Best way to create a "simulation-mode"

[gfabbris]

I started playing with this by creating "sim_framework" and "sim_devices". Right now I just commented out the import calls in the collection.py, but we can create some conditions (like not being able to read from epics). With this, I could get it to run in my Mac.

@prjemian: Is this the best way to approach it? Creating simulated motors seem trivial based on a quick look at the bluesky tutorial, but it's not obvious to me how to create a simulated scaler.

[gfabbris]

by the way, this is done in my forked copy.

[prjemian]

I did not find a full scaler in the simulators. Time to ask the DAMA team...

…

On 7/21/2020 10:13 AM, Gilberto Fabbris wrote: by the way, this is done in my forked copy. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#6 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AARMUMCMWDXHUEHK3TTZSR3R4WWAVANCNFSM4PDWLI2A>.

[gfabbris]

@prjemian: I tried the docker. The start_iocxxx.sh seems to run fine, I can access the container and see the ioc there. For instance "caget xxx:datetime" works fine if I run it within the container. But my the ioc is not visible to my computer, if I run "caget xxx:datetime", it says "Channel connect timed out: 'xxx:datetime' not found.". Any ideas?

[prjemian]

Are you starting the docker container with the --net=host option?

[prjemian]

Example here: https://github.com/prjemian/epics-docker/tree/master/n3_synApps#example-use

[gfabbris]

It turns out docker in Mac does not support --net=host option (but it doesn't return any error if you try to use it). The only way to network with the container is through a port. I've tried using -p 8000:8000 when starting the container and caget 127.0.0.1:8000:xxx:datetime but it doesn't work. Do you know if/how caget would work through a port?

[gfabbris]

By the way: https://docs.docker.com/docker-for-mac/networking/

[prjemian]

EPICS ChannelAccess (CA) uses ports 5064 and 6065: -p 5064:5064 -p 5065:5065

[gfabbris]

What PV would pyepics see? The ones below didn't work...

[prjemian]

Any of the PVs from the IOC, such as: xxx:datetime, xxx:UPTIME, and xxx:m1. These are all easy to type. Maybe we need to tell the Mac that both tcp and UDP are permitted on those ports:

-p 5064:5064/tcp -p 5065:5065/tcp -p 5064:5064/udp -p 5065:5065/udp

or maybe use docker's bridged network instead: --net=bridge (but that seems to be the default)

The first of these references is the most useful (but not sure any of them help):

• https://stackoverflow.com/questions/25170738/how-does-dockers-net-host-setting-work-and-how-can-i-do-something-similar-wi
• net=host mode bug under mac, container with default bridge mode can not access host opening port  docker/for-mac#68
• https://docs.docker.com/network/
• https://blog.codavel.com/docker-network-on-macos-how-to-reach-gigabit
• https://stackoverflow.com/questions/63092466/how-does-the-networking-work-between-macos-and-docker-linux-vm

[gfabbris]

It works! It needs (both): -p 5064:5064/tcp -p 5064:5064/udp

I don't know why, but using 5065 doesn't work (but it also doesn't hurt).

[prjemian]

One of them (5064) is the EPICS_CA_SERVER_PORT (see https://epics.anl.gov/base/R3-14/12-docs/CAref.html) that ChannelAccess listens for PV requests (does anyone have this PV name of "ssfhdsjdf"?) Once an IOC is identified (you hope it is only one IOC), the server will create a separate channel (on a different port) to connect with that PV. The other (5065, EPICS_CA_REPEATER_PORT) receives CA information from various IOCs and routes it to the correct CA client on the workstation. That's why 5065 seems to provide no particular value in this case.

[gfabbris]

This is working as discussed here. Closing this issue.