{"id":21819,"date":"2023-08-26T03:12:13","date_gmt":"2023-08-26T03:12:13","guid":{"rendered":"https:\/\/www.devopsschool.com\/blog\/?p=21819"},"modified":"2023-08-26T03:26:24","modified_gmt":"2023-08-26T03:26:24","slug":"ansible-template-and-handlers-explained-with-example","status":"publish","type":"post","link":"https:\/\/www.devopsschool.com\/blog\/ansible-template-and-handlers-explained-with-example\/","title":{"rendered":"Ansible Template and Handlers explained with Example"},"content":{"rendered":"\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"688\" src=\"https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2023\/08\/image-355-1024x688.png\" alt=\"\" class=\"wp-image-38206\" srcset=\"https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2023\/08\/image-355-1024x688.png 1024w, https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2023\/08\/image-355-300x201.png 300w, https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2023\/08\/image-355-768x516.png 768w, https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2023\/08\/image-355.png 1251w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"306\" src=\"https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2023\/08\/image-354-1024x306.png\" alt=\"\" class=\"wp-image-38205\" srcset=\"https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2023\/08\/image-354-1024x306.png 1024w, https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2023\/08\/image-354-300x90.png 300w, https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2023\/08\/image-354-768x230.png 768w, https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2023\/08\/image-354-1536x459.png 1536w, https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2023\/08\/image-354.png 1608w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p><strong>We can declare variables in<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>playbook<\/li>\n\n\n\n<li>inventory<\/li>\n\n\n\n<li>commands<\/li>\n<\/ul>\n\n\n\n<p><strong>Which can be used &amp; Intropolate only in playbook Tasks but not in the files used in playbook.<\/strong><\/p>\n\n\n\n<p><strong>Solution: Template<\/strong><br>Using Template module you can Intropolate vars mentioned in the files used in playbook.<\/p>\n\n\n\n<p><strong>Rule for using template Module<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>A file must be .j2 ext<\/li>\n\n\n\n<li>Must use a module call &#8220;template&#8221;<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Example Code for Cento\/RHEL<\/h2>\n\n\n\n<hr class=\"wp-block-separator has-css-opacity\"\/>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-1\" data-shcb-language-name=\"JavaScript\" data-shcb-language-slug=\"javascript\"><span><code class=\"hljs language-javascript\">---\n- name: Update web servers\n  <span class=\"hljs-attr\">hosts<\/span>: web\n  <span class=\"hljs-attr\">vars<\/span>:\n    myname: <span class=\"hljs-string\">\"Rajesh Kumar\"<\/span>\n\n  <span class=\"hljs-attr\">tasks<\/span>:\n  - name: Install Apache <span class=\"hljs-keyword\">in<\/span> centos7\n    ansible.builtin.yum:\n      name: httpd\n      <span class=\"hljs-attr\">state<\/span>: latest\n  - name: Copy index.html\n    ansible.builtin.copy:\n      src: index.html\n      <span class=\"hljs-attr\">dest<\/span>: <span class=\"hljs-regexp\">\/var\/<\/span>www\/html\/index.html\n  - name: Template index.html\n    <span class=\"hljs-attr\">template<\/span>:\n      src: index.html.j2\n      <span class=\"hljs-attr\">dest<\/span>: <span class=\"hljs-regexp\">\/var\/<\/span>www\/html\/index-template.html\n  - name: Starting a Apache Server\n    ansible.builtin.service:\n      name: httpd\n      <span class=\"hljs-attr\">state<\/span>: started<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-1\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">JavaScript<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">javascript<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<h2 