Request headers are not propagated even from SIDECAR_INBOUND to SIDECAR_OUTBOUND even after using streamInfo:dynamicMetadata

[kamesh....@gmail.com]

Envoy documentation fo "Data sharing between filters" claims that using "DynamicMetadata" api ...filters can share data amongst them. But i have observed that the request headers are NOT EVEN available from SIDECAR_INBOUND to SIDECAR_OUTBOUND. The value of "authorization" header received form original request was added back using 

 request_handle:streamInfo():dynamicMetadata():set("envoy.lua", "x-envoy-userjwt", jwt-value)

In function envoy_on_request(request_handle) In SIDECAR_INBOUND of "bookinfo.productpage" .

When the same metadata value was retrieved in SIDECAR_OUTBOUND as below returns "nil".

Sample filter config code as below:

apiVersion: networking.istio.io/v1alpha3

kind: EnvoyFilter

metadata:

name: custom-auth-productpage-metadata

namespace: default

spec:

workloadSelector:

labels:

app: productpage

version: v1

configPatches:

# The first patch adds the lua filter to the listener/http connection manager

- applyTo: HTTP_FILTER

match:

context: SIDECAR_INBOUND

listener:

# portNumber: 9080

filterChain:

filter:

name: "envoy.http_connection_manager"

subFilter:

name: "envoy.filters.http.wasm"

patch:

operation: INSERT_AFTER # Make it AFTER, if forwardOriginalToken: false in gatewsay jwt

value: # lua filter specification

name: envoy.lua

typed_config:

"@type": "type.googleapis.com/envoy.config.filter.http.lua.v2.Lua"

inlineCode: |

function envoy_on_request(request_handle)

request_handle:logWarn("SIDECAR_OUTBOUND")

local headers = request_handle:headers()

--local auth = headers:get("Authorization")

local jwt = headers:get("x-envoy-userjwt"). -- has same value as "Authorization"

request_handle:streamInfo():dynamicMetadata():set("envoy.lua", "x-envoy-userjwt", jwt)

request_handle:logWarn("token1: "..jwt)

end

function envoy_on_response(response_handle)

local headers = response_handle:headers()

local meta = response_handle:streamInfo():dynamicMetadata():get("envoy.filters.http.lua")["x-envoy-userjwt"]

response_handle:logWarn("token2: "..meta)

response_handle:streamInfo():dynamicMetadata():set("envoy.lua", "x-envoy-userjwt", meta)

end

- applyTo: HTTP_FILTER

match:

context: SIDECAR_OUTBOUND

listener:

# portNumber: 9080

filterChain:

filter:

name: "envoy.http_connection_manager"

subFilter:

name: "envoy.filters.http.wasm"

patch:

operation: INSERT_AFTER

value: # lua filter specification

name: envoy.lua

typed_config:

"@type": "type.googleapis.com/envoy.config.filter.http.lua.v2.Lua"

inlineCode: |

function envoy_on_request(request_handle)

request_handle:logWarn("SIDECAR_OUTBOUND")

local meta = request_handle:streamInfo():dynamicMetadata():get("envoy.filters.http.lua")["x-envoy-userjwt"]

response_handle:logWarn("token3: "..meta)

request_handle:streamInfo():dynamicMetadata():set("envoy.lua", "x-envoy-userjwt", meta)

end

function envoy_on_response(response_handle)

local headers = response_handle:headers()

local meta = response_handle:streamInfo():dynamicMetadata():get("envoy.filters.http.lua")["x-envoy-userjwt"]

response_handle:logWarn("token4: "..meta)

response_handle:streamInfo():dynamicMetadata():set("envoy.lua", "x-envoy-userjwt", meta)

end

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