Puppet - Couche d'abstraction des ressources

Dans Puppet, la couche d'abstraction des ressources (RAL) peut être considérée comme le modèle conceptualisé de base sur lequel fonctionne toute l'infrastructure et la configuration de Puppet. En RAL, chaque alphabet a sa propre signification significative qui est définie comme suit.

Ressource [R]

Une ressource peut être considérée comme l'ensemble des ressources utilisées pour modéliser une configuration dans Puppet. Ce sont essentiellement des ressources intégrées qui sont présentes par défaut dans Puppet. Ils peuvent être considérés comme un ensemble de ressources appartenant à un type de ressource prédéfini. Ils sont similaires au concept POO dans tout autre langage de programmation dans lequel l'objet est une instance de classe. Dans Puppet, sa ressource est une instance d'un type de ressource.

Abstraction [A]

L'abstraction peut être considérée comme une fonctionnalité clé où les ressources sont définies indépendamment du système d'exploitation cible. En d'autres termes, lors de l'écriture d'un fichier manifeste, l'utilisateur n'a pas à se soucier de la machine cible ou du système d'exploitation, qui est présent sur cette machine particulière. En abstraction, les ressources fournissent suffisamment d'informations sur ce qui doit exister sur l'agent Puppet.

Puppet s'occupera de toutes les fonctionnalités ou de la magie qui se produisent dans les coulisses. Indépendamment des ressources et du système d'exploitation, Puppet se chargera de la mise en œuvre de la configuration sur la machine cible, dans laquelle l'utilisateur n'a pas à s'inquiéter de la façon dont Puppet se comporte en coulisses.

Dans l'abstraction, Puppet sépare les ressources de son implémentation. Cette configuration spécifique à la plate-forme existe auprès des fournisseurs. Nous pouvons utiliser plusieurs sous-commandes avec ses fournisseurs.

Calque [L]

Il est possible que l'on définisse une configuration et une configuration de machine entière en termes de collecte de ressources, et cela peut être visualisé et géré via l'interface CLI de Puppet.

Exemple de type de ressource utilisateur

[roo[email protected] ~]# puppet describe user --providers 
user 
==== 
Manage users.
This type is mostly built to manage systemusers, 
so it is lacking some features useful for managing normalusers. 
This resource type uses the prescribed native tools for 
creating groups and generally uses POSIX APIs for retrieving informationabout them.
It does not directly modify '/etc/passwd' or anything. 

- **comment** 
   A description of the user.  Generally the user's full name.  

- **ensure** 
   The basic state that the object should be in. 
   Valid values are 'present', 'absent', 'role'.  

- **expiry** 
   The expiry date for this user. 
   Must be provided in a zero-padded YYYY-MM-DD format --- e.g. 2010-02-19. 
   If you want to make sure the user account does never expire, 
   you can pass the special value 'absent'. 
   Valid values are 'absent'. 
   Values can match '/^\d{4}-\d{2}-\d{2}$/'. 
   Requires features manages_expiry.  

- **forcelocal** 
   Forces the management of local accounts when accounts are also 
   being managed by some other NSS 
   Valid values are 'true', 'false', 'yes', 'no'. 
   Requires features libuser.  

- **gid** 
   The user's primary group.  Can be specified numerically or by name. 
   This attribute is not supported on Windows systems; use the ‘groups’ 
   attribute instead. (On Windows, designating a primary group is only 
   meaningful for domain accounts, which Puppet does not currently manage.)  

- **groups** 
   The groups to which the user belongs. The primary group should 
   not be listed, and groups should be identified by name rather than by 
   GID. Multiple groups should be specified as an array.  

- **home** 
   The home directory of the user.  The directory must be created 
   separately and is not currently checked for existence.  

- **ia_load_module**
   The name of the I&A module to use to manage this user. 
   Requires features manages_aix_lam.  

- **iterations** 
   This is the number of iterations of a chained computation of the 
   password hash (http://en.wikipedia.org/wiki/PBKDF2).  
   This parameter is used in OS X. 
   This field is required for managing passwords on OS X >= 10.8.  

- **key_membership** 
   Whether specified key/value pairs should be considered the 
   **complete list** ('inclusive') or the **minimum list** ('minimum') of 
   the user's attributes. Defaults to 'minimum'. 
   Valid values are 'inclusive', 'minimum'.  

- **keys** 
   Specify user attributes in an array of key = value pairs. 
   Requires features manages_solaris_rbac.  

