docker - can't change files (wso2) - docker

Question

i'm using docker 18.04 and running the wso2 iot-server. I want to change the ip-address using this tutorial https://docs.wso2.com/display/IOTS330/Configuring+the+IP+or+Hostname . Im using the attached docker-compose file. I'm creating a container using
sudo docker-compose up
Then i run
sudo -it -u 0 <container-id> bash
navigate to the script directory an execute the script.
After this files like conf/carbon.xml where changed and everything looks good. If I restart the container executing
docker container restart $(docker ps -a -q)
all changes where discarded. But the strange thing is, if i create a new file e. g. in the conf directory this file remains, even after a restart.
Can someone explain this to me?
version: '2.3'
services:
wso2iot-mysql:
image: mysql:5.7.20
container_name: wso2iot-mysql
hostname: wso2iot-mysql
ports:
- 3306
environment:
MYSQL_ROOT_PASSWORD: root
volumes:
- ./mysql/scripts:/docker-entrypoint-initdb.d
healthcheck:
test: ["CMD", "mysqladmin" ,"ping", "-uroot", "-proot"]
interval: 10s
timeout: 60s
retries: 5
wso2iot-broker:
image: wso2iot-broker:3.3.0
container_name: wso2iot-broker
hostname: wso2iot-broker
ports:
- "9446:9446"
- "5675:5675"
healthcheck:
test: ["CMD", "nc", "-z", "localhost", "9446"]
interval: 10s
timeout: 120s
retries: 5
depends_on:
wso2iot-mysql:
condition: service_healthy
volumes:
- ./broker:/home/wso2carbon/volumes/wso2/broker
wso2iot-analytics:
image: wso2iot-analytics:3.3.0
container_name: wso2iot-analytics
hostname: wso2iot-analytics
healthcheck:
test: ["CMD", "curl", "-k", "-f", "https://localhost:9445/carbon/admin/login.jsp"]
interval: 10s
timeout: 120s
retries: 5
depends_on:
wso2iot-mysql:
condition: service_healthy
volumes:
- ./analytics:/home/wso2carbon/volumes/wso2/analytics
ports:
- "9445:9445"
wso2iot-server:
image: wso2iot-server:3.3.0
container_name: wso2iot-server
hostname: wso2iot-server
healthcheck:
test: ["CMD", "curl", "-k", "-f", "https://localhost:9443/carbon/admin/login.jsp"]
interval: 10s
timeout: 120s
retries: 5
depends_on:
wso2iot-mysql:
condition: service_healthy
volumes:
- ./iot-server:/home/wso2carbon/volumes
ports:
- "443:9443"
links:
- wso2iot-mysql

Answer 1

As far as I know, until the container is deleted write-able layer should be available. But this is not the expected way of using Docker. In this case, if you need to run the change-ip script I think it would be better to create a new Docker image where change-ip script is executed in the process of Docker image creation.