Unable to containerise varnish, throws error "Service Unavailable" - docker

Question

varnish.local.php
<?php
return [
'acsi_varnish' => [
'clients' => [
'cache' => [
'endpoint' => [
'host' => 'dev-varnish',
'port' => '8443',
'secret' => 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx',
],
],
],
],
];
default.vcl
vcl 4.1;
backend default {
.host = "dev";
.port = "8080";
}
docker-compose-template.yml
version: '3.7'
services:
dev:
image: dev:centos7
container_name: dev
hostname: dev
volumes:
- ${HOST_BIND_MOUNT_DIR}:${CONTAINER_MOUNT_DIR}
- /sys/fs/cgroup:/sys/fs/cgroup:ro
privileged: true
networks:
dev-online:
ipv4_address: 172.100.0.2
ports:
- 443:443
# - 6082:6082
- 9001:9001
- 5672:5672
- 15672:15672
- 29015:29015
extra_hosts:
- dev:127.0.0.1
- dev-mysql:172.100.0.3
- dev-mongo-3:172.100.0.4
- dev-mongo-4:172.100.0.5
- dev-solr-6:172.100.0.6
- dev-solr-8:172.100.0.7
- dev-rethinkdb:172.100.0.8
- dev-varnish:172.100.0.10
dev-mysql:
image: dev-mysql-5.7:latest
container_name: dev-mysql
hostname: dev-mysql
user: "${V_UID}:${V_GID}"
volumes:
- ${HOST_BIND_MOUNT_DIR_MYSQL}:${CONTAINER_MOUNT_DIR_MYSQL}
networks:
dev-online:
ipv4_address: 172.100.0.3
ports:
- 3306:3306
environment:
- MYSQL_ROOT_PASSWORD:${MYSQL_ROOT_PASSWORD}
- MYSQL_DATABASE:${MYSQL_DATABASE}
extra_hosts:
- dev:172.100.0.2
- dev-mysql:127.0.0.1
- dev-mongo-3:172.100.0.4
- dev-mongo-4:172.100.0.5
- dev-solr-6:172.100.0.6
- dev-solr-8:172.100.0.7
- dev-rethinkdb:172.100.0.8
- dev-memcached:172.100.0.9
- dev-varnish:172.100.0.10
dev-mongo-3:
image: mongo-3.0:dev
container_name: dev-mongo-3
hostname: dev-mongo-3
volumes:
- ${HOST_BIND_MOUNT_DIR_MONGO_3}:${CONTAINER_MOUNT_DIR_MONGO}
privileged: true
networks:
dev-online:
ipv4_address: 172.100.0.4
ports:
- 27017:27017
environment:
- MYSQL_ROOT_PASSWORD="${MYSQL_ROOT_PASSWORD}"
- MYSQL_DATABASE="${MYSQL_DATABASE}"
extra_hosts:
- dev:172.100.0.2
- dev-mysql:172.100.0.3
- dev-mongo-3:127.0.0.1
- dev-mongo-4:172.100.0.5
- dev-solr-6:172.100.0.6
- dev-solr-8:172.100.0.7
- dev-rethinkdb:172.100.0.8
- dev-memcached:172.100.0.9
- dev-varnish:172.100.0.10
dev-mongo-4:
image: mongo-4.4:dev
container_name: dev-mongo-4
hostname: dev-mongo-4
user: "${V_UID}:${V_GID}"
volumes:
- ${HOST_BIND_MOUNT_DIR_MONGO_4}:${CONTAINER_MOUNT_DIR_MONGO}
privileged: true
networks:
dev-online:
ipv4_address: 172.100.0.5
ports:
- 27018:27017
environment:
- MYSQL_ROOT_PASSWORD="${MYSQL_ROOT_PASSWORD}"
- MYSQL_DATABASE="${MYSQL_DATABASE}"
extra_hosts:
- dev:172.100.0.2
- dev-mysql:172.100.0.3
- dev-mongo-3:172.100.0.4
- dev-mongo-4:127.0.0.1
- dev-solr-6:172.100.0.6
- dev-solr-8:172.100.0.7
- dev-rethinkdb:172.100.0.8
- dev-memcached:172.100.0.9
- dev-varnish:172.100.0.10
dev-solr-6:
image: solr-6.6:dev
container_name: dev-solr-6
hostname: dev-solr-6
networks:
dev-online:
ipv4_address: 172.100.0.6
ports:
- 8983:8983
extra_hosts:
- dev:172.100.0.2
- dev-mysql:172.100.0.3
- dev-mongo-3:172.100.0.4
- dev-mongo-4:172.100.0.5
- dev-solr-6:127.0.0.1