class=\"wp-block-heading\">index.html.j2<\/h2>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"708\" height=\"87\" src=\"https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2021\/06\/image-18.png\" alt=\"\" class=\"wp-image-21821\" srcset=\"https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2021\/06\/image-18.png 708w, https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2021\/06\/image-18-300x37.png 300w\" sizes=\"auto, (max-width: 708px) 100vw, 708px\" \/><\/figure>\n\n\n\n<p><strong>Project Requirement<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>When you Change APACHE STATIC HTML Content -&gt; HTTPD restart is not required<\/li>\n\n\n\n<li>When you Change APACHE Conf -&gt; HTTPD restart is not required<\/li>\n\n\n\n<li>HTTP should be run 90<\/li>\n\n\n\n<li>No restart should be done on STATIC<\/li>\n\n\n\n<li>Restart must be done at conf changes<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-css-opacity\"\/>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-2\" data-shcb-language-name=\"JavaScript\" data-shcb-language-slug=\"javascript\"><span><code class=\"hljs language-javascript\">---\n- name: Update web servers\n  <span class=\"hljs-attr\">hosts<\/span>: web\n  <span class=\"hljs-attr\">vars<\/span>:\n    myname: <span class=\"hljs-string\">\"Rajesh Kumar\"<\/span>\n    <span class=\"hljs-attr\">httpport<\/span>: <span class=\"hljs-number\">8090<\/span>\n\n  <span class=\"hljs-attr\">tasks<\/span>:\n  - name: Install Apache <span class=\"hljs-keyword\">in<\/span> centos7\n    ansible.builtin.yum:\n      name: httpd\n      <span class=\"hljs-attr\">state<\/span>: latest\n  - name: Copy index.html\n    ansible.builtin.copy:\n      src: index.html\n      <span class=\"hljs-attr\">dest<\/span>: <span class=\"hljs-regexp\">\/var\/<\/span>www\/html\/index.html\n  - name: Starting a Apache Server\n    ansible.builtin.service:\n      name: httpd\n      <span class=\"hljs-attr\">state<\/span>: started\n  - name: stopped a Apache Server\n    ansible.builtin.service:\n      name: httpd\n      <span class=\"hljs-attr\">state<\/span>: stopped\n  - name: Template <span class=\"hljs-keyword\">for<\/span> httpd.conf\n    <span class=\"hljs-attr\">template<\/span>:\n      src: httpd.conf.j2\n      <span class=\"hljs-attr\">dest<\/span>: <span class=\"hljs-regexp\">\/etc\/<\/span>httpd\/conf\/httpd.conf\n  - name: Starting a Apache Server\n    ansible.builtin.service:\n      name: httpd\n      <span class=\"hljs-attr\">state<\/span>: started\n\n<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-2\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">JavaScript<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">javascript<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<h2 class=\"wp-block-heading\">Example code for Template for Ubuntu<br><\/h2>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-3\" data-shcb-language-name=\"JavaScript\" data-shcb-language-slug=\"javascript\"><span><code class=\"hljs language-javascript\">---\n- name: Update web servers\n  <span class=\"hljs-attr\">hosts<\/span>: web\n  <span class=\"hljs-attr\">vars<\/span>:\n    myname: <span class=\"hljs-string\">\"Rajesh Kumar\"<\/span>\n    <span class=\"hljs-attr\">port<\/span>: <span class=\"hljs-number\">81<\/span>\n\n  <span class=\"hljs-attr\">tasks<\/span>:\n  - name: Install Apache <span class=\"hljs-keyword\">in<\/span> Ubuntu\n    ansible.builtin.apt:\n      name: apache2\n      <span class=\"hljs-attr\">state<\/span>: latest\n  - name: Copy index.html\n    ansible.builtin.copy:\n      src: index.html\n      <span class=\"hljs-attr\">dest<\/span>: <span class=\"hljs-regexp\">\/var\/<\/span>www\/html\/index.html\n  - name: stopped a Apache Server\n    ansible.builtin.service:\n      name: apache2\n      <span class=\"hljs-attr\">state<\/span>: stopped\n  - name: Template <span class=\"hljs-keyword\">for<\/span> httpd.conf\n    <span class=\"hljs-attr\">template<\/span>:\n      src: ports.conf.j2\n      <span class=\"hljs-attr\">dest<\/span>: <span class=\"hljs-regexp\">\/etc\/<\/span>apache2\/ports.conf\n  - name: Starting a Apache Server\n    ansible.builtin.service:\n      name: apache2\n      <span class=\"hljs-attr\">state<\/span>: started\n<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-3\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">JavaScript<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">javascript<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Problems<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>No change in config file but STOP and START happening<\/li>\n<\/ul>\n\n\n\n<p><strong>Solution<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Handlers<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">What is Handlers?