如果不满足某些条件，如何跳过ansible剧本中的所有其他剧本?

本文介绍了如果不满足某些条件，如何跳过ansible剧本中的所有其他剧本?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我在下面的剧本中有多个剧本.如果不满足某些条件，我想忽略所有其他播放.

因此对于下面的示例-如果在Play1中找不到任何新文件，那么我根本就不想执行Play2和Play3(应该跳过它).我该怎么办?

我在Play1中有end_play，但它只跳过了Play1，它仍然执行Play2和Play3

--- - name: Play 1 hosts: 127.0.0.1 tasks: - name: find the latest file find: paths=/var/lib/jenkins/jobs/process/workspace/files file_type=file age=-1m age_stamp=mtime register: files - meta: end_play when: files.files|count == 0 - name: Copy file, if found copy: src: "some stuff here" dest: "some other stuff here" when: files.files|count > 0 - name: Play 2 hosts: all serial: 5 tasks: - name: copy latest file copy: src=data_init/goldy.init.qa dest=/data01/admin/files/goldy.init.qa owner=golden group=golden - name: copy latest file copy: src=data_init/goldy.init.qa dest=/data02/admin/files/goldy.init.qa owner=golden group=golden - name: Play 3 hosts: 127.0.0.1 tasks: - name: execute command shell: ./data_init --init_file ./goldy.init.qa args: chdir: /var/lib/jenkins/jobs/process/workspace/data_init/

更新:

所以块模块解决方案看起来不起作用，因为您不能像这样那样在块中使用嵌套播放.

解决方案

有两种方法可以解决您的问题:

虽然您可以尝试定义hosts: localhost以便在控制器上运行某些任务，这是可以理解的，但实际上并不需要它.使用 delegate_to: localhost 和 run_once: true 关于要在控制器上运行的步骤要好得多方法.

如果出于某种原因，您真的想使用hosts: localhost进行这种操作，则需要使用 set_fact ，以便借助全局 hostvars

使用委托

剧中的任何任务都可以委派给另一位主持人.这非常简单，只需在任务中使用一个额外的delegate_to选项:

- name: Delegate a find to localhost find: path: /test file_type: any register: localhost_find delegate_to: localhost run_once: true

这样做时，我建议您也使用run_once: true，因为如果将任务委派给另一台主机，则无需这样做，也就是说，如果主机组中有十台主机，则运行十次

这是一个有关此的小例子

--- - hosts: hosts become: true gather_facts: false tasks: - name: Delegate directory creation to localhost file: path: /test state: directory delegate_to: localhost run_once: true - name: Create directory on hosts file: path: /test state: directory - name: Delegate file creation to localhost file: path: /test/localhost.txt state: touch delegate_to: localhost run_once: true - name: Create file on hosts file: path: /test/host.txt state: touch - name: Delegate a find to localhost find: path: /test file_type: any register: localhost_find delegate_to: localhost run_once: true - name: Find in the hosts for comparison find: path: /test file_type: any register: host_find - name: List /test of localhost debug: msg: "{{ localhost_find.files | map(attribute='path') | list }}" - name: List /test of host debug: msg: "{{ host_find.files | map(attribute='path') | list }}" - name: Remove /test folder on localhost file: path: /test state: absent delegate_to: localhost run_once: true - name: Delegate an empty find to localhost find: path: /test file_type: any register: empty_find delegate_to: localhost run_once: true - name: Here are our hostnames from the inventory debug: msg: "{{ inventory_hostname }}" - name: I am the evil host killer meta: end_host when: empty_find.files | count == 0 and inventory_hostname != 'host1' - debug: msg: "I am a sad message, because I will never display :'( But hopefully host1 likes me :')" - name: I am the evil playbook killer meta: end_play when: empty_find.files | count == 0 - debug: msg: "I am a sad message, because I will never display :'( No one likes me..."

在哪里可以看到，当我在上一步的主机组中拥有三台主机中的两台时，我通过结束播放跳过了最后一条调试消息.

