minion fails to connect to master using zeromq by IPv6 address

[aphor]

Description of Issue/Question

salt.minion mishandles the opts['master'] when constructing a master_uri for zeromq to connect to the master returner port when the master is provided in the minion config as an IPv6 address.

zmq requires the master_uri to be in the format tcp://[::1]:4506 but salt tries to use zmq with something like tcp://::1:4506 which is not valid, and will quietly fail to connect with no indication the URI is invalid.

Setup

The simplest way to reproduce this is to configure salt master to listen on IPv6 [::], and the minion to connect to the master via IPv6, on the same host, via IPv6 localhost address [::1]

/etc/salt/master excerpt:

interface: '::'
ipv6: True

(re)start the salt master and verify this is working using sudo lsof -i tcp:4506 and/or nc -6 -z ::1 4506

/etc/salt/minion excerpt:

master: '::1'

Steps to Reproduce Issue

salt-call --log-level=debug test.ping

[DEBUG   ] Reading configuration from /etc/salt/minion
[DEBUG   ] Including configuration from '/etc/salt/minion.d/_schedule.conf'
[DEBUG   ] Reading configuration from /etc/salt/minion.d/_schedule.conf
[DEBUG   ] Configuration file path: /etc/salt/minion
[WARNING ] Insecure logging configuration detected! Sensitive data may be logged.
[DEBUG   ] Grains refresh requested. Refreshing grains.
[DEBUG   ] Reading configuration from /etc/salt/minion
[DEBUG   ] Including configuration from '/etc/salt/minion.d/_schedule.conf'
[DEBUG   ] Reading configuration from /etc/salt/minion.d/_schedule.conf
[DEBUG   ] Please install 'virt-what' to improve results of the 'virtual' grain.
[DEBUG   ] Loading static grains from /etc/salt/grains
[DEBUG   ] Connecting to master. Attempt 1 of 1
[DEBUG   ] Master URI: tcp://::1:4506
[DEBUG   ] Initializing new AsyncAuth for ('/etc/salt/pki/minion', 'testbox', 'tcp://::1:4506')
[DEBUG   ] Generated random reconnect delay between '1000ms' and '11000ms' (2375)
[DEBUG   ] Setting zmq_reconnect_ivl to '2375ms'
[DEBUG   ] Setting zmq_reconnect_ivl_max to '11000ms'
[DEBUG   ] Initializing new AsyncZeroMQReqChannel for ('/etc/salt/pki/minion', 'testbox', 'tcp://::1:4506', 'clear')
[DEBUG   ] Connecting the Minion to the Master URI (for the return server): tcp://::1:4506
[DEBUG   ] Trying to connect to: tcp://::1:4506
[DEBUG   ] salt.crypt.get_rsa_pub_key: Loading public key
[DEBUG   ] SaltReqTimeoutError, retrying. (1/7)
...

Versions Report

Salt Version:
           Salt: 2018.3.0
 
Dependency Versions:
           cffi: 1.11.5
       cherrypy: Not Installed
       dateutil: 2.6.1
      docker-py: Not Installed
          gitdb: Not Installed
      gitpython: Not Installed
          ioflo: Not Installed
         Jinja2: 2.10
        libgit2: 0.27.3
        libnacl: Not Installed
       M2Crypto: Not Installed
           Mako: Not Installed
   msgpack-pure: Not Installed
 msgpack-python: 0.5.6
   mysql-python: Not Installed
      pycparser: 2.18
       pycrypto: 2.6.1
   pycryptodome: Not Installed
         pygit2: 0.27.1
         Python: 3.6.6 (default, Jul  7 2018, 08:32:58)
   python-gnupg: Not Installed
         PyYAML: 3.13
          PyZMQ: 17.1.2
           RAET: Not Installed
          smmap: Not Installed
        timelib: Not Installed
        Tornado: 4.5.2
            ZMQ: 4.2.5
 
System Versions:
           dist:   
         locale: UTF-8
        machine: x86_64
        release: 17.7.0
         system: Darwin
        version: 10.13.6 x86_64

[Ch3LL]

Thanks for the PR!

[aphor]

Fixed, and test coverage added.