<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>A section is plyabook similar to tasks section<\/li>\n\n\n\n<li>It contains multiple task similar to tasks section<\/li>\n\n\n\n<li>The Handler task would execute when you call from tasks&#8217;s task<\/li>\n\n\n\n<li>BUT one condition &#8211; ONLY when calling tasks&#8217;s task is CHANGED == TRUE<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"847\" height=\"706\" src=\"https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2023\/08\/image-356.png\" alt=\"\" class=\"wp-image-38208\" srcset=\"https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2023\/08\/image-356.png 847w, https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2023\/08\/image-356-300x250.png 300w, https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2023\/08\/image-356-768x640.png 768w\" sizes=\"auto, (max-width: 847px) 100vw, 847px\" \/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"529\" src=\"https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2023\/08\/image-357-1024x529.png\" alt=\"\" class=\"wp-image-38209\" srcset=\"https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2023\/08\/image-357-1024x529.png 1024w, https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2023\/08\/image-357-300x155.png 300w, https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2023\/08\/image-357-768x397.png 768w, https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2023\/08\/image-357.png 1162w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-css-opacity\"\/>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-4\" data-shcb-language-name=\"JavaScript\" data-shcb-language-slug=\"javascript\"><span><code class=\"hljs language-javascript\">---\n- name: Update web servers\n  <span class=\"hljs-attr\">hosts<\/span>: web\n  <span class=\"hljs-attr\">vars<\/span>:\n    myname: <span class=\"hljs-string\">\"Rajesh Kumar\"<\/span>\n    <span class=\"hljs-attr\">httpport<\/span>: <span class=\"hljs-number\">8090<\/span>\n\n  <span class=\"hljs-attr\">tasks<\/span>:\n  - name: Install Apache <span class=\"hljs-keyword\">in<\/span> centos7\n    ansible.builtin.yum:\n      name: httpd\n      <span class=\"hljs-attr\">state<\/span>: latest\n  - name: Copy index.html\n    ansible.builtin.copy:\n      src: index.html\n      <span class=\"hljs-attr\">dest<\/span>: <span class=\"hljs-regexp\">\/var\/<\/span>www\/html\/index.html\n  - name: Starting a Apache Server\n    ansible.builtin.service:\n      name: httpd\n      <span class=\"hljs-attr\">state<\/span>: started\n  - name: Template <span class=\"hljs-keyword\">for<\/span> httpd.conf\n    <span class=\"hljs-attr\">template<\/span>:\n      src: httpd.conf.j2\n      <span class=\"hljs-attr\">dest<\/span>: <span class=\"hljs-regexp\">\/etc\/<\/span>httpd\/conf\/httpd.conf\n    <span class=\"hljs-attr\">notify<\/span>:\n      - ReStarting a Apache Server\n\n  <span class=\"hljs-attr\">handlers<\/span>:\n  - name: ReStarting a Apache Server\n    ansible.builtin.service:\n      name: httpd\n      <span class=\"hljs-attr\">state<\/span>: restarted\n\n\n<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-4\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">JavaScript<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">javascript<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Handlers Code Example for Ubuntu<\/h2>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-5\" data-shcb-language-name=\"JavaScript\" data-shcb-language-slug=\"javascript\"><span><code class=\"hljs