feat: tool to build custom Telegraf builds (#11524)

This commit is contained in:
Sven Rebhan 2022-08-19 21:38:03 +02:00 committed by GitHub
parent c653f4dcb5
commit f1ce84f02d
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GPG Key ID: 4AEE18F83AFDEB23
13 changed files with 783 additions and 8 deletions

1
.gitignore vendored
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@ -6,6 +6,7 @@
/tools/package_lxd_test/package_lxd_test
/tools/license_checker/license_checker*
/tools/readme_config_includer/generator*
/tools/custom_builder/custom_builder*
/vendor
.DS_Store
process.yml

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@ -126,7 +126,7 @@ issues:
- path: _test\.go
text: "parameter.*seems to be a control flag, avoid control coupling"
- path: (^agent/|^cmd/|^config/|^filter/|^internal/|^logger/|^metric/|^models/|^selfstat/|^testutil/|^plugins/serializers/|^plugins/inputs/zipkin/cmd)
- path: (^agent/|^cmd/|^config/|^filter/|^internal/|^logger/|^metric/|^models/|^selfstat/|^testutil/|^tools|^plugins/serializers/|^plugins/inputs/zipkin/cmd)
text: "imports-blacklist: should not use the following blacklisted import: \"log\""
linters:
- revive

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@ -114,6 +114,7 @@ versioninfo:
go generate cmd/telegraf/telegraf_windows.go; \
build_tools:
$(HOSTGO) build -o ./tools/custom_builder/custom_builder$(EXEEXT) ./tools/custom_builder
$(HOSTGO) build -o ./tools/license_checker/license_checker$(EXEEXT) ./tools/license_checker
$(HOSTGO) build -o ./tools/readme_config_includer/generator$(EXEEXT) ./tools/readme_config_includer/generator.go
@ -223,6 +224,8 @@ clean:
rm -f telegraf
rm -f telegraf.exe
rm -rf build
rm -rf tools/custom_builder/custom_builder
rm -rf tools/custom_builder/custom_builder.exe
rm -rf tools/readme_config_includer/generator
rm -rf tools/readme_config_includer/generator.exe
rm -rf tools/package_lxd_test/package_lxd_test

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@ -27,12 +27,15 @@ import (
"github.com/influxdata/telegraf/internal"
"github.com/influxdata/telegraf/internal/goplugin"
"github.com/influxdata/telegraf/logger"
"github.com/influxdata/telegraf/plugins/aggregators"
_ "github.com/influxdata/telegraf/plugins/aggregators/all"
"github.com/influxdata/telegraf/plugins/inputs"
_ "github.com/influxdata/telegraf/plugins/inputs/all"
"github.com/influxdata/telegraf/plugins/outputs"
_ "github.com/influxdata/telegraf/plugins/outputs/all"
"github.com/influxdata/telegraf/plugins/parsers"
_ "github.com/influxdata/telegraf/plugins/parsers/all"
"github.com/influxdata/telegraf/plugins/processors"
_ "github.com/influxdata/telegraf/plugins/processors/all"
"gopkg.in/tomb.v1"
)
@ -271,7 +274,14 @@ func runAgent(ctx context.Context,
logger.SetupLogging(logConfig)
log.Printf("I! Starting Telegraf %s", internal.Version())
log.Printf("I! Starting Telegraf %s%s", internal.Version(), internal.Customized)
log.Printf("I! Available plugins: %d inputs, %d aggregators, %d processors, %d parsers, %d outputs",
len(inputs.Inputs),
len(aggregators.Aggregators),
len(processors.Processors),
len(parsers.Parsers),
len(outputs.Outputs),
)
log.Printf("I! Loaded inputs: %s", strings.Join(c.InputNames(), " "))
log.Printf("I! Loaded aggregators: %s", strings.Join(c.AggregatorNames(), " "))
log.Printf("I! Loaded processors: %s", strings.Join(c.ProcessorNames(), " "))

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@ -386,7 +386,7 @@ func (c *Config) LoadConfig(path string) error {
return err
}
}
data, err := loadConfig(path)
data, err := LoadConfigFile(path)
if err != nil {
return fmt.Errorf("Error loading config file %s: %w", path, err)
}
@ -565,7 +565,7 @@ func escapeEnv(value string) string {
return envVarEscaper.Replace(value)
}
func loadConfig(config string) ([]byte, error) {
func LoadConfigFile(config string) ([]byte, error) {
if fetchURLRe.MatchString(config) {
u, err := url.Parse(config)
if err != nil {

