Enabling SSL

Generate a Self-Signed Certificate and a Key

To generate a self-signed certificate and a single key that will be used to authenticate both the server and the client, we’ll use the JDK keytool command and create a separate keystore. This keystore will also be used as a truststore below. It’s possible to use the keystore that comes with the JDK for these purposes, and to use a separate truststore, but those options aren’t covered here.

Run the commands below in the server/etc/ directory in the binary Solr distribution. It’s assumed that you have the JDK keytool utility on your PATH, and that openssl is also on your PATH. See https://www.openssl.org/related/binaries.html for OpenSSL binaries for Windows and Solaris.

The -ext SAN=…​ keytool option allows you to specify all the DNS names and/or IP addresses that will be allowed during hostname verification if you choose to require it.

In addition to localhost and 127.0.0.1, this example includes a LAN IP address 192.168.1.3 for the machine the Solr nodes will be running on:

$ keytool -genkeypair -alias solr-ssl -keyalg RSA -keysize 2048 -keypass secret -storepass secret -validity 9999 -keystore solr-ssl.keystore.p12 -storetype PKCS12 -ext SAN=DNS:localhost,IP:192.168.1.3,IP:127.0.0.1 -dname "CN=localhost, OU=Organizational Unit, O=Organization, L=Location, ST=State, C=Country"

The above command will create a keystore file named solr-ssl.keystore.p12 in the current directory.

Convert the Certificate and Key to PEM Format for Use with curl

Convert the PKCS12 format keystore, including both the certificate and the key, into PEM format using the openssl command:

$ openssl pkcs12 -in solr-ssl.keystore.p12 -out solr-ssl.pem

If you want to use curl on OS X Yosemite (10.10), you’ll need to create a certificate-only version of the PEM format, as follows:

$ openssl pkcs12 -nokeys -in solr-ssl.keystore.p12 -out solr-ssl.cacert.pem

Set Common SSL-Related System Properties

The Solr Control Script is already setup to pass SSL-related Java system properties to the JVM. To activate the SSL settings, uncomment and update the set of properties beginning with SOLR_SSL_* in bin/solr.in.sh on *nix systems or bin\solr.in.cmd on Windows.

# Enables HTTPS. It is implicitly true if you set SOLR_SSL_KEY_STORE. Use this config
# to enable https module with custom jetty configuration.
SOLR_SSL_ENABLED=true
# Uncomment to set SSL-related system properties
# Be sure to update the paths to the correct keystore for your environment
SOLR_SSL_KEY_STORE=etc/solr-ssl.keystore.p12
SOLR_SSL_KEY_STORE_PASSWORD=secret
SOLR_SSL_TRUST_STORE=etc/solr-ssl.keystore.p12
SOLR_SSL_TRUST_STORE_PASSWORD=secret
# Require clients to authenticate
SOLR_SSL_NEED_CLIENT_AUTH=false
# Enable clients to authenticate (but not require)
SOLR_SSL_WANT_CLIENT_AUTH=false
# SSL Certificates contain host/ip "peer name" information that is validated by default. Setting
# this to false can be useful to disable these checks when re-using a certificate on many hosts
SOLR_SSL_CHECK_PEER_NAME=true

REM Enables HTTPS. It is implicitly true if you set SOLR_SSL_KEY_STORE. Use this config
REM to enable https module with custom jetty configuration.
set SOLR_SSL_ENABLED=true
REM Uncomment to set SSL-related system properties
REM Be sure to update the paths to the correct keystore for your environment
set SOLR_SSL_KEY_STORE=etc/solr-ssl.keystore.p12
set SOLR_SSL_KEY_STORE_PASSWORD=secret
set SOLR_SSL_TRUST_STORE=etc/solr-ssl.keystore.p12
set SOLR_SSL_TRUST_STORE_PASSWORD=secret
REM Require clients to authenticate
set SOLR_SSL_NEED_CLIENT_AUTH=false
REM Enable clients to authenticate (but not require)
set SOLR_SSL_WANT_CLIENT_AUTH=false
REM SSL Certificates contain host/ip "peer name" information that is validated by default. Setting
REM this to false can be useful to disable these checks when re-using a certificate on many hosts
set SOLR_SSL_CHECK_PEER_NAME=true

When you start Solr, the bin/solr script includes these settings and will pass them as system properties to the JVM.

If you are running Solr in standalone mode, you can skip to Run Single Node Solr using SSL.

If you are using SolrCloud, however, you need to Configure ZooKeeper before starting Solr.

Password Distribution via Hadoop Credential Store

Solr supports reading keystore and truststore passwords from Hadoop credential store. This approach can be beneficial if password rotation and distribution is already handled by credential stores.

If you are not using a Hadoop credential store, you can skip this step.

Hadoop credential store can be used with Solr using the following two steps.

solr.jetty.keystore.password
solr.jetty.truststore.password
javax.net.ssl.keyStorePassword
javax.net.ssl.trustStorePassword

SOLR_OPTS=" -Dsolr.ssl.credential.provider.chain=hadoop"
SOLR_HADOOP_CREDENTIAL_PROVIDER_PATH=localjceks://file/home/solr/hadoop-credential-provider.jceks
HADOOP_CREDSTORE_PASSWORD="credStorePass123"

set SOLR_OPTS=" -Dsolr.ssl.credential.provider.chain=hadoop"
set SOLR_HADOOP_CREDENTIAL_PROVIDER_PATH=localjceks://file/home/solr/hadoop-credential-provider.jceks
set HADOOP_CREDSTORE_PASSWORD="credStorePass123"

Configure ZooKeeper

After creating the keystore described above and before you start any SolrCloud nodes, you must configure your Solr cluster properties in ZooKeeper so that Solr nodes know to communicate via SSL.

