write memory error in datapower docker instance

I am new to docker. After a considerable time I am able to install docker to Centos.

Then I installed a DataPower docker.

But when I save the configuration using the DataPower GUI, I am getting a memory error.

Below are the logs I have for the docker:

idg(config)# 20170810T234610.495Z [0x8100003f][mgmt][notice] domain(default): tid(319): Domain configuration has been modified.
20170810T234610.496Z [0x00350014][mgmt][notice] web-mgmt(WebGUI-Settings): tid(303): Operational state up
20170810T234745.935Z [0x806000bb][ssl][error] ssl-server(webgui-ssl): tid(179)[10.204.48.161] gtid(65622cce598cf0a1000000b3): error writing to connection: system error (32)
20170810T234921.041Z [0x80400006][system][error] : tid(8191): Cannot create a temporary file.
20170810T234921.041Z [0x81000010][system][critic] : tid(8191): write mem: Cannot create temp file
20170810T234921.041Z [0x8100000f][system][critic] : tid(8191): Failed to save configuration to 'config:///auto-startup.cfg'
20170810T234921.041Z [0x8100003c][mgmt][critic] domain(default): tid(8191): Domain configuration not saved.
20170810T234921.041Z [0x810000d2][cli][error] : tid(4019): Saving configuration failed - An internal routine could not create a temporary file..
20170810T234921.041Z [0x81000224][cli][error] : tid(4019): === Line 2: write memory

Below is the link I used to install docker container for DataPower:

https://developer.ibm.com/datapower/docker/

Can you help me figure out why I am able modify the config, but can't save it? Since I can't save it, when I restart docker I will lose my data.

Some more information: I have a linux Centos VM where I installed the docker.

Docker version 17.03.1-ce, build c6d412e

Linux Centos 3.10.0-693.el7.x86_64

Thanks

The problem is your file system permissions. The user/group that the Docker DataPower is running as does not have permission to write to your config directory.

So, assuming your docker run command contains parameters like the following:

 >   -v $PWD/config:/drouter/config \
 >   -v $PWD/local:/drouter/local \

run this command in $PWD before running docker run:

chmod 777 config local