I am trying to add a cluster with replicas using docker-compose scale graylog-es-slave=2 but for a version 3 Dockerfile unlike Docker compose and hostname
What I am trying to do ix figure out how to get the specific node in the replica set
Here is what I have tried
D:\p\liberty-docker>docker exec 706814bf33b2 ping graylog-es-slave -c 2
PING graylog-es-slave (172.19.0.4): 56 data bytes
64 bytes from 172.19.0.4: icmp_seq=0 ttl=64 time=0.067 ms
64 bytes from 172.19.0.4: icmp_seq=1 ttl=64 time=0.104 ms
--- graylog-es-slave ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max/stddev = 0.067/0.085/0.104/0.000 ms
D:\p\liberty-docker>docker exec 706814bf33b2 ping graylog-es-slave.1 -c 2
ping: unknown host
D:\p\liberty-docker>docker exec 706814bf33b2 ping graylog-es-slave_1 -c 2
ping: unknown host
The docker-compose.yml
version: 3
service:
graylog-es-slave:
image: elasticsearch:2
command: "elasticsearch -Des.cluster.name='graylog'"
environment:
ES_HEAP_SIZE: 2g
deploy:
replicas: 2 <-- this is ignored on docker-compose just putting it here for completeness
Instead of ., use _ (underscore), and add the prefix of the project name (the directory that holds your docker-compose.yml, I assume that it is liberty-docker_graylog):
ping liberty-docker_graylog-es-slave_1
You can see that doing network ls, search for the right network, then docker network inspect network_id.
Related
I am trying to connect two locally developed projects running on docker-compose by using external networking.
From one side I have an 1st application intended to be exposed. Compose contains hosts: app and rabbit:
version: '3.4'
services:
app:
# ...
rabbit:
# ...
networks:
default:
driver: bridge
From other side I have second application expected to see 1st application:
version: '3.4'
services:
app:
# ...
networks:
- paymentservice_default
- default
networks:
paymentservice_default:
external: true
Reaching host rabbit.paymentservice_default is possible.
However service app (1st) conflicts with app (2nd):
root#6db86687229c:/app# ping app.paymentservice_default
PING app.paymentservice_default (192.168.80.6) 56(84) bytes of data.
root#6db86687229c:/app# ping app
PING app (192.168.80.6) 56(84) bytes of data.
In general from 2nd compose perspective hosts app and app.paymentservice_default shares same IP making app.paymentservice_default undiscoverable.
The question here is, do I have proper configuration and conflict can be avoided without changing service names app? Why this constraint? Taking consideration that every docker-compose configuration is shared across projects and can be developed in micro-services world.
$ docker-compose --version
docker-compose version 1.17.1, build unknown
$ docker --version
Docker version 19.03.4, build 9013bf583a
Thank you.
I use the following configuration on Docker Playground
paymentservice.docker-compose.yml
version: '3.4'
services:
app:
image: busybox
# keep container running
command: tail -f /dev/null
rabbit:
image: rabbitmq
networks:
default:
driver: bridge
other.docker-compose.yml
version: '3.4'
services:
app:
image: busybox
# keep container running
command: tail -f /dev/null
networks:
- paymentservice_default
- default
networks:
paymentservice_default:
external: true
Run both projects
$ COMPOSE_PROJECT_NAME=paymentservice docker-compose -f paymentservice.docker-compose.yml up -d
$ COMPOSE_PROJECT_NAME=other docker-compose -f other.docker-compose.yml up -d
Show Docker IPs
$ docker ps -q | xargs -n 1 docker inspect --format '{{ .Name }} {{range .NetworkSettings.Networks}} {{.IPAddress}}{{end}}' | sed 's#^/##';
I got
other_app_1 172.20.0.2 172.19.0.4
paymentservice_app_1 172.19.0.3
paymentservice_rabbit_1 172.19.0.2
and I pinged paymentservice_app_1 (172.19.0.3) from other_app_1 using app.paymentservice_default
$ docker exec -it other_app_1 ping -c 1 app.paymentservice_default
PING app.paymentservice_default (172.19.0.3): 56 data bytes
64 bytes from 172.19.0.3: seq=0 ttl=64 time=0.258 ms
--- app.paymentservice_default ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max = 0.258/0.258/0.258 ms
and I pinged other_app_1 (172.20.0.2) from other_app_1 using app
$ docker exec -it other_app_1 ping -c 1 app
PING app (172.20.0.2): 56 data bytes
64 bytes from 172.20.0.2: seq=0 ttl=64 time=0.054 ms
--- app ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max = 0.054/0.054/0.054 ms
As you can see, I can access the 1st app (of paymentservice.docker-compose.yml) from the 2nd app (of other.docker-compose.yml).