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@ -17,13 +17,13 @@ build as otherwise _all_ plugins will be selected regardless of other tags.
## Via make
When using the project's makefile, the build can be customized via the
`BUILDTAGS` environment variable containing a __space-separated__ list of the
`BUILDTAGS` environment variable containing a __comma-separated__ list of the
selected plugins (or categories) __and__ the `custom` tag.
For example
```shell
BUILDTAGS="custom inputs outputs.influxdb_v2 parsers.json" make
BUILDTAGS="custom,inputs,outputs.influxdb_v2,parsers.json" make
```
will build a customized Telegraf including _all_ `inputs`, the InfluxDB v2
@ -32,13 +32,13 @@ will build a customized Telegraf including _all_ `inputs`, the InfluxDB v2
## Via `go build`
If you wish to build Telegraf using native go tools, you can use the `go build`
command with the `-tags` option. Specify a __space-separated__ list of the
command with the `-tags` option. Specify a __comma-separated__ list of the
selected plugins (or categories) __and__ the `custom` tag as argument.
For example
```shell
go build -tags "custom inputs outputs.influxdb_v2 parsers.json" ./cmd/telegraf
go build -tags "custom,inputs,outputs.influxdb_v2,parsers.json" ./cmd/telegraf
```
will build a customized Telegraf including _all_ `inputs`, the InfluxDB v2

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@ -45,6 +45,14 @@ func Compile(filters []string) (Filter, error) {
}
}
func MustCompile(filters []string) Filter {
f, err := Compile(filters)
if err != nil {
panic(err)
}
return f
}
// hasMeta reports whether path contains any magic glob characters.
func hasMeta(s string) bool {
return strings.ContainsAny(s, "*?[")

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@ -0,0 +1,5 @@
//go:build !custom
package internal
const Customized = ""

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@ -0,0 +1,5 @@
//go:build custom
package internal
const Customized = " (customized)"

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@ -0,0 +1,81 @@
# Telegraf customization tool
Telegraf's `custom_builder` is a tool to select the plugins compiled into the
Telegraf binary. By doing so, Telegraf can become smaller, saving both disk
space and memory if only a sub-set of plugins is selected.
## Building
To build `custom_builder` run the following command:
```shell
# make build_tools
```
The resulting binary is located in the `tools/custom_builder` folder.
## Running
The easiest way of building a customized Telegraf is to use your
Telegraf configuration file(s). Assuming your configuration is
in `/etc/telegraf/telegraf.conf` you can run
```shell
# ./tools/custom_builder/custom_builder --config /etc/telegraf/telegraf.conf
```
to build a Telegraf binary tailored to your configuration.
You can also specify a configuration directory similar to
Telegraf itself. To additionally use the configurations in
`/etc/telegraf/telegraf.d` run
```shell
# ./tools/custom_builder/custom_builder \
--config /etc/telegraf/telegraf.conf \
--config-dir /etc/telegraf/telegraf.d
```
Configurations can also be retrieved from remote locations just
like for Telegraf.
```shell
# ./tools/custom_builder/custom_builder --config http://myserver/telegraf.conf
```
will download the configuration from `myserver`.
The `--config` and `--config-dir` option can be used multiple times.
In case you want to deploy Telegraf to multiple systems with
different configurations, simply specify the super-set of all
configurations you have. `custom_builder` will figure out the list
for you
```shell
# ./tools/custom_builder/custom_builder \
--config system1/telegraf.conf \
--config system2/telegraf.conf \
--config ... \
--config systemN/telegraf.conf \
--config-dir system1/telegraf.d \
--config-dir system2/telegraf.d \
--config-dir ... \
--config-dir systemN/telegraf.d
```
The Telegraf customization uses
[Golang's build-tags](https://pkg.go.dev/go/build#hdr-Build_Constraints) to
select the set of plugins. To see which tags are set use the `--tags` flag.
To get more help run
```shell
# ./tools/custom_builder/custom_builder --help
```
## Notes
Please make sure to include all `parsers` you intend to use and check the
enabled-plugins list.
Additional plugins can potentially be enabled automatically due to
dependencies without being shown in the enabled-plugins list.

