feature: Slack hook - optionally disable diff snippets and post custom messages (#763)

* continue to diffs by default, but optionally post formatted messages

* updated readme

* remove static channel name

* Update Hooks.md

2 files changed, 43 insertions, 10 deletions

diff --git a/docs/Hooks.md b/docs/Hooks.md
index bf6ea54..ca99034 100644
--- a/docs/Hooks.md
+++ b/docs/Hooks.md
@@ -140,6 +140,19 @@ hooks:
     channel: "#network-changes"
 ```
 
+Optionally you can disable snippets and post a formatted message, for instance linking to a commit in a git repo. Named parameters `%{node}`, `%{group}`, `%{model}` and `%{commitref}` are available.
+
+``` yaml
+hooks:
+  slack:
+    type: slackdiff
+    events: [post_store]
+    token: SLACK_BOT_TOKEN
+    channel: "#network-changes"
+    diff: false
+    message: "%{node} %{group} %{model} updated https://git.intranet/network-changes/commit/%{commitref}"
+```
+
 Note the channel name must be in quotes.
 
 ## Hook type: xmppdiff
diff --git a/lib/oxidized/hook/slackdiff.rb b/lib/oxidized/hook/slackdiff.rb
index 61f1743..728e5a7 100644
--- a/lib/oxidized/hook/slackdiff.rb
+++ b/lib/oxidized/hook/slackdiff.rb
@@ -1,5 +1,8 @@
 require 'slack'
 
+# defaults to posting a diff, if messageformat is supplied them a message will be posted too
+# diffenable defaults to true
+
 class SlackDiff < Oxidized::Hook
   def validate_cfg!
     raise KeyError, 'hook.token is required' unless cfg.has_key?('token')
@@ -17,16 +20,33 @@ class SlackDiff < Oxidized::Hook
         client = Slack::Client.new
         client.auth_test
         log "Connected"
-        gitoutput = ctx.node.output.new
-        diff = gitoutput.get_diff ctx.node, ctx.node.group, ctx.commitref, nil
-        title = "#{ctx.node.name.to_s} #{ctx.node.group.to_s} #{ctx.node.model.class.name.to_s.downcase}"
-        log "Posting diff as snippet to #{cfg.channel}"
-        client.files_upload(channels: cfg.channel, as_user: true,
-                             content: diff[:patch].lines.to_a[4..-1].join,
-                             filetype: "diff",
-                             title: title,
-                             filename: "change"
-                            )
+        # diff snippet - default
+        diffenable = true
+        if cfg.has_key?('diff') == true
+          if cfg.diff == false
+            diffenable = false
+          end
+        end
+        if diffenable == true
+          gitoutput = ctx.node.output.new
+          diff = gitoutput.get_diff ctx.node, ctx.node.group, ctx.commitref, nil
+          title = "#{ctx.node.name.to_s} #{ctx.node.group.to_s} #{ctx.node.model.class.name.to_s.downcase}"
+          log "Posting diff as snippet to #{cfg.channel}"
+          client.files_upload(channels: cfg.channel, as_user: true,
+                              content: diff[:patch].lines.to_a[4..-1].join,
+                              filetype: "diff",
+                              title: title,
+                              filename: "change"
+                             )
+        end
+        # message custom formatted - optional
+        if cfg.has_key?('message') == true
+          log cfg.message
+          msg = cfg.message % {:node => ctx.node.name.to_s, :group => ctx.node.group.to_s, :commitref => ctx.commitref, :model => ctx.node.model.class.name.to_s.downcase}
+          log msg
+          log "Posting message to #{cfg.channel}"
+          client.chat_postMessage(channel: cfg.channel, text: msg,  as_user: true)
+        end
         log "Finished"
       end
     end