A default installation of the Looker application uses self-signed SSL certificates for HTTPS. For production environments, we recommend installing an SSL certificate from a certificate authority such as Verisign (Symantec), GoDaddy, or Thawte.
To use an SSL certificate with Looker, you will need to create a Java keystore with your certificate and key.
We assume you have the following files:
- A certificate file named looker.pem
- An associated key file named looker.key
- Optionally, an intermediate CA chain file named ca.pem
Install the Certificate
These files should all exist in the same directory. The default is
Create the new directory and make it the current directory:
mkdir /home/looker/looker/.ssl cd /home/looker/looker/.ssl
Choose a password for the keystore and put it in a file called .keystorepass:
echo "some_password_here" > .keystorepass
If you have a CA file, append it to the end of your certificate file:
echo >> looker.pem cat ca.pem >> looker.pem
Convert the certificate and key to a
openssl pkcs12 -export \ -in looker.pem \ -inkey looker.key \ -out importme.p12
You will be prompted for an export password. Use the one you put in the .keystorepass file above.
Convert the pkcs12 keystore to a Java keystore:
keytool -importkeystore \ -srckeystore importme.p12 \ -destkeystore looker.jks \ -srcstoretype pkcs12 \ -alias 1
You will be prompted for the new keystore password and the pkcs12 keystore password. Keep using the one in the .keystorepass file.
Now you are ready to start Looker with the new keystore. Your new Looker startup command should look like:
java <your java options here> \ -jar looker.jar start \ --ssl-keystore=/home/looker/looker/.ssl/looker.jks \ --ssl-keystore-pass-file=/home/looker/looker/.ssl/.keystorepass
Validate the Certificate
Once Looker is running, you can verify that your cert is correctly installed with OpenSSL
openssl s_client -connect localhost:9999
If your hostname is
looker.yourdomain.com, you should see a line in the output like this:
subject=/OU=Domain Control Validated/CN=looker.yourdomain.com
Another way to check is with
wget. This test can be performed from any host which has network access to your Looker instance via HTTPS.
On a Looker using the default self-signed certificate, the output shows the certificate common name
$ wget https://looker.yourdomain.com:9999 --2014-12-31 12:06:03-- https://looker.yourdomain.com:9999/ Resolving looker.yourdomain.com (looker.yourdomain.com)... 192.168.23.66 Connecting to looker.yourdomain.com (looker.yourdomain.com)|192.168.23.66|:9999... connected. ERROR: cannot verify looker.yourdomain.com's certificate, issued by ‘/CN=self-signed.looker.com’: Self-signed certificate encountered. ERROR: certificate common name ‘self-signed.looker.com’ doesn't match requested host name ‘looker.yourdomain.com’. To connect to looker.yourdomain.com insecurely, use `--no-check-certificate'.
On a Looker using a certificate from a certificate authority, the certificate common name must match the DNS name that clients use to access Looker (or an equivalent wildcard certificate).
Here is an example of a server using a “real” (non-self signed) certificate:
$ wget https://looker.yourdomain.com:9999 --2014-12-31 12:06:47-- https://looker.yourdomain.com:9999/ Resolving looker.yourdomain.com (looker.yourdomain.com)... 10.10.10.10 Connecting to looker.yourdomain.com (looker.yourdomain.com)|10.10.10.10|:9999... connected. HTTP request sent, awaiting response... 302 Found Location: https://looker.yourdomain.com:9999/login [following] --2014-12-31 12:06:48-- https://looker.yourdomain.com:9999/login Connecting to looker.yourdomain.com (looker.yourdomain.com)|10.10.10.10|:9999... connected. HTTP request sent, awaiting response... 200 OK Length: 3491 (3.4K) [text/html] Saving to: ‘index.html’ 100%[====================================================>] 3,491 --.-K/s in 0.07s 2014-12-31 12:06:48 (50.5 KB/s) - ‘index.html’ saved [3491/3491]
Disabling Insecure SSL Protocols
If you need to remove insecure TLS for security compliance, add this line to your
jdk.tls.disabledAlgorithms= SSLv2Hello, SSLv3, TLSv1, TLSv1.1
After you have setup your SSL certificate you’re ready to add port forwarding for a cleaner URL.