The same works in the other direction. I pinged other_app_1 (172.19.0.4) from paymentservice_app_1 using app.paymentservice_default
$ docker exec -it paymentservice_app_1 ping -c 1 app.paymentservice_default
PING app.paymentservice_default (172.19.0.4): 56 data bytes
64 bytes from 172.19.0.4: seq=0 ttl=64 time=0.198 ms
--- app.paymentservice_default ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max = 0.198/0.198/0.198 ms
I pinged paymentservice_app_1 (172.19.0.3) from paymentservice_app_1 using app
$ docker exec -it paymentservice_app_1 ping -c 1 app
PING app (172.19.0.3): 56 data bytes
64 bytes from 172.19.0.3: seq=0 ttl=64 time=0.057 ms
--- app ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max = 0.057/0.057/0.057 ms
As you can see, I can access app service of both projects. If I like to access the service of the same project, I use the default network of the project. If I'd like to access the service of another project, I use the external network shared between both projects.
Note: I would recommend to make this more explicit by creating the shared network outside of the projects using the command line
docker network create shared-between-paymentservice-and-other
and declaring it as external in both projects.
Note: There is still the limitation that service discovery may not work if you have 3 projects with the same service name (e.g. app) in the same (external) network (sort of a namespace). In that case, it might be a better idea to rename your services, use multiple external networks, define aliases or use a totally different approach to discover/identify the Docker containers.
Afterword
Has that been the requirement? I tried to reproduce your issue, but I'm not sure if I did the same as you. For example, I'm not sure, where you are running ping. Is root#6db86687229c the Docker host or a Docker container? Which container? I assumed it is the Docker container of service app of other.docker-compose.yml. Please comment if I'm missing something or misinterpreted your question and I will update my answer. Then I may explain in more detail or make another suggestion how to do service discovery between multiple Docker Compose projects.
Appendix
Cleanup
$ COMPOSE_PROJECT_NAME=other docker-compose -f other.docker-compose.yml down
$ COMPOSE_PROJECT_NAME=paymentservice docker-compose -f paymentservice.docker-compose.yml down
Versions
$ docker --version
Docker version 20.10.0, build 7287ab3
$ docker-compose --version
docker-compose version 1.26.0, build unknown
I have a docker swarm running on 2 nodes created via Oracle VirtualBox installed on CentOS 7. I am able to deploy a stack running 6 containers equally distributed over the two machines.
However, I am unable to connect to the deployed application with ports exposed.
Here's the content of my Docker Compose File
version: "3"
services:
web:
image: <myusername>/friendlyhello:latest
deploy:
replicas: 6
resources:
limits:
cpus: "0.1"
memory: 50M
restart_policy:
condition: on-failure
ports:
- "80:80"
networks:
- webnet
networks:
webnet:
Here is the output of docker-machine ls:
NAME ACTIVE DRIVER STATE URL SWARM DOCKER ERRORS
myvm1 * virtualbox Running tcp://192.168.99.100:2376 v18.09.0
myvm2 - virtualbox Running tcp://192.168.99.101:2376 v18.09.0
Here is the error from my curl command
curl http://192.168.99.100/
curl: (7) Failed connect to 192.168.99.100:80; Connection refused
Even though my application seems to be running fine.
