forked from vieter-v/vieter
87 lines
2.1 KiB
V
87 lines
2.1 KiB
V
module env
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import os
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// The prefix that every environment variable should have
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const prefix = 'VIETER_'
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// The suffix an environment variable in order for it to be loaded from a file
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// instead
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const file_suffix = '_FILE'
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pub struct ServerConfig {
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pub:
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log_level string [default: WARN]
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log_file string [default: 'vieter.log']
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pkg_dir string
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download_dir string
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api_key string
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repo_dir string
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repos_file string
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}
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pub struct BuildConfig {
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pub:
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api_key string
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address string
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}
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fn get_env_var(field_name string) ?string {
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env_var_name := '$env.prefix$field_name.to_upper()'
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env_file_name := '$env.prefix$field_name.to_upper()$env.file_suffix'
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env_var := os.getenv(env_var_name)
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env_file := os.getenv(env_file_name)
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// If both aren't set, we report them missing
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if env_var == '' && env_file == '' {
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return error('Either $env_var_name or $env_file_name is required.')
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}
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// If they're both set, we report a conflict
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if env_var != '' && env_file != '' {
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return error('Only one of $env_var_name or $env_file_name can be defined.')
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}
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// If it's the env var itself, we return it.
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// I'm pretty sure this also prevents variable ending in _FILE (e.g.
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// VIETER_LOG_FILE) from being mistakingely read as an _FILE suffixed env
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// var.
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if env_var != '' {
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return env_var
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}
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// Otherwise, we process the file
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return os.read_file(env_file) or {
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error('Failed to read file defined in $env_file_name: ${err.msg}.')
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}
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}
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// load<T> attempts to create the given type from environment variables. For
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// each field, the corresponding env var is its name in uppercase prepended
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// with the hardcoded prefix. If this one isn't present, it looks for the env
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// var with the file_suffix suffix.
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pub fn load<T>() ?T {
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res := T{}
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$for field in T.fields {
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res.$(field.name) = get_env_var(field.name) or {
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// We use the default instead, if it's present
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mut default := ''
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for attr in field.attrs {
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if attr.starts_with('default: ') {
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default = attr[9..]
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break
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}
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}
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if default == '' {
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return err
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}
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default
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}
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}
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return res
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}
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