Ansible define complex variables bookshelf

When you want to let a variable depend on another on or just on a fact, you can set the variable on the fly in the task using the variable. Like facts, registered variables are hostlevel variables. Lets walk through each one of them and a quick example in the inventory file variables can be assigned right along with the host definition in your inventory file. You can define custom variables for each group and host that you define. If the same variable is set by more than one group for a host, ansible has. Any variables that you define for a host or a group can be used in both playbooks and templates. Changing a deeplynested dict variable in an ansible playbook. A fundamental part of working with configuration management tools is the ability to handle different operating systems within the same logic stream, such as a module. How to define complex variable in inventory file of ansible stack. Because jinja2 will only process the template variables it is told to, it will leave other variables for ansible to define. How to define complex variable in inventory file of ansible. Creating an ansible static inventory with variables. As soon as you have defined a host, special functionality becomes available in ansible. If you want to get a lookup value once and use the same value for every task in a.

However, registered variables are only stored in memory. To understand variables youll also want to dig into conditionals and loops. Mandatory variable not defined since ansible 2 issue. Use this to check all of your common roles out to one location, and share them easily between multiple playbook projects. Ansible uses variables to enable more flexibility in playbooks and roles. Provisioning and managing complex server architecture across different environments can be a challenge.

This is explanation how to make a nice dump of the variables to a file residing on the remote host. Hello, im searching for a way, where i can compare a defined variable with a variable im greping from a file. I recently had to build an ansible playbook that takes in a massive inventory structure read from a yaml file, modifies a specific key in that file, then dumps the file back to disk. While you can do a lot of complex things in jinja, only the basics are things you really need to learn at first. Ansible will search for roles in the following way. The idea that variables are relative to a given host might sound confusing, since ansible allows you to define variables on a group of hosts. But sometimes you want to use a variable across multiple roles. However, it is also possible to nest variables and define lists of variables. So i found some workaround as i described in my this article. I was defining a slightly more complex variable to later be used in an ansible template. There is also need to define variables in playbook, which normally is used for operation. According to the official documentation you can define variables in the inventory the ini way with the following syntax keyvalue. This means that the data held within the variables value should be treated as unsafe preventing unsafe character substitution and information disclosure.

If your infrastructure is designed with multiple variables like serversprotocols are running on a custom port number then you have to use ansible variable to configure the static inventory. Using bash script variables with ansible playbooks it. Playbook roles and include statements ansible documentation. But what ansible is really doing is creating a copy of that variable. Registered variables are only valid on the host for the rest of the current playbook run. Variables in ansible are how we deal with differences between systems. I was happy to have a dictionary format that worked in both ansible and jinja2 in quotes because its a bit more complex than that, see the. Ive found a few challenges addressing this topic within ansible, and hence i think its worth noting certain things that you cant do, and i think is the most. The ansible bash script makes use of ansibles extravars feature which allows you to pass a variable into an ansible playbook from a bash shell script. Markus holtermann reference variables in ansible yaml.

These variables will have the lowest priority of any variables available, and can be easily overridden by any other variable, including inventory variables. Assuming you are using the default inventory file etcansiblehosts you need to create two additional. Another way to define variables is to call ansible playbooks with the option extravars. Today i found myself in a typical dry situation when working on an ansible role. Ansible facts are backed by whatever cache plugin you have configured. Howto reference ansible variables between plays ansibles strenght is to work with all kinds of devices and services in one go. Much like many other components of ansible, this relies on a default folder structure. For instance we have a common role that will set the security groups, vpc ids, and subnets. Ansible variables seem to have a global scope, because if i set one within the role it seems to be visible to all roles which surprised me as i was expecting roles to be more selfcontained since theyre supposed to be reusable, shared on galaxy, etc. Variables are key in ansible and when you know how to flexibly use variables, a whole lot of possibilities become available. Ansible uses variables to help deal with differences between systems. As part of the video, we will use the variable we define to tell ansible where we expect our website content directory to be created varvweb and take advantage of the ansible file module to actually create the expected directory on our target system. To properly call a variable value from one server while working on another host the variable needs to be referenced properly. Registered variables are similar to facts, with a few key differences.

