AuthProxy: Allow disabling Auth Proxy cache (#83755)

* extract auth proxy settings

* simplify auth proxy methods

* add doc mentions

pkg/setting/setting_auth_proxy.go

@@ -0,0 +1,45 @@
+package setting
+
+import (
+	"strings"
+
+	"github.com/grafana/grafana/pkg/util"
+)
+
+type AuthProxySettings struct {
+	// Auth Proxy
+	Enabled          bool
+	HeaderName       string
+	HeaderProperty   string
+	AutoSignUp       bool
+	EnableLoginToken bool
+	Whitelist        string
+	Headers          map[string]string
+	HeadersEncoded   bool
+	SyncTTL          int
+}
+
+func (cfg *Cfg) readAuthProxySettings() {
+	authProxySettings := AuthProxySettings{}
+	authProxy := cfg.Raw.Section("auth.proxy")
+	authProxySettings.Enabled = authProxy.Key("enabled").MustBool(false)
+	authProxySettings.HeaderName = valueAsString(authProxy, "header_name", "")
+	authProxySettings.HeaderProperty = valueAsString(authProxy, "header_property", "")
+	authProxySettings.AutoSignUp = authProxy.Key("auto_sign_up").MustBool(true)
+	authProxySettings.EnableLoginToken = authProxy.Key("enable_login_token").MustBool(false)
+	authProxySettings.SyncTTL = authProxy.Key("sync_ttl").MustInt(15)
+	authProxySettings.Whitelist = valueAsString(authProxy, "whitelist", "")
+	authProxySettings.Headers = make(map[string]string)
+	headers := valueAsString(authProxy, "headers", "")
+
+	for _, propertyAndHeader := range util.SplitString(headers) {
+		split := strings.SplitN(propertyAndHeader, ":", 2)
+		if len(split) == 2 {
+			authProxySettings.Headers[split[0]] = split[1]
+		}
+	}
+
+	authProxySettings.HeadersEncoded = authProxy.Key("headers_encoded").MustBool(false)
+
+	cfg.AuthProxy = authProxySettings
+}