{"id":1199,"date":"2024-03-22T08:20:28","date_gmt":"2024-03-22T08:20:28","guid":{"rendered":"http:\/\/shijuvarghese.com\/?p=1199"},"modified":"2024-03-23T07:49:18","modified_gmt":"2024-03-23T07:49:18","slug":"ansible-blocks-and-error-handling","status":"publish","type":"post","link":"http:\/\/shijuvarghese.com\/?p=1199","title":{"rendered":"Ansible – Blocks, Rescue and Error Handling"},"content":{"rendered":"

Usually the Handlers work with a single task. However the “blocks<\/strong>” feature in Ansible helps us to group multiple tasks under one block<\/strong> section and attach handlers or rescue feature to it.<\/p>\n

In the below example the Block and Rescue feature will be used to display a message if one of the task out of two fails. Please note that the\u00a0httpd<\/strong> service is\u00a0NOT<\/strong> installed. Therefore the ansible task to start the httpd service will\u00a0fail<\/strong>.<\/p>\n

[root@centos9vm ~]#<\/strong> cat block_n_rescus.yml<\/p>\n

==== ====
\n– – –<\/em>
\n– name: Copy a file to managed node if the httpd server that is stopped in present state is started by the play book<\/em>
\n     hosts: 192.168.48.129<\/em>
\n     tasks:<\/em>
\n         – name: A Block of tasks<\/em>
\n             block:<\/strong><\/em>
\n                 – name: Restart httpd server<\/em>
\n                     ansible.builtin.service:<\/em>
\n                         name: httpd<\/em>
\n                         state: started<\/em>
\n                         enabled: false<\/em><\/p>\n

                – name: Copy Index file<\/em>
\n                     ansible.builtin.copy:<\/em>
\n                         src: shiju.html<\/em>
\n                         dest: \/var\/www\/html\/index.html<\/em>
\n             rescue:<\/strong><\/em>
\n                 – name: Error messahe when error identified<\/em>
\n                     ansible.builtin.debug:<\/em>
\n                         msg: “An error was seen on block”<\/em><\/p>\n

==== ===<\/p>\n

Let us execute the playbook and see if the message in\u00a0rescue<\/strong> section is displayed<\/p>\n

[root@centos9vm ~]#<\/strong> ansible-navigator run -m stdout block_n_rescus.yml<\/p>\n

======= ====
\nPLAY [Copy a file to managed node if the httpd server that is stopped in present state is started by the play book] ***<\/em><\/p>\n

TASK [Gathering Facts] *********************************************************<\/em><\/p>\n

ok: [192.168.48.129]<\/em><\/p>\n

TASK [Restart httpd server] ****************************************************<\/em>
\nfatal: [192.168.48.129]: FAILED! => {“changed”: false, “msg”: “Could not find the requested service httpd: host”}<\/em><\/p>\n

TASK [Error messahe when error identified] *************************************<\/em>
\nok: [192.168.48.129] => {<\/em>
\n “msg”: “An error was seen on block”<\/span><\/em>
\n}<\/em><\/p>\n

PLAY RECAP *********************************************************************<\/em>
\n192.168.48.129 : ok=2 changed=0 unreachable=0 failed=0 skipped=0 rescued=1 ignored=0<\/em>
\n==== ====<\/p>\n

Now let us install the httpd service<\/em> and then re-execute the playbook. As the service is present, all tasks should get executed without any error, and therefore the\u00a0rescue<\/strong> section should not get called.<\/p>\n

[root@centos9vm ~]#<\/strong> ssh 192.168.48.129 ‘dnf install httpd -y’<\/p>\n

[root@centos9vm ~]#<\/strong> ansible-navigator run -m stdout block_n_rescus.yml<\/p>\n

======= ===<\/p>\n

PLAY [Copy a file to managed node if the httpd server that is stopped in present state is started by the play book] ***<\/em><\/p>\n

TASK [Gathering Facts] *********************************************************<\/em>
\nok: [192.168.48.129]<\/em><\/p>\n

TASK [Restart httpd server] ****************************************************<\/em>
\nchanged: [192.168.48.129]<\/em><\/p>\n

TASK [Copy Index file] *********************************************************<\/em>
\nok: [192.168.48.129]<\/em><\/p>\n

PLAY RECAP *********************************************************************<\/em>
\n192.168.48.129 : ok=3 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0<\/em>
\n=== ==== ===<\/p>\n","protected":false},"excerpt":{"rendered":"

Usually the Handlers work with a single task. However the “blocks” feature in Ansible helps us to group multiple tasks under one block section and […]<\/a><\/p>\n<\/div>","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[32,21,3],"tags":[],"class_list":["post-1199","post","type-post","status-publish","format-standard","hentry","category-ansible","category-devops","category-linux"],"_links":{"self":[{"href":"http:\/\/shijuvarghese.com\/index.php?rest_route=\/wp\/v2\/posts\/1199","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/shijuvarghese.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/shijuvarghese.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/shijuvarghese.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/shijuvarghese.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1199"}],"version-history":[{"count":12,"href":"http:\/\/shijuvarghese.com\/index.php?rest_route=\/wp\/v2\/posts\/1199\/revisions"}],"predecessor-version":[{"id":1220,"href":"http:\/\/shijuvarghese.com\/index.php?rest_route=\/wp\/v2\/posts\/1199\/revisions\/1220"}],"wp:attachment":[{"href":"http:\/\/shijuvarghese.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1199"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/shijuvarghese.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1199"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/shijuvarghese.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1199"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}