Envoy Lua Local Script File - lua

Question

I am trying to implement lua script into an evnoy configuration file
What I want is to write my lua code within a local lua file and then scpecify my script file inside the envoy configuration file
This is my yaml file:
static_resources:
listeners:
- address:
socket_address:
address: 0.0.0.0
port_value: 10000
filter_chains:
- filters:
- name: envoy.filters.network.http_connection_manager
typed_config:
'#type': "type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager"
stat_prefix: http_proxy
route_config:
name: all
virtual_hosts:
- name: allbackend_cluster
domains:
- '*'
routes:
- match: { prefix: "/"}
route:
cluster: cluster_wackopicko
http_filters:
- name: envoy.filters.http.router
- name: envoy.lua
typed_config:
"#type": type.googleapis.com/envoy.extensions.filters.http.lua.v3.Lua
inline_code: |
function envoy_on_response(response_handle)
body_size = response_handle:body():length()
response_handle:headers():add("response-body-size", tostring(body_size))
response_handle:headers():add("foo", "bar")
end
clusters:
- name: cluster_wackopicko
connect_timeout: 1s
lb_policy: ROUND_ROBIN
load_assignment:
cluster_name: cluster_wackopicko
endpoints:
- lb_endpoints:
- endpoint:
address:
socket_address:
address: 127.0.0.1
port_value: 8081
What I need to change in this config file to export the lua code to external file which will be located in /envoy/lua/scripts/ folder on my ubuntu server ?

Answer 1

Envoy >= 1.23.0
Since Envoy v1.23.0 (and this PR), you can define your script in default_source_code. See documentation.
Example:
-- /envoy/lua/scripts/myscript.lua
function envoy_on_response(response_handle)
body_size = response_handle:body():length()
response_handle:headers():add("response-body-size", tostring(body_size))
response_handle:headers():add("foo", "bar")
end
name: envoy.filters.http.lua
typed_config:
"#type": type.googleapis.com/envoy.extensions.filters.http.lua.v3.Lua
default_source_code:
filename: /envoy/lua/scripts/myscript.lua
Envoy < 1.23.0
With older versions, you can use source_codes with filename. See documentation.
However, you have to add inline_code. This is a known issue.
Example:
-- /envoy/lua/scripts/myscript.lua
function add_headers(response_handle)
body_size = response_handle:body():length()
response_handle:headers():add("response-body-size", tostring(body_size))
response_handle:headers():add("foo", "bar")
end
name: envoy.filters.http.lua
typed_config:
"#type": type.googleapis.com/envoy.extensions.filters.http.lua.v3.Lua
inline_code: |
require("envoy.lua.scripts.myscript")
function envoy_on_response(response_handle)
add_headers(response_handle)
end
source_codes:
myscript.lua:
filename: /envoy/lua/scripts/myscript.lua