I have this clojure code
(let [group-name "my-test-group"
compute (compute-service provider user password)
node (create-node compute group-name)
node-id (.getId node)]
(.runScriptOnNode compute node-id ??)
(destroy-node compute node-id))
and I would like to run ls on my instance just as an example. What do I put in the ?? to make that work?
Reading the Jclouds docs it says I'm supposed to put a Statement object there but I do not know how to create a statement object for the ls command in Clojure or Java. I'd accept an example in Clojure or Java (as I can easily translate between the two).
The runScriptOnNode has several forms. As defined in the ComputeService interface, the script can be provided as a Statement object or as a simple String.
If you want to use the Statement then you can build it by using the helper methods in the Statements class (something like: Statements.exec("ls")), but it is up to you to use the Statement or the String form.
And here are the examples using the two methods (with String and with Statement) assuming the example code from the OP surrounds this code:
(.runScriptOnNode compute node-id "ls")
(.runScriptOnNode compute node-id (Statements/exec "ls"))
Related
So basically I have some python scripts with strings representing SQL statements with some named arguments, eg:
schdl_stmt = "select * from bar.schedule where date = '{date}'"
I uses this to interpolate the date dynamically.
My workflow involves running/debugging these queries in DataGrip, and so I really need a way for DataGrip to utilize this named argument syntax, else I'm stuck manually editing the statement too often.
DataGrip allows you to add custom regex patterns for such a usecase in the settings pictured below:
However I have not been able to figure out one that works for the Python named argument string pattern.
I've tried:
"{name}"
"\{name\}"
If it's simply not possible because of some caveat with how DataGrip handle's these patterns, that would be useful to know as well.
The correct pattern is
\{(\w+)\}
with 'Substitute inside SQL strings' enabled.
Please read this document for more details.
I build program, when in one part I have some ranking, and I would like to give users option to customize it.
In my code I have a function that gets objects and returnes them packed with points and position in ranking (for now it calculates the arithmetic mean of some object's values).
My question is is it possible to give e.g. admin chance to write this function via admin panel and use it, so if he would like to one day use harmonic mean he could without changing source code?
Yes, you could just store a string in the database and exec() it with suitable arguments...
However, you'll have to be careful – Python code can practically never be sandboxed perfectly. In the event that you accept any arbitrary Python code for this, and someone with nefarious intents gets to your admin panel to change the expression, they can do practically anything.
In other words, don't use raw Python for the code you store.
Context
I have a function that operates on a data structure.
I have written a spec for the data structure this function operates on.
This function returns a reagent component that is rendered in a browser (PhantomJS)
The spec has some optional keys, and depending on whether or not those keys exist in the data when it's passed to the function, the output (component to be rendered in browser) of the aforementioned function will be affected.
I am looking to use clojure.test to compare values of the data structure passed to the function generating the component with values grabbed from the rendered element, so simple unit test or input->output comparison is not what I'm going for here.
Problem
Since calling generate or sample on the spec generator will sometimes include or omit the optional fields, I would like to iterate over a reasonably large set of data generated using sample and test each of the data structures, but I don't know the "right" or idiomatic way to do this.
I have used are in clojure.test before, which is great, but since I'm testing against the rendered component in the browser, and are tests input->output it doesn't seem like the right tool for the job.
Advice on a generally accepted practice here or language/clojure.test feature that would have me doing this in the most idiomatic way would be greatly appreciated.
compare values of the data structure passed to the function generating the component with values grabbed from the rendered element
If possible, I'd use s/fdef with :args, :ret, and :fn args to specify the relationship between your function's input and output, and then check the function. There's an example in the testing section of spec guide.
iterate over a reasonably large set of data generated using sample and test each of the data structures
This is essentially what check does.
As for clojure.test integration, you can check functions as part of a test suite like this:
(deftest foo-test
(is (not (:check-failed (st/summarize-results (st/check `foo))))))
Coming from Haskell, my usual workflow would be to :l <file name.hs> on ghci and use the functions and ADT that I have there.
Right now I am using lein repl on a typical lein new app project context. I have created a testing.clj file next to my core.clj. There I defined a couple of functions, a protocol and a record implementing the protocol. I was able to use the function by (use 'testing.testing :reload) the problem is that I am not able to use the actual record:
(def c (Something. 0))
I get:
CompilerException java.lang.IllegalArgumentException: Unable to resolve classname: Something
So, what would be the a "better" workflow in this case? Where I don't want to set the functions, protocols, records directly on the REPL, but also I don't want to rely on my core.cls file? I just want a file where I can dump a bunch of stuff and play with it.
PS: My env is Mac OSX Terminal + Sublime
Edit: After a couple of minutes I was able to load the record by:
(load-file <file name>)
(import 'testing.testing.Something)
I mean, for sure there is a better way than this... :/ I just want to load everything. On the other hand I am able to use the protocol methods the record implements.
Have you tried using the convenience function that is automatically defined for creating records? In this example it would be (->Something 0).
(Something. 0) is using the Java constructor, which requires importing the Java class separately. The Java class is created automatically when you define a record to allow Java interop with things you've defined in Clojure.
Using the (->Something 0) syntax is the correct way to go and should be possible after you (use 'testing.testing :reload).
Edit Given the above didn't seem to help, here's some step-by-step instructions to get a minimal working example
You have an app directory testing created with lein new app testing
In testing/src/testing you create testing.clj containing the following two lines
(ns testing.testing)
(defrecord Something [n])
Run lein repl from within your project directory
Use the namespace with (use 'testing.testing :reload)
(:n (->Something 42)) will create an instance of Something and retrieve the value of its n member - in this case 42.
I just started to use WebRatio and I am facing a simple problem, with easy solution if I was not using this fabulous framework .... I was asked to do some sort of glosary app, and what I am trying to do right now is a simple index where appears all letters from A-Z and how many entries starting with each letter there are in my database, quite simple.
I aleady started a database with my entity: name, description and last_modified. I had been looking for some information on how to do this but I found nothing. So what I am trying to do is to fill a list with a custom query that I made (it works good on my sql editor) but I am not able to list the results in a WebRatio list. I tried to use a "query" object linked to a "simpleList" object but when I run the app it gives me error: "Expected at least one element .. inside " I would appreciate any help or resource that explains how to do this.
Thanks in advance
You shouldn't link the query unit with list because the list will make it's own database query. Instead you should specify outputs for query unit and write your custom style template for query unit to visualize the results as html. Or also (not recommended) you can link the results of query unit with a script unit and output desired html within a script unit.