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@ -0,0 +1,153 @@
package main
import (
"bytes"
"errors"
"fmt"
"os"
"path/filepath"
"github.com/influxdata/telegraf/config"
"github.com/influxdata/toml"
"github.com/influxdata/toml/ast"
)
type pluginState map[string]bool
type selection map[string]pluginState
func ImportConfigurations(files, dirs []string) (*selection, int, error) {
sel := selection(make(map[string]pluginState))
// Initialize the categories
for _, category := range categories {
sel[category] = make(map[string]bool)
}
// Gather all configuration files
var filenames []string
filenames = append(filenames, files...)
for _, dir := range dirs {
// Walk the directory and get the packages
elements, err := os.ReadDir(dir)
if err != nil {
return nil, 0, fmt.Errorf("reading directory %q failed: %w", dir, err)
}
for _, element := range elements {
if element.IsDir() || filepath.Ext(element.Name()) != ".conf" {
continue
}
filenames = append(filenames, filepath.Join(dir, element.Name()))
}
}
if len(filenames) == 0 {
return &sel, 0, errors.New("no configuration files given or found")
}
// Do the actual import
err := sel.importFiles(filenames)
return &sel, len(filenames), err
}
func (s *selection) Filter(p packageCollection) (*packageCollection, error) {
enabled := packageCollection{
packages: map[string][]packageInfo{},
}
for category, pkgs := range p.packages {
var categoryEnabledPackages []packageInfo
settings := (*s)[category]
for _, pkg := range pkgs {
if _, found := settings[pkg.Plugin]; found {
categoryEnabledPackages = append(categoryEnabledPackages, pkg)
}
}
enabled.packages[category] = categoryEnabledPackages
}
// Make sure we update the list of default parsers used by
// the remaining packages
enabled.FillDefaultParsers()
// If the user did not configure any parser, we want to include
// the default parsers if any to preserve a functional set of
// plugins.
if len(enabled.packages["parsers"]) == 0 && len(enabled.defaultParsers) > 0 {
var parsers []packageInfo
for _, pkg := range p.packages["parsers"] {
for _, name := range enabled.defaultParsers {
if pkg.Plugin == name {
parsers = append(parsers, pkg)
break
}
}
}
enabled.packages["parsers"] = parsers
}
return &enabled, nil
}
func (s *selection) importFiles(configurations []string) error {
for _, cfg := range configurations {
buf, err := config.LoadConfigFile(cfg)
if err != nil {
return fmt.Errorf("reading %q failed: %v", cfg, err)
}
if err := s.extractPluginsFromConfig(buf); err != nil {
return fmt.Errorf("extracting plugins from %q failed: %v", cfg, err)
}
}
return nil
}
func (s *selection) extractPluginsFromConfig(buf []byte) error {
table, err := toml.Parse(trimBOM(buf))
if err != nil {
return fmt.Errorf("parsing TOML failed: %w", err)
}
for category, subtbl := range table.Fields {
categoryTbl, ok := subtbl.(*ast.Table)
if !ok {
continue
}
if _, found := (*s)[category]; !found {
continue
}
for name, data := range categoryTbl.Fields {
(*s)[category][name] = true
// We need to check the data_format field to get all required parsers
switch category {
case "inputs", "processors":
pluginTables, ok := data.([]*ast.Table)
if !ok {
continue
}
for _, subsubtbl := range pluginTables {
for field, fieldData := range subsubtbl.Fields {
if field != "data_format" {
continue
}
kv := fieldData.(*ast.KeyValue)
name := kv.Value.(*ast.String)
(*s)["parsers"][name.Value] = true
}
}
}
}
}
return nil
}
func trimBOM(f []byte) []byte {
return bytes.TrimPrefix(f, []byte("\xef\xbb\xbf"))
}

