Can a Puppet script find out whether it was invoked as part of regular configuration run, i.e. a Puppet agent applying configurations at regular intervals (i.e. puppet agent), or because of one-time actions (e.g. puppet agent -t, puppet apply)?
I have not tried this yet in practice, but the following may allow a way forward:
Settings on the command line (such as --test) are also available as Puppet master variables (such as $settings::test).
The Puppet master variable $servername identifies the Puppet master for puppet agent runs and is (perhaps) undef for puppet apply runs.
Hence a recipe for an overall solution may look as follows:
$onetime = $settings::test or $settings::onetime or ($servername == undef)
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I want to remotely direct the puppet agent to execute a specified command from the puppet master when needed.
I have tried this method, but it did not achieve the expected results. I define a tagged exec like this:
exec { 'mkdir_test':
command => '/bin/mkdir -p /123',
tag => 'mkdirtest',
}
When I execute puppet kick -t mkdirtest, the directory located at '/123' will be successfully created. When I execute puppet kick or the puppet daemon executes periodically, the tagged exec will also be executed, but I want to filter the tagged exec. In other words, I don't want the specified command to be executed periodically, just when I need it.
Is there some way to do this with puppet?
Please excuse my poor english.
Thanks.
Puppet is a configuration management tool which helps you to build the infrastructure and maintain its state. So if you put an exec without conditions, it will execute the command on every run.
You can use onlyif, unless, creates and refreshonly to manage the case when you want the command to execute.
As a suggestion:
To get better answer, can you elaborate on the conditions when you want the directory to be created.
Usage of exec is frowned upon. You may want to use file resource to create directories. That would give you better control on conditions too.
There is the need that one puppet agent contacts some different puppet masters.
Reason: there are different groups that create different and independent sets of manifests.
Possible groups and their tasks
Application Vendor: configuration of application
Security: hardening
Operations: routing tables, monitoring tools
Each of these groups should run it's own puppet master - the data (manifests and appropriate data) should be strictly separated. If it is possible, one group should even not see / have access to the manifests of the others (we are using MAC on the puppet agent OSes).
Thoughts and ideas that all failed:
using (only) hira is not flexible as needed - there is the need to have different manifests.
r10k: supports more than one environment, but in each environment can only access one set of manifests.
multi but same puppet server using e.g. DNS round robin: this is the other way round. We need different puppet masters.
Some ways that might be possible but...
running multiple instances of puppet agents. That 'feels' strange. Advantage: the access rights can be limited in the way as needed (e.g. the application puppet agent can run under the application user).
patching puppet that it can handle more than one puppet master. Disadvantage: might be some work.
using other mechanisms to split responsibility. Example: use different git-repositories. Create one puppet master. The puppet master pulls all the different repositories and serves the manifests.
My questions:
Is there a straight forward way implementing this requirement with puppet?
If not, is there some best practice how to do this?
While I think what you are trying to do here is better tackled by incorporating all of your modules and data onto a single master, and that utilizing environments will be effectively the exact same situation (different masters will provide a different set of modules/data) this can be achieved by implementing a standard multi-master infrastructure (one CA master for cert signing, multiple compile masters with certs signed by the same CA master, configured to forward cert traffic elsewhere) and configure each master to have whatever you need. You then end up having to specify which master you want to check in to on each run (a cronjob or some other approach), and have the potential for one checkin to change settings set by another (kinda eliminating the hardening/security concept).
I would urge you to think deeper on how to collaborate your varied aspects (git repos for each division's hiera data and modules that have access control) so that a central master can serve your needs (and access to that master would be the only way to get data/modules from everywhere).
This type of setup will be complex to implement, but the end result will be more reliable and maintainable. Puppet inc. may even be able to do consultation to help you get it right.
There are likely other approaches too, just fyi.
I've often found it convenient to multi-home a puppet agent for development purposes, because with a local puppet server you can instantly test manifest changes - there's no requirement to commit, push and r10k deploy environment like there is if you're just using directory environments and a single (remote) puppet server.
I've found the best way to do that is to just vary the path configuration (otherwise you run into problems with e.g. the CA certs failing to verify against the other server) - a form of your "running multiple instances of puppet agents" suggestion. (I still run them all privileged, so they can all use apt package {} etc.)
