Connect docker container to VPN - maven

I have a docker container from which I build and package a Java application with maven 3. I have some dependencies deployed to a Nexus server, I can only access through a VPN from local. How can I connect my docker container to that VPN?
docker image details:
Base image : Ubuntu 16.04 LTS as base system
Java 8, maven 3, Tomcat 8 installed
To create my docker container (I didn't add any network configuration):
docker run -it --rm -v '$PWD':/app -w /app/app-parent appImage/v:02 mvn clean install
And that's the error i get:
INFO: I/O exception (java.net.NoRouteToHostException) caught when processing request to {}->http://myserver:80: No route to host (Host unreachable)

May be your problem is due to DNS only.
Try resolving nexus hostname in the container's /etc/hosts file (or change maven settings.xml so that tag of nexus repository looks for the ip instead of the hostname).
To check if that is the problem, simply connect to the container
docker exec -ti yourContainer /bin/bash
then try to contact the host (depending on what you installed on the container, you could use ping, wget or other) with hostaname and ip address.

Related

docker image running not able to access api in spring boot gradle

I have created a image of spring boot gradle project by using command gradlew jibDockerBuild
I run the image by this command docker run -p 8082:8082 demo:0.0.1-SNAPSHOT.Image is running successfully on port 8082.In project application.properties server.port is 8082 only.
I am not able accesss api so I have checked in my machine whether this process is running on the port or not by command netstat -a -n -o | find "8082".No process is running on that port.
When you install Docker on Windows by Docker Toolbox by default Docker will run on 192.168.99.100 IP (DOCKER_IP).
You can access all your containers running inside docker with DOCKER_IP on your Host machine ie Windows.
Read more on it here
Regarding your mapping query
You have mapped port, which means your container port will be mapped to DOCKER_IP:PORT
If you were using Docker on Linux or Mac it will get mapped to localhost:port as in those cases Docker is running on localhost.
The same is not true for Windows at least with Docker Toolbox.
As per your configuration, you can access your application on HOST machine by hitting
http://192.168.99.100:8082

docker ports not available

I have a spring-config-sever project that I am trying to run via Docker. I can run it from the command line and my other services and browser successfully connect via:
http://localhost:8980/aservice/dev
However, if I run it via Docker, the call fails.
My config-server has a Dockerfile:
FROM openjdk:8-jdk-alpine
VOLUME /tmp
ARG JAR_FILE=build/libs/my-config-server-0.1.0.jar
ADD ${JAR_FILE} my-config-server-0.1.0.jar
EXPOSE 8980
ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar","/my-config-server-0.1.0.jar"]
I build via:
docker build -t my-config-server .
I am running it via:
docker run my-config-server -p 8980:8980
And then I confirm it is running via
docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
1cecafdf99fe my-config-server "java -Djava.securit…" 14 seconds ago Up 13 seconds 8980/tcp suspicious_brahmagupta
When I run it via Docker, the browse fails with a "ERR_CONNECTION_REFUSED" and my calling services fails with:
Could not locate PropertySource: I/O error on GET request for
"http://localhost:8980/aservice/dev": Connection refused (Connection
refused);
Adding full answer based on comments.
First, you have to specify -p before image name.
docker run -p 8980:8980 my-config-server.
Second, just configuring localhost with host port won't make your my-service container to talk to other container. locahost in container is within itself(not host). You will need to use appropriate docker networking model so both containers can talk to each other.
If you are on Linux, the default is Bridge so you can configure my-config-server container ip docker inspect {containerIp-of-config-server} as your config server endpoint.
Example if your my-config-server ip is 172.17.0.2 then endpoint is - http://172.17.0.2:8980/
spring:
cloud:
config:
uri: http://172.17.0.2:8980
Just follow the docker documentation for little bit more understanding on how networking works.
https://docs.docker.com/network/network-tutorial-standalone/
https://docs.docker.com/v17.09/engine/userguide/networking/
If you want to spin up both containers using docker-compose, then you can link both containers using service name. Just follow Networking in Compose.
I could imagine that the application only listens on localhost, ie 127.0.0.1.
You might want to try setting the property server.address to 0.0.0.0.
Then port 8980 should also be available externally.

How to publish artifact from local jenkins to local nexus - both on docker containers?

I want to publish an artifact from Jenkins on my machine to nexus on my local machine. In the future these two will have dedicated servers, but currently, for testing purposes I want to try it that way.
Jenkins and Nexus are in separate containers.
I am able to publish to nexus from my machine, running mvn clean deploy from project root directory.
I cannot do it using Jenkins.
When I enter container with Jenkins using: docker exec -it jenkins-container bash and doing curl http://localhost:8081 I receive message
curl: (7) Failed to connect to localhost port 8081: Connection refused
As I understand I need to provide different url than localhost, but which? How can I find it? How to configure it?
Your two docker containers must be on the same network. Once done, you can communicate with each other through their name that will become host :
example : curl http://{docker_container_name}:8081
See the documentation to implement a network in docker :
https://docs.docker.com/network/

Access Docker daemon Remote api on Docker for Mac

I'm runner Docker for OSX, and having trouble getting the Docker remote API to work.
My situation is this:
Docker daemon running natively on OSX (https://www.docker.com/products/docker#/mac, so not the boot2docker variant)
Jenkins running as docker image
No I want to use the Jenkins docker-build-step plugin to build a docker image, but I want it to use the docker daemon on the host machine, so in Jenkins settings, DOCKER_URL should be something like :2375. (Reason for this is I don't want to install docker on the jenkins container if I already have it on my host machine).
Is there a way to to this or is de Docker for Mac currently not supporting this? I tried fiddling with export DOCKER_OPTS or DOCKER_HOST options but still get a Connection refused on calling http://localhost:2375/images/json for example.
Basicly the question is more about enabling the Docker for OSX remote api, with use case calling it from a Jenkins docker container.
You could consider using socat. It solved my problem, which seem to be similar.
socat TCP-LISTEN:2375,reuseaddr,fork UNIX-CONNECT:/var/run/docker.sock &
This allows you to access your macOS host Docker API from a Docker container using: tcp://[host IP address]:2375
On macOS socat can be installed like this:
brew install socat
See here for a long discussion on this topic: Plugin: Docker fails to connect via unix:// on Mac OS X
If you already added an SSH public key to your remote server, then you can use this ssh credentials for your docker connection, too. You don't need to configure the remote api on the server for this approach.
When connecting to macOS Docker Desktop, you could use ssh (after you have enabled it on Mac)
docker -H ssh:user#192.168.64.1 images
or
export DOCKER_HOST=ssh:user#192.168.64.1
docker images
I had the same issue but with mysql. I needed to expose the port of my docker hosts on port 43306 to docker image mysql running on port 3306.
Solution:
Create your docker image with -p parameter.
Example:
#> docker run -p 0.0.0.0:43306:3306 --name mysql-5.7.23xx -e MYSQL_ROOT_PASSWORD=myrootdba -d mysql/mysql-server:5.7.23 --character-set-server=utf8mb4 --collation-server=utf8mb4_unicode_ci
Now I can connect from my host docker server on port 43306 to mysql docker image.

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>.

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