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@ -0,0 +1,155 @@
package main
import (
"bytes"
"flag"
"fmt"
"log"
"os"
"os/exec"
"strings"
)
var buildTargets = []string{"build"}
var categories = []string{
"aggregators",
"inputs",
"outputs",
"parsers",
"processors",
}
const description = `
This is a tool build Telegraf with a custom set of plugins. The plugins are
select according to the specified Telegraf configuration files. This allows
to shrink the binary size by only selecting the plugins you really need.
A more detailed documentation is available at
http://github.com/influxdata/telegraf/tools/custom_builder/README.md
`
const examples = `
The following command with customize Telegraf to fit the configuration found
at the default locations
custom_builder --config /etc/telegraf/telegraf.conf --config-dir /etc/telegraf/telegraf.d
You can the --config and --config-dir multiple times
custom_builder --config global.conf --config myinputs.conf --config myoutputs.conf
or use one or more remote address(es) to load the config
custom_builder --config global.conf --config http://myserver/plugins.conf
Combinations of local and remote config as well as config directories are
possible.
`
func usage() {
_, _ = fmt.Fprint(flag.CommandLine.Output(), description)
_, _ = fmt.Fprintln(flag.CommandLine.Output(), "")
_, _ = fmt.Fprintln(flag.CommandLine.Output(), "Usage:")
_, _ = fmt.Fprintln(flag.CommandLine.Output(), " custom_builder [flags]")
_, _ = fmt.Fprintln(flag.CommandLine.Output(), "")
_, _ = fmt.Fprintln(flag.CommandLine.Output(), "Flags:")
flag.PrintDefaults()
_, _ = fmt.Fprintln(flag.CommandLine.Output(), "")
_, _ = fmt.Fprintln(flag.CommandLine.Output(), "Examples:")
_, _ = fmt.Fprint(flag.CommandLine.Output(), examples)
_, _ = fmt.Fprintln(flag.CommandLine.Output(), "")
}
func main() {
var dryrun, showtags, quiet bool
var configFiles, configDirs []string
flag.Func("config",
"Import plugins from configuration file (can be used multiple times)",
func(s string) error {
configFiles = append(configFiles, s)
return nil
},
)
flag.Func("config-dir",
"Import plugins from configs in the given directory (can be used multiple times)",
func(s string) error {
configDirs = append(configDirs, s)
return nil
},
)
flag.BoolVar(&dryrun, "dry-run", false, "Skip the actual building step")
flag.BoolVar(&quiet, "quiet", false, "Print fewer log messages")
flag.BoolVar(&showtags, "tags", false, "Show build-tags used")
flag.Usage = usage
flag.Parse()
// Check configuration options
if len(configFiles) == 0 && len(configDirs) == 0 {
log.Fatalln("No configuration specified!")
}
// Import the plugin list from Telegraf configuration files
log.Println("Importing configuration file(s)...")
cfg, nfiles, err := ImportConfigurations(configFiles, configDirs)
if err != nil {
log.Fatalf("Importing configuration(s) failed: %v", err)
}
if !quiet {
log.Printf("Found %d configuration files...", nfiles)
}
// Check if we do have a config
if nfiles == 0 {
log.Fatalln("No configuration files loaded!")
}
// Collect all available plugins
packages := packageCollection{}
if err := packages.CollectAvailable(); err != nil {
log.Fatalf("Collecting plugins failed: %v", err)
}
// Process the plugin list with the given config. This will
// only keep the plugins that adhere to the filtering criteria.
enabled, err := cfg.Filter(packages)
if err != nil {
log.Fatalf("Filtering plugins failed: %v", err)
}
if !quiet {
enabled.Print()
}
// Extract the build-tags
tagset := enabled.ExtractTags()
if len(tagset) == 0 {
log.Fatalln("Nothing selected!")
}
tags := "custom," + strings.Join(tagset, ",")
if showtags {
fmt.Printf("Build tags: %s\n", tags)
}
if !dryrun {
// Perform the build
var out bytes.Buffer
makeCmd := exec.Command("make", buildTargets...)
makeCmd.Env = append(os.Environ(), "BUILDTAGS="+tags)
makeCmd.Stdout = &out
makeCmd.Stderr = &out
if !quiet {
log.Println("Running build...")
}
if err := makeCmd.Run(); err != nil {
fmt.Println(out.String())
log.Fatalf("Running make failed: %v", err)
}
if !quiet {
fmt.Println(out.String())
}
} else if !quiet {
log.Println("DRY-RUN: Skipping build.")
}
}

