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