File Transfer with Puppet

This project implements a file transfer script using Puppet to automate the process of copying a file from the master node to agent nodes.

Directory overview

The scripts are organised in a module named 'movefile'. There are two directories inside the module; files and manifests. The files directory stores the file to be copied to the agent node while the manifests directory stores the init.pp and site.pp file. The init.pp file is the default manifest file in a Puppet module. It acts as the main entry point for defining resources and configurations in that module. The site.pp file serves as the entry point for defining how nodes in the Puppet infrastructure are configured. Puppet uses this file to determine what resources, classes, and modules to apply to each node.

User and group resources

A users.pp file containing the user and group resources is created in the manifests directory to manage user accounts and groups on a system.

User resource attributes

ensure: The 'present' value specifies that the user should exist in the node.
shell: The shell attribute in the Puppet user resource specifies the login shell assigned to the user. The login shell (Bash in this case) provides a command-line interface when the user logs into the system.
gid: The group ID 'user5066357p' becomes the default group for files the user creates. It is used to set group ownership and permissions for files created by the user
managehome: Creates the home directory in the agent node if it doesn't exist.

Group resource attribute

ensure: Similar to the ensure attribute in user resource, the 'present' value specifies that the group named 'user5066357p' should exist in the node.

multi_pipelines — User and group resources

File resource

The init.pp file is the default manifest file in a Puppet module. It acts as the main entry point for defining resources and configurations in that module. It has the file resource for managing files and directories on a system.

$user: It is an environment variable that holds the username. Using environment variables like $user improves code reusability as it removes hardcoded values, making the code more portable and maintainable.
$file_path: It is an environment variable which specifies the file's location in the agent node.
ensure: The 'present' value specifies that the file should be present.
owner: Specifies the owner of the file, which is 'user5066357p' in this case.
group: Specifies the group the file belongs to, which is also 'user5066357p'.
mode: It specifies the permissions for the file using a numeric octal value. This value defines the read, write, and execute permissions for the owner, group, and others. The value 0644 would mean that the owner is able to read and write to the file while the group and others are able to read the file only.

Check the syntax of both .pp files using 'puppet parser validate' to ensure that the Puppet agent can apply the configurations successfully.

Node definition

The site.pp file defines how the agent nodes should be configured. It defines the classes (modules) to be applied to the nodes. When the agent node requests the configuration from the master node, the Puppet master evaluates the site.pp file and other manifests, generating a catalog, which is then sent back to the agent node to apply the desired configuration. If no specific configuration is provided for a node, the default configuration in site.pp is applied. In the script created, the movefile module and users.pp file is applied to the agent node named 'pa5066357p.localdomain'.

Similarly, check the syntax of the site.pp file using 'puppet parser validate' to ensure that the Puppet agent can apply the configurations successfully.

Apply configurations

After creating the required files, it is time to apply the configurations. Run the command 'puppet agent -tv --noop' from the Puppet agent terminal. The command with the --noop flag simulates the changes but does not apply them. Puppet will show which resources would be changed, added, or removed without actually making those changes. After verifying the configurations in noop mode, use the command 'puppet agent -tv' to apply the changes to the system. Note that in a typical Puppet setup, the process of checking for configuration changes is automated and does not require manually running 'puppet agent -tv'. This is in line with the DevOps principle of automation, which in this case is the automation of configuration management.

Verify changes

The last step is to verify that the changes have been applied correctly. Similarly, this process is automated using automated testing or with monitoring tools as part of a continuous delivery pipeline.