Send Slack message when jobs finish

Author: xrchz

server.sml

@@ -125,12 +125,14 @@ fun finish id =
       case read_job_pr inp of
         NONE => "master"
       | SOME (_, branch) => Substring.string (trim_ws branch)
+    val subject = String.concat[status_to_string status,": Job ",f," ",branch]
+    val body = String.concat["See ",server,"/job/",f]
   in
     TextIO.closeIn inp;
     Posix.IO.close fd;
     GitHub.set_status f sha status;
-    send_email (String.concat[status_to_string status,": Job ",f," ",branch])
-               (String.concat["See ",server,"/job/",f,"\n"]);
+    send_email subject (String.concat[body,"\n"]);
+    Slack.send_message (String.concat[subject," - ",body]);
     ()
   end
 

serverLib.sml

@@ -365,6 +365,28 @@ structure GitHub = struct
     end
 end
 
+structure Slack = struct
+  val token = until_space (file_to_string "slack-token")
+  val channel = "CCKESLBJQ"
+  val postMessage_endpoint = "https://slack.com/api/chat.postMessage"
+  fun postMessage_curl_cmd text = (curl_path,["--silent","--show-error",
+    "--header",String.concat["Authorization: Bearer ",token],
+    "--header","Content-type: application/json;charset=utf-8",
+    "--request","POST",
+    "--data",String.concat["{\"channel\":\"",channel,"\",",
+                           "\"text\":\"",text,"\"}"],
+    postMessage_endpoint])
+  fun send_message text =
+    let
+      val text = String.translate (fn c => if c = #"\"" then """ else String.str c) text
+      val cmd = postMessage_curl_cmd text
+      val response = system_output (cgi_die 500) cmd
+    in
+      cgi_assert
+        (String.isPrefix "{\"ok\":true" response)
+        500 ["Error sending Slack message\n",response]
+    end
+end
 
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