DDevelopment & Design

All you need is docker (and fig)

IntroductionSuppose you want to run scala repl or groovy shell or any other repl-like executable. You should download executable, unpack it, set PATH environmnt variable and now you could use it. Can it be simple? Yes, dockerize everything.Prepare cont…

Introduction

Suppose you want to run scala repl or groovy shell or any other repl-like executable. You should download executable, unpack it, set PATH environmnt variable and now you could use it. Can it be simple? Yes, dockerize everything.

Prepare containers

I expect that you have installed docker and fig on your machine.
Checkout this project from github and build containers: 
$ cd docker-with-fig
$ fig build
It could take several minutes, depends on your internet connection.
You could also build only some of available container, for example with scala and groovy: 
$ fig build scala groovy
Available containers are:
  • haskell
  • scala
  • groovy
  • python27
  • python34
  • clojure

Run containers

Now you could start for example scala: 
$ fig run scala
Welcome to Scala version 2.11.6 (Java HotSpot(TM) 64-Bit Server VM, Java 1.8.0_40).
Type in expressions to have them evaluated.
Type :help for more information.

scala>
Or groovy: 
$ fig run groovy
Mar 29, 2015 7:48:22 AM java.util.prefs.FileSystemPreferences$1 run
INFO: Created user preferences directory.
Groovy Shell (2.4.2, JVM: 1.8.0_40)
Type ':help' or ':h' for help.
-------------------------------------------------------------------------------
groovy:000>
Or clojure with lein: 
$ fig run clojure
nREPL server started on port 52730 on host 127.0.0.1 - nrepl://127.0.0.1:52730
REPL-y 0.3.5, nREPL 0.2.6
Clojure 1.6.0
Java HotSpot(TM) 64-Bit Server VM 1.8.0_40-b25
    Docs: (doc function-name-here)
          (find-doc "part-of-name-here")
  Source: (source function-name-here)
 Javadoc: (javadoc java-object-or-class-here)
    Exit: Control+D or (exit) or (quit)
 Results: Stored in vars *1, *2, *3, an exception in *e

user=>
Or python 3.4: 
$ fig run python34
Python 3.4.2 (default, Oct  8 2014, 13:08:17) 
[GCC 4.9.1] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>>
Or ghci haskell: 
$fig run haskell
GHCi, version 7.6.3: http://www.haskell.org/ghc/  :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
Prelude>
You could also run command on docker container with use of files from your current directory because it is mapped to /project directory on docker. Container starts with /project directory as current directory.
For example you have a simple file in your current dir: 
$ cat simplePrint.scala 

println("Hello World")


You could run command with this file:

$ fig -f PATH_TO_DOCKER_WITH_FIG_PROJECT/fig.yml run scala scala simplePrint.scala

Hello World

First ‘scala’ in command means that you want to run scala container and ‘scala simplePrint.scala’ means that you want to execute this command on container.

Conclusion

It is simple, isn’t it? All you need is docker and fig and you could use repl or run command with scala, groovy, cojure and any other which are currently supported…

— Previous article

Need to make a quick json fixes - JSONPath for rescue

Next article —

EhCache config with BeanUtils

You May Also Like
DDevelopment & Design

Need to make a quick json fixes – JSONPath for rescue

From time to time I have a need to do some fixes in my json data. In a world of flat files I do this with grep/sed/awk tool chain. How to handle it for JSON? Searching for a solution I came across the JSONPath. It quite mature tool (from 2007) but I haven't hear about it so I decided to share my experience with others.

First of all you can try it without pain online: http://jsonpath.curiousconcept.com/. Full syntax is described at http://goessner.net/articles/JsonPath/



But also you can download python binding and run it from command line:
$ sudo apt-get install python-jsonpath-rw
$ sudo apt-get install python-setuptools
$ sudo easy_install -U jsonpath

After that you can use inside python or with simple cli wrapper:
#!/usr/bin/python
import sys, json, jsonpath

path = sys.argv[1]

result = jsonpath.jsonpath(json.load(sys.stdin), path)
print json.dumps(result, indent=2)

… you can use it in your shell e.g. for json:
{
"store": {
"book": [
      {
"category": "reference",
"author": "Nigel Rees",
"title": "Sayings of the Century",
"price": 8.95
      },
      {
"category": "fiction",
"author": "Evelyn Waugh",
"title": "Sword of Honour",
"price": 12.99
      },
      {
"category": "fiction",
"author": "Herman Melville",
"title": "Moby Dick",
"isbn": "0-553-21311-3",
"price": 8.99
      },
      {
"category": "fiction",
"author": "J. R. R. Tolkien",
"title": "The Lord of the Rings",
"isbn": "0-395-19395-8",
"price": 22.99
      }
    ],
"bicycle": {
"color": "red",
"price": 19.95
    }
  }
}

You can print only book nodes with price lower than 10 by:
$ jsonpath '$..book[?(@.price

Result:
[
  {
"category": "reference",
"price": 8.95,
"title": "Sayings of the Century",
"author": "Nigel Rees"
  },
  {
"category": "fiction",
"price": 8.99,
"title": "Moby Dick",
"isbn": "0-553-21311-3",
"author": "Herman Melville"
  }
]

Have a nice JSON hacking!From time to time I have a need to do some fixes in my json data. In a world of flat files I do this with grep/sed/awk tool chain. How to handle it for JSON? Searching for a solution I came across the JSONPath. It quite mature tool (from 2007) but I haven't hear about it so I decided to share my experience with others.