How to set environmental variables using Ansible - 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
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.
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.

Answer 3

Update to the lineinfile approach. The JAVA_HOME value should not include the bin directory. The following worked for centos:
- name: Set JAVA_HOME
lineinfile:
dest: /etc/environment
state: present
regexp: '^JAVA_HOME'
line: 'JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk'