I want to build an application. For testing it uses testcontainers. The build will run on CI and on the developers' machines. The Dockerfile is more or less:
FROM amazoncorretto:17-alpine as builder
add . .
run ./gradlew build
from amazoncorretto:17-alpine
copy --from=builder build/libs/*.jar app.jar
ENTRYPOINT ["java","-jar","/app.jar"]
And I run the build using docker build .
Part of the ./gradlew build runs tests with Testscontainers and uses
val sftpDocker = GenericContainer(DockerImageName.parse("atmoz/sftp:alpine"))
And it returns
java.lang.IllegalStateException: Could not find a valid Docker environment. Please see logs and check configuration
I know that:
Testcontainers has its own docker API client and doesn't requires installed docker inside the Alpine container 3
Someone made it using "docker:20.10.14-dind" image. But I don't know how it fits in my problem 4
I can mount the /var/run/docker.sock during docker run ... but I'm using RUN command inside dockerfile and docker build ... instead
I can expose DOCKER_HOST and testcontainers should use the default gateway's IP address. But it's way less secure than using socket
So is there a way to use a socket in this setup? If not, how should I run my host Docker to expose TCP instead of a socket?
I'm trying to install/run jenkins manually without pulling the Jenkins image from the docker-hub
for this exercise I have used the ubuntu image container and I did the following:
Install jdk-11 on the container
Set up the JAVA_HOME env variable
Install jenkins with apt-get
Run jenkins with the command service jenkins start
then status output is the following
root#42024442b87b:/# service jenkins status
Correct java version found
Jenkins Automation Server is running with the pid 89
Now I don't now how to access the jenkins server running in the container from my host.
thanks in advance
Docker containers are not reachable using the network from the host system by default. You need to expose a container's host, meaning that the port will be opened on the host machine and all traffic forwarded to the container.
Running docker with -p 8080:8080 forwards 8080. Take a look at the syntax here.
You can also specify which port on the host machine is supposed to be mapped to a container's port with something like -p 1234:8080.
You can also use the EXPOSE keyword in your Dockerfile.
I am facing an issue running a docker image based on alpine linux that runs a java process (GoCD server). The java process itself tries to run some code to clone a git repository locally however I am getting a Couldn't resolve host exception. I tried to manually clone the git repo from within the container using 'git clone' and had no issue.
In addition, I am able to ping the domain from within the docker container by running ping my-service-url.com with no issues and also from the host machine with the same result. It seems java has some difficulties resolving the name but I am not sure how to fix it.
I tried creating a new image with RUN echo 'hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4' >> /etc/nsswitch.conf. I read in another question that would fix it but no luck. The whole Dockerfile looks like the following:
FROM gocd/gocd-server:v17.5.0
RUN echo 'hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4' >> /etc/nsswitch.conf
ADD json-config-plugin-0.2.jar /godata/plugins/external/json-config-plugin-0.2.jar
ENTRYPOINT ["/docker-entrypoint.sh"]
I am running on AWS ECS, ipv4 forwarding is set to 1 and network mode is bridge. I am running out of ideas.
I am experimenting with Docker for the first time, and am trying to get a Spring Boot web app to run inside a Docker container. I am building the app (which packages up into a self-contained jar) and then adding it to the Docker image (which is what I want).
You can find my SSCCE at this Bootup repo on GitHub, whose README has all the instructions to reproduce what I'm seeing. But basically:
I build the web app into a jar
Run docker build -t bootup . which succeeds
Run docker run -it -p 9200:9200 -d --name bootup bootup and then container seems to start up just fine, as is evidence by the docker ps output below
However, when I point a browser to http://localhost:9200, I get nothing
docker ps output:
CONTAINER ID IMAGE COMMAND CREATED
a8c4ee64a1bc bootup "/bin/sh -c 'java -ja" 2 days ago
STATUS PORTS NAMES
Up 12 seconds 0.0.0.0:9200->9200/tcp bootup
The web app is configured to run on port 9200, not the Java default of 8080. You can see this for yourself by running the app outside of docker (so, just locally on you host machine) by running ./gradlew clean build && java -jar build/libs/bootup.jar.
To my knowledge, there is no Firewall running on my host that would be blocking ports (I am on Mac 10.11.5 and verified that System Preferences >> Security & Privacy >> Firewall is turned off).
Can anyone spot where I'm going awry?
