SOLR-18527: Provide a example of a secure Solr using bin/solr start -e secure

changelog/unreleased/SOLR-18527.yml

@@ -0,0 +1,10 @@
+title: >
+  Add a step-by-step tutorial and a bin/solr start -e secure example for configuring
+  a two-node SolrCloud cluster with self-signed PKCS12 certificates, HTTPS, Basic Authentication,
+  and ZooKeeper digest accounts and ACLs.
+type: added
+authors:
+  - name: Eric Pugh
+links:
+  - name: SOLR-18527
+    url: https://issues.apache.org/jira/browse/SOLR-18527

solr/bin/solr

@@ -420,6 +420,7 @@ function print_usage() {
     echo "  -e/--example <name>   Name of the example to run; available examples:"
     echo "      cloud:              SolrCloud example"
     echo "      techproducts:       Comprehensive example illustrating many of Solr's core capabilities"
+    echo "      secure:             Two-node HTTPS example with Basic Authentication and ZooKeeper ACLs"
     echo "      schemaless:         Schema-less example (schema is inferred from data during indexing)"
     echo "      films:              Example of starting with _default configset and adding explicit fields dynamically"
     echo ""
@@ -636,6 +637,17 @@ fi
 
 # Everything below here is to support start, stop and restart.
 
+if [[ "$SCRIPT_CMD" == "start" ]]; then
+  # This has to re-scan the raw args rather than reuse $EXAMPLE (set further below by the
+  # full option-parsing loop): the ulimit check right below this runs before that loop does.
+  for example_arg in "$@"; do
+    if [[ "$example_arg" == "-e" || "$example_arg" == "--example" ]]; then
+      export SOLR_ULIMIT_CHECKS=false
+      break
+    fi
+  done
+fi
+
 #Check current Ulimits for Open Files and Max Processes.  Warn if they are below the recommended values.
 
 : "${SOLR_RECOMMENDED_MAX_PROCESSES:=65000}"