consul-template using Address not ServiceAddress in template - bash

I am having a problem in that consul-template seems to be substituting the service "ServiceAddress" and not "Address" in my template and I wonder if anyone can tell me why.
From a bash session within my nginx container where consul-template is also running I can fetch the service definition from Consul with:
curl http://consul-server.service.consul:8500/v1/catalog/service/service1
[{"Node":"ip-172-31-24-202","Address":"172.31.24.202","ServiceID":"ip-172-31-24-202:service1:23141","ServiceName":"service1","ServiceTags":null,"ServiceAddress":"172.17.0.3","ServicePort":32809}]
My consul-template template file looks like:
{{range service "service1"}}server {{.Address}}:{{.Port}};
I would expect this to output the Address, and not the ServiceAddress for the service. However, the below happens:
consul-template -consul consul-server.service.consul:8500 -template "/var/templates/service1.conf.tmpl" -dry -once
server 172.17.0.3:32809

I've figured this out, .Address is part of the Consul response metadata, and not really part of the service metadata. This confused me because my consul Client is running on the same host.
I changed the -ip argument to the Registrator service I was running to be the internal IP address of the host running docker (rather than the default which is the IP of the Docker container) and everything worked.

Related

Do I need to add IP address to Memgraph instance that runs in docker?

Do I need to provide the docker instance with a real IP address instead of a loopback address 127.0.0.1?
Usually, it isn't necessary, and you should be able to connect with the default parameters which are localhost and 7687.
But if something is off, you can find the address of the Docker container with:
docker inspect -f '{{range.NetworkSettings.Networks}}{{.IPAddress}}{{end}}' container_name_or_id
And you can find the container_name_or_id with docker ps.
The connection command would look like this:
memgraph = Memgraph(host="ip_address", port=7687)

How to visit a docker service by ip address

I'm new with docker and I'm probably missing a lot, although i went through the basic documentation and I'm trying to deploy a simple Spring Boot API
I've deployed my API as a docker-spring-boot .jar file , then i installed docker and pushed it with the following commands:
sudo docker login
sudo docker tag docker-spring-boot phillalexakis/myfirstapi:01
sudo docker push phillalexakis/myfirstapi:01
Then i started the API with the docker run command:
sudo docker run -p 7777:8085 phillalexakis/myfirstapi:01
When i visit localhost:7777/hello I'm getting the desired response
This is my Dockerfile
FROM openjdk:8
ADD target/docker-spring-boot.jar docker-spring-boot.jar
EXPOSE 8085
ENTRYPOINT ["java","-jar","docker-spring-boot.jar"]
Based on this answered post this the command to get the ip address
docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' container_name_or_id
So, i run it with container_name_or_id = phillalexakis/myfirstapi:01 and I'm getting this error
Template parsing error: template: :1:24: executing "" at <.NetworkSettings.Networks>: map has no entry for key "NetworkSettings"
If i manage somehow to get the IP will i be able to visit it and get the same response?
This is how i have it in my mind: ip:7777/hello
You have used the image name and not the container name.
Get the container name by executing docker ps.
The container ID is the value in the first column, the container name is the value in the last column. You can use both.
Then, when you have the IP, you will be able to access your API at IP:8085/hello, not IP:7777/hello
The port 7777 is available on the Docker Host and maps to the port 8085 on the container. If you are accessing the container directly - which you do, when you use its IP address - you need to use the port that the container exposes.
There is also another alternative:
You can give the container a name when you start it by specifying the --name parameter:
sudo docker run -p 7777:8085 --name spring_api phillalexakis/myfirstapi:01
Now, from your Docker host, you can access your API by using that name: spring_api:8085/hello
You should never need to look up that IP address, and it often isn't useful.
If you're trying to call the service from outside Docker space, you've done the right thing: use the docker run -p option to publish its port to the host, and use the name of the host to access it. If you're trying to call it from another container, create a network, make sure to run both containers with a --net option pointing at that network, and they can reach other using the other's --name as a hostname, and the container-internal port the other service is listening on (-p options have no effect and aren't required).
The Docker-internal IP address just doesn't work in a variety of common situations. If you're on a different host, it will be unreachable. If your local Docker setup uses a virtual machine (Docker Machine, Docker for Mac, minikube, ...) you can't reach the IP address directly from the host. Even if it does work, when you delete and recreate the container, it's likely to change. Looking it up as you note also requires an additional (privileged) operation, which the docker run -p path avoids.
The invocation you have matches the docker inspect documentation (as #DanielHilgarth notes, make sure to run it on the container and not the image). In the specific situation where it will work (you are on the same native-Linux host as the container) you will need to use the unmapped port, e.g. http://172.17.0.2:8085/hello.

