Provided by: cdist_4.0.0~pre3-2_all bug

NAME

       cdist-best-practice - Practices used in real environments

PASSWORDLESS CONNECTIONS

       It is recommended to run cdist with public key authentication. This requires a
       private/public key pair and the entry "PermitRootLogin without-password" in the sshd
       server. See sshd_config(5) and ssh-keygen(1).

SPEEDING UP SSH CONNECTIONS

       When connecting to a new host, the initial delay with ssh connections is pretty big. You
       can work around this by "sharing of multiple sessions over a single network connection"
       (quote from ssh_config(5)). The following code is suitable for inclusion into your
       ~/.ssh/config:

           Host *
             ControlPath ~/.ssh/master-%l-%r@%h:%p
             ControlMaster auto
             ControlPersist 10

SPEEDING UP SHELL EXECUTION

       On the source host, ensure that /bin/sh is not bash: bash is quite slow for script
       execution. Instead, you could use dash after installing it:

           ln -sf /bin/dash /bin/sh

MULTI MASTER OR ENVIRONMENT SETUPS

       If you plan to distribute cdist among servers or use different environments, you can do so
       easily with the included version control git. For instance if you plan to use the typical
       three environments production, integration and development, you can realise this with git
       branches:

           # Go to cdist checkout
           cd /path/to/cdist

           # Create branches
           git branch development
           git branch integration
           git branch production

           # Make use of a branch, for instance production
           git checkout production

       Similar if you want to have cdist checked out at multiple machines, you can clone it
       multiple times:

           machine-a % git clone git://your-git-server/cdist
           machine-b % git clone git://your-git-server/cdist

SEPERATING WORK BY GROUPS

       If you are working with different groups on one cdist-configuration, you can delegate to
       other manifests and have the groups edit only their manifests. You can use the following
       snippet in conf/manifests/init:

           # Include other groups
           sh -e "$__manifest/systems"

           sh -e "$__manifest/cbrg"

MAINTAINING MULTIPLE CONFIGURATIONS

       When you need to manage multiple sites with cdist, like company_a, company_b and private
       for instance, you can easily use git for this purpose. Including a possible common base
       that is reused across the different sites:

           # create branches
           git branch company_a company_b common private

           # make stuff for company a
           git checkout company_a
           # work, commit, etc.

           # make stuff for company b
           git checkout company_b
           # work, commit, etc.

           # make stuff relevant for all sites
           git checkout common
           # work, commit, etc.

           # change to private and include latest common stuff
           git checkout private
           git merge common

       The following .git/config is taken from a a real world scenario:

           # Track upstream, merge from time to time
           [remote "upstream"]
              url = git://git.schottelius.org/cdist
              fetch = +refs/heads/*:refs/remotes/upstream/*

           # Same as upstream, but works when being offline
           [remote "local"]
              fetch = +refs/heads/*:refs/remotes/local/*
              url = /home/users/nico/p/cdist

           # Remote containing various ETH internal branches
           [remote "eth"]
              url = sans.ethz.ch:/home/services/sans/git/cdist-eth
              fetch = +refs/heads/*:refs/remotes/eth/*

           # Public remote that contains my private changes to cdist upstream
           [remote "nico"]
              url = git.schottelius.org:/home/services/git/cdist-nico
              fetch = +refs/heads/*:refs/remotes/nico/*

           # The "nico" branch will be synced with the remote nico, branch master
           [branch "nico"]
              remote = nico
              merge = refs/heads/master

           # ETH stable contains rock solid configurations used in various places
           [branch "eth-stable"]
              remote = eth
              merge = refs/heads/stable

       Have a look at git-remote(1) to adjust the remote configuration, which allows

MULTIPLE DEVELOPERS WITH DIFFERENT TRUST

       If you are working in an environment that requires different people to work on the same
       configuration, but having different privileges, you can implement this scenario with a
       gateway host and sudo:

       ·   Create a dedicated user (for instance cdist)

       ·   Setup the ssh-pubkey for this user that has the right to configure all hosts

       ·   Create a wrapper to update the cdist configuration in ~cdist/cdist

       ·   Allow every developer to execute this script via sudo as the user cdist

       ·   Allow run of cdist as user cdist on specific hosts on a per user/group base

       ·   f.i. nico ALL=(ALL) NOPASSWD: /home/cdist/bin/cdist config hostabc

       For more details consult sudoers(5)

TEMPLATING

       ·   create directory files/ in your type (convention)

       ·   create the template as an executable file like files/basic.conf.sh, it will output
           text using shell variables for the values

           #!/bin/sh
           # in the template, use cat << eof (here document) to output the text
           # and use standard shell variables in the template
           # output everything in the template script to stdout
           cat << EOF
           server {
             listen                          80;
             server_name                     $SERVERNAME;
             root                            $ROOT;

             access_log /var/log/nginx/$SERVERNAME_access.log
             error_log /var/log/nginx/$SERVERNAME_error.log
           }
           EOF

       ·   in the manifest, export the relevant variables and add the following lines in your
           manifest:

           # export variables needed for the template
             export SERVERNAME='test"
             export ROOT='/var/www/test'
           # render the template
             mkdir -p "$__object/files"
             "$__type/files/basic.conf.sh" > "$__object/files/basic.conf"
           # send the rendered template
             __file /etc/nginx/sites-available/test.conf  \
               --state present
               --source "$__object/files/basic.conf"

TESTING A NEW TYPE

       If you want to test a new type on a node, you can tell cdist to only use an object of this
       type: Use the --initial-manifest parameter with - (stdin) as argument and feed object into
       stdin of cdist:

           # Singleton type without parameter
           echo __ungleich_munin_server | cdist --initial-manifest - munin.panter.ch

           # Singleton type with parameter
           echo __ungleich_munin_node --allow 1.2.3.4 | \
               cdist --initial-manifest - rails-19.panter.ch

           # Normal type
           echo __file /tmp/stdintest --mode 0644 | \
               cdist --initial-manifest - cdist-dev-01.ungleich.ch

OTHER CONTENT IN CDIST REPOSITORY

       Usually the cdist repository contains all configuration items. Sometimes you may have
       additional resources that you would like to store in your central configuration
       repositiory (like password files from KeepassX, Libreoffice diagrams, etc.).

       It is recommended to use a subfolder named "non-cdist" in the repository for such content:
       It allows you to easily distinguish what is used by cdist and what not and also to store
       all important files in one repository.

SEE ALSO

       ·   cdist(1)

       ·   cdist-tutorial(7)

COPYING

       Copyright (C) 2011-2013 Nico Schottelius. Free use of this software is granted under the
       terms of the GNU General Public License version 3 (GPLv3).

AUTHOR

       Nico Schottelius <nico-cdist--@--schottelius.org>
           Author.

                                            04/07/2016                      CDIST-BEST-PRACTIC(7)