github.com/zntrio/harp/v2@v2.0.9/pkg/tasks/from/template.go (about)

     1  // Licensed to Elasticsearch B.V. under one or more contributor
     2  // license agreements. See the NOTICE file distributed with
     3  // this work for additional information regarding copyright
     4  // ownership. Elasticsearch B.V. licenses this file to you under
     5  // the Apache License, Version 2.0 (the "License"); you may
     6  // not use this file except in compliance with the License.
     7  // You may obtain a copy of the License at
     8  //
     9  //     http://www.apache.org/licenses/LICENSE-2.0
    10  //
    11  // Unless required by applicable law or agreed to in writing,
    12  // software distributed under the License is distributed on an
    13  // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    14  // KIND, either express or implied.  See the License for the
    15  // specific language governing permissions and limitations
    16  // under the License.
    17  
    18  package from
    19  
    20  import (
    21  	"context"
    22  	"fmt"
    23  	"io"
    24  
    25  	bundlev1 "github.com/zntrio/harp/v2/api/gen/go/harp/bundle/v1"
    26  	"github.com/zntrio/harp/v2/pkg/bundle"
    27  	"github.com/zntrio/harp/v2/pkg/bundle/template"
    28  	"github.com/zntrio/harp/v2/pkg/bundle/template/visitor/secretbuilder"
    29  	"github.com/zntrio/harp/v2/pkg/tasks"
    30  	"github.com/zntrio/harp/v2/pkg/template/engine"
    31  )
    32  
    33  // BundleTemplateTask implements secret-container generation from BundleTemplate
    34  // manifest.
    35  type BundleTemplateTask struct {
    36  	TemplateReader  tasks.ReaderProvider
    37  	OutputWriter    tasks.WriterProvider
    38  	TemplateContext engine.Context
    39  }
    40  
    41  // Run the task.
    42  func (t *BundleTemplateTask) Run(ctx context.Context) error {
    43  	var (
    44  		reader io.Reader
    45  		writer io.Writer
    46  		spec   *bundlev1.Template
    47  		err    error
    48  	)
    49  
    50  	// Create input reader
    51  	reader, err = t.TemplateReader(ctx)
    52  	if err != nil {
    53  		return fmt.Errorf("unable to open input bundle template: %w", err)
    54  	}
    55  
    56  	// Parse the input specification
    57  	spec, err = template.YAML(reader)
    58  	if err != nil {
    59  		return fmt.Errorf("unable to parse template: %w", err)
    60  	}
    61  
    62  	// Initialize output
    63  	b := &bundlev1.Bundle{
    64  		Template: spec,
    65  	}
    66  
    67  	// Initialize a bundle creator
    68  	v := secretbuilder.New(b, t.TemplateContext)
    69  
    70  	// Execute the template to generate an output bundle
    71  	if err = template.Execute(spec, v); err != nil {
    72  		return fmt.Errorf("unable to generate output bundle from template: %w", err)
    73  	}
    74  
    75  	// Create output writer
    76  	writer, err = t.OutputWriter(ctx)
    77  	if err != nil {
    78  		return fmt.Errorf("unable to open output bundle: %w", err)
    79  	}
    80  
    81  	// Dump all content
    82  	if err = bundle.ToContainerWriter(writer, b); err != nil {
    83  		return fmt.Errorf("unable to dump bundle content: %w", err)
    84  	}
    85  
    86  	// No error
    87  	return nil
    88  }