add support for slack mentions from github handles

phongulus · phongulus · commit 7692668f774e · 2024-04-22T12:48:36.000+08:00
diff --git a/lib/action.ml b/lib/action.ml
@@ -10,6 +10,46 @@ let action_error msg = raise (Action_error msg)
 let log = Log.from "action"
 
 module Action (Github_api : Api.Github) (Slack_api : Api.Slack) = struct
+  let canonical_regex = Re2.create_exn {|\.|\-|\+.*|@.*|}
+  (* Match email domain, everything after '+', as well as dots and hyphens *)
+
+  let username_to_slack_id_tbl = Stringtbl.empty ()
+
+  let canonicalize_email_username email =
+    email |> Re2.rewrite_exn ~template:"" canonical_regex |> String.lowercase_ascii
+
+  let refresh_username_to_slack_id_tbl ~ctx =
+    log#info "updating github to slack username mapping";
+    match%lwt Slack_api.list_users ~ctx () with
+    | Error e ->
+      log#warn "couldn't fetch list of Slack users: %s" e;
+      Lwt.return_unit
+    | Ok res ->
+      List.iter
+        (fun (user : Slack_t.user) ->
+          match user.profile.email with
+          | None -> ()
+          | Some email ->
+            let username = canonicalize_email_username email in
+            Stringtbl.replace username_to_slack_id_tbl username user.id
+        )
+        res.members;
+      Lwt.return_unit
+
+  let rec refresh_username_to_slack_id_tbl_background_lwt ~ctx : unit Lwt.t =
+    let%lwt () = refresh_username_to_slack_id_tbl ~ctx in
+    let%lwt () = Lwt_unix.sleep (Time.days 1) in
+    (* Updates mapping every 24 hours *)
+    refresh_username_to_slack_id_tbl_background_lwt ~ctx
+
+  let match_github_login_to_slack_id cfg_opt login =
+    let login =
+      match cfg_opt with
+      | None -> login
+      | Some cfg -> List.assoc_opt login cfg.user_mappings |> Option.default login
+    in
+    login |> canonicalize_email_username |> Stringtbl.find_opt username_to_slack_id_tbl
+
   let partition_push (cfg : Config_t.config) n =
     let default = Stdlib.Option.to_list cfg.prefix_rules.default_channel in
     let rules = cfg.prefix_rules.rules in
@@ -191,21 +231,27 @@ module Action (Github_api : Api.Github) (Slack_api : Api.Slack) = struct
   let generate_notifications (ctx : Context.t) (req : Github.t) =
     let repo = Github.repo_of_notification req in
     let cfg = Context.find_repo_config_exn ctx repo.url in
+    let slack_match_func = match_github_login_to_slack_id (Some cfg) in
     match ignore_notifications_from_user cfg req with
     | true -> Lwt.return []
     | false ->
     match req with
     | Github.Push n ->
       partition_push cfg n |> List.map (fun (channel, n) -> generate_push_notification n channel) |> Lwt.return
-    | Pull_request n -> partition_pr cfg n |> List.map (generate_pull_request_notification n) |> Lwt.return
-    | PR_review n -> partition_pr_review cfg n |> List.map (generate_pr_review_notification n) |> Lwt.return
+    | Pull_request n ->
+      partition_pr cfg n |> List.map (generate_pull_request_notification ~slack_match_func n) |> Lwt.return
+    | PR_review n ->
+      partition_pr_review cfg n |> List.map (generate_pr_review_notification ~slack_match_func n) |> Lwt.return
     | PR_review_comment n ->
-      partition_pr_review_comment cfg n |> List.map (generate_pr_review_comment_notification n) |> Lwt.return
-    | Issue n -> partition_issue cfg n |> List.map (generate_issue_notification n) |> Lwt.return
-    | Issue_comment n -> partition_issue_comment cfg n |> List.map (generate_issue_comment_notification n) |> Lwt.return
+      partition_pr_review_comment cfg n
+      |> List.map (generate_pr_review_comment_notification ~slack_match_func n)
+      |> Lwt.return
+    | Issue n -> partition_issue cfg n |> List.map (generate_issue_notification ~slack_match_func n) |> Lwt.return
+    | Issue_comment n ->
+      partition_issue_comment cfg n |> List.map (generate_issue_comment_notification ~slack_match_func n) |> Lwt.return
     | Commit_comment n ->
       let%lwt channels, api_commit = partition_commit_comment ctx n in
-      let notifs = List.map (generate_commit_comment_notification api_commit n) channels in
+      let notifs = List.map (generate_commit_comment_notification ~slack_match_func api_commit n) channels in
       Lwt.return notifs
     | Status n ->
       let%lwt channels = partition_status ctx n in
@@ -220,28 +266,28 @@ module Action (Github_api : Api.Github) (Slack_api : Api.Slack) = struct
     in
     Lwt_list.iter_s notify notifications
 
