Clojure Q&A - Recent questions tagged clj-http

REST API response body is not a string?

Sat, 20 Feb 2021 08:42:46 +0000

It's been a while since I've written Clojure, so I am rusty.

Basically, I'm trying to write code which does an HTTP GET on a REST API and converts that JSON array of objects into clojure data (list of Maps?). The JSON data looks like this:

[
    {
        "id": 1,
        "category": "technical",
        "asin": "0131103628",
        "title": "C Programming Language, 2nd Edition",
        "publication_date": "1988-04-01T00:00:00Z",
        "review": "The C book.",
        "created_at": "2020-03-06T20:48:00Z"
    },
    {
        "id": 2,
        "category": "technical",
        "asin": "0387966080",
        "title": "The Science of Fractal Images",
        "publication_date": "1988-07-19T00:00:00Z",
        "review": "The book on fractal algorithms.  Sadly, no longer in print.  I had to search high and low for a used copied.",
        "created_at": "2020-03-06T20:48:00Z"
    },
    // etc..
]

I'm using http-kit (I've also tried clj-http) to call the REST API and return the body. Later, I try converting the body to Clojure data. I've tried using both org.clojure/data.json and cheshire. However, I don't belive the data is being converted correctly.

(defn get-books-body
  []
  (:body @(client/get books-url api-options)))

(defn get-books
  []
  (parse-string get-books-body true))

When I try to display the type of the body, it shows up as an address instead of a string:

clojure-json-test.core=> (type get-books-body)
clojure_json_test.core$get_books_body

And I cannot look at the first record, after converting from JSON:

clojure-json-test.core=> (first get-books)
Execution error (IllegalArgumentException) at clojure-json-test.core/eval3169 (form-      init15378865171954877190.clj:1).
Don't know how to create ISeq from: clojure_json_test.core$get_books

Any idea what I am doing wrong?

Reading a JSON stream over HTTP, indefinitely?

Sat, 29 Feb 2020 07:59:50 +0000

I am trying to read a json HTTP stream and use the json elements, indefinitely.

I came up with this code below, but it does close the stream and only returns 30 results - how do I indefinitely use the HTTP stream?

Thanks for your help!

(ns core
  (:require [clj-http.client :as http]
            [cheshire.core :as json]
            [clojure.java.io :as io]
            [clojure.core.async :as async]))

(def gh-url "https://api.github.com/events")
(def chan (async/chan 100))

(async/go
  (loop [r (async/<! chan)]
    (when (not-empty r) (println (:type r)))
    (recur (async/<! chan))))

(defn read-gh-stream [url]
  (with-open [stream (-> url (http/get {:as :stream}) :body)]
    (let [lines (-> stream io/reader (json/parse-stream true))]
      (doseq [l lines]
        (async/go
          (async/>! chan l))))))

How to do a HTTP request over a unix socket in Clojure

Sat, 04 Jan 2020 15:08:16 +0000

I want to a HTTP request over a UNIX socket, like the following example using curl and docker:

$ curl --unix-socket /var/run/docker.sock http://localhost/images/json
[
  {
    "Containers": -1,
    "Created": 1577395270,
    "Id": "sha256:ce6c1e7ac56533e2742030f033cf0d8cf0adc996c7bb87453eb5adc266b2ef2e",
    "Labels": null,
    "ParentId": "",
    "RepoDigests": [
      "busybox@sha256:7fe0cb3632d9ea7b2a9ab4427e339e01f7cdfeff50674804cb8946664976c610"
    ],
    "RepoTags": [
      "busybox:musl"
    ],
    "SharedSize": -1,
    "Size": 1461385,
    "VirtualSize": 1461385
  }
]

As far as I've seen, clj-http doesn't seem to support this.

What would be a recommended/idiomatic way of doing this in Clojure?