README
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config package
The config package wraps the common viper methods and types but adds some custom processing.
This probably could be done using custom decode hooks for viper, but I have not had time to understand them in detail.
Using a wrapper also allows custom methods on config for further functionality.
Unless the file format is given to LoadConfig then all the viper formats are supported.
Expansion of values
The following package functions and type methods are overridden to add expansion of embedded strings of the form ${name} and $name:
The string values are passed to ExpandString which supports a range of data substitutions.
Documentation
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Index ¶
- func Checksum(r io.Reader) (c uint32, err error)
- func ChecksumFile(path string) (c uint32, err error)
- func ChecksumString(in string) (c uint32, err error)
- func GetString(s string, values ...map[string]string) string
- func GetStringMapString(s string, values ...map[string]string) map[string]string
- func GetStringSlice(s string, values ...map[string]string) []string
- type AESValues
- func (a *AESValues) Checksum() (c uint32, err error)
- func (a AESValues) DecodeAES(in []byte) (out []byte, err error)
- func (a AESValues) DecodeAESString(in string) (out string, err error)
- func (a AESValues) EncodeAES(in []byte) (out []byte, err error)
- func (a AESValues) EncodeAESString(in string) (out string, err error)
- func (a AESValues) String() string
- func (a AESValues) WriteAESValues(w io.Writer) error
- type Config
- func (c *Config) ExpandString(input string, values map[string]string) (value string)
- func (c *Config) GetString(s string, values ...map[string]string) string
- func (c *Config) GetStringMapString(s string, values ...map[string]string) (m map[string]string)
- func (c *Config) GetStringSlice(s string, values ...map[string]string) (slice []string)
- type Options
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func ChecksumFile ¶
func ChecksumString ¶
func GetString ¶
Returns the configuration item as a string with ExpandString() applied, passing the first "values" if given
func GetStringMapString ¶
Types ¶
type AESValues ¶
An AESValues structure contains the values required to create a Geneos Gateway AES key files and also the encode and decode AES passwords in the configuration
func NewAESValues ¶
NewAESValues returns a new AESValues structure or an error
func ReadAESValues ¶
ReadAESValues returns an AESValues struct populated with the contents read from r. The caller must close the Reader on return.
func ReadAESValuesFile ¶
ReadAESValuesFile returns an AESValues struct populated with the contents of the file passed as path.
func (AESValues) DecodeAESString ¶
DecodeAESString returns a plain text of the input or an error
func (AESValues) EncodeAESString ¶
type Config ¶
Config embeds Viper and also exposes the config type used
func LoadConfig ¶
LoadConfig loads configuration files from internal defaults, external defaults and the given configuration file. The configuration file can be passed as an option. Each layer is only loaded once, if given. Internal defaults are passed as a []byte intended to be loaded from an embedded file. External defaults and the main configuration file are passed as ordered slices of strings. The first match is loaded.
LoadConfig("geneos")
//go:embed somefile.json
var myDefaults []byte
LoadConfig("geneos", config.SetDefaults(myDefaults, "json"), )
Options can be passed to change the default behaviour and to pass any embedded defaults or an existing viper.
for defaults see: https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html ... find windows equiv
func (*Config) ExpandString ¶
ExpandString() returns input with any occurrences of the form ${name} interpolated using os.Expand for the supported format types in the order given below:
"${enc:keyfile[|keyfile...]:encodedvalue}"
The item "encodedvalue" is an AES256 ciphertext in Geneos format - or a reference to one - which will be decoded using the key file(s) given. Each "keyfile" must be one of either an absolute path, a path relative to the working directory of the program, or if prefixed with "~/" then relative to the home directory of the user running the program. The first valid decode (see below) is returned.
The "encodedvalue" must be either prefixed "+encs+" to align with Geneos or will otherwise be looked up using the forms of any of the other references below, but without the surrounding dollar-brackets "${...}".
To minimise (but not eliminate) false decodes that occur in some circumstances when using the wrong key file, the decoded value is only returned if it is a valid UTF-8 string as per utf8.Valid.
Examples:
* password: ${enc:~/.keyfile:+encs+9F2C3871E105EC21E4F0D5A7921A937D} * password: ${enc:/etc/geneos/keyfile.aes:env:ENCODED_PASSWORD}
"${path.to.config}"
Any value containing one or more dots "." will be looked-up in the existing configuration that the method is called on. The configuration is not changed and values are resolved each time ExpandString() is called. No locking of the configuration is done.
"${name}"
"name" will be substituted with the corresponding value from the map "values". If 'values' is empty (as opposed to the key "name" not being found) then name is looked up as an environment variable, see below.
"${env:name}"
"name" will be substituted with the contents of the environment variable of the same name.
"${file://path/to/file}" or "${file:~/path/to/file}"
The contents of the referenced file will be read. Multiline files are used as-is; this can, for example, be used to read PEM certificate files or keys. As an enhancement to a standard file url, if the first "/" is replaced with a tilde "~" then the path is relative to the home directory of the user running the process.
"${https://host/path}" or "${http://host/path}"
The contents of the URL are fetched and used similarly as for local files above. The URL is passed to http.Get and supports any embedded Basic Authentication and other features from that function.
The form "$name" is NOT supported, unlike os.Expand.
Expansion is not recursive. Configuration values are read and stored as literals and are expanded each time they are used. For each substitution any leading and trailing whitespace are removed. External sources are fetched each time they are used and so there may be a performance impact as well as the value unexpectedly changing during a process lifetime.
Any errors (particularly from substitutions from external files or remote URLs) may result in an empty or corrupt string being returned. Error returns are intentionally discarded.
It is not currently possible to escape the syntax supported by Expand and if it is necessary to have a configuration value be a literal of the form "${name}" then set an otherwise unused item to the value and refer to it using the dotted syntax, e.g. for YAML
config:
real: ${config.temp}
temp: "${unchanged}"
In the above a reference to ${config.real} will return the literal string ${unchanged} as there is no recursive lookups.
func (*Config) GetString ¶
Returns the configuration item as a string with ExpandString() applied, passing the first "values" if given
func (*Config) GetStringMapString ¶
type Options ¶
type Options func(*configOptions)
func AddConfigDirs ¶
AddConfigDirs() adds one or more directories to search for the configuration and defaults files. Directories are searched in FIFO order, so any directories given are checked before the built-in list.
func IgnoreSystemDir ¶
func IgnoreSystemDir() Options
IgnoreSystemDir() tells LoadConfig() not to search in the system configuration directory. This only applies on UNIX-like systems and is normally /etc/[appName]
func IgnoreUserConfDir ¶
func IgnoreUserConfDir() Options
IgnoreUserConfDir() tells LoadConfig() not to search in the user config directory (OS defined as per Go os.UserConfDir())
func IgnoreWorkingDir ¶
func IgnoreWorkingDir() Options
IgnoreWorkingDir() tells LoadConfig not to search the working directory for configuration files. This should be used when the caller may be running in an unknown location.
func SetAppName ¶
SetAppName() overrides to mapping of the configName to the application name. Application name is used for the containing directories, while configName is used for the files in those directories.
func SetConfigFile ¶
SetConfigFile() allows the caller to override the searching for a config file in the given directories and instead loads only the given file (after defaults are loaded as normal).
func SetDefaults ¶
SetDefaults() takes a []byte slice and a format type to load embedded defaults
Source Files