该剧本的输出:

PLAY [hosts] ************************************************************************************************************************** TASK [Delegate directory creation to localhost] *************************************************************************************** ok: [host1 -> localhost] TASK [Create directory on hosts] **************************************************************************************************** ok: [host3] ok: [host2] ok: [host1] TASK [Delegate file creation to localhost] ******************************************************************************************** changed: [host1 -> localhost] TASK [Create file on hosts] **************************************************************************************************** changed: [host2] changed: [host1] changed: [host3] TASK [Delegate a find to localhost] *************************************************************************************************** ok: [host1 -> localhost] TASK [Find in the host for comparison] ************************************************************************************************ ok: [host1] ok: [host3] ok: [host2] TASK [List /test of localhost] ******************************************************************************************************** ok: [host1] => { "msg": [ "/test/localhost.txt" ] } ok: [host2] => { "msg": [ "/test/localhost.txt" ] } ok: [host3] => { "msg": [ "/test/localhost.txt" ] } TASK [List /test of host] ************************************************************************************************************* ok: [host1] => { "msg": [ "/test/host.txt" ] } ok: [host2] => { "msg": [ "/test/host.txt" ] } ok: [host3] => { "msg": [ "/test/host.txt" ] } TASK [Remove /test folder on localhost] *********************************************************************************************** changed: [host1 -> localhost] TASK [Delegate an empty find to localhost] ******************************************************************************************** ok: [host1 -> localhost] TASK [Here are our hostnames from the inventory] ************************************************************************************** ok: [host1] => { "msg": "host1" } ok: [host2] => { "msg": "host2" } ok: [host3] => { "msg": "host3" } TASK [debug] ************************************************************************************************************************** ok: [host1] => { "msg": "I am a sad message, because I will never display :'( But hopefully host1 likes me :')" } PLAY RECAP **************************************************************************************************************************** host1 : ok=12 changed=3 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0 host2 : ok=6 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0 host3 : ok=6 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0

在输出中，您可以轻松地发现委托，就像输出

changed: [host1 -> localhost]

当未委派的任务刚开始时

changed: [host1]

使用hostvars

我要说的是，这种方法比现有技术要少一些，但是如果您想委托边缘案例，它可能会派上用场.我以前使用过它，所以这并不是说不可能以正确的解决方案结束它.

这里是例子

--- - hosts: localhost gather_facts: false tasks: - name: Find in localhost find: path: /not/existing/folder file_type: any register: find - name: This will register the list under find.files as a variable on the host, making it accessible via hostvars set_fact: find_result: "{{ find.files }}" - meta: end_play when: find.files | count == 0 - debug: msg: I am the sanity check message, proving the end_play did happen - hosts: hosts gather_facts: false tasks: - name: Just to show we are not cheating with an empty host group, we display the hosts names debug: msg: "{{ inventory_hostname }}" - name: To show it is really our empty list and not an empty string or a null variable debug: msg: "{{ hostvars['localhost']['find_result'] }}" - meta: end_play when: "hostvars['localhost']['find_result'] | count == 0" - debug: msg: I am a first sanity check message, proving the end_play did happen - debug: msg: I am a second sanity check message, proving the end_play did happen - hosts: localhost gather_facts: false tasks: - name: To show it is really our empty list and not an empty string or a null variable debug: msg: "{{ hostvars['localhost']['find_result'] }}" - meta: end_play when: "hostvars['localhost']['find_result'] | count == 0" - debug: msg: I am a first sanity check message, proving the end_play did happen - debug: msg: I am a second sanity check message, proving the end_play did happen

您可以看到，在主机的每个新任务组的开头，我只是运行meta以结束播放，这是基于find结果中注册的变量find_result

这是这一个的输出

PLAY [localhost] ********************************************************************************************************************** TASK [Find in localhost] ************************************************************************************************************** ok: [localhost] TASK [This will register the list under find.files as a variable on the host, making it accessible via hostvars] ********************* ok: [localhost] PLAY [hosts] ************************************************************************************************************************** TASK [Just to show we are not cheating with an empty host group, we display the hosts names] ****************************************** ok: [host1] => { "msg": "host1" } ok: [host2] => { "msg": "host2" } ok: [host3] => { "msg": "host3" } TASK [To show it is really our empty list and not an empty string or a null variable] ************************************************ ok: [host1] => { "msg": [] } ok: [host2] => { "msg": [] } ok: [host3] => { "msg": [] } PLAY [localhost] ********************************************************************************************************************** TASK [To show it is really our empty list and not an empty string or a null variable] ************************************************ ok: [localhost] => { "msg": [] } PLAY RECAP **************************************************************************************************************************** host1 : ok=2 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0 host2 : ok=2 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0 host3 : ok=2 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0 localhost : ok=3 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0

I have multiple plays in below playbook. I want to ignore all other plays if some condition is not met.

