Enable declarative projects.

This allows fully declarative project specifications. This is best
illustrated by example:

* I create a new project, setting the declarative spec file to
  "spec.json" and the declarative input to a git repo pointing
  at git://github.com/shlevy/declarative-hydra-example.git
* hydra creates a special ".jobsets" jobset alongside the project
* Just before evaluating the ".jobsets" jobset, hydra fetches
  declarative-hydra-example.git, reads spec.json as a jobset spec,
  and updates the jobset's configuration accordingly:
{
    "enabled": 1,
    "hidden": false,
    "description": "Jobsets",
    "nixexprinput": "src",
    "nixexprpath": "default.nix",
    "checkinterval": 300,
    "schedulingshares": 100,
    "enableemail": false,
    "emailoverride": "",
    "keepnr": 3,
    "inputs": {
        "src": { "type": "git", "value": "git://github.com/shlevy/declarative-hydra-example.git", "emailresponsible": false },
        "nixpkgs": { "type": "git", "value": "git://github.com/NixOS/nixpkgs.git release-16.03", "emailresponsible": false }
    }
}
* When the "jobsets" job of the ".jobsets" jobset completes, hydra
  reads its output as a JSON representation of a dictionary of
  jobset specs and creates a jobset named "master" configured
  accordingly (In this example, this is the same configuration as
  .jobsets itself, except using release.nix instead of default.nix):
{
    "enabled": 1,
    "hidden": false,
    "description": "js",
    "nixexprinput": "src",
    "nixexprpath": "release.nix",
    "checkinterval": 300,
    "schedulingshares": 100,
    "enableemail": false,
    "emailoverride": "",
    "keepnr": 3,
    "inputs": {
        "src": { "type": "git", "value": "git://github.com/shlevy/declarative-hydra-example.git", "emailresponsible": false },
        "nixpkgs": { "type": "git", "value": "git://github.com/NixOS/nixpkgs.git release-16.03", "emailresponsible": false }
    }
}

src/lib/Hydra/Helper/AddBuilds.pm

@@ -22,7 +22,8 @@ use Hydra::Helper::CatalystUtils;
 our @ISA = qw(Exporter);
 our @EXPORT = qw(
     fetchInput evalJobs checkBuild inputsToArgs
-    restartBuild getPrevJobsetEval
+    restartBuild getPrevJobsetEval updateDeclarativeJobset
+    handleDeclarativeJobsetBuild
 );
 
 
@@ -467,4 +468,66 @@ sub checkBuild {
 };
 
 
+sub updateDeclarativeJobset {
+    my ($db, $project, $jobsetName, $declSpec) = @_;
+
+    my @allowed_keys = qw(
+        enabled
+        hidden
+        description
+        nixexprinput
+        nixexprpath
+        checkinterval
+        schedulingshares
+        enableemail
+        emailoverride
+        keepnr
+    );
+    my %update = ( name => $jobsetName );
+    foreach my $key (@allowed_keys) {
+        $update{$key} = $declSpec->{$key};
+        delete $declSpec->{$key};
+    }
+    txn_do($db, sub {
+        my $jobset = $project->jobsets->update_or_create(\%update);
+        $jobset->jobsetinputs->delete;
+        while ((my $name, my $data) = each %{$declSpec->{"inputs"}}) {
+            my $input = $jobset->jobsetinputs->create(
+                { name => $name,
+                  type => $data->{type},
+                  emailresponsible => $data->{emailresponsible}
+                });
+            $input->jobsetinputalts->create({altnr => 0, value => $data->{value}});
+        }
+        delete $declSpec->{"inputs"};
+        die "invalid keys in declarative specification file\n" if (%{$declSpec});
+    });
+};
+
+
+sub handleDeclarativeJobsetBuild {
+    my ($db, $project, $build) = @_;
+
+    eval {
+        my $id = $build->id;
+        die "Declarative jobset build $id failed" unless $build->buildstatus == 0;
+        my $declPath = ($build->buildoutputs)[0]->path;
+        my $declText = read_file($declPath)
+            or die "Couldn't read declarative specification file $declPath: $!";
+        my $declSpec = decode_json($declText);
+        txn_do($db, sub {
+            my @kept = keys %$declSpec;
+            push @kept, ".jobsets";
+            $project->jobsets->search({ name => { "not in" => \@kept } })->update({ enabled => 0, hidden => 1 });
+            while ((my $jobsetName, my $spec) = each %$declSpec) {
+                updateDeclarativeJobset($db, $project, $jobsetName, $spec);
+            }
+        });
+    };
+    $project->jobsets->find({ name => ".jobsets" })->update({ errormsg => $@, errortime => time, fetcherrormsg => undef })
+        if defined $@;
+
+};
+
+
 1;

src/lib/Hydra/Helper/CatalystUtils.pm

@@ -264,7 +264,7 @@ Readonly our $inputNameRE   => "(?:[A-Za-z_][A-Za-z0-9-_]*)";
 
 sub parseJobsetName {
     my ($s) = @_;
-    $s =~ /^($projectNameRE):($jobsetNameRE)$/ or die "invalid jobset specifier ‘$s’\n";
+    $s =~ /^($projectNameRE):(\.?$jobsetNameRE)$/ or die "invalid jobset specifier ‘$s’\n";
     return ($1, $2);
 }