If I build a cmake file, create an executeble with make and delete everything except the executable, the executable is still functional. Can I,
build the file but the only output is the file that can be executed with ./project
or
have all of the files build, create the executable with make, then delete everything except the executable afterwards
and if so, how do I?
If I am getting this correctly, you want to create a stand-alone binary that cannot be executed even if the docker image does not has any dependencies then you need to use static option during the build - i am not expert in this - maybe as described in the following answer of Compiling a static executable with CMake.
Next you might use a multi-stage builds in docker which will makes you able to have a final minimal image with your executable file only without any build dependencies, just the needed packages for your run-time environment. I have an example not with make, it was created using g++ but achieving the similar concept as below:
FROM gcc:5 as builder
COPY ./hello_world_example.cc /hello_world_example.cc
RUN g++ -o hello_world_binary -static hello_world_example.cc && chmod +x hello_world_binary
FROM debian:jessie
COPY --from=builder /hello_world_binary /hello_world_binary
CMD ["/hello_world_binary"]
And the final result when you run the container:
$ docker run --rm -it helloworldimage:latest
Hello from Dockerized image
Why do you need that?
You can add install() command to your CMakeLists.txt and then call make install to copy your executable into CMAKE_INSTALL_PREFIX directory. If you set CMAKE_INSTALL_PREFIX to an empty dir, you'd end with a directory containing only your executable file.
Related
[EDIT - added clarity]
Here is my current env setup :
$GOPATH = /home/fzd/go
projectDir = /home/fzd/go/src/github.com/fzd/amazingo
amazingo has a go.mod file that lists several (let's say thousands) dependencies.
So far, I used to go build -t bin/amazingo cmd/main.go, but I want to share this with other people and have a build command that is environment-independent. Using go build has the advantage of downloading each dependency once -- and then using those in ${GOPATH}/pkg/mod, which saves time and bandwidth.
I want to build in a multistage docker image, so I go with
> cat /home/fzd/go/src/github.com/fzd/amazingo/Dockerfile
FROM golang:1.17 as builder
COPY . .
RUN CGO_ENABLED=0 GOOS=linux go build -o /bin/amazingo cmd/main.go
FROM alpine:latest
COPY --from=builder /bin/amazingo /amazingo
ENTRYPOINT ["/amazingo"]
As you can expect it, the builder is "naked" when I start it, so it has to download all my dependencies when I docker build -t amazingo:0.0.1 . . But it will do so everytime I call it, which can be several times a day.
Fortunately, I already have most of these dependencies on my disk. I would be happy to share these files (that are located in my $GOPATH/pkg/mod) with the builder, and help it build faster on my machine.
So the question is: how can I share my ${GOPATH} (or ${GOPATH}/mod/pkg) with the builder ?
I tried adding the following to the builder
ARG SRC_GOPATH
COPY ${SRC_GOPATH} /go
and call docker build --build-arg SRC_GOPATH=${GOPATH} -o amazingo:0.0.1 ., but it wasn't good enough - I got an error (COPY failed: file not found in build context or excluded by .dockerignore: stat home/fzd/go: file does not exist)
I hope this update brings a bit more clarity to the problem.
=======
I have a project with a go.mod file.
I want to build that project using a multistage docker image.
(this article is a perfect example)
The issue is that I have "lots" of dependencies, and each of them will be downloaded inside my Docker builder stage.
Is there a way to "share" my GOPATH/pkg/mod with the docker build... command (in some ways, having a local cache) ?
Your end goal isn't completely clear, but the way that I use a multistage build would look something like this for a (dirt-simple) go app, assuming that you ultimately want the docker container to run your go app. You will need to get your source into the build container somehow as well - that is not shown here:
FROM golang:1.17.2-alpine3.14 as builder
WORKDIR /my/app/source/dir
RUN go get && go build -o /path/to/my/app/binary
FROM alpine3.14 AS release
# install runtime deps, if any
# create necessary files and folders, if any
COPY --from=builder /path/to/my/app/binary /usr/local/bin
ENTRYPOINT /usr/local/bin/binary --options
In this way, the source of your application and all dependencies will not be present in the released image, only the compiled binary.
