Clojure.lang.LazySeq cannot be assigned to clojure.lang.IFn
I am new to Riemann and Clojure. All I want to do is send email notifications to three email groups when the TTL expires. I created some kind of configuration file where I store a list of letters:
{
:email_group_1 (
"first@example.com"
"second@example.ru"
)
:email_group_2 (
"third@example.com"
)
}
My riemann config looks like this:
(logging/init {:console true})
(import org.apache.log4j.Level)
(logging/set-level Level/DEBUG)
(require '[clojure.java.io :as io])
(import '[java.io PushbackReader])
(let [host "0.0.0.0"]
(tcp-server {:host host :port 60001})
(udp-server {:host host})
(ws-server {:host host :port 60003}))
(repl-server {:host "127.0.0.1"})
(def cwd (System/getProperty "user.dir"))
(def emails
(with-open [r (io/reader (str cwd "/etc/emails.clj"))]
(read (PushbackReader. r))))
(periodically-expire 5)
(def email (mailer))
(defn notify [& egroups]
(for [egroup egroups]
(rollup 1 60 (apply email (emails egroup)))))
(let [index (index)]
(streams
(default :ttl 60
index
(expired
(where (service "service_connect_active")
#(info "expired" %)
(notify :email_group_1 :email_group_2))))))
The code looks good (to me), but when this service expired I get the following error:
09:45:39 riemann.1 | INFO [2015-05-08 10:45:39,313] Thread-5 - riemann.config - expired {:ttl 60, :time 357766884827/250, :state expired, :service service_connect_active, :host ava.local}
09:45:39 riemann.1 | WARN [2015-05-08 10:45:39,319] Thread-5 - riemann.config - clojure.lang.LazySeq@841649b8 threw
09:45:39 riemann.1 | java.lang.ClassCastException: clojure.lang.LazySeq cannot be cast to clojure.lang.IFn
09:45:39 riemann.1 | at riemann.config$eval66$stream__70$fn__75.invoke(riemann.development.config:34)
09:45:39 riemann.1 | at riemann.config$eval66$stream__70.invoke(riemann.development.config:45)
09:45:39 riemann.1 | at riemann.streams$match$stream__3514$fn__3525.invoke(streams.clj:1209)
09:45:39 riemann.1 | at riemann.streams$match$stream__3514.invoke(streams.clj:1209)
09:45:39 riemann.1 | at riemann.streams$default$stream__3731$fn__3742.invoke(streams.clj:1328)
09:45:39 riemann.1 | at riemann.streams$default$stream__3731.invoke(streams.clj:1328)
09:45:39 riemann.1 | at riemann.core$stream_BANG_$fn__4415.invoke(core.clj:19)
09:45:39 riemann.1 | at riemann.core$stream_BANG_.invoke(core.clj:18)
09:45:39 riemann.1 | at riemann.core$reaper$worker__4529$fn__4539.invoke(core.clj:303)
09:45:39 riemann.1 | at riemann.core$reaper$worker__4529.invoke(core.clj:297)
09:45:39 riemann.1 | at riemann.service.ThreadService$thread_service_runner__1973$fn__1974.invoke(service.clj:71)
09:45:39 riemann.1 | at riemann.service.ThreadService$thread_service_runner__1973.invoke(service.clj:70)
09:45:39 riemann.1 | at clojure.lang.AFn.run(AFn.java:22)
09:45:39 riemann.1 | at java.lang.Thread.run(Thread.java:745)
Can someone please help me? Thank.
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"Cannot fail clojure.lang.IFn" invariably indicates that it expects a function to receive something that cannot be considered as such ...
(defn notify [& egroups]
(for [egroup egroups]
(rollup 1 60 (apply email (emails egroup)))))
Returns the LazySeq generated folding streams, not the actual stream (in Riemann, a stream is an IFn). So when Riemann tries to call the stream as IFn, your error comes up ...
How about something like:
(defn notify [& egroups]
(rollup 1 60 (apply email (mapcat emails egroups))))
Here, we just convert the group list to the mail list up and then get on with our lives.
Alternatively, if you really want multiple streams (avoiding shared lines: :) for example, apply them to the swap.
(defn notify [& egroups]
(apply rollup 1 60 (map email (map emails groups))))
Hope this helps, I am obviously not fully replicating your config.
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