From a container running on Docker for Windows, how can I access a port on the host?

I'm running a CentOS-based container on Docker for Windows and trying to connect to an http service running on port 8545 of my host environment.
I've tried this, attempting a variety of suspected host names and IP addresses:
curl http://localhost:8545
But the error message I get is "curl: (7) Failed connect to localhost:8545; Connection refused"
How should I figure out what IP Address to use? Is there anything I need to configure as far as allowing the port number to be accessed from inside the container?
Localhost is not working yet I think with Docker for Windows.
There is few things you can try. First you can add EXPOSE 'portnumber' in the dockerfile so the container will listen on this port. You can also use docker run with -p 8545:8545, it will map the port of the container and the host.
To get the Ip address of the container you can use:
docker inspect -f "{{ .NetworkSettings.Networks.nat.IPAddress }}" containername
You can access the host using its ip but localhost/127.0.0.1 won't work (they will resolve to the Linux VM that is part of docker for windows). If you use the default network settings, your host should be reachable on 10.0.75.1 from your container

How to access webserver running on localhost from a docker container on a network?

I have the following system configuration:
Docker container running on user defined network
docker-machine (with VirtualBox on OS:X forwarding port 9000 to 9000)
Local webserver running on http://localhost:9000
I do not know how to make a basic http request against this webserver, from within my docker container.
To test this I am using:
docker exec testcontainer curl --data "foobaz=foo" http://{hostname}:9000/
where I have tried, for hostnames:
'localhost'
'127.0.0.1'
'192.168.99.100' (docker-machine IP)
Each time I receive errors or timeouts. When I run the curl command locally (not in docker and on my host OS:X machine) I am able to successfully post the http request.
I cannot disconnect the docker container from my user-defined network. I also cannot add my webserver to that network, as it is not running in a container. Also, I know it is trivial to connect the other way (curl to a webserver running in a docker container) but this is not my use case.
How can I successfully route that http request from the docker container which is part of a user defined network to my localhost webserver?
You can do this with the actual IP address of your local computer.
So for example, if your en0 IP is 10.100.20.32 on your host OS, you can run:
docker exec testcontainer curl --data "foobaz=foo" http://10.100.20.32:9000/
which will successfully allow you to make the http requests.
Note that if you are doing this from a container on the host docker network, this is trivial, as you can directly access localhost or 0.0.0.0 without having to use the actual machine IP.
You might want to check what the IP address of the container is - you can find this out by running docker inspect.
However, if you want to access the server process running in your container using the docker machine IP, then you should "expose" port 9000 that your contained app is listening on (using Dockerfile) - in this way, you will still need to figure out which port the 9000 container port is mapped to (this shows when you list your containers via $ docker ps. You can also specify port binding option in command line when starting your container like this: $ docker run -p 9000:9000 <your-container>.

Docker private registry issue

I run private registry on UBUNTU 14.04:
docker run -d -p 5000:5000 registry
The proces appeard on my docker proces list. I wrote command : curl my-external-ip and I got this:
"\"docker-registry server\""
THE PROBLEM IS that
when I try to push image on localhost it works fine, but after I want to push to external ip (It must be available for for more people) I got this:
The push refers to a repository [MY-EXTERNAL-IP:5000/hello] (len: 1)
unable to ping registry endpoint https://MY-EXTERNAL-IP:5000/v0/
v2 ping attempt failed with error: Get https://MY-EXTERNAL-IP:5000/v2/: EOF
v1 ping attempt failed with error: Get ht*ps://MY-EXTERNAL-IP:5000/v1/_ping: EOF
I am using proxy at my company, but I added export http_proxy, https_proxy, ftp_proxy to my docker file and --insecure-registry.
It looks that your docker daemon can't access docker registry(your-external-ip) through https protocol(usually it uses 443 port).
Maybe you can check it first.
But with insecure mode, the network occured on http protocol. So you can tell you docker daemon to trust insecure-registry.
Try to run docker daemon with --insecure-registry="YOUR_EXTERNAL_IP"
It seems like your Docker daemon still doesn't understand that registry on your $EXTERNAL_IP should be accessed over HTTP rather than HTTPS. You need to be sure that daemon runs with the --insecure-registry $EXTERNAL_IP option:
ps aux | grep docker
If you'll not be able to find it there, you probably made a mistake in your DOCKER_OPTIONS.

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