CICS Transaction Gateway for Multiplatforms 9.3 for Linux on IBM Z container
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This document defines the process to upgrade IBM Semeru Runtime Open Edition 11.0.13 to IBM Semeru Runtime Open Edition 11.0.21


The following are the steps to upgrade JRE on a container:

 1. Use the Dockerfile provided with the readme.txt

  	The provided Dockerfile does the following. 
    		* Makes the user as root user.     
   		* Removes the existing JRE.
    		* Yum installs wget for the wget command. 
    		* Downloads the gunzip file from the link provided. 
    		* Untar and rename the JRE. 
    		* Move the JRE to the /opt/ibm/cicstg/bin directory. 
    		* Removes the wget command. After doing all the changes. 

 2. The user has to supply the JRE_LINK from where the JRE is downloaded. For downloading the IBM Semeru Runtime Open Edition 11.0.21.0,
	https://github.com/ibmruntimes/semeru11-binaries/releases/download/jdk-11.0.21%2B9_openj9-0.41.0/ibm-semeru-open-jre_s390x_linux_11.0.21_9_openj9-0.41.0.tar.gz
   
 3. Execute the following command. 

    For podman, 
    	podman build . -t <IFIX-IMAGE> --build-arg JRE_LINK=<JRE_LINK of the example of step2 > 
    Example:
      podman build . -t <IFIX-IMAGE> --build-arg JRE_LINK=https://github.com/ibmruntimes/semeru11-binaries/releases/download/jdk-11.0.21%2B9_openj9-0.41.0/ibm-semeru-open-jre_s390x_linux_11.0.21_9_openj9-0.41.0.tar.gz


Verifying the security Signature
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Complete the following in the same order to verify the digital signature.

1. Verify the signature for the image using OpenSSL.
openssl enc -d -A -base64 -in ibm-cicstg-container-linux-s390x.tar.gz.cosign.sig -out cosigndecode.sig
openssl dgst -verify PRD0000012key.pem.pub.key -keyform PEM -sha256 -signature cosigndecode.sig -binary ibm-cicstg-container-linux-s390x.tar.gz