Scripting Maven Deployments with Ruby

Recently I had to import a number of legacy projects into a Maven-type structure. I knocked up the following script to make the task easier for repeated applications. Basically what it does is the following:

  • Tried to parse the filenames of jars in the current directory;
  • Does a Nexus search to see if it can locate the artifact;
  • If it finds the artifact in Nexus, it can use the GAV parameters for that artifact, otherwise, it generates a GAV stanza for inclusion in the POM.
  • For each artifact that could not be located in Nexus, it generates a mvn deploy:deploy-file command to upload the dependency

Error handling is non-existent in this file, so caveat emptor!

#!/usr/bin/ruby
require 'net/http'
require 'rexml/document'
include REXML
# Nexus server
host="nexus-server"
port=8080
# Could also use GAV parameters in query string
url="http://#{host}:#{port}/nexus/service/local/data_index?q="
print "<dependencies>","\n"
# Open file for dependencies entries
depsFile=File.open("dependencies.xml",'w')
depsFile.write("</dependencies><dependencies>\n")
# Track unprocessed jars
errors=[]
# Jars to be uploaded to Nexus
uploads=[]
for jarFile in Dir.glob("*.jar")
    if jarFile =~ /([A-Za-z\-\.0-9]+?)(?:\-)?(\d+(?:\.\d+)*)?.jar/
        artifact=$1
        version=$2
        if artifact =~ /(\S+)\.(.*)/
            group=$1
            artifact=$2
        else
            group=artifact.gsub("\-", "\.")
        end
        if version.nil?
            version="1.0"
        end
        # Create a default stanza template
        stanza = "<dependency>\n"
        stanza < < '  <groupId>#{group}\n'
        stanza < < '  <artifactId>#{artifact}<artifactid>\n'
        stanza < < '  <version>#{version}\n'
        stanza < < "  <packaging>jar\n"
        stanza < < "</dependency>\n\n"
        puts "Searching Nexus for #{artifact}"
        query="#{url}#{artifact}"
        resp = Net::HTTP.get_response(URI.parse(query))
        respDoc = REXML::Document.new(resp.body)
        XPath.each(respDoc, "//search-results/totalCount") do |count|
            matches = Integer(count.text)
            if matches > 0
                idx=1; artifactMap = {}
                XPath.each( count, "//data/artifact") do |ar|
                    artifactId=ar.elements["artifactId"].text
                    artifactGroupId=ar.elements["groupId"].text
                    artifactVersion=ar.elements["version"].text
                    artifactRepo=ar.elements["repoId"].text
                    puts "#{idx}. #{artifactGroupId}:#{artifactId}:#{artifactVersion} (repo:#{artifactRepo})"
                    artifactMap[idx]={"group",artifactGroupId, "artifact",artifactId, "version",artifactVersion}
                    idx+=1
                end
                puts "Found #{matches} possible match(es) for #{group}:#{artifact}:#{version}"
                puts "Enter artifact number, or enter to use generated artifact:"
                num=gets.chomp
                if !num.empty?
                    num=Integer(num)
                    entry=artifactMap[num]
                    group=entry["group"];artifact=entry["artifact"];version=entry["version"]
                else
                    uploads.push( {"artifact",artifact,"group",group,"version",version,"file",jarFile} )
                end
            else
                uploads.push( {"artifact",artifact,"group",group,"version",version,"file",jarFile} )
            end
            stanza = eval('"' + stanza + '"')
            depsFile.write(stanza)
        end
    else
        errors < < jarFile
    end
end
depsFile.write("</dependencies>\n")
depsFile.close
puts "Finished processing.\nCheck the file dependencies.xml for generated XML"
# Generate the upload script
File.open("upload_deps.sh", "w") { |f|
    f.puts "#!/bin/bash\n\n"
    uploads.each do |dep|
        # Send the file to the correct repo
        repo="http://#{host}:#{port}/nexus/content/repositories/"
        if dep["version"] =~ /(.*)SNAPSHOT/
            repo < < "snapshots"
        else
            repo << "releases"
        end
        line="mvn deploy:deploy-file -Dfile=#{dep["file"]} -DartifactId=#{dep["artifact"]} -DgroupId=#{dep["group"]} -Dversion=#{dep["version"]} -Dpackaging=jar -DrepositoryId=nexus -DgeneratePom=true -Durl=#{repo}"
        f.puts "echo \"Uploading #{dep["file"]}...\""
        f.puts line
    end
}
puts <<HERE
The file upload_deps.sh contains Maven commands to upload dependencies not currently in Nexus.
This assumes that you have a stanza in $MVN_HOME/conf/settings.xml as follows:
<server>
    <id>nexus</id>
    <username>$USERNAME</username>
    <password>$PASSWORD</password>
Where the appropriate Nexus deployment credentials are in <username> and <password>.
HERE
if !errors.empty?
    puts "The following jar files could not be processed and need to be manually defined:"
    errors.each do |error|
        puts error
    end
end

GSoC Commons-Net SSH Concluded

Today is officially “pencils-down” day for the Google Summer of Code Project 2009. I have been a mentor this year for the Apache Commons-Net SSH project, which aims to add SSH and SCP support to Commons-Net.