+  let fetch_config ~ctx ~repo =
+    match%lwt Github_api.get_config ~ctx ~repo with
+    | Ok config ->
+      Context.set_repo_config ctx repo.url config;
+      Context.print_config ctx repo.url;
+      Lwt.return @@ Ok ()
+    | Error e -> action_error e
+
   (** [refresh_repo_config ctx n] fetches the latest repo config if it's
       uninitialized, or if the incoming request [n] is a push
       notification containing commits that touched the config file. *)
   let refresh_repo_config (ctx : Context.t) notification =
     let repo = Github.repo_of_notification notification in
-    let fetch_config () =
-      match%lwt Github_api.get_config ~ctx ~repo with
-      | Ok config ->
-        Context.set_repo_config ctx repo.url config;
-        Context.print_config ctx repo.url;
-        Lwt.return @@ Ok ()
-      | Error e -> action_error e
-    in
     match Context.find_repo_config ctx repo.url with
-    | None -> fetch_config ()
+    | None -> fetch_config ~ctx ~repo
     | Some _ ->
     match notification with
     | Github.Push commit_pushed_notification ->
       let commits = commit_pushed_notification.commits in
       let modified_files = List.concat_map Github.modified_files_of_commit commits in
       let config_was_modified = List.exists (String.equal ctx.config_filename) modified_files in
-      if config_was_modified then fetch_config () else Lwt.return @@ Ok ()
+      if config_was_modified then fetch_config ~ctx ~repo else Lwt.return @@ Ok ()
     | _ -> Lwt.return @@ Ok ()
 
   let do_github_tasks ctx (repo : repository) (req : Github.t) =
@@ -265,15 +311,15 @@ module Action (Github_api : Api.Github) (Slack_api : Api.Slack) = struct
       end
     | _ -> Lwt.return_unit
 
+  let repo_is_supported secrets (repo : Github_t.repository) =
+    List.exists (fun (r : repo_config) -> String.equal r.url repo.url) secrets.repos
+
   let process_github_notification (ctx : Context.t) headers body =
     let validate_signature secrets payload =
       let repo = Github.repo_of_notification payload in
       let signing_key = Context.gh_hook_secret_token_of_secrets secrets repo.url in
       Github.validate_signature ?signing_key ~headers body
     in
-    let repo_is_supported secrets (repo : Github_t.repository) =
-      List.exists (fun (r : repo_config) -> String.equal r.url repo.url) secrets.repos
-    in
     try%lwt
       let secrets = Context.get_secrets_exn ctx in
       match Github.parse_exn headers body with
@@ -337,9 +383,7 @@ module Action (Github_api : Api.Github) (Slack_api : Api.Slack) = struct
         Lwt.return_none
     in
     let process link =
-      let with_gh_result_populate_slack (type a) ~(api_result : (a, string) Result.t)
-        ~(populate : repository -> a -> Slack_t.message_attachment) ~repo
-        =
+      let with_gh_result_populate_slack (type a) ~(api_result : (a, string) Result.t) ~populate ~repo =
         match api_result with
         | Error _ -> Lwt.return_none
         | Ok item -> Lwt.return_some @@ (link, populate repo item)
diff --git a/lib/slack.ml b/lib/slack.ml
@@ -46,7 +46,24 @@ let markdown_text_attachment ~footer markdown_body =
 let make_message ?username ?text ?attachments ?blocks ~channel () =
   { channel; text; attachments; blocks; username; unfurl_links = Some false; unfurl_media = None }
 