- **managehome** 
   Whether to manage the home directory when managing the user. 
   This will create the home directory when 'ensure => present', and 
   delete the home directory when ‘ensure => absent’. Defaults to ‘false’. 
   Valid values are ‘true’, ‘false’, ‘yes’, ‘no’.  

- **membership** 
   Whether specified groups should be considered the **complete list** 
   (‘inclusive’) or the **minimum list** (‘minimum’) of groups to which 
   the user belongs. Defaults to ‘minimum’. 
   Valid values are ‘inclusive’, ‘minimum’. 

- **name** 
   The user name. While naming limitations vary by operating system, 
   it is advisable to restrict names to the lowest common denominator.  

- **password** 
   The user's password, in whatever encrypted format the local system requires. 
   * Most modern Unix-like systems use salted SHA1 password hashes. You can use 
      Puppet's built-in ‘sha1’ function to generate a hash from a password. 
   * Mac OS X 10.5 and 10.6 also use salted SHA1 hashes. 
   * Mac OS X 10.7 (Lion) uses salted SHA512 hashes. 
   The Puppet Labs [stdlib][] module contains a ‘str2saltedsha512’ 
   function which can generate password hashes for Lion. 
   * Mac OS X 10.8 and higher use salted SHA512 PBKDF2 hashes. 
   When managing passwords on these systems the salt and iterations properties 
   need to be specified as well as the password. 
   [stdlib]: https://github.com/puppetlabs/puppetlabs-stdlib/ 
   Be sure to enclose any value that includes a dollar sign ($) in single 
   quotes (') to avoid accidental variable interpolation. 
   Requires features manages_passwords.  

- **password_max_age** 
   The maximum number of days a password may be used before it must be changed. 
Requires features manages_password_age.  

- **password_min_age** 
   The minimum number of days a password must be used before it may be changed. 
Requires features manages_password_age.  

- **profile_membership** 
   Whether specified roles should be treated as the **complete list** 
   (‘inclusive’) or the **minimum list** (‘minimum’) of roles 
   of which the user is a member. Defaults to ‘minimum’. 
   Valid values are ‘inclusive’, ‘minimum’. 

- **profiles** 
   The profiles the user has.  Multiple profiles should be 
   specified as an array. 
Requires features manages_solaris_rbac.  

- **project** 
   The name of the project associated with a user. 
   Requires features manages_solaris_rbac.  

- **purge_ssh_keys** 
   Purge ssh keys authorized for the user 
   if they are not managed via ssh_authorized_keys. 
   When true, looks for keys in .ssh/authorized_keys in the user's home directory. 
   Possible values are true, false, or an array of 
   paths to file to search for authorized keys. 
   If a path starts with ~ or %h, this token is replaced with the user's home directory. 
   Valid values are ‘true’, ‘false’.  

- **role_membership** 
   Whether specified roles should be considered the **complete list** 
   (‘inclusive’) or the **minimum list** (‘minimum’) of roles the user has. 
   Defaults to ‘minimum’. 
Valid values are ‘inclusive’, ‘minimum’.  

- **roles** 
   The roles the user has.  Multiple roles should be 
   specified as an array. 
Requires features manages_solaris_rbac.  

- **salt** 
   This is the 32 byte salt used to generate the PBKDF2 password used in 
   OS X. This field is required for managing passwords on OS X >= 10.8. 
   Requires features manages_password_salt. 

- **shell** 
   The user's login shell.  The shell must exist and be 
   executable. 
   This attribute cannot be managed on Windows systems. 
   Requires features manages_shell. 

- **system** 
   Whether the user is a system user, according to the OS's criteria; 
   on most platforms, a UID less than or equal to 500 indicates a system 
   user. Defaults to ‘false’. 
   Valid values are ‘true’, ‘false’, ‘yes’, ‘no’.  

- **uid** 
   The user ID; must be specified numerically. If no user ID is 
   specified when creating a new user, then one will be chosen 
   automatically. This will likely result in the same user having 
   different UIDs on different systems, which is not recommended. 
   This is especially noteworthy when managing the same user on both Darwin and 
   other platforms, since Puppet does UID generation on Darwin, but 
   the underlying tools do so on other platforms. 
   On Windows, this property is read-only and will return the user's 
   security identifier (SID).  

