PCAS (using pcaspy) in docker ""server isnt attached to a network"

["Sparger, John E." <spargerje@ornl.gov>]

Hi,

 

If I try to run pcaspy in docker, I get the following error in CAS:

 

```

filename="../../../../src/cas/io/bsdSocket/casDGIntfIO.cc" line number=121

server isnt attached to a network - unable to continue

filename="../../../../src/cas/io/bsdSocket/caServerIO.cc" line number=116

Attempt to set server's IP address/port failed unable to attach explicit interface

filename="../../../../src/cas/generic/caServerI.cc" line number=59

server isnt attached to a network - CA server internals init unable to continue

terminate called after throwing an instance of 'int'

```

 

I understand that this has something to do with CAS's interface detection. However, if I run `softIOC` with the following db

 

```

echo "record(ai,"test_pv") {

field(VAL,"3")

}" > test.db

 

softIOC -d test.db

```

 

It works fine and I can `caget testpv` from another container without issue. This leads me to believe that the plumbing is there but that there is some assumption made in how CAS detects broadcast interfaces that is not holding true in docker.

 

Have you all been able to successfully run pcaspy  or cas-based servers in docker? Are there some environment variables I can set to help cas along?

 

I should note that setting `EPICS_CAS_INTF_ADDR_LIST="localhost"` WILL allow pcaspy will run in docker, but then the PVs are not visible outside that docker container, so it's not that useful.

 

Also for reference, here is what ifconfig returns from inside the container:

 

```

ifconfig

eth0      Link encap:Ethernet  HWaddr 02:42:ac:11:00:02 

          inet addr:172.17.0.2  Bcast:0.0.0.0  Mask:255.255.0.0

          inet6 addr: fe80::42:acff:fe11:2/64 Scope:Link

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

          RX packets:237 errors:0 dropped:0 overruns:0 frame:0

          TX packets:186 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:0

          RX bytes:240235 (234.6 KiB)  TX bytes:11013 (10.7 KiB)

 

lo        Link encap:Local Loopback 

          inet addr:127.0.0.1  Mask:255.0.0.0

          inet6 addr: ::1/128 Scope:Host

          UP LOOPBACK RUNNING  MTU:65536  Metric:1

          RX packets:3 errors:0 dropped:0 overruns:0 frame:0

          TX packets:3 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:1

          RX bytes:208 (208.0 B)  TX bytes:208 (208.0 B)

```

 

Thanks for the help,

 

John Sparger