How to halt a integrant system

Context: I'm trying to set up integrant so that I can stop and start my jetty server

I'm getting:
IllegalArgumentException Don't know how to create ISeq from: clojure.lang.Var$Unbound clojure.lang.RT.seqFrom (RT.java:542)

When trying to halt my integrant system.

My Code:

(defn handler [request]

{:status 200

 :headers {"Content-Type" "text/html"}

 :body "Hello World!"})



(def config

    {:handlers/system {:port 3000

                       :host "localhost"

                       :join? true

                       :http? true

                       :ssl? false}})



(defmethod ig/init-key :handlers/system [_ cfg]

  (jetty/run-jetty handler cfg))



(defmethod ig/halt-key! :handlers/system [_ server]

    (.stop server))



(defn start 

    (def sys (ig/init config)))



(defn stop 

    (ig/halt! sys))



(defn resume 

    (ig/resume config sys))



(defn reset 

    (stop)

    (start))

What am I doing wrong?

asked Nov 19 '18 at 14:16

Clojure Pls

162

3

Using def inside a function is something of a code smell; it's only rarely, if ever, appropriate. Usually, you'd be better off with a top-level (def sys (atom nil)), and then (reset sys (ig/init config)) inside your start function. (Of course, this means the other users would be @sys, not sys, to deref the atom's contents; thus, (ig/halt! @sys), and you'd probably want to reset the contents to nil when doing so).
– Charles Duffy
Nov 19 '18 at 14:20

2

Or use alter-var-root like github.com/weavejester/integrant-repl does (which might also be the lib you want to use instead)
– cfrick
Nov 19 '18 at 18:07

I've updated my code accordingly, thanks for the advice!
– Clojure Pls
Nov 20 '18 at 11:32

add a comment |

Context: I'm trying to set up integrant so that I can stop and start my jetty server

I'm getting:
IllegalArgumentException Don't know how to create ISeq from: clojure.lang.Var$Unbound clojure.lang.RT.seqFrom (RT.java:542)

When trying to halt my integrant system.

My Code:

(defn handler [request]

{:status 200

 :headers {"Content-Type" "text/html"}

 :body "Hello World!"})



(def config

    {:handlers/system {:port 3000

                       :host "localhost"

                       :join? true

                       :http? true

                       :ssl? false}})



(defmethod ig/init-key :handlers/system [_ cfg]

  (jetty/run-jetty handler cfg))



(defmethod ig/halt-key! :handlers/system [_ server]

    (.stop server))



(defn start 

    (def sys (ig/init config)))



(defn stop 

    (ig/halt! sys))



(defn resume 

    (ig/resume config sys))



(defn reset 

    (stop)

    (start))

What am I doing wrong?

asked Nov 19 '18 at 14:16

Clojure Pls

162

3

Using def inside a function is something of a code smell; it's only rarely, if ever, appropriate. Usually, you'd be better off with a top-level (def sys (atom nil)), and then (reset sys (ig/init config)) inside your start function. (Of course, this means the other users would be @sys, not sys, to deref the atom's contents; thus, (ig/halt! @sys), and you'd probably want to reset the contents to nil when doing so).
– Charles Duffy
Nov 19 '18 at 14:20

2

Or use alter-var-root like github.com/weavejester/integrant-repl does (which might also be the lib you want to use instead)
– cfrick
Nov 19 '18 at 18:07

I've updated my code accordingly, thanks for the advice!
– Clojure Pls
Nov 20 '18 at 11:32

add a comment |

Context: I'm trying to set up integrant so that I can stop and start my jetty server

I'm getting:
IllegalArgumentException Don't know how to create ISeq from: clojure.lang.Var$Unbound clojure.lang.RT.seqFrom (RT.java:542)

When trying to halt my integrant system.

My Code:

(defn handler [request]

{:status 200

 :headers {"Content-Type" "text/html"}

 :body "Hello World!"})



(def config

    {:handlers/system {:port 3000

                       :host "localhost"

                       :join? true

                       :http? true

                       :ssl? false}})



(defmethod ig/init-key :handlers/system [_ cfg]

  (jetty/run-jetty handler cfg))



(defmethod ig/halt-key! :handlers/system [_ server]

    (.stop server))



(defn start 

    (def sys (ig/init config)))



(defn stop 

    (ig/halt! sys))



(defn resume 

    (ig/resume config sys))



(defn reset 

    (stop)

    (start))

What am I doing wrong?

asked Nov 19 '18 at 14:16

Clojure Pls

162

Context: I'm trying to set up integrant so that I can stop and start my jetty server

I'm getting:
IllegalArgumentException Don't know how to create ISeq from: clojure.lang.Var$Unbound clojure.lang.RT.seqFrom (RT.java:542)

When trying to halt my integrant system.

