I am trying to connect to docker daemon running on a remote host (a camera running on a remote location).
Steps followed:
I have followed the steps in the docker documentation in order to create the certificates needed for this. After this, I have uploaded the certificates to the remote server and I have initialized docker daemon. The log messages indicate that docker daemon is running and listening:
2021-12-14T11:09:18.871+01:00 axis-b8a44f0e633b [ INFO ] dockerdwrapper[32307]: Started logging.
2021-12-14T11:09:18.900+01:00 axis-b8a44f0e633b [ INFO ] dockerdwrapper[32307]: Starting dockerd in TLS mode using SD card as storage.
2021-12-14T11:09:19.307+01:00 axis-b8a44f0e633b [ INFO ] dockerdwrapper[32314]: time="2021-12-14T11:09:19.305675739+01:00" level=info msg="Starting up"
2021-12-14T11:09:19.316+01:00 axis-b8a44f0e633b [ INFO ] dockerdwrapper[32314]: time="2021-12-14T11:09:19.315363522+01:00" level=info msg="parsed scheme: \"unix\"" module=grpc
2021-12-14T11:09:19.316+01:00 axis-b8a44f0e633b [ INFO ] dockerdwrapper[32314]: time="2021-12-14T11:09:19.315509937+01:00" level=info msg="scheme \"unix\" not registered, fallback to default scheme" module=grpc
2021-12-14T11:09:19.317+01:00 axis-b8a44f0e633b [ INFO ] dockerdwrapper[32314]: time="2021-12-14T11:09:19.315661800+01:00" level=info msg="ccResolverWrapper: sending update to cc: {[{unix:///run/containerd/containerd.sock <nil> 0 <nil>}] <nil> <nil>}" module=grpc
2021-12-14T11:09:19.317+01:00 axis-b8a44f0e633b [ INFO ] dockerdwrapper[32314]: time="2021-12-14T11:09:19.316791271+01:00" level=info msg="ClientConn switching balancer to \"pick_first\"" module=grpc
2021-12-14T11:09:19.326+01:00 axis-b8a44f0e633b [ INFO ] dockerdwrapper[32314]: time="2021-12-14T11:09:19.324681745+01:00" level=info msg="parsed scheme: \"unix\"" module=grpc
2021-12-14T11:09:19.326+01:00 axis-b8a44f0e633b [ INFO ] dockerdwrapper[32314]: time="2021-12-14T11:09:19.324845221+01:00" level=info msg="scheme \"unix\" not registered, fallback to default scheme" module=grpc
2021-12-14T11:09:19.326+01:00 axis-b8a44f0e633b [ INFO ] dockerdwrapper[32314]: time="2021-12-14T11:09:19.325024579+01:00" level=info msg="ccResolverWrapper: sending update to cc: {[{unix:///run/containerd/containerd.sock <nil> 0 <nil>}] <nil> <nil>}" module=grpc
2021-12-14T11:09:19.326+01:00 axis-b8a44f0e633b [ INFO ] dockerdwrapper[32314]: time="2021-12-14T11:09:19.325135502+01:00" level=info msg="ClientConn switching balancer to \"pick_first\"" module=grpc
2021-12-14T11:09:19.411+01:00 axis-b8a44f0e633b [ INFO ] dockerdwrapper[32314]: time="2021-12-14T11:09:19.408483444+01:00" level=info msg="[graphdriver] using prior storage driver: overlay2"
2021-12-14T11:09:19.434+01:00 axis-b8a44f0e633b [ INFO ] dockerdwrapper[32314]: time="2021-12-14T11:09:19.430353521+01:00" level=warning msg="Your kernel does not support swap memory limit"
2021-12-14T11:09:19.434+01:00 axis-b8a44f0e633b [ INFO ] dockerdwrapper[32314]: time="2021-12-14T11:09:19.430512819+01:00" level=warning msg="Your kernel does not support CPU realtime scheduler"
2021-12-14T11:09:19.434+01:00 axis-b8a44f0e633b [ INFO ] dockerdwrapper[32314]: time="2021-12-14T11:09:19.431814516+01:00" level=info msg="Loading containers: start."
2021-12-14T11:09:20.103+01:00 axis-b8a44f0e633b [ INFO ] dockerdwrapper[32314]: time="2021-12-14T11:09:20.102087081+01:00" level=info msg="Default bridge (docker0) is assigned with an IP address 172.17.0.0/16. Daemon option --bip can be used to set a preferred IP address"
2021-12-14T11:09:20.377+01:00 axis-b8a44f0e633b [ INFO ] dockerdwrapper[32314]: time="2021-12-14T11:09:20.375156590+01:00" level=info msg="Loading containers: done."
2021-12-14T11:09:20.530+01:00 axis-b8a44f0e633b [ INFO ] dockerdwrapper[32314]: time="2021-12-14T11:09:20.528313336+01:00" level=info msg="Docker daemon" commit=unsupported graphdriver(s)=overlay2 version=dev
2021-12-14T11:09:20.530+01:00 axis-b8a44f0e633b [ INFO ] dockerdwrapper[32314]: time="2021-12-14T11:09:20.529844450+01:00" level=info msg="Daemon has completed initialization"
2021-12-14T11:09:20.663+01:00 axis-b8a44f0e633b [ INFO ] dockerdwrapper[32314]: time="2021-12-14T11:09:20.662757526+01:00" level=info msg="API listen on [::]:2376"
When running netstat -anp |grep 2376 I get: tcp 0 0 :::2376 :::*LISTEN 31526/dockerd.
Issue:
However, when I try to make a call from the client (my laptop at home) using:
sudo docker -D --tlsverify --tlscacert=ca.pem --tlscert=cert.pem --tlskey=key.pem -H=<camera_ip_address>:2376 images
I get the following response:
DEBU[0062] FIXME: Got an status-code for which error does not match any expected type!!!: -1 module=api status_code=-1
Cannot connect to the Docker daemon at tcp://<camera_ip_address>:2376. Is the docker daemon running
My suspicion:
Since docker daemon seems to be running correctly and listing on the right port on the remote server, I believe the issue could be related to the DNS and IP address that I'm setting during the creation of the certificates. However, the information that I have found is that a docker container inherits the DNS settings of the host.
I'm using the host (in my case a camera) DNS and the IP that I'm setting is the one that I use to ssh into the host from my laptop.
