Maven Repository – Go Offline with dependencies

Maven Repository

My team uses the pom.xml to generate a repository which is handed off to the secondary developers. For instance, I have a custom db2 jar

## Update your localRepository
Start a Shell
cd ~/.m2
vim settings.xml
add `<localRepository>/Users/userid/git/client-app/documentation/repo/local_repo</localRepository>`
Note: the path is relative to the location of my repo
You may have to create the folder local_repo
Save the file to where it makes most sense

## Take the Repo Offline
Change directory to the `repo` folder
`mvn dependency:go-offline`
cd local_repo
remove any previous zip
Run `zip -9 -v -r repo.zip ‘base-path-for-jars-you-want/’` (Only archives into the zip the dependencies you want)
Upload the zip to the `client-app` wiki

## Remove your local repository line
Start a shell
cd ~/.m2
vim settings.xml
remove the `<localRepository>` node
Save the file

Maven Animal Sniffer Plugin

For the past few years, most of my personal and professional projects are built using Maven.  The dependency management and corresponding build lifecycle enable me to do some complex builds (for instance HBase 1.2.5 Client Jars).

Command

 mvn dependency:tree -f demo-app/pom.xml

Result

[INFO] demo.app:demo-app:jar:1.0-SNAPSHOT
[INFO] +- junit:junit:jar:4.12:test
[INFO] |  \- org.hamcrest:hamcrest-core:jar:1.3:test
[INFO] \- org.apache.hbase:hbase:pom:1.2.5:compile
[INFO]    +- com.github.stephenc.findbugs:findbugs-annotations:jar:1.3.9-1:compile
[INFO]    \- log4j:log4j:jar:1.2.17:compile

When these dependencies change underlying the build change, the build and debugging is a pain. I ran into this plugin Maven Animal Sniffer Plugin. I did have to enable a specific configuration <configuration><includeJavaHome>false</includeJavaHome></configuration>

Command

mvn animal-sniffer:build -f demo-app/pom.xml 

Result

[INFO] --- animal-sniffer-maven-plugin:1.16:build (default-cli) @ demo-app ---
[INFO] Parsing signatures from com.github.stephenc.findbugs:findbugs-annotations:jar:1.3.9-1
[INFO] Parsing signatures from log4j:log4j:jar:1.2.17
[INFO] Parsing signatures from /Users/paulbastide/Downloads/animal/demo-app/target/classes
[INFO] Wrote signatures for 337 classes.

I can now store this along with my build. The generated file demo-app/target/demo-app-1.0-SNAPSHOT.signature can then be used to check plugin

Primer: Tips for using Random Test Files

On Mac and Linux, create a random file (https://stackoverflow.com/questions/257844/quickly-create-a-large-file-on-a-linux-system)
dd if=/dev/urandom of=random-test-file-100m bs=1024k count=100

Example:
$ dd if=/dev/urandom of=random-test-file-100m bs=1024k count=100
100+0 records in
100+0 records out
102400000 bytes transferred in 10.143507 secs (10095128 bytes/sec)

This is a random file. You should also use shasum -A 256 and make sure the file you are using for test is what you get back. Do also remember 1024 bytes to a KB… use blocksizes of 1024

On linux, create a fast file (https://stackoverflow.com/a/11779492):
fallocate -l 100M test-file-100m

This takes less than a second. The file is not good for testing random behaviors with large files as the generated file is huge, but the same bytes repated for 100M.

To check the size of the sample files, you can use human readable format settings (https://unix.stackexchange.com/a/281113).

MacBook-Air:test user$ ls -lSh
total 24
-rw-r–r– 1 user staff 10K Dec 20 19:53 setup.log