How to set environmental variables using Ansible

Question

I need to set the variables like JAVA_HOME and update PATH. There are a number of ways of doing this. One way is to update the /etc/environment variable and include a line for JAVA_HOME using the lineinfile module and then run the command source /etc/environment directly on the guest OS (CentOS in my case).

Another way is to execute the export command e.g.

export JAVA_HOME=/usr/java/jre1.8.0_51 export PATH=$PATH:$JAVA_HOME 

Is there a cleaner way to do this as all these require manipulating files and running commands directly on the OS to update the environment variables?

Answer 1

Yes, there is a cleaner way. You can set environment variables per task:

  tasks:   - shell: echo JAVA_HOME is $JAVA_HOME     environment:       JAVA_HOME: /usr/java/jre1.8.0_51     register: shellout   - debug: var=shellout 

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Output:

TASK: [shell echo JAVA_HOME is $JAVA_HOME] **********************************  changed: [localhost]  TASK: [debug var=shellout] ****************************************************  ok: [localhost] => {     "var": {         "shellout": {             "changed": true,              "cmd": "echo JAVA_HOME is \"$JAVA_HOME\"",              "delta": "0:00:00.005797",              "end": "2015-08-07 06:32:47.295061",              "invocation": {                 "module_args": "echo JAVA_HOME is \"$JAVA_HOME\"",                  "module_name": "shell"             },              "rc": 0,              "start": "2015-08-07 06:32:47.289264",              "stderr": "",              "stdout": "JAVA_HOME is /usr/java/jre1.8.0_51",              "stdout_lines": [                 "JAVA_HOME is /usr/java/jre1.8.0_51"             ],              "warnings": []         }     } } 

If you set the environment variable like above in a task, it is only available for this specific task. In subsequent tasks it does not exist unless you define it again.

Though you can define env vars per play as well:

- hosts:   - localhost   gather_facts: no   environment:     JAVA_HOME: /usr/java/jre1.8.0_51   tasks:      ... 

Now it's gonna be available for all tasks of this play.

See Setting the Environment and FAQ: How can I set the PATH or any other environment variable for a task or entire playbook? in the docs.

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Another example with a script task:

  tasks:   - script: /tmp/script.sh     environment:       JAVA_HOME: /usr/java/jre1.8.0_51     register: shellout   - debug: var=shellout 

Where the script simply has this content:

#!/bin/sh  echo JAVA_HOME is $JAVA_HOME 

Answer 2

I found that a workaround to do this was to use the lineinfile command in Ansible:

- name: Set JAVA_HOME   lineinfile: dest=/etc/environment state=present regexp='^JAVA_HOME' >      line='JAVA_HOME=/opt/jre1.8.0_51/bin' 

While this is not ideal, it allows you to create new environmental variables. Of course, you should use variables to construct your directory path. I have included the explicit path to simplify my example.