fix(setup): Set curl --resolve flag conditionally

curl 8.x no longer treats CURLOPT_RESOLVE parse failures as a warning.
Because 'elasticsearch' is not an IP address, using it as the ADDR
segment in the --resolve flag is illegal.

In 7.x, curl would print a warning but fall back to the hostname in the
URL, as if --resolve had not been set.

This issue went under the radar because:

1. curl 8.x is used in Elastic v8 images (Ubuntu base[1]), whereas our
   default Elastic v9 images still ship with curl 7.x (RHEL base[2]).
2. The warning was not printed due to the usage of the -s flag.

Fixes #1137

[1]: https://github.com/elastic/elasticsearch/blob/v8.19.8/build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/DockerBase.java#L16
[2]: https://github.com/elastic/elasticsearch/blob/v9.2.2/build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/DockerBase.java#L17

Author: antoineco

setup/lib.sh

@@ -29,15 +29,14 @@ function augment_curl_args {
 	if [[ -n "${ELASTIC_PASSWORD:-}" ]]; then
 		args_ref+=( '-u' "elastic:${ELASTIC_PASSWORD}" )
 	fi
+	if [[ -n "${ELASTICSEARCH_ADDR:-}" ]]; then
+		args_ref+=( '--resolve' "elasticsearch:9200:${ELASTICSEARCH_ADDR}" )
+	fi
 }
 
 # Poll the 'elasticsearch' service until it responds with HTTP code 200.
 function wait_for_elasticsearch {
-	local elasticsearch_host="${ELASTICSEARCH_HOST:-elasticsearch}"
-
-	local -a args=( '-s' '-D-' '-m15' '-w' '%{http_code}' 'https://elasticsearch:9200/'
-		'--resolve' "elasticsearch:9200:${elasticsearch_host}" '--cacert' "$es_ca_cert"
-		)
+	local -a args=( '-s' '-D-' '-m15' '-w' '%{http_code}' 'https://elasticsearch:9200/' '--cacert' "$es_ca_cert" )
 
 	augment_curl_args args
 
@@ -70,11 +69,7 @@ function wait_for_elasticsearch {
 
 # Poll the Elasticsearch users API until it returns users.
 function wait_for_builtin_users {
-	local elasticsearch_host="${ELASTICSEARCH_HOST:-elasticsearch}"
-
-	local -a args=( '-s' '-D-' '-m15' 'https://elasticsearch:9200/_security/user?pretty'
-		'--resolve' "elasticsearch:9200:${elasticsearch_host}" '--cacert' "$es_ca_cert"
-		)
+	local -a args=( '-s' '-D-' '-m15' 'https://elasticsearch:9200/_security/user?pretty' '--cacert' "$es_ca_cert" )
 
 	augment_curl_args args
 
@@ -119,11 +114,9 @@ function wait_for_builtin_users {
 function check_user_exists {
 	local username=$1
 
-	local elasticsearch_host="${ELASTICSEARCH_HOST:-elasticsearch}"
-
 	local -a args=( '-s' '-D-' '-m15' '-w' '%{http_code}'
 		"https://elasticsearch:9200/_security/user/${username}"
-		'--resolve' "elasticsearch:9200:${elasticsearch_host}" '--cacert' "$es_ca_cert"
+		'--cacert' "$es_ca_cert"
 		)
 
 	augment_curl_args args
@@ -154,11 +147,9 @@ function set_user_password {
 	local username=$1
 	local password=$2
 
-	local elasticsearch_host="${ELASTICSEARCH_HOST:-elasticsearch}"
-
 	local -a args=( '-s' '-D-' '-m15' '-w' '%{http_code}'
 		"https://elasticsearch:9200/_security/user/${username}/_password"
-		'--resolve' "elasticsearch:9200:${elasticsearch_host}" '--cacert' "$es_ca_cert"
+		'--cacert' "$es_ca_cert"
 		'-X' 'POST'
 		'-H' 'Content-Type: application/json'
 		'-d' "{\"password\" : \"${password}\"}"
@@ -187,11 +178,9 @@ function create_user {
 	local password=$2
 	local role=$3
 
-	local elasticsearch_host="${ELASTICSEARCH_HOST:-elasticsearch}"
-
 	local -a args=( '-s' '-D-' '-m15' '-w' '%{http_code}'
 		"https://elasticsearch:9200/_security/user/${username}"
-		'--resolve' "elasticsearch:9200:${elasticsearch_host}" '--cacert' "$es_ca_cert"
+		'--cacert' "$es_ca_cert"
 		'-X' 'POST'
 		'-H' 'Content-Type: application/json'
 		'-d' "{\"password\":\"${password}\",\"roles\":[\"${role}\"]}"
@@ -219,11 +208,9 @@ function ensure_role {
 	local name=$1
 	local body=$2
 
-	local elasticsearch_host="${ELASTICSEARCH_HOST:-elasticsearch}"
-
 	local -a args=( '-s' '-D-' '-m15' '-w' '%{http_code}'
 		"https://elasticsearch:9200/_security/role/${name}"
-		'--resolve' "elasticsearch:9200:${elasticsearch_host}" '--cacert' "$es_ca_cert"
+		'--cacert' "$es_ca_cert"
 		'-X' 'POST'
 		'-H' 'Content-Type: application/json'
 		'-d' "$body"