docker service ls
ID NAME MODE REPLICAS IMAGE PORTS
i5nw2wcir9j3 getstartedlab_web replicated 6/6 harmanspall/friendlyhello:latest *:80->80/tcp
docker service ps getstartedlab_web
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
dn7mrfo1yvg4 getstartedlab_web.1 harmanspall/friendlyhello:latest myvm1 Running Running 28 minutes ago
jxkr1psbvmpc getstartedlab_web.2 harmanspall/friendlyhello:latest myvm2 Running Running 28 minutes ago
jttd4t6b9gz5 getstartedlab_web.3 harmanspall/friendlyhello:latest myvm1 Running Running 28 minutes ago
zhs0c7ygj8cs getstartedlab_web.4 harmanspall/friendlyhello:latest myvm2 Running Running 28 minutes ago
mx6gykk3qocd getstartedlab_web.5 harmanspall/friendlyhello:latest myvm1 Running Running 28 minutes ago
pku7f60ij0bq getstartedlab_web.6 harmanspall/friendlyhello:latest myvm2 Running Running 28 minutes ago
My Docker network list, as seen from Swarm Manager:
NETWORK ID NAME DRIVER SCOPE
5c502a957a70 bridge bridge local
a3b1f749c09f docker_gwbridge bridge local
80nens8mmp6i getstartedlab_webnet overlay swarm
c9647a0f6c30 host host local
mj60zgzhiwjf ingress overlay swarm
5adba823ce78 none null local
Any pointers would be appreciated.
~~ EDIT ~~
This does not seem to be an issue with connectivity to VMs since I am able to ping my Virtualbox
ping 192.168.99.100 -c 5
PING 192.168.99.100 (192.168.99.100) 56(84) bytes of data.
64 bytes from 192.168.99.100: icmp_seq=1 ttl=64 time=0.246 ms
64 bytes from 192.168.99.100: icmp_seq=2 ttl=64 time=0.215 ms
64 bytes from 192.168.99.100: icmp_seq=3 ttl=64 time=0.226 ms
64 bytes from 192.168.99.100: icmp_seq=4 ttl=64 time=0.251 ms
64 bytes from 192.168.99.100: icmp_seq=5 ttl=64 time=0.262 ms
--- 192.168.99.100 ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 3999ms
rtt min/avg/max/mdev = 0.215/0.240/0.262/0.017 ms
It also fails when I try curl from inside the VM
docker-machine ssh myvm1 "curl http://192.168.99.100/"
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0curl: (7) Failed to connect to 192.168.99.100 port 80: Connection refused
exit status 7
docker-machine ssh myvm1 "curl http://localhost/"
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0curl: (7) Failed to connect to localhost port 80: Connection refused
exit status 7
I am a beginner to docker.Please correct me if anything wrong.
As shown in this docker swarm tutorial https://www.youtube.com/watch?v=nGSNULpHHZc , i am trying to setup multhost setup for my hyperledger fabric application.
I am using two oracle linux servers namely server 1 and server 2.
I connected both the servers using the docker swarm as managers and created overlay network called my-net.
I followed the same syntax given in the above mentioned tutorial and created the service using the beolw mentioned syntax.
docker service create --name myservice --network my-net --replicas 2 alpine sleep 1d
As expected it created one conatianer in each the server.
Say for example server 1 coantainer IP is 10.0.0.4 and server 2 container IP 10.0.0.5.
Now, i am trying to ping from the second servers container to first server's container as shown below and it is pinging.
# docker exec -it ContainerID sh
/ # ping 10.0.0.4
PING 10.0.0.4 (10.0.0.4): 56 data bytes
64 bytes from 10.0.0.4: seq=0 ttl=64 time=0.082 ms
64 bytes from 10.0.0.4: seq=1 ttl=64 time=0.062 ms
64 bytes from 10.0.0.4: seq=2 ttl=64 time=0.067 ms
^C
--- 10.0.0.4 ping statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max = 0.062/0.070/0.082 ms
Now, I am trying to create my service(1) using the beolw mentioned syntax.
docker service create --name myservice1 --network my-net --replicas 2 hyperledger/fabric-peer sleep 1d
As expected this also created one conatianer in each the server.
Say for example server 1 coantainer IP is 10.0.0.6 and server 2 container IP 10.0.0.7.
