Add GitlabPulls input plugin

src/lib/Hydra/Plugin/GitlabPulls.pm

@@ -0,0 +1,94 @@
+# This plugin allows to build Gitlab merge requests.
+#
+# The declarative project spec.json file must contains an input such as
+#   "pulls": {
+#      "type": "gitlabpulls",
+#      "value": "https://gitlab.com 42",
+#      "emailresponsible": false
+#   }
+# where 42 is the project id of a repository.
+#
+# The values source_repo_url and source_branch can then be used to
+# build the git input value.
+
+package Hydra::Plugin::GitlabPulls;
+
+use strict;
+use parent 'Hydra::Plugin';
+use HTTP::Request;
+use LWP::UserAgent;
+use JSON;
+use Hydra::Helper::CatalystUtils;
+use File::Temp;
+use POSIX qw(strftime);
+
+sub supportedInputTypes {
+    my ($self, $inputTypes) = @_;
+    $inputTypes->{'gitlabpulls'} = 'Open Gitlab Merge Requests';
+}
+
+sub _query {
+    my ($url, $ua) = @_;
+    my $req = HTTP::Request->new('GET', $url);
+    my $res = $ua->request($req);
+    my $content = $res->decoded_content;
+    die "Error pulling from the gitlab pulls API: $content\n"
+        unless $res->is_success;
+    return (decode_json $content, $res);
+}
+
+# We need to query the Gitlab API for each merge request to get the
+# source repository URL.
+sub _enhanceGitlabPull {
+    my ($pull, $baseUrl, $ua) = @_;
+    my $projectId = $pull->{source_project_id};
+    (my $repo, my $res) = _query("$baseUrl/api/v4/projects/$projectId", $ua);
+    $pull->{source_repo_url} = $repo->{http_url_to_repo};
+}
+
+sub _iterate {
+    my ($url, $baseUrl, $pulls, $ua) = @_;
+    my ($pulls_list, $res) = _query($url, $ua);
+
+    foreach my $pull (@$pulls_list) {
+        _enhanceGitlabPull($pull, $baseUrl, $ua);
+        $pulls->{$pull->{iid}} = $pull;
+    }
+    # TODO Make Link header parsing more robust!!!
+    my @links = split ',', $res->header("Link");
+    my $next = "";
+    foreach my $link (@links) {
+        my ($url, $rel) = split ";", $link;
+        if (trim($rel) eq 'rel="next"') {
+            $next = substr trim($url), 1, -1;
+            last;
+        }
+    }
+    _iterate($next, $baseUrl, $pulls, $ua) unless $next eq "";
+}
+
+sub fetchInput {
+    my ($self, $type, $name, $value, $project, $jobset) = @_;
+    return undef if $type ne "gitlabpulls";
+
+    (my $baseUrl, my $projectId) = split ' ', $value;
+    my $url = "$baseUrl/api/v4/projects/$projectId/merge_requests?per_page=100&state=opened";
+
+    my %pulls;
+    my $ua = LWP::UserAgent->new();
+    _iterate($url, $baseUrl, \%pulls, $ua);
+    
+    my $tempdir = File::Temp->newdir("gitlab-pulls" . "XXXXX", TMPDIR => 1);
+    my $filename = "$tempdir/gitlab-pulls.json";
+    open(my $fh, ">", $filename) or die "Cannot open $filename for writing: $!";
+    print $fh encode_json \%pulls;
+    close $fh;
+    system("jq -S . < $filename > $tempdir/gitlab-pulls-sorted.json");
+    my $storePath = trim(`nix-store --add "$tempdir/gitlab-pulls-sorted.json"`
+        or die "cannot copy path $filename to the Nix store.\n");
+    chomp $storePath;
+    my $timestamp = time;
+    return { storePath => $storePath, revision => strftime "%Y%m%d%H%M%S", gmtime($timestamp) };
+}
+
+1;