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@ -0,0 +1,354 @@
package main
import (
"bufio"
"errors"
"fmt"
"go/ast"
"go/parser"
"go/token"
"io/fs"
"log"
"os"
"path/filepath"
"regexp"
"sort"
"strings"
"github.com/influxdata/telegraf/filter"
)
// Define the categories we can handle and package filters
var packageFilter = filter.MustCompile([]string{
"*/all",
"*/*_test",
"inputs/example",
"inputs/main",
})
type packageInfo struct {
Category string
Plugin string
Path string
Tag string
DefaultParser string
}
type packageCollection struct {
packages map[string][]packageInfo
defaultParsers []string
}
// Define the package exceptions
var exceptions = map[string][]packageInfo{
"parsers": {
{
Category: "parsers",
Plugin: "influx_upstream",
Path: "plugins/parsers/influx/influx_upstream",
Tag: "parsers.influx",
},
},
"processors": {
{
Category: "processors",
Plugin: "aws_ec2",
Path: "plugins/processors/aws/ec2",
Tag: "processors.aws_ec2",
},
},
}
func (p *packageCollection) collectPackagesForCategory(category string) error {
var entries []packageInfo
pluginDir := filepath.Join("plugins", category)
// Add exceptional packages if any
if pkgs, found := exceptions[category]; found {
entries = append(entries, pkgs...)
}
// Walk the directory and get the packages
elements, err := os.ReadDir(pluginDir)
if err != nil {
return err
}
for _, element := range elements {
path := filepath.Join(pluginDir, element.Name())
if !element.IsDir() {
continue
}
var fset token.FileSet
pkgs, err := parser.ParseDir(&fset, path, sourceFileFilter, parser.ParseComments)
if err != nil {
log.Printf("parsing directory %q failed: %v", path, err)
continue
}
for name, pkg := range pkgs {
if packageFilter.Match(category + "/" + name) {
continue
}
// Extract the names of the plugins registered by this package
registeredNames := extractRegisteredNames(pkg, category)
if len(registeredNames) == 0 {
log.Printf("WARN: Could not extract information from package %q", name)
continue
}
// Extract potential default parsers for input and processor packages
var defaultParser string
switch category {
case "inputs", "processors":
var err error
defaultParser, err = extractDefaultParser(path)
if err != nil {
log.Printf("Getting default parser for %s.%s failed: %v", category, name, err)
}
}
for _, plugin := range registeredNames {
path := filepath.Join("plugins", category, element.Name())
tag := category + "." + element.Name()
entries = append(entries, packageInfo{
Category: category,
Plugin: plugin,
Path: filepath.ToSlash(path),
Tag: tag,
DefaultParser: defaultParser,
})
}
}
}
p.packages[category] = entries
return nil
}
func (p *packageCollection) FillDefaultParsers() {
// Make sure we ignore all empty-named parsers which indicate
// that there is no parser used by the plugin.
parsers := map[string]bool{"": true}
// Iterate over all plugins that may have parsers and collect
// the defaults
p.defaultParsers = make([]string, 0)
for _, category := range []string{"inputs", "processors"} {
for _, pkg := range p.packages[category] {
name := pkg.DefaultParser
if seen := parsers[name]; seen {
continue
}
p.defaultParsers = append(p.defaultParsers, name)
parsers[name] = true
}
}
}
func (p *packageCollection) CollectAvailable() error {
p.packages = make(map[string][]packageInfo)
for _, category := range categories {
if err := p.collectPackagesForCategory(category); err != nil {
return err
}
}
p.FillDefaultParsers()
return nil
}
func (p *packageCollection) ExtractTags() []string {
var tags []string
for category, pkgs := range p.packages {
_ = category
for _, pkg := range pkgs {
tags = append(tags, pkg.Tag)
}
}
sort.Strings(tags)
return tags
}
func (p *packageCollection) Print() {
fmt.Println("-------------------------------------------------------------------------------")
fmt.Println("Enabled plugins:")
fmt.Println("-------------------------------------------------------------------------------")
for _, category := range categories {
pkgs := p.packages[category]
