--- title: Ansible Release 12: the Windows Vista Moment «... description: Ansible release 12 introduces multiple breaking changes that turn existing playbooks into ticking time bombs. Key issues include: `when` conditions now require... canonical: https://daily.dev/posts/ansible-release-12-the-windows-vista-moment-ipspace-net-blog-4bqzp7kqd twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Ansible Release 12: the Windows Vista Moment « ipSpace.net blog | daily.dev og:description: Ansible release 12 introduces multiple breaking changes that turn existing playbooks into ticking time bombs. Key issues include: `when` conditions now require... og:url: https://daily.dev/posts/ansible-release-12-the-windows-vista-moment-ipspace-net-blog-4bqzp7kqd og:image: https://api.daily.dev/og/posts/4BQZP7Kqd.png og:image:alt: Ansible Release 12: the Windows Vista Moment « ipSpace.net blog og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Ansible Release 12: the Windows Vista Moment « ipSpace.net blog **[ipSpace.net Blog](https://daily.dev/sources/ipspace)** · 5 min read · 0 upvotes · 0 comments ## Summary Ansible release 12 introduces multiple breaking changes that turn existing playbooks into ticking time bombs. Key issues include: `when` conditions now require strict True/False boolean results instead of Python-truthy values; Jinja2 macros returning no text now return None instead of an empty string; tests on undefined variables now throw errors instead of returning False; some built-in filters like `ipaddr` must now use fully-qualified domain names (e.g., `ansible.utils.ipaddr`); and critically, device configuration modules like `ios_config` and `eos_config` no longer render Jinja2 templates in the `src` parameter, instead pushing raw Jinja2 code to network devices. The author compares the release to Windows Vista for its disruptive scope of behavioral changes. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### What breaking changes does Ansible 12 introduce for `when` conditions in playbooks? Ansible 12 requires `when` conditions to produce a strict True/False boolean result. Previously, Python-truthy values like non-empty strings were accepted. Because Python's `and`/`or` operators return the value of an operand rather than a boolean, most compound `when` expressions now silently produce non-boolean results. The fix is to use explicit checks like `x is string and x != ''` or the `truthy` test on every `when` expression. _Teams migrating Ansible playbooks track breaking changes like these on daily.dev before they hit production._ ### Why does `ipaddr` filter throw an error in Ansible 12 and how do I fix it? In Ansible 12, the short-form `ipaddr` filter no longer works and throws an error. You must use the fully-qualified name `ansible.utils.ipaddr` instead. Notably, this change is not documented in the official Ansible 12 Porting Guide. Interestingly, module short names like `ios_config` still work without their FQDN equivalent, making the inconsistency hard to predict. _Ansible network automation engineers catching undocumented filter renames find the community discussion on daily.dev useful._ ### Do ios_config and eos_config modules still render Jinja2 templates from the `src` parameter in Ansible 12? No — in Ansible 12, `ios_config` and `eos_config` modules no longer render Jinja2 templates specified in the `src` parameter. Instead, they push the raw Jinja2 code directly to the device, which causes failures. Installing `ansible.netcommon` 8.1.0 and `arista.eos` 12.0.0 on top of Ansible 11.10 works correctly, suggesting the regression is in Ansible core rather than the collection modules. _Network engineers deciding whether to upgrade Ansible for device automation follow regression reports like this on daily.dev._ ## Similar posts on daily.dev - [How to collaborate with AI to improve your Ansible skills](https://daily.dev/posts/how-to-collaborate-with-ai-to-improve-your-ansible-skills-izxeypqlm) · Red Hat Developer · 0 upvotes · 0 comments - [netlab 26.09: Syslog, More DNS, Netmiko « ipSpace.net blog](https://daily.dev/posts/netlab-26-09-syslog-more-dns-netmiko-ipspace-net-blog-7hzbp4smq) · ipSpace.net Blog · 0 upvotes · 0 comments - [Ansible Security Automation: Risks & 7 Best Practices](https://daily.dev/posts/ansible-security-automation-risks-7-best-practices-lvgbynirc) · Spacelift · 2 upvotes · 0 comments --- Tags: [#networking](https://daily.dev/tags/networking), [#ansible](https://daily.dev/tags/ansible) [View this post on daily.dev](https://daily.dev/posts/ansible-release-12-the-windows-vista-moment-ipspace-net-blog-4bqzp7kqd) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Ansible Release 12: the Windows Vista Moment « ipSpace.net blog","url":"https://daily.dev/posts/ansible-release-12-the-windows-vista-moment-ipspace-net-blog-4bqzp7kqd","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/ansible-release-12-the-windows-vista-moment-ipspace-net-blog-4bqzp7kqd"},"datePublished":"2026-08-11T08:54:54.000Z","dateModified":"2026-08-24T06:51:08.667Z","description":"Ansible release 12 introduces multiple breaking changes that turn existing playbooks into ticking time bombs. 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