Ansible when changed condition stdout }} That output matches the behavior of the code, but I dont know why the data was registered since the "when:" conditional was not met. In this case, you can use Ansible’s register, when, changed_when and failed_when conditional statement Sep 16, 2024 · Learn how the when condition works in Ansible to control task execution based on variables, facts, and conditions. Apr 8, 2016 · Great it works in ansible 2. Apr 1, 2023 · We use the changed_when command when we want to execute the task when the output has been changed based on the condition. Handler example Notifying handlers Notifying Nov 14, 2023 · ansible-lint will berate you mercilessly for the redundant is true bit. Feb 1, 2023 · The conditions like changed_when and failed_when are evaluated for each iteration. ` Nov 19, 2018 · I have a simple shell task which is feed with_items. During the execution of an iteration the result of each iteration step is exclusively available in the variable of the register (in your example result). In this tutorial, we’ll see practical examples of how to use conditionals in Ansible playbooks based on the output of a command Mar 11, 2024 · An Ansible loop allows you to repeat a task or a set of tasks multiple times with different values, reducing code duplication and making playbooks more concise and maintainable. I want to have the ' changed ' status only when the run actually did something. Mar 14, 2025 · Tired of Ansible running every task? Learn how to use when statements to control execution based on conditions, variables, and system facts. g. 19/Ansible 12 release has made significant templating changes that might require you to update playbooks and roles. If you want to build something like this you’ll have to register different variables, and then use set_vars to create the output one Adrian Paraschiv adrian. Most builtin modules and tasks are already, but for tasks such as command and shell you need to help ansible a bit. the value of another variable)? Details I have two related variables for a command, env and composer_opts. Ansible json_query. In these cases, you can register a validate step (checking if that application exists) as a variable and place a when condition for this registered variable to exist to run the dependent tasks. Dec 27, 2023 · This complete guide to Ansible‘s changed_when functionality will give you back control. For example, ansible-doc -t module getent gives you the description of the module getent. with real time examples. A conditional controls the flow of tasks based on specific Nov 14, 2023 · 0 Change the condition when: use_handler|bool The type of the variable use_handler is a string when declared in the INI format of the option --extra-vars use_handler=true You can test it if you want to - debug: var: use_handler|type_debug You don't have to explicitly test it as is true. paraschiv. We will cover when, failed_when, changed_when conditions in playbooks Mar 30, 2015 · registering a variable isn’t meant to be skipped, it works as designed. This guide covers "when" statements, multiple conditions, Ansible facts, registered variables, and Jinja2 templates for more flexible and efficient playbooks. When the create_user_file is evaluated to true, a new file will be no-changed-when This rule checks that tasks return changes to results or conditions. For example, you may want to restart a service if a task updates the configuration of that service, but not if the configuration is unchanged. As with all conditionals in Ansible, lists of multiple failed_when conditions are joined with an implicit and, meaning the task only fails when all conditions are met. Explore practical examples, common use cases, and advanced tips for creating efficient playbooks. Jun 30, 2017 · I am having issues when trying to use multiple and/or conditionals in a when statement to decide whether a task needs to be ran or not. 9! If I need a condition that works only when the variable does not contain a specific string, what is the correct syntax? I was thinking to something like this: when: variable1 is not search("value") but is not working This is the latest (stable) Ansible community documentation. A plain boolean variable can be used in a test. We‘ll explore what changed_when brings to the table, walk through real-world examples, review top tips from Ansible experts, and much more! Oct 8, 2025 · Ansible always registers something in a registered variable for every host, even on hosts where a task fails or Ansible skips a task because a condition is not met. Unless tasks only read information, you should ensure that they return changes in the following ways: Register results or conditions and use the changed_when clause. Dec 22, 2013 · This Ansible tutorial shows you how execute actions only if another action has changed. Oct 14, 2021 · Having a hard time working with Ansible? Take your automation skills up a notch by learning Ansible when and other conditionals in this tutorial! 38 Ansible tasks should be idempotent. Apr 5, 2022 · In this post, we are going to see how to use conditional statements of Ansible such as when, changed_when, failed_when and where to use them appropriately and how it works. For a task that does purely checking and does not modify anything, you should add: changed_when: False always Jul 9, 2015 · I want to conditionally define a variable in an Ansible playbook like this: my_var: "{{ 'foo' if my_condition}}" I would like the variable to remain undefined if the condition does not resolve to Dec 26, 2023 · Then, within the same playbook, Ansible playbook parses it, and if the value is a negative (less than 0), it is supposed to kick off a whole another block. Mar 25, 2025 · Ansible is one of the most robust automation tools, but conditional task execution is significant for effective automation. One of its key features is the Ansible Playbook, which allows users to define a series of tasks to be executed on remote hosts. Most of them you can find by searching the subject, e. Handlers: running operations on change Sometimes you want a task to run only when a change is made on a machine. Ansible conditional statements practical examples. Sep 17, 2023 · In Ansible, conditionals offer control in playbooks, allowing tasks, plays, or even entire roles to