enable basic jsonnet in process

cmd/drone-server/config/config.go

@@ -54,6 +54,7 @@ type (
 		Datadog  Datadog
 		Docker   Docker
 		HTTP     HTTP
+		Jsonnet  Jsonnet
 		Logging  Logging
 		// Prometheus Prometheus
 		Proxy        Proxy
@@ -116,6 +117,11 @@ type (
 		Token    string `envconfig:"DRONE_DATADOG_TOKEN"`
 	}
 
+	// Jsonnet configures the jsonnet plugin
+	Jsonnet struct {
+		Enabled bool `envconfig:"DRONE_JSONNET_ENABLED"`
+	}
+
 	// Kubernetes provides kubernetes configuration
 	Kubernetes struct {
 		Enabled            bool   `envconfig:"DRONE_KUBERNETES_ENABLED"`

cmd/drone-server/inject_plugin.go

@@ -57,6 +57,7 @@ func provideConfigPlugin(client *scm.Client, contents core.FileService, conf spe
 			conf.Yaml.Secret,
 			conf.Yaml.SkipVerify,
 		),
+		config.Jsonnet(contents, conf.Jsonnet.Enabled),
 		config.Repository(contents),
 	)
 }

go.mod

@@ -35,6 +35,7 @@ require (
 	github.com/golang/protobuf v1.2.0
 	github.com/google/btree v0.0.0-20180813153112-4030bb1f1f0c
 	github.com/google/go-cmp v0.2.0
+	github.com/google/go-jsonnet v0.12.1
 	github.com/google/gofuzz v0.0.0-20170612174753-24818f796faf
 	github.com/google/wire v0.2.1
 	github.com/googleapis/gnostic v0.2.0

go.sum

@@ -89,6 +89,8 @@ github.com/google/btree v0.0.0-20180813153112-4030bb1f1f0c h1:964Od4U6p2jUkFxvCy
 github.com/google/btree v0.0.0-20180813153112-4030bb1f1f0c/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ=
 github.com/google/go-cmp v0.2.0 h1:+dTQ8DZQJz0Mb/HjFlkptS1FeQ4cWSnN941F8aEG4SQ=
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
+github.com/google/go-jsonnet v0.12.1 h1:v0iUm/b4SBz7lR/diMoz9tLAz8lqtnNRKIwMrmU2HEU=
+github.com/google/go-jsonnet v0.12.1/go.mod h1:gVu3UVSfOt5fRFq+dh9duBqXa5905QY8S1QvMNcEIVs=
 github.com/google/gofuzz v0.0.0-20170612174753-24818f796faf h1:+RRA9JqSOZFfKrOeqr2z77+8R2RKyh8PG66dcu1V0ck=
 github.com/google/gofuzz v0.0.0-20170612174753-24818f796faf/go.mod h1:HP5RmnzzSNb993RKQDq4+1A4ia9nllfqcQFTQJedwGI=
 github.com/google/wire v0.2.1 h1:TYj4Z2qjqxa2ufb34UJqVeO9aznL+i0fLO6TqThKZ7Y=
@@ -112,6 +114,8 @@ github.com/hashicorp/go-multierror v1.0.0 h1:iVjPR7a6H0tWELX5NxNe7bYopibicUzc7uP
 github.com/hashicorp/go-multierror v1.0.0/go.mod h1:dHtQlpGsu+cZNNAkkCN/P3hoUDHhCYQXV3UM06sGGrk=
 github.com/hashicorp/go-retryablehttp v0.0.0-20180718195005-e651d75abec6 h1:qCv4319q2q7XKn0MQbi8p37hsJ+9Xo8e6yojA73JVxk=
 github.com/hashicorp/go-retryablehttp v0.0.0-20180718195005-e651d75abec6/go.mod h1:fXcdFsQoipQa7mwORhKad5jmDCeSy/RCGzWA08PO0lM=
+github.com/hashicorp/go-rootcerts v1.0.0 h1:ueI78wUjYExhCvMLow4icJnayNNFRgy0d9EGs/a1T44=
+github.com/hashicorp/go-rootcerts v1.0.0/go.mod h1:K6zTfqpRlCUIjkwsN4Z+hiSfzSTQa6eBIzfwKfwNnHU=
 github.com/hashicorp/golang-lru v0.5.0 h1:CL2msUPvZTLb5O648aiLNJw3hnBxN2+1Jq8rCOH9wdo=
 github.com/hashicorp/golang-lru v0.5.0/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
 github.com/hashicorp/nomad v0.0.0-20190125003214-134391155854 h1:L7WhLZt2ory/kQWxqkMwOiBpIoa4BWoadN7yx8LHEtk=

plugin/config/jsonnet.go

@@ -0,0 +1,77 @@
+// Copyright 2019 Drone.IO Inc. All rights reserved.
+// Use of this source code is governed by the Drone Non-Commercial License
+// that can be found in the LICENSE file.
+
+// +build !oss
+
+package config
+
+import (
+	"bytes"
+	"context"
+	"strings"
+
+	"github.com/drone/drone/core"
+
+	"github.com/google/go-jsonnet"
+)
+
+// Jsonnet returns a configuration service that fetches the
+// jsonnet file directly from the source code management (scm)
+// system and converts to a yaml file.
+func Jsonnet(service core.FileService, enabled bool) core.ConfigService {
+	return &jsonnetPlugin{
+		enabled: enabled,
+		repos:   &repo{files: service},
+	}
+}
+
+type jsonnetPlugin struct {
+	enabled bool
+	repos   *repo
+}
+
+func (p *jsonnetPlugin) Find(ctx context.Context, req *core.ConfigArgs) (*core.Config, error) {
+	if p.enabled == false {
+		return nil, nil
+	}
+
+	// if the file extension is not jsonnet we can
+	// skip this plugin by returning zero values.
+	if strings.HasSuffix(req.Repo.Config, ".jsonnet") == false {
+		return nil, nil
+	}
+
+	// get the file contents.
+	config, err := p.repos.Find(ctx, req)
+	if err != nil {
+		return nil, err
+	}
+
+	// TODO(bradrydzewski) temporarily disable file imports
+	// TODO(bradrydzewski) handle object vs array output
+
+	// create the jsonnet vm
+	vm := jsonnet.MakeVM()
+	vm.MaxStack = 500
+	vm.StringOutput = false
+	vm.ErrorFormatter.SetMaxStackTraceSize(20)
+
+	// convert the jsonnet file to yaml
+	buf := new(bytes.Buffer)
+	docs, err := vm.EvaluateSnippetStream(req.Repo.Config, config.Data)
+	if err != nil {
+		return nil, err
+	}
+
+	// the jsonnet vm returns a stream of yaml documents
+	// that need to be combined into a single yaml file.
+	for _, doc := range docs {
+		buf.WriteString("---")
+		buf.WriteString("\n")
+		buf.WriteString(doc)
+	}
+
+	config.Data = buf.String()
+	return config, nil
+}

plugin/config/jsonnet_oss.go

@@ -0,0 +1,24 @@
+// Copyright 2019 Drone IO, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build oss
+
+package config
+
+import "github.com/drone/drone/core"
+
+// Jsonnet returns a no-op configuration service.
+func Jsonnet(service core.FileService, enabled bool) core.ConfigService {
+	return new(noop)
+}

plugin/config/jsonnet_test.go

@@ -0,0 +1,7 @@
+// Copyright 2019 Drone.IO Inc. All rights reserved.
+// Use of this source code is governed by the Drone Non-Commercial License
+// that can be found in the LICENSE file.
+
+// +build !oss
+
+package config