Running rust on Docker: Empty reply from server - docker

I'd like to run a rust web app in a docker container. I'm new to both technologies so I've started out simple.
Here is main.rs:
extern crate iron;
use iron::prelude::*;
use iron::status;
fn main() {
fn hello_world(_: &mut Request) -> IronResult<Response> {
Ok(Response::with((status::Ok, "Hello World!")))
}
Iron::new(hello_world).http("127.0.0.1:8080").unwrap();
}
Cargo.toml
[package]
name = "docker"
version = "0.1.0"
[dependencies]
iron = "*"
Dockerfile (adapted from this tutorial)
FROM jimmycuadra/rust
EXPOSE 8080
COPY Cargo.toml /source
COPY src/main.rs /source/src/
CMD cargo run
These are the commands I ran:
docker build -t oror/rust-test
docker run -it -p 8080:8080 --rm -v $(pwd):/source -w /source oror/rust-test cargo run
docker ps
Terminal Ouput
ifconfig to get my machine's IP address: 192.168.0.6
curl 192.168.0.6:8080 to connect to my rust web app
curl: (52) Empty reply from server
I've tried localhost:8080 and I still get the same output.
What am I missing?

The problem is your web server is listening to requests from 127.0.0.1 (local interface) but from inside your container. From the container point of view, your host is outside so you need to listen to requests from 0.0.0.0, then it should works.
Iron::new(hello_world).http("0.0.0.0:8080").unwrap();
If you need to filter where your requests come from, I suggest you to do it from outside your container with a firewall or something like that.

Related

HTTP call to Logic App in a Docker Container

I've followed getting started with Logic Apps in a Container, in Azure Tips & Tricks #311, which worked OK. I also consulted Vinnie James, which is similar
The Logic App runs on receipt of a HTTP request, which - inside VS Code - is localhost, easily used from a browser
But when I go to the next step, to build an image and run it in Docker, I'm not at all clear how to to make a similar HTTP request; Docker is running on the same W10 machine, using WSL-2
Dockerfile (corrected):
FROM mcr.microsoft.com/azure-functions/dotnet:3.0.14492-appservice
ENV AzureWebJobsStorage=DefaultEndpointsProtocol=https;AccountName=XXX;AccountKey=XXX;EndpointSuffix=core.windows.net
ENV AzureWebJobsScriptRoot=/home/site/wwwroot \
AzureFunctionsJobHost__Logging__Console__IsEnabled=true \
FUNCTIONS_V2_COMPATIBILITY_MODE=true
ENV WEBSITE_HOSTNAME localhost
ENV WEBSITE_SITE_NAME testqueue1
ENV AZURE_FUNCTIONS_ENVIRONMENT Development
COPY . /home/site/wwwroot
Attempted Docker run: docker run -p 80:7071 image1
Response is HTTP request sent, awaiting response... No data received
This despite (very simple) Logic App issuing a 200 response immediately after trigger; looks like App is not initiated ...
First of all and regarding the answer in the comments: please just add the contents of the Dockerfile and the run command to the question, otherwise they're difficult to read.
Taking into account that you have the following Dockerfile:
FROM mcr.microsoft.com/azure-functions/node:3.0
ENV AzureWebJobsStorage DefaultEndpointsProtocol=https;AccountName=XXX;AccountKey=XXX;EndpointSuffix=core.windows.net
ENV AzureWebJobsScriptRoot=/home/site/wwwroot \
AzureFunctionsJobHost__Logging__Console__IsEnabled=true \
FUNCTIONS_V2_COMPATIBILITY_MODE=true
ENV WEBSITE_HOSTNAME localhost
ENV WEBSITE_SITE_NAME test1
ENV AZURE_FUNCTIONS_ENVIRONMENT Development
COPY . /home/site/wwwroot
and that you're running it with docker run -p 5000 image1
The main thing that I see here is that you're only indicating the containerPort but not the hostPort, so you're exposing a random port in the host.
If you do docker ps, you'll be able to see the port that you're forwarding. For example let's say that I have my image busybox and that I run it with docker run -it --rm -p 5000 busybox.
❯ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
05927642abfc busybox "sh" 6 seconds ago Up 5 seconds 0.0.0.0:51883->5000/tcp elated_gauss
As you can see, I'd have to access to the port 51883 in localhost to access to the port 5000 in the container.
On the other hand, if I run my container with: docker run -it --rm -p 5000:5000 busybox
❯ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
c0aab9646d1a busybox "sh" 1 second ago Up 1 second 0.0.0.0:5000->5000/tcp busy_roentgen
Now I can access to the port 5000 of the container referring to the port 5000 on localhost.