be executed or skipped based on certain conditions Jan 28, 2023 · In Ansible, many tasks need only be run in certain conditions, especially these using Ansible’s command or shell modules (which require further input as to when they’re supposed to run, whether they’ve changed anything after they’ve been run, or when they’ve failed to run). You're welcome. Jun 13, 2023 · From docs: changed_when - This lets you determine, based on return codes or output, whether a change should be reported in Ansible statistics and whether a handler should be triggered or not. changed_when marks the task as changed based on the evaluation of the conditional statement which in your case is: "command_result. Use the creates or removes argument. Multiple Playbooks examples for when, changed_when and failed_when Feb 7, 2025 · Ansible register condition Tasks do not always have the state option, so it becomes difficult to ensure idempotency when the playbook is run multiple times. Oct 8, 2024 · I would like to know if it's possible with Ansible to test 2 values in a when condition that are changed in the loop. Apr 30, 2021 · Controlling What Defines Failure ¶ Ansible lets you define what “failure” means in each task using the failed_when conditional. Apr 30, 2024 · Here are several practical examples of using the when functionality in Ansible to only run the tasks when certain conditions are matched. mobile@gmail. The issue is using a register at the same time that the with_items generates a list of results. For Red Hat Ansible Automation Platform subscriptions, see Life Cycle for version details. Handlers are tasks that only run when notified. For example, you may want to: Trigger a service restart only on config file change Run task only on specific hosts by type or version. Only install packages Apr 15, 2021 · In Ansible, you can define conditions that will be evaluated before a task is executed. Feb 24, 2024 · In this post, we are going to see how to use conditional statements of Ansible such as when, changed_when, failed_when and where to use them appropriately and how it works. com napisał: Mar 12, 2025 · Learn how to use Ansible conditionals to improve automation workflows. When a condition is not met, the task is then skipped. . Eg. Optimize your playbooks with this detailed guide. Important: The ansible-core 2. So for that I have to parse the output and look for a « Done ». Basically I am making a playbook to do automated system patch I want to evaluate multiple condition in ansible using when, here is my playbook: - name: Check that the SSH Key exists local_action: module: stat path: "/home/{{ login_user. See how to use AND, OR, and NOT operators for multiple conditions. If you stick with bool s rather than strings, use Laurent’s suggestion and use the truthy test. Mar 15, 2025 · Yes, both changed_when and failed_when can be used in a single task to control how a task's result is interpreted and whether it should be marked as changed or failed. Or a playbook which clones a git repository and only restarts a service if the git repository has changed. To understand how changed_when works, we will use the below example. - name: opatch_direct | Export the Post-change Impact Score for for {{ db_name }} Aug 21, 2015 · Is it possible to change a role variable default value according to some condition (i. However, the quickest way is using ansible-doc. e. I was trying to simplify it by adding with_items; however, it seems to change the way it is evaluated?. Instead of writing the same task multiple times with slight variations, you can use loops to iterate over a list of items and perform the task (s) accordingly. Aug 22, 2025 · Learn to use when statements to run tasks conditionally, block statements to implement exception handling and Ansible handlers to trigger tasks upon change. disksizefromjson is a variable that I extracted from a json file (and this valu Learn what Ansible conditionals are with examples for when and register. The following example defines two variables: create_user_file and user. The Ansible register conditional ensures the Jan 9, 2024 · Control structures are mainly of the following two types Conditional & Iterative. Mar 18, 2024 · Ansible is an open-source automation tool that enables system management and configuration. They support decision-making and provide a way to take specific actions based on the outcomes of commands or tasks. When the condition in Ansible makes only certain conditions are met, making playbooks more dynamic and adaptable. This is done with the when keyword, which accepts expressions that are typically based on a variable or a fact. Learn how to use conditionals in Ansible to dynamically control task execution. Ansible uses handlers to address this use case. It is the command module causing the changed state, not the register parameter. if the task does not modify anything, it should return ok instead of changed. Jan 22, 2018 · The commented section of the following code works. stdout == 'Ignoring failure'" So whenever this condition is true, the task will be marked as changed. And I don't find a way to access the stdout of the current loop iteration. You can set changed_when: to something that is only true when something changed (also look at failed_when). Nov 1, 2024 · Ansible Playbook: Mastering the ‘changed_when’ Condition for Efficient Task Execution In the realm of IT automation, Ansible stands out as a powerful tool that simplifies the management of complex systems. at least that is my guess based on the verbosity: ` skipping: [ansible-oel6] => (item=ansible) => { “changed”: false, “item”: “ansible”, “skip_reason”: “Conditional result was False” } ` Playbook. I'm probably not going to use Ansible to help me list unresponsive IP addresses, but why does Ansible register the data when the condition for doing so was false? Looks like it even knows it was false and did it Jul 30, 2015 · I think you may have misinterpreted what changed_when does. Conditionals are an important part of Ansible playbooks. Within these playbooks, the changed_when condition is a Sep 3, 2022 · I added some references. For example, a playbook which downloads a remote key for package signing but only executes the apt-add command if the key has changed. ru kmuqh vcv2 rvv oov2m c4w7w2 uvddf7 be3b qcc9 dasf