Java8/gradle support for proxy settings

[padiazg]

Modified Dockerfile for java8 to accept gradle_ops via --build_arg
With this modification now you can pass graddle_ops using --build_arg, so you can specify proxy settings for Gradle.
Signed-off-by: Patricio Diaz [email protected]

Description

• Moved org.gradle.daemon=false to gradle.propoerties, deleted it from Dockerfile
• Added ARG and ENV command to Dockerfile to catch GRADLE_OPTS passed as parameter.
• Updated README.md to show how to use it in an corporate proxy scenario

Motivation and Context

This is needed for successfully building functions if you are behind a proxy
#105

• I have raised an issue to propose this change (required)

Which issue(s) this PR fixes

Fixes #105

How Has This Been Tested?

1. Created new project folder
2. Copied manually modified template folder into it.
3. faas-cli.exe new java8-proxy --lang java
4. faas-cli up -f java8-proxy.yml -b gradle_opts="-Dhttp.proxyHost=my-proxy -Dhttp.proxyPort=3128 -Dhttps.proxyHost=my-proxy -Dhttps.proxyPort=3128"

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I've read the CONTRIBUTION guide
• I have signed-off my commits with git commit -s
• I have added tests to cover my changes.
• All new and existing tests passed.

[tessellator]

I think this looks great! However, I am concerned about always having to specify any additional gradle opts on the command line. Personally, I would like to have the ability to persist and version control the options in addition to providing them on the command line. Persisting the options would reduce tribal knowledge and/or additional scripts required to build functions.

This could be achieved by moving the gradle.properties file into the function folder and adding a command to the Dockerfile to move it into the root project folder before building, e.g.:

...
COPY . /home/app/
RUN if [ -f /home/app/function/gradle.properties ] ; then mv /home/app/function/gradle.properties /home/app/gradle.properties ; fi
RUN gradle build
...

If you want to ensure that org.gradle.daemon=false is always specified, you could instead append a function-local gradle.properties file to the gradle.properties file in the root build folder.

This approach would continue to work with the --build-arg change you have already made. What do you think?

[padiazg]

I like your suggestion, as I'm not an experienced Java programmer. I'll try it and see to add it to the PR.

Can you explain this a little more to me, please:

If you want to ensure that org.gradle.daemon=false is always specified, you could instead append a function-local gradle.properties file to the gradle.properties file in the root build folder.

[tessellator]

Absolutely! I apologize for not being clear in my previous comment. All I mean is that you could replace:

RUN if [ -f /home/app/function/gradle.properties ] ; then mv /home/app/function/gradle.properties /home/app/gradle.properties ; fi

with

RUN if [ -f /home/app/function/gradle.properties ] ; then cat /home/app/function/gradle.properties >> /home/app/gradle.properties ; fi

in my previous example. This would ensure that the gradle.properties file you created in this PR would always be used (org.gradle.daemon=false), and that anything a dev added in a gradle.properties file with their function (like proxy settings) would be appended to it.

[alexellis]

Sorry this PR has become inactive, I'm going to close. Feel free to raise a new one if required to cover java11, java11-vert-x and so forth. cc @pmlopes