Update gradle build

[devinbileck]

Resolves concerns discussed in bisq-network/bisq#1901 (comment)

• Update build.gradle to ensure reproducible builds
• Generate MD5 hash file and print it during gradle build
• Update source/target compatibility to 1.10

[cbeams]

NACK, per comments.

[cbeams]

This line isn't necessary.

Suggested change

apply plugin: 'java'

[devinbileck]

Thanks, you're right. That's what I get for following examples too closely. I will remove it.

[cbeams]

No need to do this. We're not using 1.10 syntax, and furthermore this plugin is Groovy-based, not Java based, so the whole thing is kind of irrelevant.

[devinbileck]

My intention was for consistency with https://github.com/bisq-network/bisq/blob/master/build.gradle#L19.
But good point, I hadn't considered it is completely irrelevant. Perhaps I should just remove it?

[cbeams]

I'm producing a different checksum result locally than what you report at bisq-network/bisq#1901 in the commit comment on bisq-network/bisq@ee96822:

~/Work/bisq-network/gradle-witness[update-gradle-build]
$ git log -1 --oneline
a4a1b2d (HEAD -> update-gradle-build, devinbileck/update-gradle-build) Update source/target compatibility to 1.10

$ ./gradlew --version
------------------------------------------------------------
Gradle 4.10.2
------------------------------------------------------------

Build time:   2018-09-19 18:10:15 UTC
Revision:     b4d8d5d170bb4ba516e88d7fe5647e2323d791dd

Kotlin DSL:   1.0-rc-6
Kotlin:       1.2.61
Groovy:       2.4.15
Ant:          Apache Ant(TM) version 1.9.11 compiled on March 23 2018
JVM:          10.0.2 ("Oracle Corporation" 10.0.2+13)
OS:           Mac OS X 10.12.5 x86_64

$ ./gradlew clean build
> Task :compileGroovy
> Task :jar
md5=ae4796f320ef3200515183fa9d3f4759

BUILD SUCCESSFUL in 2s
4 actionable tasks: 4 executed

$ cat ./build/libs/gradle-witness.jar.MD5
ae4796f320ef3200515183fa9d3f4759

(your commit comment says you produce the md5 sum 237be11ebb7604afa5ff478ec33d1df5)

[devinbileck]

Argg! I will investigate further.

[devinbileck]

It is due to different line endings in the witness.properties file. If I change it to LF (vs CRLF) I get the same result as you. Shall I add a .gitattributes file to ensure consistent line endings and prevent issues like this in the future?

[cbeams]

ACK. I can confirm I now get the same md5 sum when building the jar locally. Thanks, @devinbileck.