I am new to docker.I am running a Pi hole server in a docker container (called container manager in synology DSM). I was trying to run gravity vm to sync 2 pi holes which needs ssh. But the docker container does not have ssh enabled, how can i enable ssh in a running docker container
To use SSH directly with a container, you need to install a SSH server inside the container.
But you can usually create a shell inside a container from host with docker exec -it <c-id> sh.
ok good idea i installed ssh server by opening shell (apt install -y openssh-server) in docker but while i try to ssh it still says connection refused
ssh: connect to host 192...* port 22: Connection refused.
You also need to open the port on host to be forwarded into container.
docker run -p 2000:22 …
Probably not 22 on host, as thatbis already used by the hosts SSH, but a different one on the outside.
Note: opening shell and installing packages is not the way to do it with containers, as that is lost upon container re-create or upgrade. If you really need to install an additional package, you would usually create your own image with your own Dockerfile.
Thats a valid point i did know that docker updates worked that way. here is my current docker compose file for pi hole . Can you let me know what should i add in this docker file to enable ssh and port forward 22.
version: “3”
services:
pihole:
container_name: pihole
image: pihole/pihole:latest
ports:
- “192.168.1.198:53:53/tcp”
- “192.168.1.198:53:53/udp”
- “192.168.1.198:67:67/udp” # Only required if you are using Pi-hole as your DHCP server
- “192.168.1.198:80:80/tcp”
networks:
- ph_network
- ph_bridge
environment:
TZ: ‘Asia/Kolkata’
WEBPASSWORD: ‘*********’
DNSMASQ_LISTENING: local
# Volumes store your data between container upgrades
volumes:
- ‘/volume1/docker/pihole/pihole:/etc/pihole’
- ‘/volume1/docker/pihole/dnsmasq.d:/etc/dnsmasq.d’
cap_add:
- NET_ADMIN # Required if you are using Pi-hole as your DHCP server, else not needed
restart: unless-stopped
networks:
ph_bridge:
driver: bridge
ipam:
config:
- subnet: 192.168.10.0/24
gateway: 192.168.10.1
ip_range: 192.168.10.2/32
ph_network:
name: ad_blocker
external: true
Check the ports section 
Enable SSH into a docker container with the three different commands, which are explained properly here. As you mentioned about the problem you are facing in enabling SSH as you are new to Docker this manual will help you out in every condition you are related to.