-let generate_pull_request_notification notification channel =
+let format_slack_mention = Option.map_default (sprintf " (<@%s>)") ""
+let github_handle_regex = Re2.create_exn {|(?:^|\s)@([\w][\w-]{1,})|} (* Match GH handles in messages *)
+
+let add_slack_mentions_to_body slack_match_func body =
+  let replace_match m =
+    let gh_handle = Re2.Match.get_exn ~sub:(`Index 0) m in
+    let gh_handle_without_at = Re2.Match.get_exn ~sub:(`Index 1) m in
+    sprintf "%s%s" gh_handle (format_slack_mention (slack_match_func gh_handle_without_at))
+  in
+  Re2.replace_exn github_handle_regex body ~f:replace_match
+
+let format_attachments ~slack_match_func ~footer ~body =
+  let format_mention_in_markdown (md : unfurl) =
+    { md with text = Option.map (add_slack_mentions_to_body slack_match_func) md.text }
+  in
+  Option.map (fun t -> markdown_text_attachment ~footer t |> List.map format_mention_in_markdown) body
+
+let generate_pull_request_notification ~slack_match_func notification channel =
   let { action; number; sender; pull_request; repository } = notification in
   let ({ body; title; html_url; labels; merged; _ } : pull_request) = pull_request in
   let action, body =
@@ -65,9 +82,9 @@ let generate_pull_request_notification notification channel =
     sprintf "<%s|[%s]> Pull request #%d %s %s by *%s*" repository.url repository.full_name number
       (pp_link ~url:html_url title) action sender.login
   in
-  make_message ~text:summary ?attachments:(Option.map (markdown_text_attachment ~footer:None) body) ~channel ()
+  make_message ~text:summary ?attachments:(format_attachments ~slack_match_func ~footer:None ~body) ~channel ()
 
-let generate_pr_review_notification notification channel =
+let generate_pr_review_notification ~slack_match_func notification channel =
   let { action; sender; pull_request; review; repository } = notification in
   let ({ number; title; html_url; _ } : pull_request) = pull_request in
   let action_str =
@@ -89,9 +106,11 @@ let generate_pr_review_notification notification channel =
     sprintf "<%s|[%s]> *%s* <%s|%s> #%d %s" repository.url repository.full_name sender.login review.html_url action_str
       number (pp_link ~url:html_url title)
   in
-  make_message ~text:summary ?attachments:(Option.map (markdown_text_attachment ~footer:None) review.body) ~channel ()
+  make_message ~text:summary
+    ?attachments:(format_attachments ~slack_match_func ~footer:None ~body:review.body)
+    ~channel ()
 
-let generate_pr_review_comment_notification notification channel =
+let generate_pr_review_comment_notification ~slack_match_func notification channel =
   let { action; pull_request; sender; comment; repository } = notification in
   let ({ number; title; html_url; _ } : pull_request) = pull_request in
   let action_str =
@@ -112,9 +131,11 @@ let generate_pr_review_comment_notification notification channel =
     | None -> None
     | Some a -> Some (sprintf "New comment by %s in <%s|%s>" sender.login comment.html_url a)
   in
-  make_message ~text:summary ~attachments:(markdown_text_attachment ~footer:file comment.body) ~channel ()
+  make_message ~text:summary
+    ?attachments:(format_attachments ~slack_match_func ~footer:file ~body:(Some comment.body))
+    ~channel ()
 
-let generate_issue_notification notification channel =
+let generate_issue_notification ~slack_match_func notification channel =
   let ({ action; sender; issue; repository } : issue_notification) = notification in
   let { number; body; title; html_url; labels; _ } = issue in
   let action, body =
@@ -133,9 +154,10 @@ let generate_issue_notification notification channel =
     sprintf "<%s|[%s]> Issue #%d %s %s by *%s*" repository.url repository.full_name number (pp_link ~url:html_url title)
       action sender.login
   in
-  make_message ~text:summary ?attachments:(Option.map (markdown_text_attachment ~footer:None) body) ~channel ()
 
-let generate_issue_comment_notification notification channel =
+  make_message ~text:summary ?attachments:(format_attachments ~slack_match_func ~footer:None ~body) ~channel ()
+
+let generate_issue_comment_notification ~slack_match_func notification channel =
   let { action; issue; sender; comment; repository } = notification in
   let { number; title; _ } = issue in
   let action_str =
@@ -152,7 +174,9 @@ let generate_issue_comment_notification notification channel =
     sprintf "<%s|[%s]> *%s* <%s|%s> on #%d %s" repository.url repository.full_name sender.login comment.html_url
       action_str number (pp_link ~url:issue.html_url title)
   in
-  make_message ~text:summary ~attachments:(markdown_text_attachment ~footer:None comment.body) ~channel ()
+  make_message ~text:summary
+    ?attachments:(format_attachments ~slack_match_func ~footer:None ~body:(Some comment.body))
+    ~channel ()
 
 let git_short_sha_hash hash = String.sub hash 0 8
 
@@ -312,7 +336,7 @@ let generate_status_notification (cfg : Config_t.config) (notification : status_
   in
   make_message ~text:summary ~attachments:[ attachment ] ~channel ()
 