So for below example - If I cannot find any new file in Play1 then I don't want to execute Play2 and Play3 at all (it should skip it). How can I do that?

I have end_play in Play1 but it only skips Play1 and it still executes Play2 and Play3

--- - name: Play 1 hosts: 127.0.0.1 tasks: - name: find the latest file find: paths=/var/lib/jenkins/jobs/process/workspace/files file_type=file age=-1m age_stamp=mtime register: files - meta: end_play when: files.files|count == 0 - name: Copy file, if found copy: src: "some stuff here" dest: "some other stuff here" when: files.files|count > 0 - name: Play 2 hosts: all serial: 5 tasks: - name: copy latest file copy: src=data_init/goldy.init.qa dest=/data01/admin/files/goldy.init.qa owner=golden group=golden - name: copy latest file copy: src=data_init/goldy.init.qa dest=/data02/admin/files/goldy.init.qa owner=golden group=golden - name: Play 3 hosts: 127.0.0.1 tasks: - name: execute command shell: ./data_init --init_file ./goldy.init.qa args: chdir: /var/lib/jenkins/jobs/process/workspace/data_init/

Update:

So block module solution doesn't work looks like because you cannot use nested play in block like that..

解决方案

There are two ways to approach your issue:

Although it is understandable that you tried defining a hosts: localhost to run some tasks on the controller, you don't really need this. Using delegate_to: localhost and run_once: true on the steps you want to run on your controller is a far better approach.

If you really want to go this way (using hosts: localhost), for some reason, then you'll need to save the return of your find, with set_fact in order to reuse it in other hosts with the help of the global hostvars

Using delegation

Any task in the play can be delegated to another host. This is quite simple to do and would just use one extra delegate_to options on your task:

- name: Delegate a find to localhost find: path: /test file_type: any register: localhost_find delegate_to: localhost run_once: true

When doing so, I would advice you to also use run_once: true, because, if you delegate the task to another host, there is no need to, let's say run it ten times if you have ten hosts in your host group.

Here is a little example about that

--- - hosts: hosts become: true gather_facts: false tasks: - name: Delegate directory creation to localhost file: path: /test state: directory delegate_to: localhost run_once: true - name: Create directory on hosts file: path: /test state: directory - name: Delegate file creation to localhost file: path: /test/localhost.txt state: touch delegate_to: localhost run_once: true - name: Create file on hosts file: path: /test/host.txt state: touch - name: Delegate a find to localhost find: path: /test file_type: any register: localhost_find delegate_to: localhost run_once: true - name: Find in the hosts for comparison find: path: /test file_type: any register: host_find - name: List /test of localhost debug: msg: "{{ localhost_find.files | map(attribute='path') | list }}" - name: List /test of host debug: msg: "{{ host_find.files | map(attribute='path') | list }}" - name: Remove /test folder on localhost file: path: /test state: absent delegate_to: localhost run_once: true - name: Delegate an empty find to localhost find: path: /test file_type: any register: empty_find delegate_to: localhost run_once: true - name: Here are our hostnames from the inventory debug: msg: "{{ inventory_hostname }}" - name: I am the evil host killer meta: end_host when: empty_find.files | count == 0 and inventory_hostname != 'host1' - debug: msg: "I am a sad message, because I will never display :'( But hopefully host1 likes me :')" - name: I am the evil playbook killer meta: end_play when: empty_find.files | count == 0 - debug: msg: "I am a sad message, because I will never display :'( No one likes me..."

Where you can see, that, I am skipping the very last debug message by ending the play, when I ended two out of the three hosts I have in my hosts group on the step before.

