$ bin/fetch-istio-envoy --help
fetch-istio-envoy - Retrieve a file from Envoy as used by Istio.
usage:
fetch-istio-envoy ISTIO_REF [ENVOY_PATH]
Create a temporary directory and fill it with information
about the relationship between the specified ISTIO_REF
(which can be a branch, tag, or commit hash) and the underlying
Envoy code that the Istio uses.
Optionally specify an ENVOY_PATH, which is an unqualified path
to a file within the relevant Envoy git tree, to download
from GitHub as the file `envoy-file` in the temporary directory.
If ENVOY_PATH is not specified, then it defaults to
source/extensions/tracers/datadog/span.cc.
Print the path to the temporary directory to standard output.
example:
$ fetch-istio-envoy 1.20.0 source/extensions/tracers/datadog/span.cc
/tmp/tmp.A7FFDYU52Z
$ cd /tmp/tmp.A7FFDYU52Z
$ ls -l
-rw-rw-r-- 1 david david 41 Dec 6 20:04 envoy-commit
-rw-rw-r-- 1 david david 83 Dec 6 20:04 envoy-commit.url
-rw-rw-r-- 1 david david 2992 Dec 6 20:04 envoy-file
-rw-rw-r-- 1 david david 123 Dec 6 20:04 envoy-file.url
-rw-rw-r-- 1 david david 42 Dec 6 20:04 envoy-path
-rw-rw-r-- 1 david david 81 Dec 6 20:04 envoy-tree.url
-rw-rw-r-- 1 david david 335 Dec 6 20:04 istio-deps
-rw-rw-r-- 1 david david 7 Dec 6 20:04 istio-ref
-rw-rw-r-- 1 david david 1881 Dec 6 20:04 Makefile
-rw-rw-r-- 1 david david 41 Dec 6 20:04 proxy-tree
-rw-rw-r-- 1 david david 76 Dec 6 20:04 proxy-tree.url
-rw-rw-r-- 1 david david 4101 Dec 6 20:04 proxy-workspace
$ nl -ba envoy-file | grep -w 'set_name'
44 span_->set_name(operation);