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cloud engineer

Archives for October 2018

Force Rewrite To HTTPS Except For Page

Here’s how to force a rewrite pages to https except for a couple of pages.

RewriteEngine On
 
RewriteCond %{HTTPS} =off
RewriteCond %{REQUEST_URI} !^\/page1\/
RewriteCond %{REQUEST_URI} !^\/page2\/
RewriteRule (.*) https://%{HTTP_HOST}/$1 [L,R=301]    
 
RewriteCond %{HTTPS} =on
RewriteCond %{REQUEST_URI} \/page1\/ [OR]
RewriteCond %{REQUEST_URI} \/page2\/
RewriteRule (.*) http://%{HTTP_HOST}/$1 [L,R=301]

The first rule-set will redirect all pages not /page1/ or /page2/ to the same URL but https://.
The second rule will make sure that /page1/ and /page2/ are redirected back to http:// if accessed via https://.

Here’s the Stackdriver source.

SSL Expiry

It’s not always clear how to find out when your SSL certificate is expiring. Openssl should be able to tell you.

$ openssl x509 -enddate -noout -in certificate.crt

Working with SSMTP

Sometimes you just want something simple. There’s no need to configure sendmail every time you build a box.

Instead, you can install and use ssmtp coupled with a Gmail account.

Testing a Network Port Connection

You can test a network port connection using the “nc” command on Linux and “telnet” on Windows.

Format:
$ nc -zv domain.com port
C:\> telnet domain.com port

$ nc -zv domain.com 80
Connection to domain.com 80 port [tcp/http] succeeded!
C:\> telnet -zv domain.com 80
Connecting To domain.com...Could not open connection to the host, on port 80: Connect failed

For Telnet, if a connection is successful, it returns no message.

Limitations when Stopping RDS

There are several cases where there will be a need to stop a RDS instance. It could be due to testing, development activity, or simply to save money. Whatever the reasons may be, you’ll need to be aware of the limitations when stopping RDS instances. Here are several cases where it may become an issue.

  • You can’t stop a DB instance that has a Read Replica, or that is a Read Replica.
  • You can’t stop a DB instance that is in a Multi-AZ deployment.
  • You can’t stop a DB instance that uses Microsoft SQL Server Mirroring.
  • You can’t modify a stopped DB instance.
  • You can’t delete an option group that is associated with a stopped DB instance.
  • You can’t delete a DB parameter group that is associated with a stopped DB instance.