Add ability to pull images directly from a registry (#378)

* add registry image source

Signed-off-by: Alex Goodman <alex.goodman@anchore.com>

* use explicit source for fetching image + add scheme and registry tests

Signed-off-by: Alex Goodman <alex.goodman@anchore.com>

* adjust test variable name and add credential helper function

Signed-off-by: Alex Goodman <alex.goodman@anchore.com>

internal/config/application.go

@@ -40,6 +40,7 @@ type Application struct {
 	FileClassification fileClassification `yaml:"file-classification" json:"file-classification" mapstructure:"file-classification"`
 	FileContents       fileContents       `yaml:"file-contents" json:"file-contents" mapstructure:"file-contents"`
 	Secrets            secrets            `yaml:"secrets" json:"secrets" mapstructure:"secrets"`
+	Registry           registry           `yaml:"registry" json:"registry" mapstructure:"registry"`
 }
 
 func newApplicationConfig(v *viper.Viper, cliOpts CliOnlyOptions) *Application {

internal/config/registry.go

@@ -0,0 +1,72 @@
+package config
+
+import (
+	"os"
+
+	"github.com/anchore/stereoscope/pkg/image"
+
+	"github.com/spf13/viper"
+)
+
+type RegistryCredentials struct {
+	Authority string `yaml:"authority" json:"authority" mapstructure:"authority"`
+	// IMPORTANT: do not show the username in any YAML/JSON output (sensitive information)
+	Username string `yaml:"-" json:"-" mapstructure:"username"`
+	// IMPORTANT: do not show the password in any YAML/JSON output (sensitive information)
+	Password string `yaml:"-" json:"-" mapstructure:"password"`
+	// IMPORTANT: do not show the token in any YAML/JSON output (sensitive information)
+	Token string `yaml:"-" json:"-" mapstructure:"token"`
+}
+
+type registry struct {
+	InsecureSkipTLSVerify bool                  `yaml:"insecure-skip-tls-verify" json:"insecure-skip-tls-verify" mapstructure:"insecure-skip-tls-verify"`
+	Auth                  []RegistryCredentials `yaml:"auth" json:"auth" mapstructure:"auth"`
+}
+
+func (cfg registry) loadDefaultValues(v *viper.Viper) {
+	v.SetDefault("registry.insecure-skip-tls-verify", false)
+	v.SetDefault("registry.auth", []RegistryCredentials{})
+}
+
+// nolint: unparam
+func (cfg *registry) parseConfigValues() error {
+	// there may be additional credentials provided by env var that should be appended to the set of credentials
+	authority, username, password, token :=
+		os.Getenv("SYFT_REGISTRY_AUTH_AUTHORITY"),
+		os.Getenv("SYFT_REGISTRY_AUTH_USERNAME"),
+		os.Getenv("SYFT_REGISTRY_AUTH_PASSWORD"),
+		os.Getenv("SYFT_REGISTRY_AUTH_TOKEN")
+
+	if hasNonEmptyCredentials(authority, password, token) {
+		// note: we prepend the credentials such that the environment variables take precedence over on-disk configuration.
+		cfg.Auth = append([]RegistryCredentials{
+			{
+				Authority: authority,
+				Username:  username,
+				Password:  password,
+				Token:     token,
+			},
+		}, cfg.Auth...)
+	}
+	return nil
+}
+
+func hasNonEmptyCredentials(authority, password, token string) bool {
+	return authority != "" && password != "" || authority != "" && token != ""
+}
+
+func (cfg *registry) ToOptions() *image.RegistryOptions {
+	var auth = make([]image.RegistryCredentials, len(cfg.Auth))
+	for i, a := range cfg.Auth {
+		auth[i] = image.RegistryCredentials{
+			Authority: a.Authority,
+			Username:  a.Username,
+			Password:  a.Password,
+			Token:     a.Token,
+		}
+	}
+	return &image.RegistryOptions{
+		InsecureSkipTLSVerify: cfg.InsecureSkipTLSVerify,
+		Credentials:           auth,
+	}
+}

internal/presenter/poweruser/test-fixtures/snapshot/TestJSONPresenter.golden

@@ -223,6 +223,10 @@
     "exclude-pattern-names": null,
     "reveal-values": false,
     "skip-files-above-size": 0
+   },
+   "registry": {
+    "insecure-skip-tls-verify": false,
+    "auth": null
    }
   }
  },