mirror of
https://github.com/hashicorp/packer.git
synced 2026-09-19 22:41:40 -04:00
Lucas Bajolet
5ce9b1867b
The file datasource is meant to be used to pre-create a file that can then be used elsewhere in the build process by its path. This is useful for example when building a configuration file from a template, so then the resulting file can be referenced by components which only accept file paths.
132 lines
3.6 KiB
Go
132 lines
3.6 KiB
Go
// Copyright (c) HashiCorp, Inc.
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// SPDX-License-Identifier: MPL-2.0
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//go:generate packer-sdc struct-markdown
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//go:generate packer-sdc mapstructure-to-hcl2 -type DatasourceOutput,Config
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package file
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import (
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"fmt"
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"log"
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"os"
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"path/filepath"
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"github.com/hashicorp/hcl/v2/hcldec"
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"github.com/hashicorp/packer-plugin-sdk/common"
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"github.com/hashicorp/packer-plugin-sdk/hcl2helper"
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"github.com/hashicorp/packer-plugin-sdk/template/config"
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"github.com/zclconf/go-cty/cty"
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)
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type Config struct {
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common.PackerConfig `mapstructure:",squash"`
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// The contents of the file to create
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//
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// This is useful especially for files that involve templating so that
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// Packer can dynamically create files and expose them for later importing
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// as attributes in another entity.
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//
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// If no contents are specified, the resulting file will be empty.
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Contents string `mapstructure:"contents" required:"false"`
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// The file or directory to write the contents to.
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Destination string `mapstructure:"destination" required:"false"`
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}
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type Datasource struct {
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config Config
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}
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type DatasourceOutput struct {
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// The path of the file created
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Path string `mapstructure:"path"`
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}
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func (d *Datasource) ConfigSpec() hcldec.ObjectSpec {
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return d.config.FlatMapstructure().HCL2Spec()
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}
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func (d *Datasource) Configure(raws ...interface{}) error {
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err := config.Decode(&d.config, nil, raws...)
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if err != nil {
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return err
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}
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return nil
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}
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func (d *Datasource) OutputSpec() hcldec.ObjectSpec {
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return (&DatasourceOutput{}).FlatMapstructure().HCL2Spec()
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}
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func (d *Datasource) Execute() (cty.Value, error) {
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nulVal := cty.NullVal(cty.EmptyObject)
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dest, err := d.createTempOutputFile()
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if err != nil {
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return nulVal, fmt.Errorf("failed to create output file: %s", err)
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}
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defer dest.Close()
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log.Printf("[INFO] data/file - Writing to %q", dest.Name())
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written, err := dest.Write([]byte(d.config.Contents))
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if err != nil {
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defer os.Remove(d.config.Destination)
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return nulVal, fmt.Errorf("failed to write contents to %q: %s", d.config.Destination, err)
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}
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if written != len(d.config.Contents) {
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defer os.Remove(d.config.Destination)
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return nulVal, fmt.Errorf(
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"failed to write contents to %q: expected to write %d bytes, but wrote %d instead",
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d.config.Destination,
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len(d.config.Contents),
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written)
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}
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output := DatasourceOutput{
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Path: dest.Name(),
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}
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return hcl2helper.HCL2ValueFromConfig(output, d.OutputSpec()), nil
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}
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func (d *Datasource) createTempOutputFile() (*os.File, error) {
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// If we did not get a destination, we'll create a temp file in the
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// system's temporary directory
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if d.config.Destination == "" {
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return os.CreateTemp("", "")
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}
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// First try to stat the destination, to determine if it already exists and its type
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st, statErr := os.Stat(d.config.Destination)
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if statErr == nil {
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if st.IsDir() {
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return os.CreateTemp(d.config.Destination, "")
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}
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return os.OpenFile(d.config.Destination, os.O_TRUNC|os.O_RDWR, 0644)
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}
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outDir := filepath.Dir(d.config.Destination)
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// In case the destination does not exist, we'll get the dirpath,
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// and create it if it doesn't already exist
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err := os.MkdirAll(outDir, 0755)
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if err != nil {
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return nil, fmt.Errorf("failed to create destination directory %q: %s", outDir, err)
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}
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// Check if the destination is a directory after the previous step.
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//
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// This happens if the path specified ends with a `/`, in which case the
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// destination is a directory, and we must create a temporary file in
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// this destination directory.
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destStat, statErr := os.Stat(d.config.Destination)
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if statErr == nil && destStat.IsDir() {
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return os.CreateTemp(d.config.Destination, "")
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}
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return os.Create(d.config.Destination)
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}
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