This section assumes you have created and started an external ZooKeeper. See Setting Up an External ZooKeeper Ensemble for more information.

The urlScheme cluster-wide property needs to be set to https before any Solr node starts up. The examples below use the zkcli tool that comes with Solr to do this.

$ server/scripts/cloud-scripts/zkcli.sh -zkhost server1:2181,server2:2181,server3:2181 -cmd clusterprop -name urlScheme -val https

C:\> server\scripts\cloud-scripts\zkcli.bat -zkhost server1:2181,server2:2181,server3:2181 -cmd clusterprop -name urlScheme -val https

Be sure to use the correct zkhost value for your system. If you have set up your ZooKeeper ensemble to use a chroot for Solr, make sure to include it in the zkhost string, e.g., -zkhost server1:2181,server2:2181,server3:2181/solr.

Update Cluster Properties for Existing Collections

If you are using SolrCloud and have collections created before enabling SSL, you will need to update the cluster properties to use HTTPS.

If you do not have existing collections or are not using SolrCloud, you can skip ahead and start Solr.

Updating cluster properties can be done with the Collections API CLUSTERPROP command, as in this example (update the hostname and port as appropriate for your system):

$ http://localhost:8983/solr/admin/collections?action=CLUSTERPROP&name=urlScheme&val=https

This command only needs to be run on one node of the cluster, the change will apply to all nodes.

Once this and all other steps are complete, you can go ahead and start Solr.

Run Single Node Solr using SSL

Start Solr using the Solr control script as shown in the examples below. Customize the values for the parameters shown as needed and add any used in your system.

$ bin/solr -p 8984

C:\> bin\solr.cmd -p 8984

Run SolrCloud with SSL

Start each Solr node with the Solr control script as shown in the examples below. Customize the values for the parameters shown as necessary and add any used in your system.

If you created the SSL key without all DNS names or IP addresses on which Solr nodes run, you can tell Solr to skip hostname verification for inter-node communications by setting the -Dsolr.ssl.checkPeerName=false system property.

$ bin/solr -cloud -s cloud/node1 -z server1:2181,server2:2181,server3:2181 -p 8984

C:\> bin\solr.cmd -cloud -s cloud\node1 -z server1:2181,server2:2181,server3:2181

Create a SolrCloud Collection using bin/solr

Create a 2-shard, replicationFactor=1 collection named mycollection using the _default configset:

bin/solr create -c mycollection -shards 2

bin\solr.cmd create -c mycollection -shards 2

The create action will pass the SOLR_SSL_* properties set in your include file to the SolrJ code used to create the collection.

Retrieve SolrCloud Cluster Status using curl

To get the resulting cluster status (again, if you have not enabled client authentication, remove the -E solr-ssl.pem:secret option):

$ curl -E solr-ssl.pem:secret --cacert solr-ssl.pem "https://localhost:8984/solr/admin/collections?action=CLUSTERSTATUS&indent=on"

You should get a response that looks like this:

{
  "responseHeader":{
    "status":0,
    "QTime":2041},
  "cluster":{
    "collections":{
      "mycollection":{
        "shards":{
          "shard1":{
            "range":"80000000-ffffffff",
            "state":"active",
            "replicas":{"core_node1":{
                "state":"active",
                "base_url":"https://127.0.0.1:8984/solr",
                "core":"mycollection_shard1_replica1",
                "node_name":"127.0.0.1:8984_solr",
                "leader":"true"}}},
          "shard2":{
            "range":"0-7fffffff",
            "state":"active",
            "replicas":{"core_node2":{
                "state":"active",
                "base_url":"https://127.0.0.1:7574/solr",
                "core":"mycollection_shard2_replica1",
                "node_name":"127.0.0.1:7574_solr",
                "leader":"true"}}}},
        "maxShardsPerNode":"1",
        "router":{"name":"compositeId"},
        "replicationFactor":"1"}},
    "properties":{"urlScheme":"https"}}}

Index Documents using post.jar

Use post.jar to index some example documents to the SolrCloud collection created above:

cd example/exampledocs

java -Djavax.net.ssl.keyStorePassword=secret -Djavax.net.ssl.keyStore=../../server/etc/solr-ssl.keystore.p12 -Djavax.net.ssl.trustStore=../../server/etc/solr-ssl.keystore.p12 -Djavax.net.ssl.trustStorePassword=secret -Durl=https://localhost:8984/solr/mycollection/update -jar post.jar *.xml

Query Using curl

Use curl to query the SolrCloud collection created above, from a directory containing the PEM formatted certificate and key created above (e.g., example/etc/) - if you have not enabled client authentication (system property -Djetty.ssl.clientAuth=true), then you can remove the -E solr-ssl.pem:secret option:

curl -E solr-ssl.pem:secret --cacert solr-ssl.pem "https://localhost:8984/solr/mycollection/select?q=*:*"

Index a Document using CloudSolrClient

From a java client using SolrJ, index a document. In the code below, the javax.net.ssl.* system properties are set programmatically, but you could instead specify them on the java command line, as in the post.jar example above:

System.setProperty("javax.net.ssl.keyStore", "/path/to/solr-ssl.keystore.p12");
System.setProperty("javax.net.ssl.keyStorePassword", "secret");
System.setProperty("javax.net.ssl.trustStore", "/path/to/solr-ssl.keystore.p12");
System.setProperty("javax.net.ssl.trustStorePassword", "secret");
String zkHost = "127.0.0.1:2181";
CloudSolrClient client = new CloudSolrClient.Builder(Collections.singletonList(zkHost),Optional.empty()).build();
client.setDefaultCollection("mycollection");
SolrInputDocument doc = new SolrInputDocument();
doc.addField("id", "1234");
doc.addField("name", "A lovely summer holiday");
client.add(doc);
client.commit();