Using environment variables in readonlyrest.yml (Elasticsearch on Systemd)

Hi there
I’m wanting to use environment variables (CentOS) in my readonlyrest.yml.
It seems that this has been supported in various ways in the past although I can’t get it working at the moment. I am using version 7.16.2.

I have tried the following syntaxes, found in previous support threads:


But each time it results in an error, e.g.:
“Cannot resolve ENV Variable ‘MY_ENV_VAR’”

Is this still supported and if so what syntax should I use?

Many thanks

Hey there, sorry to bump, but just wondering whether environment variables are currently expected to work as per documentation or are there issues with it?
I thought maybe upgrading to 8.2.2/1.40 would solve the problem but using an environment variable such as ${LDAP_PASS} causes an exception:

uncaught exception in thread [main]
java.lang.IllegalStateException:failed to load plugin class []
Likely root cause: org.elasticsearch.ElasticsearchException: Invalid ROR SSL configuration. Cannot resolve ENV variable ‘LDAP_PASS’.

Not a big issue, just curious because I’ve been unable to get it to work.

Just to confirm (as that would be the obvious next question!), I have created the environment variable:

export LDAP_PASS=myldappass
> LDAP_PASS=myldappass

Please take a look at the documentation. Here is an example in our tests.

If it doesn’t work, it probably means that JVM process doesn’t see the env (probably sth wrong with exporting)

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For info, in case anyone else has the same problem and comes across this post (this isn’t a ROR problem, but you might find yourself looking here)…

The issue is that if you are running elasticsearch as a service, it doesn’t have access to system environment variables.

To get around this, look in the elasticsearch system service file, something like this (I am running CentOS):

You will see the line:

You can set environment variables for elasticsearch inside that file, i.e. append:


systemctl daemon-reload

Then restart elasticsearch, and the environment variable should be picked up.


Great point @joemo2023, very useful note. Thanks for taking the time to write this for the future googler’s benefit. :+1:

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