Trouble connecting to a TCP server through Docker on WSL 2

I'm using WSL2 on Windows 10 using an Ubuntu image, and Docker for Desktop Windows (2.2.2.0) with the WSL integration.
I have a super basic rust tcp server. I think the only relevant bit is:
let listener = TcpListener::bind("127.0.0.1:8080").unwrap();
println!("Listening on 8080");
for stream in listener.incoming() {
println!("Received connection");
let stream = stream.unwrap();
handle_connection(stream);
}
I can cargo install and run the binary without issue; the line above prints, I can curl localhost:8080 from WSL and see the response as I'd expect from the rest of the code.
I wanted to turn it into a docker image. Here's the Dockerfile.
FROM rust:1.40 as builder
COPY . .
RUN cargo install --path . --root .
FROM debian:buster-slim
COPY --from=builder ./bin/coolserver ./coolserver
EXPOSE 8080
ENTRYPOINT ["./coolserver"]
I then do:
docker build -t coolserver .
docker run -it --rm -p 8080:8080 coolserver
I see Listening on 8080 as expected (i.e. no panic), but attempting to curl localhost:8080 yields curl: (52) Empty reply from server. This, I don't know what to make of. Logging suggests my program gets to the point where it reaches listener.incoming(), but does not enter into the block.
To see if it was something to do with my setup (Docker for Desktop, WSL, etc.) or my Dockerfile, I followed the README for the docker-http-https-echo image, successfully. I can curl it on the specified ports.
I don't know how to debug further. Thanks in advance.
EXPOSE keyword is to open up ports for inter container communication for using these ports from host you have to use -p 8080:8080 while running docker via docker run
#CarlosRafaelRamirez resolved it for me. It was as simple as binding to 0.0.0.0 rather than the loopback address 127.0.0.1. More info here: https://pythonspeed.com/articles/docker-connection-refused/

Docker Port Not Exposing Golang

I am building a golang WebService in docker. The build seems fine but I am unable to expose the port for external (outside of container) access. When I curl from the command line (inside the container) the app appears to work fine.
I saw quite a few posts of similar problems but unfortunately many were not resolved or didn't seem applicable.
FROM golang:alpine
RUN mkdir /go/src/webservice_refArch
ADD . /go/src/webservice_refArch
WORKDIR /go/src/webservice_refArch
RUN apk add curl
RUN cd /go/src/webservice_refArch/ && go get ./...
RUN cd /go/src/webservice_refArch/cmd/reference-w-s-server && go build -o ../../server
EXPOSE 7878
ENTRYPOINT ["./server", "--port=7878"]
I have tried both:
:7878
localhost:7878
I was facing the same issue. Then what I did is change the ListernHost from localhost to 0.0.0.0 and it worked.
To debug this tried curl inside the container it was working fine but outside the container the response of the curl was blank. The port mapped but the content was not served outside the container. Once you change the "localhost" to 0.0.0.0 it will work.
See https://docs.docker.com/engine/reference/run/#expose-incoming-ports, just expose port in dockerfile is not enough.
You can add -p 7878:7878 when start container, or use -P to let docker set a automatical host port mapping for you.
If you do not want to do above, you can also add --net=host when start the container, then container will use host's network, if also works for you.
if you are trying to access the port inside your docker container from your local machine, you need map it to the desired port on your local machine
docker run -p 7878:7878 IMAGE
Then you should be able to access it on your host