For Puppet 3, I'd do this by varying the libdir with --libdir (because the ssldir was under the libdir), but now (Puppet 4+) it looks more sensible to vary the --confdir. So, for example:
$ sudo puppet agent -t # Runs against main puppet server
$ sudo puppet agent -t \
--server=puppet.dev.example.com \
--confdir=/etc/puppetlabs/puppet-dev # Runs against dev puppet server
I'm working on a tool which manages WordPress instances using puppet. The flow is the following: the user adds the data of the new WordPress installation in the web interface and then that web interface is supposed to send a message to the puppet master to tell it to deploy it to the selected machine.
Currently the setup is done via a manifest file which contains the declaration of all WordPress instances, and that is applied manually via puppet apply on the puppet agent. This brings me to my 2 questions:
Are manifests the correct way of doing this? If so, is it possible to apply them from the puppet master to a specific node instead of going to the agent?
Is it possible to automatically have a puppet run triggered once the list of instances is altered?
To answer your first question, yes there's absolutely a way of doing this via a puppetmaster, what you have at the moment is a masterless setup which assumes you're distributing your configuration with some kind of version control (like git) or manual process. This is a totally legitimate way of doing things if you don't want a centralized master.
If you want to use a master, you'll need to drop your manifest in the $modulepath of your master (it varies depending on your version, you can find it using puppet config print modulepath on your master) and then point the puppet agent at the master.
If you want to go down the master route, I'd suggest following the puppet documentation which will help you get started.
The second question brings me on to a philosphical argument of 'is this really want you want to do?'
Puppet traditionally (in my opinion) is a declarative config management tool that is designed to make your systems look a certain way. You write code to determine 'this is how I want it to look' and Puppet will converge to make it look that way. What you're looking to do is more of an orchestration task (ie when X do Y). There are ways of doing this with Puppet like using mcollective (to trigger a puppet run) which is managed by a webhook, but I think there are better tools for the job.
I'd suggest looking at ansible, saltstack or Chef's knife tool to do deploys like this.
I need your help to understand the better implementation approach for the below requirement:
Suppose my puppet master server name is: server.example.com which I need to update in 500 puppet agent nodes to contact to puppet master server. One way is to add server=server.example.com in puppet.conf on all the agent nodes and second way is to run the command "puppet agent --test --server server.example.com" on all agent nodes. But this needs to be performed either manually or some kind of automation needs to be performed. Is there some better way?
Second option is I can create a CNAME with name 'puppet' on puppet master server so that all agent nodes automatically make the communication with the puppet master. But in case I have multiple puppet master in the same domain than how I can manage it?
I will highly appreciate if someone can throw some light on the best practice to achieve this.
Thanks,
Sanjiv
The best practice is to take full advantage of puppet automation by adding server=server.example.com which is the address of the master. Since you are dealing with 500 nodes, manual approach is not encouraged.
By default puppet agents communicate with the master every 30minutes. But in some cases if you want to force puppet agents to communicate with master within this default time period, then use a parallel ssh or similar tool to invoke puppet agent --test
If you are considering multiple puppet masters then you need to ensure that DNS or the proxy server is properly configured in the network and point to right puppet master at a given point of time.
This might be helpful: https://docs.puppetlabs.com/guides/scaling_multiple_masters.html
You can have the client's puppet.conf as a template where server can take a variable in puppet or reading it from hiera. The server name will get propagated to your clients during the next puppet run by agents.
When using the Ansible provisioner, the delegate_to: ip_address can be used to execute actions on the machine that originally invoked ansible (the host) instead of the guest.
When using Puppet, what would be a similar equivelent?
Functions in a manifest are executed on the puppet master (if using agent). Resources are evaluated by the agent on the node. Note that this happens in stages, so functions are all called when the manifest is compiled and resources happen later after the compiled catalog is sent to the agent. Catalog caching can also prevent functions from being called on ever invocation of the puppet master.
Puppet implements a client / server paradigm (agent / master in Puppet jargon). I'm not sure whether that maps cleanly to Ansible's guest / host.
Nevertheless, Puppet DSL functions run on the master during catalog building. You can write custom DSL functions relatively easily, and you can run arbitrary commands (within the capabilities of the relevant user) via the built-in generate() function.
Additionally, if the master manages itself (which is common) then you can use exported resources to cause resources to be defined during building of any node's catalog that can later be collected and applied to the master.
Puppet does not provide any means, however, to cause code to run on the master as part of the process of the agent applying a catalog to a different node.