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
Related
I want to build on top of a windows docker container by installing a couple programs. The files total .5 GB and I want to keep the layers as small as possible. I am hoping I can run the setup files from the build-context, and then have the build-context swept away at the end so I don't have a needless copy of the source files for the setup.exe embedded in my container layers. However, I have not found an example where this is the case. Instead I mostly see people run a COPY command to a temporary build folder, run their setup, then remove the folder. Won't those files still be in the container layers because the COPY command creates a new layer when it's done?
I don't know if the container can see the build-context directly. I was hoping for some magical folder filled with the build-context files so I could run a script using it, but haven't found anything.
It seems like the alternative is to create a private file-server and perform a RUN that can download them from that private server and unpack them, run the install, and remove them (all as 1 docker step). I understand this would make it more available to others who need to rerun the build, but I'm not convinced we'll need to rerun it. It's not likely to change as the container will build patches for a legacy application. Just seems like a lot to host files on a private, public-facing server for something that will get called once every couple years if ever.
So are these my two options?
Make a container with needless copies of source files embedded within
Host the files on a private file server and download/install/remove them
Or am I missing another option or point about how the containers work?
It's a long shot as Windows is a tricky thing with file system, but you could do this way:
In your Dockerfile use a COPY command, install then RUN del ... to remove the installation files
Build your image docker build -t my-large-image:latest .
Run your image docker run --name my-large-container my-large-image:latest
Stop the container
Export your container filesystem docker export my-large-container > my-large-container.tar
Import the filesystem to a new image cat my-large-container.tar | docker import - my-small-image
Caveat is you need to run the container once which might not be what you want. And also I haven't tested with windows container, sorry.
I usually do the download or copy in one step, then in the next step I do the silent installation and remove the installer.
# escape=`
FROM mcr.microsoft.com/dotnet/framework/wcf:4.8-windowsservercore-ltsc2016
SHELL ["powershell", "-Command", "$ErrorActionPreference = 'Stop'; $ProgressPreference = 'SilentlyContinue';"]
ADD https://download.visualstudio.microsoft.com/download/pr/6afa582f-fa26-4a73-8cb9-194321e85f8d/ecea51ead62beb7acc73ad9799511ffdb3083ad384fe04ec50e2cbecfb426482/VS_RemoteTools.exe VS_RemoteTools_x64.exe
RUN Start-Process .\\VS_RemoteTools_x64.exe -ArgumentList #('/install','/quiet','/norestart') -NoNewWindow -Wait; `
Remove-Item -Path C:/VS_RemoteTools_x64.exe -Force;
But otherwise, I don't think you can mount a custom volume while it's being built.
I didn't find a satisfactory answer to this. Docker seems designed for only the modern era and assumes you'll be able to download what you need via scripts and tools hitting APIs and file servers. The easiest option I found that I eventually went with was to host the files on a private file server or service (in my case, AWS S3).
I really wish there was a way to have files hosted by the docker daemon in some way, eg. if it acted like a temporary server that you could get data from via http instead of needing to COPY the files and create a layer. Alas, I found no such feature.
Taking this route made my container about a GB smaller.
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
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.
FROM "this line works but cant show code"
RUN yum install -y java-1.8.0-openjdk.x86_64 && yum clean all
COPY /resources/accounts.txt /home/resources/accounts.txt
COPY elk_casino_server /home/elk_casino_server
CMD ["jar","cvmf","/home/elk_casino_server/src/META-INF/MANIFEST.MF","/home/server.jar","/home/elk_casino_server/src/Main.class"]
CMD ["java","-jar","/home/server.jar"]
Please take a little more time to format your code snippets correctly and to make sure you ask a clear question.
Your Dockerfile uses the COPY instruction to copy two resources into your container image:
/resources/accounts.txt (available within the image at /home/resources/accounts.txt)
/elk_casino_server (available within the image at /home/elk_casino_server)
Unfortunately, your CMD instructions are trying to execute something very different. Only one command instruction can be defined and the latter will be accepted, which is:
CMD ["java","-jar","/home/server.jar"]
At no point do you copy /home/server.jar into your container image.
The parameter order of the char command seems to be wrong. The manifest-addition should come after the jar-file, not before it.
jar cfm jar-file manifest-addition input-file(s)
see: Packaging Programs in JAR Files: Modifying a Manifest File
Also: If there are more than one CMD, the last one overrides the others. Since I think you want to pack the jar at build time, RUN might be a better choice.
Both points combined:
RUN jar cvmf /home/server.jar /home/elk_casino_server/src/META-INF/MANIFEST.MF /home/elk_casino_server/src/Main.class
I have a big tar/executable (over 30GB) I COPY/ADD it but this is used only for the installation. Once the application is installed I don't need it anymore.
How can I do? I am trying to use it but:
Everytime I run a build, it takes minutes to define the build context.
I'd like to share this image, if I create a tar with docker save, Is the final version or each layer included in it?
I found some solutions that said I can use RUN wget tar ... && rm tar but I don't want to create webserver for that.
Why isn't possible to mount a volume during build process?! It would be very useful.
Use Docker's multi-stage builds. This mechanism allows you to drop intermediate artifacts and therefore achieve a lightweight image.
Example:
FROM alpine:latest as build
# copy large file
# build
FROM alpine:latest as output
# copy necessary files built in the previous stage
COPY --from=build app /app
Anything built in the build stage will not be included in the final image, unless you explicitly COPY them.
Docs: https://docs.docker.com/develop/develop-images/multistage-build/
This is solvable using 2 different context.
Please follow these steps as mentioned below.
Objective is to create a
docker image that will have you large-build file.
docker image that will have you real codebase/executables.
For this you have to create 2 folders (Build & CodeBase) as follow.
Application<br/>
|---> BUILD <br/>
|======|--->Large-File<br/>
|======|--->Dockerfile<br/>
|--->CodeBase<br/>
|======|--->SRC+Other stuff<br/>
|======|--->Dockerfile<br/>
Build & Codebase both folders will have individual Dockerfile and arrange files accordingly.
Dockerfile(Build)
FROM **Base-Image**
COPY Large-File /tmp/Large-File
Build this and tag it with some name like (base-build-app-image)
#>cd Application <==Application root folder as mentioned above==>
#>docker build -t base-build-app-image BUILD <==path of your build-folder==>
Dockerfile(Codebase)
FROM base-build-app-image
RUN *****
CMD *****
RUN rm -f **/tmp/Large-File**
RUN rm -f **Remove installation files that is not required**
ENTRYPOINT *****
Build this-code-base and base-build-app-image is already in your local docker-repository and your large iso file is not in the current-buid-context
#>cd Application <==Application root folder as mentioned above==>
#>docker build CodeBase <==path of your code-base==>
This time since the context size is only your code base and since this doesn't include that Large file - it will definitely reduce your build time.
You can also take an advance of using docker-compose to do both operations together so you will not have to execute 2 separate commands.
If you need help on preparing this docker-compose file then do let me know in comments.
If anything is not clear then leave a comment or come over chat to fix this issue.