How to log the workspace name using the HTTP or file log plugins

How to add the workspace name to the HTTP or file logs.

Kong Gateway (Enterprise) already includes a native workspace_name field in the log-serializer output for http-log/file-log (and every other log plugin), e.g. "workspace_name":"default", with zero configuration required. This is the recommended way to get the workspace’s name into your logs and requires no custom Lua.

If you need the value under a custom key, or combined with other logic, you can still leverage custom fields by Lua. Note that untrusted_lua defaults to strict, and under strict (or the lax tier), untrusted_lua_sandbox_requires has no effect at all – it is only consulted by the legacy sandbox tier. To use the recipe below, first explicitly opt into the legacy sandbox tier by setting both

untrusted_lua = sandbox
untrusted_lua_sandbox_requires = kong.workspaces

(KONG_UNTRUSTED_LUA=sandbox and KONG_UNTRUSTED_LUA_SANDBOX_REQUIRES=kong.workspaces as environment variables), as documented here. With that in place, the following custom field can be configured

 "custom_fields_by_lua": { "ws_name": "local workspaces=require \"kong.workspaces\" local get_ws_id=workspaces.get_workspace_id local fetch_ws=workspaces.select_workspace_by_id_with_cache local ws_id=get_ws_id() local ws=ws_id and fetch_ws(ws_id) local ws_name=ws and ws.name return ws_name" }

When setting it up on the manager GUI, it looks like so:

The image above truncates the full line used. Here it is for reference.

local workspaces=require "kong.workspaces" local get_ws_id=workspaces.get_workspace_id local fetch_ws=workspaces.select_workspace_by_id_with_cache local ws_id=get_ws_id() local ws=ws_id and fetch_ws(ws_id) local ws_name=ws and ws.name return ws_name

Here’s a snippet from the resulting log, when using the file-log plugin

{"upstream_uri":"/anything","workspace":"6044b661-6f96-4e0c-9d31-40027d50ee25","ws_name":"testDK","response":{"size":303,"headers":{"content-type":"application/json; charset=utf-8","content-length":"58","connection":"close","server":"kong/3.14.0.0-enterprise-edition","x-kong-response-latency":"5"} ....

Note the added field:

"ws_name":"testDK"

HTTP log can be used as well to the same effect. If untrusted_lua is left at its default (strict) and only untrusted_lua_sandbox_requires is set, require("kong.workspaces") is not allowed and the log plugin fails to add the custom field (though the plugin fails open, so the request itself still succeeds) – both settings above (untrusted_lua = sandbox and untrusted_lua_sandbox_requires = kong.workspaces) must be set together for the recipe to work.