Connection refused on docker container

I'm new to Docker and trying to make a demo Rails app. I made a dockerfile that looks like this:
FROM ruby:2.2
MAINTAINER marko#codeship.com
# Install apt based dependencies required to run Rails as
# well as RubyGems. As the Ruby image itself is based on a
# Debian image, we use apt-get to install those.
RUN apt-get update && apt-get install -y \
build-essential \
nodejs
# Configure the main working directory. This is the base
# directory used in any further RUN, COPY, and ENTRYPOINT
# commands.
RUN mkdir -p /app
WORKDIR /app
# Copy the Gemfile as well as the Gemfile.lock and install
# the RubyGems. This is a separate step so the dependencies
# will be cached unless changes to one of those two files
# are made.
COPY Gemfile Gemfile.lock ./
RUN gem install bundler && bundle install --jobs 20 --retry 5
# Copy the main application.
COPY . ./
# Expose port 8080 to the Docker host, so we can access it
# from the outside.
EXPOSE 8080
# The main command to run when the container starts. Also
# tell the Rails dev server to bind to all interfaces by
# default.
CMD ["bundle", "exec", "rails", "server", "-b", "0.0.0.0", "-p", "8080"]
I then built it like so:
docker build -t demo .
And call a command to start the server which does start the server on port 8080:
Johns-MacBook-Pro:demo johnkealy$ docker run -it demo
=> Booting WEBrick
=> Rails 4.2.5 application starting in development on http://0.0.0.0:8080
=> Run `rails server -h` for more startup options
=> Ctrl-C to shutdown server
[2016-04-23 16:50:34] INFO WEBrick 1.3.1
[2016-04-23 16:50:34] INFO ruby 2.2.4 (2015-12-16) [x86_64-linux]
[2016-04-23 16:50:34] INFO WEBrick::HTTPServer#start: pid=1 port=8080
I then try to find the correct IP to navigate to:
Johns-MacBook-Pro:demo johnkealy$ docker-machine ip default
192.168.99.100
I navigate to http://192.168.99.100:8080 and get the error This site can’t be reached 192.168.99.100 refused to connect.
What could I be doing wrong ?
You need to publish the exposed ports by using the following options:
-P (upper case) or --publish-all that will tell Docker to use random ports from your host and map them to the exposed container's ports.
-p (lower case) or --publish=[] that will tell Docker to use ports you manually set and map them to the exposed container's ports.
The second option is preferred because you already know which ports are mapped. If you use the first option then you will need to call docker inspect demo and check which random ports are being used from your host at the Ports section.
Just run the following command:
docker run -it -p 8080:8080 demo
After that your url will work.
If you are using Docker toolkit on window 10 home you will need to access the webpage through docker-machine ip command. It is generally 192.168.99.100:
It is assumed that you are running with publish command like below.
docker run -it -p 8080:8080 demo
With Window 10 pro version you can access with localhost or corresponding loopback 127.0.0.1:8080 etc (Tomcat or whatever you wish). This is because you don't have a virtual box there and docker is running directly on Window Hyper V and loopback is directly accessible.
Verify the hosts file in window for any digression. It should have
127.0.0.1 mapped to localhost
I had the same problem. I was using Docker Toolbox on Windows Home.
Instead of localhost I had to use http://192.168.99.100:8080/.
You can get the correct IP address using the command:
docker-machine ip
The above command returned 192.168.99.100 for me.
Command EXPOSE in your Dockerfile lets you bind container's port to some port on the host machine but it doesn't do anything else.
When running container, to bind ports specify -p option.
So let's say you expose port 5000. After building the image when you run the container, run docker run -p 5000:5000 name. This binds container's port 5000 to your laptop/computers port 5000 and that portforwarding lets container to receive outside requests.
This should do it.
In Docker Quickstart Terminal run following command:
$ docker-machine ip 192.168.99.100
In Windows, you also normally need to run command line as administrator.
As standard-user:
docker build -t myimage -f Dockerfile .
Sending build context to Docker daemon 106.8MB
Step 1/1 : FROM mcr.microsoft.com/dotnet/core/runtime:3.0
Get https://mcr.microsoft.com/v2/: dial tcp: lookup mcr.microsoft.com on [::1]:53: read udp [::1]:45540->[::1]:53: read:
>>>connection refused
But as an administrator.
docker build -t myimage -f Dockerfile .
Sending build context to Docker daemon 106.8MB
Step 1/1 : FROM mcr.microsoft.com/dotnet/core/runtime:3.0
3.0: Pulling from dotnet/core/runtime
68ced04f60ab: Pull complete e936bd534ffb: Pull complete caf64655bcbb: Pull complete d1927dbcbcab: Pull complete Digest: sha256:e0c67764f530a9cad29a09816614c0129af8fe3bd550eeb4e44cdaddf8f5aa40
Status: Downloaded newer image for mcr.microsoft.com/dotnet/core/runtime:3.0
---> f059cd71a22a
Successfully built f059cd71a22a
Successfully tagged myimage:latest
Make sure that you use the -p flag before the image name like this:
docker run -p 8080:8080 demo