My Code:

(defn handler [request]

{:status 200

 :headers {"Content-Type" "text/html"}

 :body "Hello World!"})



(def config

    {:handlers/system {:port 3000

                       :host "localhost"

                       :join? true

                       :http? true

                       :ssl? false}})



(defmethod ig/init-key :handlers/system [_ cfg]

  (jetty/run-jetty handler cfg))



(defmethod ig/halt-key! :handlers/system [_ server]

    (.stop server))



(defn start 

    (def sys (ig/init config)))



(defn stop 

    (ig/halt! sys))



(defn resume 

    (ig/resume config sys))



(defn reset 

    (stop)

    (start))

What am I doing wrong?

clojure

asked Nov 19 '18 at 14:16

Clojure Pls

162

asked Nov 19 '18 at 14:16

Clojure Pls

162

asked Nov 19 '18 at 14:16

Clojure Pls

162

asked Nov 19 '18 at 14:16

Clojure Pls

162

asked Nov 19 '18 at 14:16

Clojure Pls

162

3

Using def inside a function is something of a code smell; it's only rarely, if ever, appropriate. Usually, you'd be better off with a top-level (def sys (atom nil)), and then (reset sys (ig/init config)) inside your start function. (Of course, this means the other users would be @sys, not sys, to deref the atom's contents; thus, (ig/halt! @sys), and you'd probably want to reset the contents to nil when doing so).
– Charles Duffy
Nov 19 '18 at 14:20

2

Or use alter-var-root like github.com/weavejester/integrant-repl does (which might also be the lib you want to use instead)
– cfrick
Nov 19 '18 at 18:07

I've updated my code accordingly, thanks for the advice!
– Clojure Pls
Nov 20 '18 at 11:32

add a comment |

3

Using def inside a function is something of a code smell; it's only rarely, if ever, appropriate. Usually, you'd be better off with a top-level (def sys (atom nil)), and then (reset sys (ig/init config)) inside your start function. (Of course, this means the other users would be @sys, not sys, to deref the atom's contents; thus, (ig/halt! @sys), and you'd probably want to reset the contents to nil when doing so).
– Charles Duffy
Nov 19 '18 at 14:20

2

Or use alter-var-root like github.com/weavejester/integrant-repl does (which might also be the lib you want to use instead)
– cfrick
Nov 19 '18 at 18:07

I've updated my code accordingly, thanks for the advice!
– Clojure Pls
Nov 20 '18 at 11:32

Using def inside a function is something of a code smell; it's only rarely, if ever, appropriate. Usually, you'd be better off with a top-level (def sys (atom nil)), and then (reset sys (ig/init config)) inside your start function. (Of course, this means the other users would be @sys, not sys, to deref the atom's contents; thus, (ig/halt! @sys), and you'd probably want to reset the contents to nil when doing so).
– Charles Duffy
Nov 19 '18 at 14:20

Or use alter-var-root like github.com/weavejester/integrant-repl does (which might also be the lib you want to use instead)
– cfrick
Nov 19 '18 at 18:07

I've updated my code accordingly, thanks for the advice!
– Clojure Pls
Nov 20 '18 at 11:32

add a comment |

1 Answer
1

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oldest

votes

The problem was in the config where :join? was set to true. This was blocking the process and meant that after using ctrl + c in the repl, sys hadn't been set to the return value of (ig/init config), and so when stop was called it was attempting to call .stop on an unbound fn, causing the error mentioned in the OP.

answered Nov 20 '18 at 11:36

Clojure Pls

162

add a comment |

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answered Nov 20 '18 at 11:36

Clojure Pls

162

add a comment |

answered Nov 20 '18 at 11:36

Clojure Pls

162

add a comment |

answered Nov 20 '18 at 11:36

Clojure Pls

162

answered Nov 20 '18 at 11:36

Clojure Pls

162

answered Nov 20 '18 at 11:36

Clojure Pls

162

answered Nov 20 '18 at 11:36

Clojure Pls

162

answered Nov 20 '18 at 11:36

Clojure Pls

162

add a comment |

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