-let generate_commit_comment_notification api_commit notification channel =
+let generate_commit_comment_notification ~slack_match_func api_commit notification channel =
   let { commit; _ } = api_commit in
   let { sender; comment; repository; _ } = notification in
   let commit_id =
@@ -330,7 +354,9 @@ let generate_commit_comment_notification api_commit notification channel =
     | None -> None
     | Some p -> Some (sprintf "New comment by %s in <%s|%s>" sender.login comment.html_url p)
   in
-  make_message ~text:summary ~attachments:(markdown_text_attachment ~footer:path comment.body) ~channel ()
+  make_message ~text:summary
+    ?attachments:(format_attachments ~slack_match_func ~footer:path ~body:(Some comment.body))
+    ~channel ()
 
 let validate_signature ?(version = "v0") ?signing_key ~headers body =
   match signing_key with
diff --git a/lib/slack_message.ml b/lib/slack_message.ml
@@ -40,6 +40,7 @@ let base_attachment repository = { empty_attachment with footer = Some (simple_f
 let pp_label (label : label) = label.name
 let pp_github_user (user : github_user) = gh_name_of_string user.login
 let pp_github_team (team : github_team) = gh_name_of_string team.slug
+let pretext_slack_mention = Option.map (sprintf "<@%s>")
 
 let populate_pull_request repository (pull_request : pull_request) =
   let ({
@@ -182,10 +183,6 @@ let populate_commit ?(include_changes = true) repository (api_commit : api_commi
   {
     (base_attachment repository) with
     footer = Some (simple_footer repository ^ " " ^ commit.committer.date);
-    (*
-    author_name = Some author.login;
-    author_link = Some author.html_url;
-    *)
     author_icon =
       ( match author with
       | Some author -> Some author.avatar_url
diff --git a/src/monorobot.ml b/src/monorobot.ml
@@ -47,9 +47,11 @@ let check_gh_action file json config secrets state =
       Lwt_main.run
         ( if json then
           let module Action = Action.Action (Api_remote.Github) (Api_local.Slack_json) in
+          let%lwt () = Action.refresh_username_to_slack_id_tbl ~ctx in
           Action.process_github_notification ctx headers body
         else
           let module Action = Action.Action (Api_remote.Github) (Api_local.Slack_simple) in
+          let%lwt () = Action.refresh_username_to_slack_id_tbl ~ctx in
           Action.process_github_notification ctx headers body
         )
     )
diff --git a/src/request_handler.ml b/src/request_handler.ml
@@ -11,7 +11,7 @@ let run ~ctx ~addr ~port =
   let ip = Unix.inet_addr_of_string addr in
   let signature = sprintf "listen %s:%d" (Unix.string_of_inet_addr ip) port in
   let connection = Unix.ADDR_INET (ip, port) in
-  let%lwt () =
+  let request_handler_lwt =
     Httpev.setup_lwt { default with name = "monorobot"; connection; access_log_enabled = false } (fun _http request ->
       let module Arg = Args (struct let req = request end) in
       let body r = Lwt.return (`Body r) in
@@ -56,4 +56,9 @@ let run ~ctx ~addr ~port =
           )
     )
   in
+  let refresh_username_to_slack_id_tbl_background_lwt =
+    try%lwt Daemon.unless_exit @@ Action.refresh_username_to_slack_id_tbl_background_lwt ~ctx
+    with Daemon.ShouldExit -> Lwt.return_unit
+  in
+  let%lwt () = Lwt.join [ refresh_username_to_slack_id_tbl_background_lwt; request_handler_lwt ] in
   Lwt.return_unit

Original file line number	Diff line number	Diff line change
`@@ -47,9 +47,11 @@ let check_gh_action file json config secrets state =`
`47`	`47`	`Lwt_main.run`
`48`	`48`	`( if json then`
`49`	`49`	`let module Action = Action.Action (Api_remote.Github) (Api_local.Slack_json) in`
	`50`	`+ let%lwt () = Action.refresh_username_to_slack_id_tbl ~ctx in`
`50`	`51`	`Action.process_github_notification ctx headers body`
`51`	`52`	`else`
`52`	`53`	`let module Action = Action.Action (Api_remote.Github) (Api_local.Slack_simple) in`
	`54`	`+ let%lwt () = Action.refresh_username_to_slack_id_tbl ~ctx in`
`53`	`55`	`Action.process_github_notification ctx headers body`
`54`	`56`	`)`
`55`	`57`	`)`