Docker container with Blazegraph Triple Store not working possibly due to networking

I'm preparing a Docker image to teach my students the basics of Linked Data. I want them to actually prepare proper RDF and simulate the process of publishing it on the web as Linked Data, so I have prepared a Docker image comprising:
Triple Store: Blazegraph, listening to port 9999.
GRefine. I have copied an instance of Open Refine, with the RDF extension included. Listening to port 3333.
Linked Data Server: I have copied an instance of Jetty, with Pubby inside it. Listening to port 8080.
I have tested the three in my localhost (runing Ubuntu 14.04) and they work fine. This is the Dockerfile I'm using to build the image:
FROM ubuntu:14.04
MAINTAINER Mikel Egaña Aranguren <my.email#x.com>
RUN apt-get update && apt-get install -y openjdk-7-jre wget curl
RUN mkdir /LinkedDataServer
COPY google-refine-2.5 /LinkedDataServer/google-refine-2.5
COPY blazegraph /LinkedDataServer/blazegraph
COPY jetty /LinkedDataServer/jetty
EXPOSE 9999
EXPOSE 3333
EXPOSE 8080
WORKDIR /LinkedDataServer
CMD java -server -jar blazegraph/bigdata-bundled.jar
CMD google-refine-2.5/refine -i 0.0.0.0
WORKDIR /LinkedDataServer/jetty
CMD java -jar start.jar jetty.port=8080
I run the container and it does map the appropriate ports:
docker run -d -p 9999:9999 -p 3333:3333 -p 8080:8080 mikeleganaaranguren/linked-data-server:0.0.1
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
a08709d23acb mikeleganaaranguren/linked-data-server:0.0.1 /bin/sh -c 'java -ja 5 seconds ago Up 4 seconds 0.0.0.0:3333->3333/tcp, 0.0.0.0:8080->8080/tcp, 0.0.0.0:9999->9999/tcp dreamy_engelbart
The triple store, for example, seems to be working. If I go to 127.0.0.1:9999, I can access the triple store:
However, if try to do anything (queries, upload data, ...), the triple store simply fails with an "ERROR: Could not contact server". Since the same setting works on the host, I assume I'm doing something wrong with Docker. I have tried with -P instead of mapping the ports, and with --net=host, but I get the same error.
PS: Jetty also fails in the same fashion, and GRefine is not even working.
You'll need to make sure to use the IP of the docker container to access the Blazegraph instance. Outside of the container, it will not be running on 127.0.0.1, but rather the IP assigned to the docker container.
You'll need to run something like
docker inspect --format '{{ .NetworkSettings.IPAddress }}' "CONTAINER ID"
Where CONTAINER ID is the value of your docker instance.

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