The project has been a great success, mainly down to the super work performed by the student, Shikhar, who has put in tremendous work to get a fully functional SSH/SCP client built (with thanks to the efforts of the Mina SSHD project, whose codebase we originally based the effort on). All of the goals for the project have been ticked, and some extra ones accomplished too.

I had great help and input from Chico, another Apache committer, throughout the project, and so it’s been a great experience all round. This will form the basis of a release, but for now, the code is hosted on googlecode at: http://code.google.com/p/commons-net-ssh/

Headless R / X11 and Cygwin/X

Running R on a Linux server in headless mode (i.e. producing graphics without XWindows running) can be tricky. Some people recommend using a virtual X framebuffer. However, I’ve found that the best approach (at least im my opinion) is to use the R interface to Cairo. This allows R to produce png graphics in headless mode, and also produces very nice looking graphs. I configured R as follows (after downloading and building pixman-0.15.18, and cairo-1.8.8:

./configure --with-gnu-ld --with-x --with-cairo

This will produce an R binary with cairo support that can be run non-interactively and produce graphical output – very useful for running automated statistical reports.

You can check that Cairo support is enabled by checking the return value of the capabilities() function:

> capabilities()
jpeg png tiff tcltk X11 aqua http/ftp sockets
TRUE TRUE FALSE FALSE FALSE FALSE TRUE TRUE
libxml fifo cledit iconv NLS profmem cairo
TRUE TRUE TRUE TRUE TRUE FALSE TRUE

Finally, some notes on connecting X11 clients using Cygwin (which I always forget how to do). On the server, check /etc/ssh/sshd_config for the line

X11Forwarding yes

And then run a local X server:

XWin -clipboard -emulate3buttons -multiwindow

Once this is running, from an xterm, run ssh, passing in the -X argument to enable X forwarding.

ssh -X -l username myserver

X11-based applications can then be run from this session.

John Carpenter Themes

I have been playing with Lilypond a little more, and here are some themes that I have transcribed. They are all from John Carpenter movies: the first is the theme from “Halloween”, which is an interesting 5/4 time piano riff; the second is the synth theme from “Escape From New York”, and the final is the ending credits music of “The Thing” (known as “Humanity Part II” on the soundtrack album). The last one is a bit messy as I couldnt get Lilypond to hold the ties across multiple bars properly.

carpenter.pdf

carpenter.pdf

This is still not 100% finished – there are some omissions. Plus, my transcription may be incorrect in places.

Here is the PDF:

carpenter.pdf

And the Lilypond source:

carpenter

Compiling The kdb/R interface on Win32

I have been playing with the kdb/R interface from kx.com, and had some problems installing with Cygwin gcc. It may be possible to get this to work with Cygwin gcc + a Win32 threads library, but in the meantime I installed MinGW, and it works perfectly. Here are the steps (basically as per the kx docs):

1. Download c.o from here: http://kx.com/q/w32/
2. gcc -c base.c -I. -I "${R_HOME}/include/"
3. gcc -Wl,--export-all-symbols -shared -o qserver.dll c.o base.o ${r
-HOME}/bin/R.dll -lws2_32

The resulting qserver.dll can be loaded via dyn.load(), and then (just using the qserver.R supplied by kx) from within R:

source("qserver.R")
conn < - open_connection("server", 12345)
result <- execute(conn, "select avg bid by sym from fx_quote")
x <- as.data.frame(mapply(FUN=c, result))
> head(x, 10)
V1 V2
1 AUD= 0.792402880224811
2 AUD=D2 0.791632149468651
3 AUD=EBS 0.790402776387278
4 AUDCHF=R 0.85955071021153
5 AUDJPY=R 75.0707755671935
6 BRL= 1.97194091379422
7 CAD= 1.15980648929715
8 CAD=D2 1.15962545479939
9 CAD=EBS 1.14104373919176
10 CADJPY=R 81.6389284332255

London UseR Group Talk – Slides

The inaugural London UseR event was a great success, with a lot of interesting people and a very constructive networking atmosphere!

I gave a (slightly disjointed) talk on concurrency and the bigmemory package in R (more on that later this year at UseR! 2009 in France).

The slides are here.

R User Group Meeting, London

On Tuesday March 31st, Mango Solutions are sponsoring the inaugural London R User Group Meeting. It will be a great opportunity to meet other R users and find out how people are using it. As the first one of its kind in London, I would expect a high level of interest. There will be a number of speakers presenting on various topics, using the UseR! panel format (short talks at around 15 minutes or so). I will be giving a short presentation, most likely following on from the real-time data integration work I presented on at UseR! 2008.

See this page for details on the event:

http://www.mango-solutions.com/events/UseRLondon.html

Posted in R

Project Euler Problem #28

Problem 28 on the Project Euler website asks what is the sum of both diagonals in a 1001×1001 clockwise spiral. This was an interesting one: the relationship between the numbers on the diagonals is easy to deduce, but expressing it succinctly in R took a little bit of tweaking. I’m sure it could be compressed even further.

# Problem 28
spiral.size <- function(n) {
        stopifnot(n %% 2 ==1)
        
        if (n==1) {
                return(1)
        }
        sum(cumsum(rep(2*seq(1,floor(n/2)), rep(4,floor(n/2))))+1)+1
}

spiral.size(1001)