Now, I am trying to ping from the second servers container to first server's container as shown below.
This time i am getting ping not found error,
# docker exec -it ContainerID sh
# ping 10.0.0.6
sh: 1: ping: not found
Can anyone please help what is the problem with the second myservice1.
The Fabric Docker images are based on a bare bones base Ubuntu image and do not include utilities like ping. Once you "exec" into the peer containers, you use "apt" to install ping:
apt-get update
apt-get install inetutils-ping
Added -ping at the end
Expanding on Gari Singh's answer, on a Fabric network I've spun this week, the inetutils has been split in different packages:
# apt-cache search inetutils
inetutils-ftp - File Transfer Protocol client
inetutils-ftpd - File Transfer Protocol server
inetutils-inetd - internet super server
inetutils-ping - ICMP echo tool
inetutils-syslogd - system logging daemon
inetutils-talk - talk to another user
inetutils-talkd - remote user communication server
inetutils-telnet - telnet client
inetutils-telnetd - telnet server
inetutils-tools - base networking utilities (experimental pac
so to install e.g. ping the correct command has become:
# apt-get install inetutils-ping
The Ubuntu version of the peer is:
# cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=16.04
DISTRIB_CODENAME=xenial
DISTRIB_DESCRIPTION="Ubuntu 16.04.5 LTS"
docker container gives unknowHost exception when
ping "private Network hostname"
ping: unknown host
But when I ping by IP it gives result
8 packets transmitted, 8 packets received, 0% packet loss
The work around seems to be adding host entry to /etc/hosts file in the running docker container but I am using the docker in K8 platform that dynamically creates new container so I can not manually add host entries. I was wondering why it can not resolve host name. Any help appreciated :)
You can add hostAliases in Pod Spec. For details, see the official doc.
Here is an example of Pod where hostAliases are used:
apiVersion: v1
kind: Pod
metadata:
name: hostaliases-pod
spec:
restartPolicy: Never
hostAliases:
- ip: "8.8.8.8"
hostnames:
- "foo.local"
- "bar.local"
containers:
- name: cat-hosts
image: busybox
command:
- ping
args:
- "foo.local"
If we see the logs of the pod:
$ kubectl logs po/hostaliases-pod
PING foo.local (8.8.8.8): 56 data bytes
64 bytes from 8.8.8.8: seq=0 ttl=61 time=51.333 ms
64 bytes from 8.8.8.8: seq=1 ttl=61 time=59.600 ms
....
As it is said in official doc, there is some limitations:
HostAlias is only supported in 1.7+.
HostAlias support in 1.7 is limited to non-hostNetwork Pods because kubelet only manages the hosts file for non-hostNetwork Pods.
In 1.8, HostAlias is supported for all Pods regardless of network configuration.
I am looking for a solution to ping a Docker container using its hostname, from another Docker Container.
I tried as follow:
starting first Docker container:
docker run --rm -ti --hostname=repohost --name=repo repo
starting second Docker container, link to first and start bash:
docker run --rm -ti --hostname=repo2host --link repo:rp repo2 /bin/bash
on bash started on repo2
ping repohost
it remain on pending without any result.
Can someone tell me if there is a solution for this?
You should be able to ping using the alias you gave in the link command (the part after the :), in your case ping rp should work.
The following works for me, given a running container called furious_turing:
$ docker run -it --link furious_turing:ft debian /bin/bash
root#06b18931d80b:/# ping ft
PING ft (172.17.0.3): 48 data bytes
56 bytes from 172.17.0.3: icmp_seq=0 ttl=64 time=0.136 ms
56 bytes from 172.17.0.3: icmp_seq=1 ttl=64 time=0.091 ms
56 bytes from 172.17.0.3: icmp_seq=2 ttl=64 time=0.092 ms
^C--- ft ping statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max/stddev = 0.091/0.106/0.136/0.000 ms
root#06b18931d80b:/#
If you need to ping on another name, you can add entries to /etc/hosts with the --add-host argument to docker run.
One way to achieve what you need would be with WeaveDNS.