Of course you don't have to specify an output path for that, I think it just makes it a little clearer in this example. And of course you can use whatever base image/images you want to - I'm treating this as though you don't need the go runtime on your release image.
Goal
I am using Docker to run JMeter in Azure Devops. I am trying to use Blazemeter's Parallel Controller, which is not native to JMeter. So, according to the justb4/jmeter image documentation, I used the following command to get the image going and run the JMeter test:
docker run --name jmetertest -i -v /home/vsts/work/1/s/plugins:/plugins -v $ROOTPATH:/test -w /test justb4/jmeter ${#:2}
Error
However, it produces the following error while trying to accommodate for the plugin (I know the plugin makes the difference due to testing without the plugin):
cp: can't create '/test/lib/ext': No such file or directory
As far as I understand, this is an error produced when one of the parent directories of the directory you are trying to make does not exist. Is there something I am doing wrong, or is there actually something wrong with the image?
References
For reference, I will include links to the image documentation and the repository.
Image: https://hub.docker.com/r/justb4/jmeter
Repository: https://github.com/justb4/docker-jmeter
Looking into the Dockerfile:
ENV JMETER_HOME /opt/apache-jmeter-${JMETER_VERSION}
Looking into entrypoint.sh
if [ -d /plugins ]
then
for plugin in /plugins/*.jar; do
cp $plugin $(pwd)/lib/ext
done;
fi
It basically copies the plugins from /plugins folder (if it is present) to /lib/ext folder relative to current working directory
I don't know why did you add this stanza -w /test to your command line but it explicitly "tells" the container that local working directory is /test, not /opt/apache-jmeter-xxxx, that's why the script is failing to copy the files.
In general I don't think that the approach is very valid because:
In Azure DevOps you won't have your "local" folder (unless you want to add plugins binaries under the version control system)
Some JMeter Plugins have other .jars as the dependencies so when you're installing the plugin you should:
put the plugin itself under /lib/ext folder of your JMeter installation
put the plugin dependencies under /lib folder of your JMeter installation
So I would recommend amending the Dockerfile, download JMeter Plugins Manager and installed the plugin(s) you need from the command line
Something like:
RUN wget https://jmeter-plugins.org/get/ -O /opt/apache-jmeter-${JMETER_VERSION}/lib/ext/jmeter-plugins-manager.jar
RUN wget https://repo1.maven.org/maven2/kg/apc/cmdrunner/2.2/cmdrunner-2.2.jar -P /opt/apache-jmeter-${JMETER_VERSION}/lib/
RUN java -cp /opt/apache-jmeter-${JMETER_VERSION}/lib/ext/jmeter-plugins-manager.jar org.jmeterplugins.repository.PluginManagerCMDInstaller
RUN /opt/apache-jmeter-${JMETER_VERSION}/bin/./PluginsManagerCMD.sh install bzm-parallel
I am building a Wasm application and to compile it I have a shell script.
When I run it manually from terminal I have the following:
/app/Go/assets$ ./script.compile.wasm.sh
Wasm compiled
The content of the file is:
#!/bin/sh
GOOS=js GOARCH=wasm go build -o ./app.wasm ./wasm.go
echo "Wasm compiled"
The wasm file is properly compiled.
But when I run it from Docker I get:
Step 15/20 : RUN ./assets/compile.wasm.sh
---> Running in 38dd56259b0f
go: cannot find main module; see 'go help modules'
Wasm compiled
The compilation fails.
The Docker line looks like:
RUN ./assets/compile.wasm.sh
In your local case, you're launching the script from the assets directory; in the Dockerfile case you're launching it from its parent directory. This matters because when the script references files like ./wasm.go, those are resolved relative to the current directory and not the directory containing the script.
You can resolve this by making sure you're in the assets directory in the Dockerfile too:
# Only for this command; will reset afterwards
RUN cd assets && ./compile.wasm.sh
# For this and all following commands, unless reset with another WORKDIR
WORKDIR /app/Go/assets
RUN ./compile.wasm.sh
I am trying to follow the 2 steps mentioned below:
1) Downloaded source code of
https://sourceforge.net/projects/hunspell/files/Hyphen/2.8/hyphen-2.8.8.tar.gz/download
2) Compiled it and you will get binary named example:
hyphen-2.8.8$ ./example ~/dev/smc/hyphenation/hi_IN/hyph_hi_IN.dic
~/hi_sample.text
I have downloaded and uncompressed the tar file. My question is how to create a dockerfile to automate this?
