Add host_override NH option (#9984)
sets the host header to the upstream parent instead of the original request
diff --git a/doc/admin-guide/files/strategies.yaml.en.rst b/doc/admin-guide/files/strategies.yaml.en.rst
index f5b8443..19353d0 100644
--- a/doc/admin-guide/files/strategies.yaml.en.rst
+++ b/doc/admin-guide/files/strategies.yaml.en.rst
@@ -230,6 +230,8 @@
(**self** should only be necessary when the local hostname can only be translated to an IP address
with a DNS lookup.)
+- **host_override**: A boolean value that will set the host header to the selected parent rather than the original host. **true** sets host header to selected parent. **false** (default) leaves the host header untouched.
+
Example:
::
@@ -254,6 +256,7 @@
- passive
- strategy: 'strategy-2'
policy: rr_strict
+ host_override: true
hash_url: cache
hash_key: path+query
go_direct: true
diff --git a/proxy/http/remap/NextHopConsistentHash.cc b/proxy/http/remap/NextHopConsistentHash.cc
index fe23dbe..51a14ed 100644
--- a/proxy/http/remap/NextHopConsistentHash.cc
+++ b/proxy/http/remap/NextHopConsistentHash.cc
@@ -496,5 +496,7 @@
ParentResultStr[result.result]);
}
+ setHostHeader(txnp, result.hostname);
+
return;
}
diff --git a/proxy/http/remap/NextHopRoundRobin.cc b/proxy/http/remap/NextHopRoundRobin.cc
index f2e8725..508228e 100644
--- a/proxy/http/remap/NextHopRoundRobin.cc
+++ b/proxy/http/remap/NextHopRoundRobin.cc
@@ -171,6 +171,7 @@
result->last_parent = cur_hst_index;
result->last_group = cur_grp_index;
result->retry = parentRetry;
+ setHostHeader(txnp, result->hostname);
ink_assert(result->hostname != nullptr);
ink_assert(result->port != 0);
NH_Debug(NH_DEBUG_TAG, "[%" PRIu64 "] Chosen parent = %s.%d", sm_id, result->hostname, result->port);
diff --git a/proxy/http/remap/NextHopSelectionStrategy.cc b/proxy/http/remap/NextHopSelectionStrategy.cc
index a924c87..bb8482a 100644
--- a/proxy/http/remap/NextHopSelectionStrategy.cc
+++ b/proxy/http/remap/NextHopSelectionStrategy.cc
@@ -82,6 +82,10 @@
cache_peer_result = n["cache_peer_result"].as<bool>();
}
+ if (n["host_override"]) {
+ host_override = n["host_override"].as<bool>();
+ }
+
// failover node.
YAML::Node failover_node_n = n["failover"];
if (failover_node_n) {
@@ -255,6 +259,16 @@
return passive_health.markNextHop(txnp, hostname, port, status, ih, now);
}
+void
+NextHopSelectionStrategy::setHostHeader(TSHttpTxn txnp, const char *hostname)
+{
+ if (host_override && nullptr != hostname) {
+ HttpSM *sm = reinterpret_cast<HttpSM *>(txnp);
+ sm->t_state.hdr_info.client_request.value_set(MIME_FIELD_HOST, MIME_LEN_HOST, hostname, strlen(hostname));
+ NH_Debug(NH_DEBUG_TAG, "[%" PRIu64 "] overriding host header with parent %s", sm->sm_id, hostname);
+ }
+}
+
bool
NextHopSelectionStrategy::nextHopExists(TSHttpTxn txnp, void *ih)
{
diff --git a/proxy/http/remap/NextHopSelectionStrategy.h b/proxy/http/remap/NextHopSelectionStrategy.h
index 1fe49cb..d327acd 100644
--- a/proxy/http/remap/NextHopSelectionStrategy.h
+++ b/proxy/http/remap/NextHopSelectionStrategy.h
@@ -202,6 +202,8 @@
const time_t now = 0);
bool nextHopExists(TSHttpTxn txnp, void *ih = nullptr);
+ void setHostHeader(TSHttpTxn txnp, const char *hostname);
+
virtual ParentRetry_t responseIsRetryable(int64_t sm_id, HttpTransact::CurrentInfo ¤t_info, HTTPStatus response_code);
void retryComplete(TSHttpTxn txn, const char *hostname, const int port);
@@ -211,6 +213,7 @@
bool parent_is_proxy = true;
bool ignore_self_detect = false;
bool cache_peer_result = true;
+ bool host_override = false;
NHPolicyType policy_type = NH_UNDEFINED;
NHSchemeType scheme = NH_SCHEME_NONE;
NHRingMode ring_mode = NH_ALTERNATE_RING;
