96 lines
2.4 KiB
Go
96 lines
2.4 KiB
Go
package configuration
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import (
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"errors"
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"flag"
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"fmt"
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"io/ioutil"
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"os"
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"path/filepath"
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"strings"
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"time"
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"gopkg.in/yaml.v2"
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)
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var (
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ErrConfigurationFileDoesNotExist = errors.New("configuration file does not exist")
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ErrConfigurationFilePathUndefined = errors.New("configuration file path wasn't provided")
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)
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// Config is an application's configuration.
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type Config struct {
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configPath string
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// Applications describes configuration for remote application's endpoints.
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// Key is an application's name.
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Applications map[string]struct {
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// Endpoint is a remote application endpoint which should give us metrics
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// in Prometheus format.
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Endpoint string
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// Headers is a list of headers that should be added to metrics request.
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Headers map[string]string
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// TimeBetweenRequests is a minimal amount of time which should pass
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// between requests.
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TimeBetweenRequests time.Duration
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}
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// Datastore describes data storage configuration.
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Datastore struct {
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// ValidTimeout is a timeout for which every data entry will be considered
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// as valid. After that timeout if value wasn't updated it will be considered
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// as invalid and purged from memory.
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ValidTimeout time.Duration `yaml:"valid_timeout"`
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} `yaml:"datastore"`
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}
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// NewConfig returns new configuration.
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func NewConfig() *Config {
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c := &Config{}
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c.initialize()
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return c
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}
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// Initializes configuration.
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func (c *Config) initialize() {
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flag.StringVar(&c.configPath, "config", "", "Configuration file path.")
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}
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// Parse parses configuration.
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func (c *Config) Parse() error {
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if c.configPath == "" {
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return ErrConfigurationFilePathUndefined
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}
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if strings.HasPrefix(c.configPath, "~") {
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userDir, err := os.UserHomeDir()
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if err != nil {
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return fmt.Errorf("%s: %w", "file path normalization: getting user's home directory", err)
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}
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c.configPath = strings.Replace(c.configPath, "~", userDir, 1)
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}
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cfgPath, err := filepath.Abs(c.configPath)
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if err != nil {
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return fmt.Errorf("%s: %w", "file path normalization: getting absolute path", err)
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}
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c.configPath = cfgPath
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if c.configPath == "" {
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return fmt.Errorf("%s: %w", "file path normalization", ErrConfigurationFilePathUndefined)
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}
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fileData, err := ioutil.ReadFile(c.configPath)
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if err != nil {
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return fmt.Errorf("%s: %w", "configuration file read", err)
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}
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err = yaml.Unmarshal(fileData, c)
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if err != nil {
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return fmt.Errorf("%s: %w", "configuration file parsing", err)
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}
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return nil
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}
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