Conditional blocks in the Caddyfile depending on env var?

[JnAlu (Jonardhan Aluguda)]

Is there a way to put blocks and/or snippets in the Caddyfile conditionally depending on env vars for Caddy v2?

{
  # staging lets encrypt for testing. Comment out for production.
  acme_ca https://acme-staging-v02.api.letsencrypt.org/directory  # Want to disable this if $CURRENT_ENV is not "prod"

  admin off  # Want to enable this if $CURRENT_ENV is not "dev"

  debug  # Want to enable this if $LOG_LEVEL DEBUG or lower
}

{
  …
  log {
      level ${LOG_LEVEL}

      # format single_field common_log
      output file {$LOG_FILE} {
          roll_size 10MB
          roll_keep 10
      }
  }  
}

If I can’t do this as above, outside of me using an external templating library, I am thinking could set the default config/Caddyfile to reflect what should be in prod and then patch it to be what I want for dev, staging and test environment

[francislavoie]

You can have literal Caddyfile tokens as your env var values, and they get expanded in-place. They can even be multiline (if the env var values contain newlines).

But there’s no conditional statements for this. You can set a default value for the env though.

Caddyfile Concepts - Caddy Documentation

[JnAlu (Jonardhan Aluguda)]

@francislavoie

You can have literal Caddyfile tokens as your env var values, and they get expanded in-place. They can even be multiline (if the env var values contain newlines).

1. Oh You mean my Caddyfile can look like this:

{$Global_block}

and then, it’s up to me to:

export $Global_block = "
{
  # staging lets encrypt for testing. Comment out for production.
  acme_ca https://acme-staging-v02.api.letsencrypt.org/directory  # Want to disable this if $CURRENT_ENV is not "prod"

  admin off  # Want to enable this if $CURRENT_ENV is not "dev"

  debug  # Want to enable this if $LOG_LEVEL DEBUG or lower
}
"

or

export $Global_block = "
{
}
"

?

2. If this is correct - then what’s the difference between a Caddyfile that’s:

{$Global_block}

vs.

{$env.Global_block}

?

[francislavoie]

Yeah, pretty much.

@JnAlu

2. If this is correct - then what’s the difference between a Caddyfile that’s:

{$Global_block}

vs.

{$env.Global_block}

{$ENV} only works in the Caddyfile (not in JSON) and is replaced at config adapt time i.e. when the Caddyfile is turned into JSON.

{env.ENV} is replaced at runtime, and may not work everywhere in the config (the code must actually run the placeholder replacer for that config value, many do but not all)