現在下記のような環境でDockerを利用しています。

$ dinghy -v
Dinghy 4.4.2
$ docker-machine -v
docker-machine version 0.8.2, build e18a919
$ VBoxManage -v
5.1.10r112026
$ docker-compose -v
docker-compose version 1.8.1, build 878cff1
$ docker -v
Docker version 1.12.3, build 6b644ec

dinghy経由でVirtualbox上にdockerを立ち上げているのですが、ホストPC（Mac）の再起動後にたまに下記のエラーが出てdockerに接続できなくなることがあります。

Traceback (most recent call last):
  File "<string>", line 3, in <module>
  File "compose/cli/main.py", line 62, in main
  File "compose/cli/main.py", line 114, in perform_command
  File "compose/cli/main.py", line 835, in up
  File "compose/project.py", line 372, in up
  File "compose/project.py", line 539, in warn_for_swarm_mode
  File "site-packages/docker/api/daemon.py", line 33, in info
  File "site-packages/docker/utils/decorators.py", line 47, in inner
  File "site-packages/docker/client.py", line 139, in _get
  File "site-packages/requests/sessions.py", line 477, in get
  File "site-packages/requests/sessions.py", line 465, in request
  File "site-packages/requests/sessions.py", line 573, in send
  File "site-packages/requests/adapters.py", line 370, in send
  File "site-packages/requests/packages/urllib3/connectionpool.py", line 544, in urlopen
  File "site-packages/requests/packages/urllib3/connectionpool.py", line 341, in _make_request
  File "site-packages/requests/packages/urllib3/connectionpool.py", line 761, in _validate_conn
  File "site-packages/requests/packages/urllib3/connection.py", line 253, in connect
  File "site-packages/backports/ssl_match_hostname/__init__.py", line 147, in match_hostname
backports.ssl_match_hostname.CertificateError: hostname '192.168.99.100' doesn't match either of 'localhost', '192.168.99.101'
docker-compose returned -1

証明書のIPと実際にdockerが立ち上がってるIPが違っているというエラーなので、下記のコマンドで証明書を作り直すと接続できるようになりました。

$ docker-machine regenerate-certs dinghy

これぐらいdocker-machineかdinghy側でよしなにやっといて欲しいと思ったら、dinghy側の人はdocker-machine側でやるべきやけどドキュメントぐらい書いとくかっていう感じらしい。

dinghyのissue

dinghyのFAQ