Output of that playbook:

PLAY [hosts] ************************************************************************************************************************** TASK [Delegate directory creation to localhost] *************************************************************************************** ok: [host1 -> localhost] TASK [Create directory on hosts] **************************************************************************************************** ok: [host3] ok: [host2] ok: [host1] TASK [Delegate file creation to localhost] ******************************************************************************************** changed: [host1 -> localhost] TASK [Create file on hosts] **************************************************************************************************** changed: [host2] changed: [host1] changed: [host3] TASK [Delegate a find to localhost] *************************************************************************************************** ok: [host1 -> localhost] TASK [Find in the host for comparison] ************************************************************************************************ ok: [host1] ok: [host3] ok: [host2] TASK [List /test of localhost] ******************************************************************************************************** ok: [host1] => { "msg": [ "/test/localhost.txt" ] } ok: [host2] => { "msg": [ "/test/localhost.txt" ] } ok: [host3] => { "msg": [ "/test/localhost.txt" ] } TASK [List /test of host] ************************************************************************************************************* ok: [host1] => { "msg": [ "/test/host.txt" ] } ok: [host2] => { "msg": [ "/test/host.txt" ] } ok: [host3] => { "msg": [ "/test/host.txt" ] } TASK [Remove /test folder on localhost] *********************************************************************************************** changed: [host1 -> localhost] TASK [Delegate an empty find to localhost] ******************************************************************************************** ok: [host1 -> localhost] TASK [Here are our hostnames from the inventory] ************************************************************************************** ok: [host1] => { "msg": "host1" } ok: [host2] => { "msg": "host2" } ok: [host3] => { "msg": "host3" } TASK [debug] ************************************************************************************************************************** ok: [host1] => { "msg": "I am a sad message, because I will never display :'( But hopefully host1 likes me :')" } PLAY RECAP **************************************************************************************************************************** host1 : ok=12 changed=3 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0 host2 : ok=6 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0 host3 : ok=6 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0

In the output, you can easily spot the delegation, as is will output

changed: [host1 -> localhost]

When a non-delegated task would just go

changed: [host1]

Using hostvars

I would say the approach is a little bit less state of the art, but could become handy if you would like to delegate on edge cases. I have used it before, so it is not like there is no situation where it could not end up has being the right solution.

Here is the example

--- - hosts: localhost gather_facts: false tasks: - name: Find in localhost find: path: /not/existing/folder file_type: any register: find - name: This will register the list under find.files as a variable on the host, making it accessible via hostvars set_fact: find_result: "{{ find.files }}" - meta: end_play when: find.files | count == 0 - debug: msg: I am the sanity check message, proving the end_play did happen - hosts: hosts gather_facts: false tasks: - name: Just to show we are not cheating with an empty host group, we display the hosts names debug: msg: "{{ inventory_hostname }}" - name: To show it is really our empty list and not an empty string or a null variable debug: msg: "{{ hostvars['localhost']['find_result'] }}" - meta: end_play when: "hostvars['localhost']['find_result'] | count == 0" - debug: msg: I am a first sanity check message, proving the end_play did happen - debug: msg: I am a second sanity check message, proving the end_play did happen - hosts: localhost gather_facts: false tasks: - name: To show it is really our empty list and not an empty string or a null variable debug: msg: "{{ hostvars['localhost']['find_result'] }}" - meta: end_play when: "hostvars['localhost']['find_result'] | count == 0" - debug: msg: I am a first sanity check message, proving the end_play did happen - debug: msg: I am a second sanity check message, proving the end_play did happen

Where you can see that, at the beginning of each new tasks group for a host, I just run the meta to end the play, based on the variable find_result registered out of the find result

Here is the output for this one

PLAY [localhost] ********************************************************************************************************************** TASK [Find in localhost] ************************************************************************************************************** ok: [localhost] TASK [This will register the list under find.files as a variable on the host, making it accessible via hostvars] ********************* ok: [localhost] PLAY [hosts] ************************************************************************************************************************** TASK [Just to show we are not cheating with an empty host group, we display the hosts names] ****************************************** ok: [host1] => { "msg": "host1" } ok: [host2] => { "msg": "host2" } ok: [host3] => { "msg": "host3" } TASK [To show it is really our empty list and not an empty string or a null variable] ************************************************ ok: [host1] => { "msg": [] } ok: [host2] => { "msg": [] } ok: [host3] => { "msg": [] } PLAY [localhost] ********************************************************************************************************************** TASK [To show it is really our empty list and not an empty string or a null variable] ************************************************ ok: [localhost] => { "msg": [] } PLAY RECAP **************************************************************************************************************************** host1 : ok=2 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0 host2 : ok=2 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0 host3 : ok=2 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0 localhost : ok=3 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0