language-javascript\">---\r\n- name: Update web servers\r\n  <span class=\"hljs-attr\">hosts<\/span>: localhost\r\n  <span class=\"hljs-attr\">vars<\/span>:\r\n    myname: <span class=\"hljs-string\">\"Rajesh Kumar\"<\/span>\r\n    <span class=\"hljs-attr\">port<\/span>: <span class=\"hljs-number\">81<\/span>\r\n\r\n  <span class=\"hljs-attr\">tasks<\/span>:\r\n  - name: Install Apache <span class=\"hljs-keyword\">in<\/span> Ubuntu\r\n    ansible.builtin.apt:\r\n      name: apache2\r\n      <span class=\"hljs-attr\">state<\/span>: latest\r\n  - name: Copy index.html\r\n    ansible.builtin.copy:\r\n      src: index.html\r\n      <span class=\"hljs-attr\">dest<\/span>: <span class=\"hljs-regexp\">\/var\/<\/span>www\/html\/index.html\r\n  - name: Template <span class=\"hljs-keyword\">for<\/span> httpd.conf\r\n    <span class=\"hljs-attr\">template<\/span>:\r\n      src: ports.conf.j2\r\n      <span class=\"hljs-attr\">dest<\/span>: <span class=\"hljs-regexp\">\/etc\/<\/span>apache2\/ports.conf\r\n    <span class=\"hljs-attr\">notify<\/span>:\r\n      - ReStarting a Apache Server\r\n  - name: Starting a Apache Server\r\n    ansible.builtin.service:\r\n      name: apache2\r\n      <span class=\"hljs-attr\">state<\/span>: started\r\n\r\n  <span class=\"hljs-attr\">handlers<\/span>:\r\n  - name: ReStarting a Apache Server\r\n    ansible.builtin.service:\r\n      name: apache2\r\n      <span class=\"hljs-attr\">state<\/span>: restarted\r\n<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-5\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">JavaScript<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">javascript<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<script src=\"https:\/\/gist.github.com\/devops-school\/e8a5e9d9bb9cdc00e0229aaa71dc9e72.js\"><\/script>\n\n\n<div class=\"epyt-gallery\" data-currpage=\"1\" id=\"epyt_gallery_51409\"><figure class=\"wp-block-embed wp-block-embed-youtube is-type-video is-provider-youtube epyt-figure\"><div class=\"wp-block-embed__wrapper\"><iframe loading=\"lazy\"  id=\"_ytid_75715\"  width=\"760\" height=\"427\"  data-origwidth=\"760\" data-origheight=\"427\" src=\"https:\/\/www.youtube.com\/embed\/?enablejsapi=1&#038;autoplay=0&#038;cc_load_policy=0&#038;cc_lang_pref=&#038;iv_load_policy=1&#038;loop=0&#038;rel=1&#038;fs=1&#038;playsinline=0&#038;autohide=2&#038;theme=dark&#038;color=red&#038;controls=1&#038;disablekb=0&#038;\" class=\"__youtube_prefs__  no-lazyload\" title=\"YouTube player\"  data-epytgalleryid=\"epyt_gallery_51409\"  allow=\"fullscreen; accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen data-no-lazy=\"1\" data-skipgform_ajax_framebjll=\"\"><\/iframe><\/div><\/figure><div class=\"epyt-gallery-list\"><div>Sorry, there was a YouTube error.<\/div><\/div><\/div>","protected":false},"excerpt":{"rendered":"<p>We can declare variables in Which can be used &amp; Intropolate only in playbook Tasks but not in the files used in playbook. Solution: TemplateUsing Template module you can Intropolate vars mentioned in the files used in playbook. Rule for using template Module Example Code for Cento\/RHEL index.html.j2 Project Requirement Example code for Template for&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"_kad_post_classname":"","_joinchat":[],"footnotes":""},"categories":[2],"tags":[],"class_list":["post-21819","post","type-post","status-publish","format-standard","hentry","category-uncategorised"],"_links":{"self":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts\/21819","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/comments?post=21819"}],"version-history":[{"count":10,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts\/21819\/revisions"}],"predecessor-version":[{"id":38849,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts\/21819\/revisions\/38849"}],"wp:attachment":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/media?parent=21819"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/categories?post=21819"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/tags?post=21819"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}