Https://github.com/docker/docker/issues/31238

Docker Engine Swarm
1

Containers can’t connect to other containers using host aliases.

This is my docker-compose.yml file:

version: "3"

services:
  mongo:
    image: mongo
    ports:
      - 27017:27017
    networks:
      mynet:
        aliases:
          - mongo
    deploy:
      placement:
        constraints: [node.role == manager]

  redis:
    image: redis
    ports:
      - 6379:6379
    networks:
      mynet:
        aliases:
          - redis
    deploy:
      placement:
        constraints: [node.role == worker]

  app:
    image: node
    ports:
      - 3030:3030
    networks:
      - mynet
    depends_on:
      - redis
      - mongo
    deploy:
      mode: replicated
      replicas: 2
      placement:
        constraints: [node.role == worker]

networks:
  mynet:

Description

root@mongo-container:/# ping mongo # works
root@mongo-container:/# ping redis # doesn't work

root@redis-container:/# ping redis # works
root@redis-container:/# ping mongo # doesn't work

root@app-container:/# ping mongo # doesn't work
root@app-container:/# ping redis # doesn't work

Steps to reproduce the issue:

  1. Deploy this stack. docker stack deploy -c docker-compose.ym app
  2. SSH into running containers and ping each other

Describe the results you received:
Containers are not able to resolve other container’s alias/hostname.

Additional information you deem important (e.g. issue happens only occasionally):

Output of docker version:

Client:
 Version:      1.13.1
 API version:  1.26
 Go version:   go1.7.5
 Git commit:   092cba3
 Built:        Wed Feb  8 06:50:14 2017
 OS/Arch:      linux/amd64

Server:
 Version:      1.13.1
 API version:  1.26 (minimum version 1.12)
 Go version:   go1.7.5
 Git commit:   092cba3
 Built:        Wed Feb  8 06:50:14 2017
 OS/Arch:      linux/amd64
 Experimental: true

Output of docker info:

Containers: 2
 Running: 2
 Paused: 0
 Stopped: 0
Images: 14
Server Version: 1.13.1
Storage Driver: aufs
 Root Dir: /var/lib/docker/aufs
 Backing Filesystem: extfs
 Dirs: 41
 Dirperm1 Supported: true
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins: 
 Volume: local
 Network: bridge host ipvlan macvlan null overlay
Swarm: active
 NodeID: 0wf5g7qztz9n0mqqn29nwpn6o
 Is Manager: true
 ClusterID: ukgmh2ci2x922oj0wc83b4sjr
 Managers: 1
 Nodes: 3
 Orchestration:
  Task History Retention Limit: 5
 Raft:
  Snapshot Interval: 10000
  Number of Old Snapshots to Retain: 0
  Heartbeat Tick: 1
  Election Tick: 3
 Dispatcher:
  Heartbeat Period: 5 seconds
 CA Configuration:
  Expiry Duration: 3 months
 Node Address: 10.132.52.172
 Manager Addresses:
  10.132.52.172:2377
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version: aa8187dbd3b7ad67d8e5e3a15115d3eef43a7ed1
runc version: 9df8b306d01f59d3a8029be411de015b7304dd8f
init version: 949e6fa
Security Options:
 apparmor
 seccomp
  Profile: default
Kernel Version: 4.4.0-63-generic
Operating System: Ubuntu 16.04.2 LTS
OSType: linux
Architecture: x86_64
CPUs: 1
Total Memory: 992.4 MiB
Name: bounty1
ID: VLXO:ZKIE:I2O7:LYGV:IFZD:UK33:TKEG:VYFZ:PLPE:3KJB:GD6N:C5XZ
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): false
Registry: https://index.docker.io/v1/
Experimental: true
Insecure Registries:
 10.132.52.172:5000
 127.0.0.0/8
Live Restore Enabled: false

Additional environment details (AWS, VirtualBox, physical, etc.):
Platform: DigitalOcean, 1GB, 3 nodes