shell command on a specific node, run

           $ rake run:$NODE[command]

       If you don’t inform a command in the command line, you will be prompted for one.

       To check the existing tasks, run

           $ rake -T

WRITING COOKBOOKS

       Since chake is actually a wrapper for Chef Solo, you should read the [chef documentation](
       <https://docs.chef.io/>).
        In special, look at the [Chef Solo Documentation]( <https://docs.chef.io/
       chef_solo.html>).

THE NODE BOOTSTRAPPING PROCESS

       When chake acts on a node for the first time, it has to bootstrap  it.  The  bootstrapping
       process includes doing the following:

       •   installing chef and rsync

       •   disabling the chef client daemon

       •   setting up the hostname

NODE URLS

       The  keys  in  the hash that is represented in nodes.yaml is a node URL. All components of
       the URL but the hostname are optional, so just listing hostnames is the simplest  form  of
       specifying your nodes. Here are all the components of the node URLs:

           [backend://][username@]hostname[:port][/path]

       •   backend: backend to use to connect to the host. ssh or local (default: ssh)

       •   username: user name to connect with (default: the username on your local workstation)

       •   hostname: the hostname to connect to (default: none)

       •   port: port number to connect to (default: 22)

       •   /path:  where to store the cookbooks at the node (default: /var/tmp/chef.$USERNAME)

EXTRA FEATURES

# HOOKS

       You  can  define  rake  tasks  that  will  be  executed before bootstrapping nodes, before
       uploading configuration management content to nodes, and before converging.  To  do  this,
       you just need to enhance the corresponding tasks:

       •   bootstrap_common: executed before bootstrapping nodes (even if nodes have already been
           bootstrapped)

       •   upload_common: executed before uploading content to the node

       •   converge_common: executed before converging (i.e. running chef)

       Example:

           task :bootstrap_common do
             sh './scripts/pre-bootstrap-checks'
           end

# ENCRYPTED FILES

       Any files ending matching .gpg and .asc will be decrypted with GnuPG before being sent  to
       the  node.  You can use them to store passwords and other sensitive information (SSL keys,
       etc) in the repository together with the rest of the configuration.

# REPOSITORY-LOCAL SSH CONFIGURATION

       If you need special SSH configuration parameters, you can create a file called .ssh_config
       (or  whatever  file name you have in the $CHAKE_SSH_CONFIG environment variable, see below
       for details) in at the root of your repository, and chake will use it when calling ssh.

# LOGGING IN TO A HOST

       To  easily  login  to  one  of  your  host,  just  run  rake  login:$HOSTNAME.  This  will
       automatically  use  the  repository-local  SSH configuration as above so you don’t have to
       type -F .ssh_config all the time.

# RUNNING ALL SSH INVOCATIONS WITH SOME PREFIX COMMAND

       Some times, you will also want or need to prefix your SSH  invocations  with  some  prefix
       command  in  order  to  e.g.  tunnel it through some central exit node. You can do this by
       setting $CHAKE_SSH_PREFIX on your environment. Example:

           CHAKE_SSH_PREFIX=tsocks rake converge

       The above will make all SSH invocations to all hosts be called as tsocks ssh [...]

# CONVERGING LOCAL HOST

       If you want to manage your local workstation with chake, you can declare a local node like
       this in nodes.yaml:

           local://thunderbolt:
             run_list:
               - role[workstation]

       To  apply  the  configuration  to  the  local  host,  you  can  use  the conventional rake
       converse:thunderbolt, or the special target rake local.

       When converging all nodes, chake will skip nodes  that  are  declared  with  the  local://
       backend and whose hostname does not match the hostname  in the declaration. For example:

           local://desktop:
             run_list:
               - role[workstation]
           local://laptop:
             run_list:
               - role[workstation]

       When you run rake converge on desktop, laptop will be skipped, and vice-versa.

ENVIRONMENT VARIABLES

       •   $CHAKE_SSH_CONFIG: Local SSH configuration file. Defaults to .ssh_config.

       •   $CHAKE_SSH_PREFIX: Command to prefix SSH (and rsync over SSH) calls with.

       •   $CHAKE_RSYNC_OPTIONS:  extra  options  to  pass to rsync. Useful to e.g. exclude large
           files from being upload to each server.

       •   $CHAKE_NODES: File containing the list of servers to be managed. Default: nodes.yaml.

       •   $CHAKE_NODES_D: Directory containing node definition  files  servers  to  be  managed.
           Default: nodes.d.

       •   $CHAKE_TMPDIR: Directory used to store temporary cache files. Default: tmp/chake.

       •   $CHAKE_CHEF_CONFIG:  Chef  configuration file, relative to the root of the repository.
           Default: config.rb.

NAME

INTRODUCTION

CREATING THE REPOSITORY

MANAGING NODES

PREPARINGS NODES TO BE MANAGED

CHECKING CONNECTIVITY AND INITIAL HOST SETUP

APPLYING COOKBOOKS

WRITING COOKBOOKS

THE NODE BOOTSTRAPPING PROCESS

NODE URLS

EXTRA FEATURES

# HOOKS

# ENCRYPTED FILES

# REPOSITORY-LOCAL SSH CONFIGURATION

# LOGGING IN TO A HOST

# RUNNING ALL SSH INVOCATIONS WITH SOME PREFIX COMMAND

# CONVERGING LOCAL HOST

ENVIRONMENT VARIABLES

SEE ALSO