Providers 
--------- 

- **aix** 
   User management for AIX. 
   * Required binaries: '/bin/chpasswd', '/usr/bin/chuser', 
   '/usr/bin/mkuser', '/usr/sbin/lsgroup', '/usr/sbin/lsuser', 
   '/usr/sbin/rmuser'. 
   * Default for ‘operatingsystem’ == ‘aix’. 
   * Supported features: ‘manages_aix_lam’, ‘manages_expiry’, 
   ‘manages_homedir’, ‘manages_password_age’, ‘manages_passwords’, 
   ‘manages_shell’. 

- **directoryservice** 
   User management on OS X. 
   * Required binaries: ‘/usr/bin/dscacheutil’, ‘/usr/bin/dscl’, 
   ‘/usr/bin/dsimport’, ‘/usr/bin/plutil’, ‘/usr/bin/uuidgen’. 
   * Default for ‘operatingsystem’ == ‘darwin’. 
   * Supported features: ‘manages_password_salt’, ‘manages_passwords’, 
   ‘manages_shell’.

- **hpuxuseradd** 
   User management for HP-UX. This provider uses the undocumented ‘-F’ 
   switch to HP-UX's special ‘usermod’ binary to work around the fact that 
   its standard ‘usermod’ cannot make changes while the user is logged in. 
   * Required binaries: ‘/usr/sam/lbin/useradd.sam’, 
   ‘/usr/sam/lbin/userdel.sam’, ‘/usr/sam/lbin/usermod.sam’. 
   * Default for ‘operatingsystem’ == ‘hp-ux’. 
   * Supported features: ‘allows_duplicates’, ‘manages_homedir’, 
   ‘manages_passwords’.  

- **ldap** 
   User management via LDAP. 
   This provider requires that you have valid values for all of the 
   LDAP-related settings in ‘puppet.conf’, including ‘ldapbase’.
   You will almost definitely need settings for ‘ldapuser’ and ‘ldappassword’ in order 
   for your clients to write to LDAP. 
* Supported features: ‘manages_passwords’, ‘manages_shell’.  

- **pw** 
   User management via ‘pw’ on FreeBSD and DragonFly BSD. 
   * Required binaries: ‘pw’. 
   * Default for ‘operatingsystem’ == ‘freebsd, dragonfly’. 
   * Supported features: ‘allows_duplicates’, ‘manages_expiry’, 
   ‘manages_homedir’, ‘manages_passwords’, ‘manages_shell’. 

- **user_role_add** 
   User and role management on Solaris, via ‘useradd’ and ‘roleadd’. 
   * Required binaries: ‘passwd’, ‘roleadd’, ‘roledel’, ‘rolemod’, 
   ‘useradd’, ‘userdel’, ‘usermod’. 
   * Default for ‘osfamily’ == ‘solaris’. 
   * Supported features: ‘allows_duplicates’, ‘manages_homedir’, 
   ‘manages_password_age’, ‘manages_passwords’, ‘manages_solaris_rbac’.  

- **useradd** 
   User management via ‘useradd’ and its ilk.  Note that you will need to 
   install Ruby's shadow password library (often known as ‘ruby-libshadow’) 
   if you wish to manage user passwords. 
   * Required binaries: ‘chage’, ‘luseradd’, ‘useradd’, ‘userdel’, ‘usermod’. 
   * Supported features: ‘allows_duplicates’, ‘libuser’, ‘manages_expiry’, 
   ‘manages_homedir’, ‘manages_password_age’, ‘manages_passwords’, 
   ‘manages_shell’, ‘system_users’.  

- **windows_adsi** 
   Local user management for Windows. 
   * Default for 'operatingsystem' == 'windows'. 
   * Supported features: 'manages_homedir', 'manages_passwords'.

Ressource de test

Dans Puppet, tester une ressource indique directement qu'il faut d'abord appliquer les ressources que l'on souhaite utiliser pour configurer un nœud cible, de sorte que l'état de la machine change en conséquence.

Pour les tests, nous allons appliquer la ressource localement. Comme nous avons une ressource prédéfinie ci-dessus avecuser = vipin. Une façon d'appliquer une ressource est par CLI. Cela peut être fait en réécrivant la ressource complète dans une seule commande, puis en la passant à une sous-commande de ressource.

puppet resource user vipin ensure = present uid = '505' 
shell = '/bin/bash' home = '/home/vipin'

Testez la ressource appliquée.

[[email protected] ~]# cat /etc/passwd | grep "vipin" 
vipin:x:505:501::/home/vipin:/bin/bash

La sortie ci-dessus montre que la ressource est appliquée au système et que nous avons un nouvel utilisateur créé avec le nom de Vipin. Il est conseillé de le tester vous-même car tous les codes ci-dessus sont testés et fonctionnent.