Hi all just a heads up. Docker Alpine image for zenoh (~45MB) builds well however is not able to run because I keep getting
Error Relocating: /usr/local/bin/zenohd: __register_atfork: symbol not found
Error Relocating: /usr/local/bin/zenohd: __res_init: symbol not foundDoes someone have an idea regarding this incompatibility with Alpine Docker containers?
For Alpine I didn’t try to target x86_64-unknown-linux-gnu.
But I managed to make it work targeting x86_64-unknown-linux-musl, defining RUSTFLAGS '-Ctarget-feature=-crt-static’ (to force dynamic link of the plugins/backends libs, as default is static with MUSL) and having the follwing in my ~/.cargo/config:
[target.x86_64-unknown-linux-musl]
linker = "x86_64-linux-musl-gcc"Also I’m running on MacOS with musl-cross installed.
Hmm I changed the build for aarch64-unknown-linux-musl target but I get
error: cannot produce cdylib for `zenoh-plugin-storages v0.5.0-dev (/project/plugins/zenoh-plugin-storages)` as the target `aarch64-unknown-linux-musl` does not support these crate typesMaybe I am drifting in the wrong direction
Success on Debian-slim (rpi4) docker run --init -d -p 7447:7447/tcp -p 7447:7447/udp -p 8000:8000/tcp shantanoodesai/zenoh:latest for anyone willing to try. Please not there are changes to the docker image so I advice to run it in detached mode with -d. If you wish to give in-memory example a try
docker run --init -d -p 7447:7447/tcp -p 7447:7447/udp -p 8000:8000/tcp shantanoodesai/zenoh:latest --mem-storage demo/example/**everything mentioned in the getting started page works
I just tested on my MacOS (x86 with arm64 emulation) and it run wells, even without the
-d option.I just wonder why the zenohd binary is 59Mb while in the
eclipse/zenoh image (alpine x86_64 based) it’s only 5.5Mb. Did you build in release mode ?
32 replies
Actually I merged last Thursday (eclipse-zenoh/zenoh@59fd21b). It’s in a new side crate named zenoh-ext that extends the
zenoh::net::Session with a declare_querying_subscriber() function. You can see an example of usage here.By default the
QueryingSubscriber starts with a query on the same resource it subscribes to (but it could be configured to query on another resource). The results of the query are merged/sorted/deduplicated with the live publications that may occur in parallel, before to be delivered to the QueryingSubscriberuser. At any time, the user can re-issue a query and the same behaviour will re-occur.
musl cross compilation for aarch64 apparently the cdylib was causing problems when compiling for aarch64-unknown-linux-musl but on my local x84_64 based machine I replaced the crates that had cdylib to staticlib and it seems to cross-compile.This produces
*.a files as opposed to *.so files.Not sure if this is good or not but I am trying to spin it up in an apline container and see if this works.
14 replies
Hi, everyone! I just tried the example in "your first zenoh app". First, I launch the dockerized router:
$ podman run --init -p 7447:7447/tcp -p 7447:7447/udp -p 8000:8000/tcp eclipse/zenoh --mem-storage='/myhome/**'Then, I launch the Python script that produces temperature readings, and I see:
Traceback (most recent call last):
File "/***/zenoh-server.py", line 18, in <module>
z = Zenoh({})
zenoh.ZError: IO error (Unable to bind udp port 224.0.0.224:7447) at /root/.cargo/registry/src/github.com-1ecc6299db9ec823/zenoh-0.5.0-beta.8/src/net/runtime/orchestrator.rs:350. - Caused by Address already in use (os error 98)Everything locally. Am I doing something wrong? Shouldn't the peer find the router?
"multicast_address": "224.0.0.224:7448" to the config works! Thanks, @Mallets
1 reply
udp/131.176.207.40:7447 or tcp/131.176.207.40:7447. A broker is just en entity mediating communications between two clients.
Hi @gardenest , you can define the topology by manually interconnecting the different peers with each other. To do so, you need to configure each zenoh session with the following :
- a tcp listener with a specific tcp port to listen on (so that other peers can easily connect to it)
- one or more peers to connect to
- deactivate multicast and gossip discovery so that peers do not connect automatically to each other.
Here is an example in python :
from zenoh import Zenoh
z = Zenoh({"listener": "tcp/0.0.0.0:7447",
"peer": "tcp/127.0.0.1:7448,tcp/127.0.0.1:7449",
"multicast_scouting": "false",
"peers_autoconnect": "false"})I have another question is about the memory usage of peer. I'm trying to testing it via the example zn_pub.py and zn_sub.py and testing scenario is one subscriber with many publishers. The situation is when new publisher application start, the memory usage of the existed publisher will become larger each time. How can I prevent this kind of situation?
- use a zenoh router and configure all pubs and sub as clients.
- configure a "mesh" of peers where each zn_pub is only connected to the zn_sub.
For this second solution, using zn_pub.py and zn_sub.py examples you need to write a config file to deactivate multicast and gossip discovery :
Then you can run zn_sub.py and zn_pub.py like this :$ cat config multicast_scouting=false peers_autoconnect=falsepython3 examples/zenoh-net/zn_sub.py -c config -l tcp/0.0.0.0:7447python3 examples/zenoh-net/zn_pub.py -c config -e tcp/127.0.0.1:7447python3 examples/zenoh-net/zn_pub.py -c config -e tcp/127.0.0.1:7447
I have another question about session establishment. Looking at some captures taken with wireshark, I can see that the zenoh client when trying to establish a session with a router, sends along with an init header, an attachment header with some payload. Is that for authentication? how should the router handle that information and how should be the response?
hi @AlexandreVSantos_gitlab , the attachment is used for exchanging additional information. At the moment is used only for these 2 cases:
1) user-password authentication
2) shared-memory probing to see if the client/router can operate over a shm segment
By default user-password authentication is disabled and SHM is enabled. So, what you see is problably SHM probing. In that case, the router will simply ignore the attachment in case does not support SHM. In the contrary, it will answer to the query.