- dev-solr-8:172.100.0.7
- dev-rethinkdb:172.100.0.8
- dev-memcached:172.100.0.9
- dev-varnish:172.100.0.10
dev-solr-8:
image: solr-8.6:dev
container_name: dev-solr-8
hostname: dev-solr-8
user: "${V_UID}:${V_GID}"
volumes:
- ${HOST_BIND_MOUNT_DIR_SOLR}:${CONTAINER_MOUNT_DIR_SOLR_8}
networks:
dev-online:
ipv4_address: 172.100.0.7
ports:
- 8984:8983
environment:
- SOLR_HEAP=2g
extra_hosts:
- dev:172.100.0.2
- dev-mysql:172.100.0.3
- dev-mongo-3:172.100.0.4
- dev-mongo-4:172.100.0.5
- dev-solr-6:172.100.0.6
- dev-solr-8:127.0.0.1
- dev-rethinkdb:172.100.0.8
- dev-memcached:172.100.0.9
- dev-varnish:172.100.0.10
dev-rethinkdb:
image: rethinkdb
container_name: dev-rethinkdb
hostname: dev-rethinkdb
user: "${V_UID}:${V_GID}"
volumes:
- ${HOST_BIND_MOUNT_DIR_RETHINKDB}:${CONTAINER_MOUNT_DIR_RETHINKDB}
networks:
dev-online:
ipv4_address: 172.100.0.8
ports:
- 28015:28015
- 8080:8080
extra_hosts:
- dev:172.100.0.2
- dev-mysql:172.100.0.3
- dev-mongo-3:172.100.0.4
- dev-mongo-4:172.100.0.5
- dev-solr-6:172.100.0.6
- dev-solr-8:172.100.0.7
- dev-rethinkdb:127.0.0.1
- dev-memcached:172.100.0.9
- dev-varnish:172.100.0.10
dev-memcached:
image: memcached
container_name: dev-memcached
hostname: dev-memcached
user: "${V_UID}:${V_GID}"
networks:
dev-online:
ipv4_address: 172.100.0.9
ports:
- 11211:11211
extra_hosts:
- dev:172.100.0.2
- dev-mysql:172.100.0.3
- dev-mongo-3:172.100.0.4
- dev-mongo-4:172.100.0.5
- dev-solr-6:172.100.0.6
- dev-solr-8:172.100.0.7
- dev-rethinkdb:172.100.0.8
- dev-memcached:127.0.0.1
- dev-varnish:172.100.0.10
dev-varnish:
image: varnish:7.2.1-alpine
container_name: dev-varnish
hostname: dev-varnish
user: '0'
volumes:
- "./default.vcl:/etc/varnish/default.vcl"
ports:
- "6082:8443"
tmpfs:
- /var/lib/varnish/varnishd:exec
networks:
dev-online:
ipv4_address: 172.100.0.10
extra_hosts:
- dev:172.100.0.2
- dev-mysql:172.100.0.3
- dev-mongo-3:172.100.0.4
- dev-mongo-4:172.100.0.5
- dev-solr-6:172.100.0.6
- dev-solr-8:172.100.0.7
- dev-rethinkdb:172.100.0.8
- dev-varnish:127.0.0.1
- dev-memcached:172.100.0.9
networks:
dev-online:
driver: bridge
ipam:
driver: default
config:
- subnet: 172.100.0.0/24
I am trying to containerise the varnish service which is already working in "dev" container, but after i containerise, i don't see it is working, i am not sure what is going wrong here.
the connection should work in the below flow
https://loadwebsite.com -> "dev" container -> "dev-varnish" container -> "dev" container
the browser throws the error below
"Service Unavailable
The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later."

Answer 1

Please run run docker compose ps dev-varnish to see if the varnishd process is running
Finally run docker compose exec -ti dev-varnish varnishlog -g request to run the varnishlog binary inside the container and output the logs
Please attach the output from varnishlog -g request to your question. This will clarify how Varnish is behaving and can lead to a possible solution.