### Description

Running kamailio in kubernetes (steps [here](https://github.com/CyCoreSystems/astricon-2016/issues/1)) but getting an "invalid host or interface name" error when parsing the alias in kamailio.cfg

As per https://github.com/kamailio/kamailio/blob/9df27ff7afbf1cf8ee7b3afd1741355e9f... DOTS and MINUS are not allowed?

GCE FQDN of server nodes currently have a format like this: ```gke-foo-cluster-default-pool-4b9e42c9-50mh.c.foo-project-0.internal```

### Troubleshooting

Doesn't exist. node names in the cloud are not customizable.

#### Reproduction

set the alias in kamailio.cfg to ```my-server.my-domain.internal```

#### Debugging Data

N/A

#### Log Messages

``` 2017-08-31T03:34:27Z gke-foo-cluster-default-pool-4b9e42c9-50mh confd[15]: INFO Backend set to env 2017-08-31T03:34:27Z gke-foo-cluster-default-pool-4b9e42c9-50mh confd[15]: INFO Starting confd 2017-08-31T03:34:27Z gke-foo-cluster-default-pool-4b9e42c9-50mh confd[15]: INFO Backend nodes set to 2017-08-31T03:34:27Z gke-foo-cluster-default-pool-4b9e42c9-50mh confd[15]: INFO /etc/kamailio/kamailio.cfg has md5sum 17481ad2235ef9698da57c6e90d5ac2b should be fb5d75c2654ab2264b11fab5802bd4b7 2017-08-31T03:34:27Z gke-foo-cluster-default-pool-4b9e42c9-50mh confd[15]: INFO Target config /etc/kamailio/kamailio.cfg out of sync 2017-08-31T03:34:27Z gke-foo-cluster-default-pool-4b9e42c9-50mh confd[15]: INFO Target config /etc/kamailio/kamailio.cfg has been updated 0(1) CRITICAL: <core> [cfg.y:3372]: yyerror_at(): parse error in config file /etc/kamailio/kamailio.cfg, line 35, column 30-36: syntax error 0(1) CRITICAL: <core> [cfg.y:3372]: yyerror_at(): parse error in config file /etc/kamailio/kamailio.cfg, line 35, column 30-36: invalid host or interface name 0(1) CRITICAL: <core> [cfg.y:3375]: yyerror_at(): parse error in config file /etc/kamailio/kamailio.cfg, line 35, column 37: ERROR: bad config file (3 errors)

```

#### SIP Traffic

N/A

### Possible Solutions

Let the parser accept server and domain names with "-"

### Additional Information

Kamailio version: upstream? as per the Dockerfile the image is coming from:

``` FROM debian:jessie

# Debian Linux RUN apt-get update && apt-get install -y curl && apt-get clean

# Install kamailio RUN curl -qO http://deb.kamailio.org/kamailiodebkey.gpg && \ apt-key add kamailiodebkey.gpg && \ echo "deb http://deb.kamailio.org/kamailio jessie main\ndeb-src http://deb.kamailio.org/kamailio jessie main" > /etc/apt/sources.list.d/kamailio.list RUN apt-get update && apt-get install -y kamailio kamailio-json-modules kamailio-postgres-modules kamailio-redis-modules kamailio-utils-modules && apt-get clean

# Install confd (we need at least 0.7.0 for the "exists" function RUN curl -o /usr/sbin/confd -O -J -L "https://github.com/kelseyhightower/confd/releases/download/v0.11.0/confd-0.1..." RUN chmod +x /usr/sbin/confd ```

* **Operating System**:

Debian Jessie ``` Linux gke-foo-cluster-default-pool-4b9e42c9-50mh 4.4.52+ #1 SMP Thu Jun 15 15:23:01 PDT 2017 x86_64 GNU/Linux

``` Please confirm if this docker image is built from the Kamailio's upstream version in order to fix it if not.

tks.