走らせてください。時々 pypi に接続の問題が発生し、それが壊れていると思わせるために騒々しく顔に出されます。念のために言っておきますが、転がしてみてください。
これらの赤いエラー行にもかかわらず、結論は「正常に構築されました」です。
$ docker build .
Sending build context to Docker daemon 2.048 kB
Step 1 : FROM docker-registry.aws.example.com:5000/cmcrc/python2:20160517120608
---> 1e5034711aa9
Step 2 : RUN pip install prometheus-client requests
---> Running in f3c580fc93ae
Collecting prometheus-client
Retrying (Retry(total=4, connect=None, read=None, redirect=None)) after connection broken by 'NewConnectionError('<pip._vendor.requests.packages.urllib3.connection.HTTPConnection object at 0x7fe15a1d8610>: Failed to establish a new connection: [Errno -2] Name or service not known',)': /pypi/prometheus-client/
Retrying (Retry(total=3, connect=None, read=None, redirect=None)) after connection broken by 'NewConnectionError('<pip._vendor.requests.packages.urllib3.connection.HTTPConnection object at 0x7fe15a1d87d0>: Failed to establish a new connection: [Errno -2] Name or service not known',)': /pypi/prometheus-client/
Retrying (Retry(total=2, connect=None, read=None, redirect=None)) after connection broken by 'NewConnectionError('<pip._vendor.requests.packages.urllib3.connection.HTTPConnection object at 0x7fe15a1d8990>: Failed to establish a new connection: [Errno -2] Name or service not known',)': /pypi/prometheus-client/
Retrying (Retry(total=1, connect=None, read=None, redirect=None)) after connection broken by 'NewConnectionError('<pip._vendor.requests.packages.urllib3.connection.HTTPConnection object at 0x7fe15a1d8b50>: Failed to establish a new connection: [Errno -2] Name or service not known',)': /pypi/prometheus-client/
Retrying (Retry(total=0, connect=None, read=None, redirect=None)) after connection broken by 'NewConnectionError('<pip._vendor.requests.packages.urllib3.connection.HTTPConnection object at 0x7fe15a1d8d10>: Failed to establish a new connection: [Errno -2] Name or service not known',)': /pypi/prometheus-client/
Downloading prometheus_client-0.0.13.tar.gz
Collecting requests
Retrying (Retry(total=4, connect=None, read=None, redirect=None)) after connection broken by 'NewConnectionError('<pip._vendor.requests.packages.urllib3.connection.HTTPConnection object at 0x7fe159e9d4d0>: Failed to establish a new connection: [Errno -2] Name or service not known',)': /pypi/requests/
Retrying (Retry(total=3, connect=None, read=None, redirect=None)) after connection broken by 'NewConnectionError('<pip._vendor.requests.packages.urllib3.connection.HTTPConnection object at 0x7fe159e9da10>: Failed to establish a new connection: [Errno -2] Name or service not known',)': /pypi/requests/
Retrying (Retry(total=2, connect=None, read=None, redirect=None)) after connection broken by 'NewConnectionError('<pip._vendor.requests.packages.urllib3.connection.HTTPConnection object at 0x7fe159e9dc50>: Failed to establish a new connection: [Errno -2] Name or service not known',)': /pypi/requests/
Retrying (Retry(total=1, connect=None, read=None, redirect=None)) after connection broken by 'NewConnectionError('<pip._vendor.requests.packages.urllib3.connection.HTTPConnection object at 0x7fe159e9de10>: Failed to establish a new connection: [Errno -2] Name or service not known',)': /pypi/requests/
Retrying (Retry(total=0, connect=None, read=None, redirect=None)) after connection broken by 'NewConnectionError('<pip._vendor.requests.packages.urllib3.connection.HTTPConnection object at 0x7fe159e9dfd0>: Failed to establish a new connection: [Errno -2] Name or service not known',)': /pypi/requests/
Downloading requests-2.10.0-py2.py3-none-any.whl (506kB)
Building wheels for collected packages: prometheus-client
Running setup.py bdist_wheel for prometheus-client: started
Running setup.py bdist_wheel for prometheus-client: finished with status 'done'
Stored in directory: /root/.cache/pip/wheels/04/94/f5/b803b2ff65e8344e99ca99b7f7cb8194224017167809a32b78
Successfully built prometheus-client
Installing collected packages: prometheus-client, requests
Successfully installed prometheus-client-0.0.13 requests-2.10.0
---> 19c5e3cfe08f
Removing intermediate container f3c580fc93ae
Successfully built 19c5e3cfe08f