There are only 3 commands involved:
./configure
make all-recursive
make install
I can select the official python image as a base container. But how do I write the commands in a docker file?
You can do that with a RUN command:
FROM python:<version number here>
RUN ./configure && make-recursive && make install
CMD ['<some command here>']
what you use for <some command here> depends on what the image is meant to do. Remember that docker containers only run as long as that command is executing, so if you put the configure/make/install steps in a script and use that as your entry point, it's going to build your program, and then the container will halt.
Also you need to get the downloaded files into the container. That can be done using a COPY or an ADD directive (before the RUN of course). If you have the tar.gz file saved locally, then ADD will both copy the file into the container and expand it into a directory automatically. COPY will not expand it, so if you do that, you'll need to add a tar -zxvf or similar to the RUN.
If you want to download the file directly into the container, that could be done with ADD <source URL>, but in that case it won't expand it, so you'll have to do that in the RUN. COPY doesn't allow sourcing from a URL. This post explains COPY vs ADD in more detail.
You can have the three commands in a shell script and then use the following docker commands
COPY ./<path to your script>/<script-name>.sh /
ENTRYPOINT ["/<script-name>.sh"]
CMD ["run"]
For reference, you can create your docker file as they have created for one of the projects I worked on Apache Artemis Active Mq:
https://github.com/apache/activemq-artemis/blob/master/artemis-docker/Dockerfile-ubuntu
I am working on a cxx project using docker and cmake to build and I'm now tasked to integrate a third party library that I have locally.
To get started I added a project containing only a src folder and a single cpp file with a main function as well as includes that I will need from the library mentioned above. At this point, I'm already stuck as my included files are not found when I build in the docker environment. When I call cmake without docker on the project then I do not get the include error.
My directory tree:
my_new_project
CMakeLists.txt
src
my_new_project.cpp
In the CMakeLists.txt I've the following content:
CMAKE_MINIMUM_REQUIRED (VERSION 3.6)
project(my_new_project CXX)
file(GLOB SRC_FILES src/*.cpp)
add_executable(${PROJECT_NAME} ${SRC_FILES})
include_directories(/home/me/third_party_lib/include)
What is needed to make this build in the Docker environment? Would I need to convert the third party library into another project and add it as dependency (similar to what I do with projects from GitHub)?
I would be glad for any pointers into the right direction!
Edit:
I've copied the entire third party project root and can now get add include directories with include_directories(/work/third_party_lib/include), but would that be the way to go?
When you are building a new dockerized app, you need to COPY/ADD all your src, build and cmake files and define RUN instructions in your Dockerfile. This will be used to build your docker image that captures all the necessary binaries, resources, dependencies, etc.. Once the image is built, you can run the container from that image on docker, which can expose ports, bind volumes, devices, etc for your application.
So essentially, create your Dockerfile:
# Get the GCC preinstalled image from Docker Hub
FROM gcc:4.9
# Copy the source files under /usr/src
COPY ./src/my_new_project /usr/src/my_new_project
# Copy any other extra libraries or dependencies from your machine into the image
COPY /home/me/third_party_lib/include /src/third_party_lib/include
# Specify the working directory in the image
WORKDIR /usr/src/
# Run your cmake instruction you would run
RUN cmake -DKRISLIBRARY_INCLUDE_DIR=/usr/src/third_party_lib/include -DKRISLIBRARY_LIBRARY=/usr/src/third_party_lib/include ./ && \
make && \
make install
# OR Use GCC to compile the my_new_project source file
# RUN g++ -o my_new_project my_new_project.cpp
# Run the program output from the previous step
CMD ["./my_new_project"]
You can then do a docker build . -t my_new_project and then docker run my_new_project to try it out.
Also there are few great examples on building C** apps as docker containers:
VS Code tutorials: https://blogs.msdn.microsoft.com/vcblog/2018/08/14/c-development-with-docker-containers-in-visual-studio-code/
GCC image and sample: https://hub.docker.com/_/gcc/
For more info on the this, please refer to the docker docs:
https://docs.docker.com/engine/reference/builder/