Inside a role you can have tasks, files, handlers and variables. Again, there are also two ways to define ansible playbook specifical variables. How to manage multistage environments with ansible digitalocean. For example, if you define a variable in the vars section of a play, you are defining the variable for the set of hosts in the play. This method pulls in variables based on the clients os and uses those variables specific to that machines needs. To understand variables youll also want to read conditionals and loops. Common return values are documented here, the following are the fields unique to this lookup. Variables set by dynamic inventory are inventory variables. That means the lookup value could be different in different tasks. Howto reference ansible variables between plays home.

In a playbook, its possible to define variables directly inline like so. Ansibles immaturity compared to chefpuppet really shows when talking about the prioritized variable loading facts. And thats not covering passing extra variables via command line, inventory variables, or system facts. You can do this using a jinja template which you could include in a debug task, like so. Howto introduction to ansible variables homeliquidat. They can be used to loop through a set of given values, access various information like the hostname of a system and replace certain strings in templates by system specific values. Step 2 defining nested variables for complex configuration. How to compare parameters of two defined variables. In the chef world we had about 4 different places to store attributes with 3 different priorities. Ansible allows you to reference variables in your playbooks using the jinja2 templating system. Managing multiple servers with ansible groups low end box. Ansible roles an ultimate way to solve your confusion with.

In simple terms, ansible enables you to define your infrastructure as code in a simple declarative manner. Inventory is used to define the hierarchy of hosts and the groups to which they belong. Ansible provides an internal data type for declaring variable values as unsafe. I use this approach to query an elaborate aws cluster, and then preprocess the. In this section, we will look at nesting variables for complex configuration options. I put together the following gist as an example of how to assign complex vars to variables or facts in ansible. This ordering is so important for organization and design that this page was one of two pages i had new people read and bookmark. Roles can take advantage of these variables as well, of course. Ansible works based on your inventory and it will execute the tasks in multiple systems in your infrastructure at the same time. How to deploy multiple php applications using ansible on. There are some other ways that may be more efficient standalone e. Working with lists and dictionary variables in ansible. If you notice any issues in this documentation, you can edit this document to.

Role default variables allow you to set default variables for included or dependent roles see below. Accessing information about other hosts with magic variables. All roles are referencing the same named variable are sharing the same global variable. To become more flexible, ansible offers the possibility to use variables in loops, but also to use information the target system provides. Variable of variable in ansible playbook techieroop. Weve discovered a subtle difference between how ansible variables and facts work. While developing ansible playbook for my on project i have some one usecase regarding use variable of variable in ansible playbook. Changing a deeplynested dict variable in an ansible. You also can specify group variables or host variables that will help. Ansible evaluates lookups for a variable every time that variable is used in the task at the time the task is run. One way that ive solved a similar issue is to create starter roles, that can have other roles layered on them. We wanted a way to reboot a specific juniper router that would be easy for the user to manage. List all ansible variables for a host or group with an ad. Ansible dump all variables in a file bugbear thoughts.

Host variables validation in ansible david schweikert. In ansible, you may need to perform multiple actions that notify a common handler. Variables one of the ways to make playbooks more generic is to use ansible variables. These variables can be defined in your playbook, but its a good habit to define them in. In ansible, as we have seen in previous videos, you can declare define variables in numerous places. How specify a list value as variable in ansible inventory. If the compared variable equals the grep variable, it. Handling different operating systems with variables. Of course we could also define the list you were walking over in another file, like a groupvarswebservers file to define all the variables needed for the webservers group. Ansible is a powerful configuration management system used to set up and. The inventory source can be a file, or a script, or a directory containing such files and scripts. If you want to print multipleall variables in a more convenient way by seeing them directly on the console, you might be interested in this.

Define variables for all hosts in ansible dynamic inventory. Hello, i use ansible to run tasks in remote machine, i want to work with variables from this remote machine. Takes dictionaries as input and returns a list with each item in the list being a dictionary with key and value as keys to the previous dictionarys structure. Unfortunately ansible doesnt have really a concept of global vars, but there is a trick you can define group variables for all groups, that is indeed like a global variable. Note however that setting variables directly in the inventory is not the preferred practice in ansible. Its nice enough to know about how to define variables, but how do you use them.