sort.Slice(pkgs, func(i, j int) bool { return pkgs[i].Plugin < pkgs[j].Plugin })
fmt.Printf("%s (%d):\n", category, len(pkgs))
for _, pkg := range pkgs {
fmt.Printf(" %-30s %s\n", pkg.Plugin, pkg.Path)
}
fmt.Println("-------------------------------------------------------------------------------")
}
}
func sourceFileFilter(d fs.FileInfo) bool {
return strings.HasSuffix(d.Name(), ".go") && !strings.HasSuffix(d.Name(), "_test.go")
}
func findFunctionDecl(file *ast.File, name string) *ast.FuncDecl {
for _, decl := range file.Decls {
d, ok := decl.(*ast.FuncDecl)
if !ok {
continue
}
if d.Name.Name == name && d.Recv == nil {
return d
}
}
return nil
}
func findAddStatements(decl *ast.FuncDecl, pluginType string) []*ast.CallExpr {
var statements []*ast.CallExpr
for _, stmt := range decl.Body.List {
s, ok := stmt.(*ast.ExprStmt)
if !ok {
continue
}
call, ok := s.X.(*ast.CallExpr)
if !ok {
continue
}
fun, ok := call.Fun.(*ast.SelectorExpr)
if !ok {
continue
}
e, ok := fun.X.(*ast.Ident)
if !ok {
continue
}
if e.Name == pluginType && (fun.Sel.Name == "Add" || fun.Sel.Name == "AddStreaming") {
statements = append(statements, call)
}
}
return statements
}
func extractPluginInfo(file *ast.File, pluginType string, declarations map[string]string) ([]string, error) {
var registeredNames []string
decl := findFunctionDecl(file, "init")
if decl == nil {
return nil, nil
}
calls := findAddStatements(decl, pluginType)
if len(calls) == 0 {
return nil, nil
}
for _, call := range calls {
switch arg := call.Args[0].(type) {
case *ast.Ident:
resval, found := declarations[arg.Name]
if !found {
return nil, fmt.Errorf("cannot resolve registered name variable %q", arg.Name)
}
registeredNames = append(registeredNames, strings.Trim(resval, "\""))
case *ast.BasicLit:
if arg.Kind != token.STRING {
return nil, errors.New("registered name is not a string")
}
registeredNames = append(registeredNames, strings.Trim(arg.Value, "\""))
default:
return nil, fmt.Errorf("unhandled argument type: %v (%T)", arg, arg)
}
}
return registeredNames, nil
}
func extractPackageDeclarations(pkg *ast.Package) map[string]string {
declarations := make(map[string]string)
for _, file := range pkg.Files {
for _, d := range file.Decls {
gendecl, ok := d.(*ast.GenDecl)
if !ok {
continue
}
for _, spec := range gendecl.Specs {
spec, ok := spec.(*ast.ValueSpec)
if !ok {
continue
}
for _, id := range spec.Names {
valspec, ok := id.Obj.Decl.(*ast.ValueSpec)
if !ok || len(valspec.Values) != 1 {
continue
}
valdecl, ok := valspec.Values[0].(*ast.BasicLit)
if !ok || valdecl.Kind != token.STRING {
continue
}
declarations[id.Name] = strings.Trim(valdecl.Value, "\"")
}
}
}
}
return declarations
}
func extractRegisteredNames(pkg *ast.Package, pluginType string) []string {
var registeredNames []string
// Extract all declared variables of all files. This might be necessary when
// using references across multiple files
declarations := extractPackageDeclarations(pkg)
// Find the registry Add statement and extract all registered names
for fn, file := range pkg.Files {
names, err := extractPluginInfo(file, pluginType, declarations)
if err != nil {
log.Printf("%q error: %v", fn, err)
continue
}
registeredNames = append(registeredNames, names...)
}
return registeredNames
}
func extractDefaultParser(pluginDir string) (string, error) {
re := regexp.MustCompile(`^\s*#?\s*data_format\s*=\s*"(.*)"\s*$`)
// Exception for exec which uses JSON by default
if filepath.Base(pluginDir) == "exec" {
return "json", nil
}
// Walk all config files in the package directory
elements, err := os.ReadDir(pluginDir)
if err != nil {
return "", err
}
for _, element := range elements {
path := filepath.Join(pluginDir, element.Name())
if element.IsDir() || filepath.Ext(element.Name()) != ".conf" {
continue
}
// Read the config and search for a "data_format" entry
file, err := os.Open(path)
if err != nil {
return "", err
}
scanner := bufio.NewScanner(file)
for scanner.Scan() {
match := re.FindStringSubmatch(scanner.Text())
if len(match) == 2 {
return match[1], nil
}
}
}
return "", nil
}