Currently there doesn't seem to be other way how to identify the internal version of the KIE server the decision server image is using, just to run the image, wait till deployed.

Then issue request like:
http://kie-app-amq-test.openshift.example.com/kie-server/services/rest/server

(where "kie-app-amq-test.openshift.example.com" is the service for the decision server pod),
which will return information as follows:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<response type="SUCCESS" msg="Kie Server info">
    <kie-server-info>
        <capabilities>KieServer</capabilities>
        <capabilities>BRM</capabilities>
        <location>http://kie-app-1-2yz3y:8080/kie-server/services/rest/server</location>
        <name>kieserver-kie-app-1-2yz3y</name>
        <id>kieserver-kie-app-1-2yz3y</id>
        <version>6.3.0.Final-redhat-5</version>
    </kie-server-info>
</response>

From the above it's visible the internal KIE server version being "6.3.0.Final-redhat-5".
(similarly it's possible to obtain this version from pod log).

But suppose request remotely to scan decisionserver63 image e.g. with skopeo (or manual e.g. curl request following the Docker registry v2 format, and inspecting the manifest).

Current result:
Currently there isn't environment variable, which would specify the corresponding KIE server version.

Expected result:
KIE_SERVER_VERSION (or some other Env variable present in decisionserver image) that could be used for this purpose (remote inspection of an image) without the need to run the image.