97 lines
1.4 KiB
Markdown
97 lines
1.4 KiB
Markdown
# Env Source
|
|
|
|
The env source reads config from environment variables
|
|
|
|
## Format
|
|
|
|
We expect environment variables to be in the standard format of FOO=bar
|
|
|
|
Keys are converted to lowercase and split on underscore.
|
|
|
|
|
|
### Example
|
|
|
|
```
|
|
DATABASE_ADDRESS=127.0.0.1
|
|
DATABASE_PORT=3306
|
|
```
|
|
|
|
Becomes
|
|
|
|
```json
|
|
{
|
|
"database": {
|
|
"address": "127.0.0.1",
|
|
"port": 3306
|
|
}
|
|
}
|
|
```
|
|
|
|
## Prefixes
|
|
|
|
Environment variables can be namespaced so we only have access to a subset. Two options are available:
|
|
|
|
```
|
|
WithPrefix(p ...string)
|
|
WithStrippedPrefix(p ...string)
|
|
```
|
|
|
|
The former will preserve the prefix and make it a top level key in the config. The latter eliminates the prefix, reducing the nesting by one.
|
|
|
|
#### Example:
|
|
|
|
Given ENVs of:
|
|
|
|
```
|
|
APP_DATABASE_ADDRESS=127.0.0.1
|
|
APP_DATABASE_PORT=3306
|
|
VAULT_ADDR=vault:1337
|
|
```
|
|
|
|
and a source initialized as follows:
|
|
|
|
```
|
|
src := env.NewSource(
|
|
env.WithPrefix("VAULT"),
|
|
env.WithStrippedPrefix("APP"),
|
|
)
|
|
```
|
|
|
|
The resulting config will be:
|
|
|
|
```
|
|
{
|
|
"database": {
|
|
"address": "127.0.0.1",
|
|
"port": 3306
|
|
},
|
|
"vault": {
|
|
"addr": "vault:1337"
|
|
}
|
|
}
|
|
```
|
|
|
|
|
|
## New Source
|
|
|
|
Specify source with data
|
|
|
|
```go
|
|
src := env.NewSource(
|
|
// optionally specify prefix
|
|
env.WithPrefix("MICRO"),
|
|
)
|
|
```
|
|
|
|
## Load Source
|
|
|
|
Load the source into config
|
|
|
|
```go
|
|
// Create new config
|
|
conf := config.NewConfig()
|
|
|
|
// Load file source
|
|
conf.Load(src)
|
|
```
|