Updates:
I ran a curl, netstat and lsof on the host:
HOST:
curl http://localhost:9200
curl: (52) Empty reply from server
netstat -an | grep 9200
tcp6 0 0 ::1.9200 *.* LISTEN
tcp4 0 0 *.9200 *.* LISTEN
lsof -n -i4TCP:9200 | grep LISTEN
com.docke 2578 myuser 19u IPv4 <someHexNumber> 0t0 TCP *:wap-wsp (LISTEN)
And then docker exec'd into the container and ran another netstat:
CONTAINER:
netstat -an | grep 9200
bash: netstat: command not found
Update w/ photos:
Picture of my browser (Chrome) pointed to http://localhost:9200:
Picture of the source code at http://localhost:9200:
Picture of Chrome Developer Tools inspecting the page at http://localhost:9200:
Picture of the Network tab in Chrome Developer Tools:
What the heck is going on here?!?!? According to the source, the browser should be rendering my Well hello there, from Dockerland! message just fine. According to the actual browser page, it looks like there is a networking error. And according to Chrome Developer Tools, my app is returning all sorts of HTML/CSS/JS content that is not even remotely apart of my app (check out the source code, see for yourself)!!!
The Dockerfile doesn't expose 9200 to the daemon. Add
EXPOSE 9200
to the Dockerfile before ENTRYPOINT
Assuming you are using Docker Toolbox and not the beta ...
There is a 3 step process for exposing a port properly:
use EXPOSE 8080 where 8080 is just a port number in the Dockerfile
use -p 8080:8080 in your docker run command
Make sure that you setup port forwarding in Oracle Virtual Box so that the boot2docker machine is able to receive requests from port 8080.
This applies to both Windows and OSX where Docker Toolbox is being used. Linux doesn't use Oracle VirtualBox to run docker so those hosts do not need to do the third point
I ran your repo as-is on Docker 1.12 on OSX.
If you look carefully at your container startup:
2016-08-29 20:52:31.028 INFO 5 --- [ main] o.eclipse.jetty.server.ServerConnector : Started ServerConnector#47949d1a{HTTP/1.1}{0.0.0.0:8080}
2016-08-29 20:52:31.033 INFO 5 --- [ main] .s.b.c.e.j.JettyEmbeddedServletContainer : Jetty started on port(s) 8080 (http/1.1)
Although application.yml and Dockerfile both contain 9200, the application is starting on 8080
Going to add another answer here because I saw something related to the Github Repo that you posted:
So the repo is a spring boot repo with an application.yml file.
Your Dockerfile looks like this:
FROM openjdk:8
RUN mkdir /opt/bootup
ADD build/libs/bootup.jar /opt/bootup
WORKDIR /opt/bootup
EXPOSE 9200
ENTRYPOINT java -jar bootup.jar
Which is adding the built jar to the image. If my understanding is correct, the jar does not include application.yml because:
It is not part of the build (gradle would package the src/main only). It is sitting on the project root folder
It is not explicitly added to Docker
So therefore one can assume that your app is actually running on 8080 (the default) at the moment?
A couple of options that one could try:
Try exposing 8080 instead of 9200 (or expose both) and see if that makes a difference?
The entrypoint command can append the port --server.port=9200
The application.yml file should be added to the image (you might need to add an argument to reference it properly) [ADD application.yml /opt/bootup, after first ADD command]
Include the application.yml file in src/main/resources so that spring boot can pick it up automatically.
References
Spring Boot reference documentation on the order of loading for external configuration
Good News! (for MacOSx 10.15.7)
I found the same issue as you, and I was able to solve it by directly opening VirutalBox connection
Go here first:
changed to bridged then logged into the virtual machine within VirtualBox
And found the actual machine's adapter labeled:
eth0
after I noted the setting it was originally NAT so I changed to bridged and then
I was able to use its address vs. localhost.
After I used the public address I used:
curl -i [bridged_ip_address_here]:9200
it then worked flawlessly.
However I also noticed some firewalls and accessibility options that needed permission as well.
I pray this helps you.
I am new to docker. I want to run my java application on tomcat server using docker images/containers. Can anyone suggest best method to do that?
First find a docker image with the version of tomcat you want. You can search docker images using, docker search so try
docker search tomcat
next pull it locally
docker pull <your/image>
then run commands on it to install your software
docker run <your/image> <your command and args>
then find your container ID by running
docker images
and commit you changes
docker commit <container_id> <some_name>
I'd recommend the docker tutorial to get started.
P.S. this answer will show you how to transfer files to docker.