Gary Richardson's questions

I can't seem to create a tag on a resource if the value contains a quote. For example:

aws ec2 create-tags --resource $someResource --tags 'Key=mykey,Value={"json":"value"}'

fails with:

Error parsing parameter '--tags': should be: Key value pairs, with multiple values separated by a space.

But if I run it without the quotes in the value, it succeeds:

aws ec2 create-tags --resource $someResource --tags 'Key=mykey,Value={json:value}'

I've tried a few different combinations of quoting/escaping, but I just can't seem to set the JSON value from the CLI.

For completeness, I updated my tools yesterday:

aws --version
aws-cli/1.3.6 Python/2.7.5 Darwin/13.1.0

Thanks!

I'm building raw disk images (ie, dd, chroot to install linux). During the customization process I may delete files, use temporary files, etc.

What is the best way to delete these files to ensure the image is most compressible?

I'm assuming if I simply rm the file, it's just deleting records from the FAT to mark the blocks as available. This leaves the data in place, so when I gzip or bzip2 the image it still has to pack that data up. I assume things would be a lot tighter if I could tell the FS to write zeros to the blocks instead.

A bit of detail: these are CentOS 6.4 installs on ext4, but I would expect the answer applies to most linux distros using most file systems. The base filesystem I generate is via a command like dd if=/dev/zero of=filesystem.image bs=1M count=10240. A typical 10GB disk image from a vanilla install will compress down to roughly 500MB. I bet if I did a more aggressive cleanup of temp files and such, I could get it a lot tighter.

Thanks!

I'm building a virtual disk image of an install from a script process (DD image, chroot to install). I then convert this image to a VMware vmdk image and boot it. I'm installing CentOS 6.4 as the guest operating system.

The guest boots and I'm able to SSH in. From SSH, this works perfectly.

If I try to use the VMware console to log in, many keys are mapped incorrectly. For example, pressing / (forward slash) generates a - (hyphen/dash). The keyboard map is incorrect on both Fusion and vSphere hosts.

What is the correct keyboard map to change to in order to fix the console?

Thanks!

I'm using prefork apache 2.2 and I can't seem to figure out why there is a MaxClients directive and a ServerLimit directive.

I understand that you need to increase both of these in step -- google has told me this over and over again. As far as I can tell they both control the maximum number of Apache process running at any time.

Why do they both exist? For prefork, they seem redundant. Is there a subtle difference I'm missing?

I'm trying to to use virtual_free to limit the number of large memory jobs running each grid node in my cluster. This seems to be working as expected.

After I modified my code to submit jobs with the memory instances, qstat -f -q $queueName no longer shows a list of jobs waiting for a slot.

The jobs are submitted with a specific queue (-q $queueName).

I'm guessing this is happening due to the magic of SGE queue selection. Is there a way to make my jobs show up as before?

Thanks!

UPDATE

I'm using:

qstat -f -u * -q $queueName

to view the queue. If I drop the queue argument, I can see the jobs. If I examine a specific job, I can see that it has the correct hard_queue_list value set.

I'm also using Sun Grid Engine 6.1u4

I have a wildcard SSL cert, which is working fine:

<VirtualHost *:443>
    ServerName star.mydomain.com
    DocumentRoot /dev/null

    SSLEngine On
    SSLCertificateFile /etc/httpd/conf.d/star.mydomain.com.crt
    SSLCertificateKeyFile /etc/httpd/conf.d/star.mydomain.com.key
    SSLCertificateChainFile /etc/httpd/conf.d/star.mydomain.com.gd_bundle.crt
</VirtualHost>

I then have the various sub domains that listen on the SSL port:

<Virtualhost *:80 *:443>
    ServerName staging.mydomain.com
    DocumentRoot /var/www/staging.mydomain.com/
    CustomLog logs/staging.mydomain.com.log combined

    AccessFileName .htaccess
    DirectoryIndex index.php index.html
</VirtualHost>

<Virtualhost *:80 *:443>
    ServerName www.mydomain.com
    DocumentRoot /var/www/www.mydomain.com/
    CustomLog logs/www.mydomain.com.log combined

    AccessFileName .htaccess
    DirectoryIndex index.php index.html
</VirtualHost>

Which is great. I can go to http://staging.mydomain.com/ or https://staging.mydomain.com/ and everything is happy.

Now the trick is, as far as I can tell, there is know way to know if the request is SSL or not in this configuration.

For example, all the environment variables point to the request being non-ssl even when it's an SSL request. I suspect this is due to the implementation of mod_ssl.

In particular, I want to do something like this in the virtualhosts:

RewriteCond %{SERVER_PORT} 80
RewriteCond %{REQUEST_URI} dashboard
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI} [L]

But I get a redirect loop because SERVER_PORT is always 80, even under SSL.

I've also tried added a SetEnv IS_SSL 1 in the first star.mydomain.com virtualhost, but the variable also isn't available to mod_rewrite.

Without creating separate ssl/non-ssl virtual hosts for each domain, is there a way of making this work?

Thanks!

I want to export an NFS share from my Mac to a linux VMware, but I'm running into a problem with the export.

Things work fine when I export as:

/Users/garyrichardson/leap/nfs -rw 172.16.180.130

Macintosh-3:~ garyrichardson$ showmount -e
Exports list on localhost:
/Users/garyrichardson/leap/nfs      172.16.180.130

But if I try to use no_root_squash, the mount doesn't show up:

/Users/garyrichardson/leap/nfs -rw 172.16.180.130(no_root_squash)

Macintosh-3:~ garyrichardson$ showmount -e
Exports list on localhost:

Am I using the wrong syntax? Is no_root_squash not support under snow leopard?

What's the postfix equivalent to sendmail -bp?

I have a weird situation going on with an open network port. My main question is, why would there not be a program associated with an open TCP port:

netstat -ln --program
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address               Foreign Address             State       PID/Program name   
tcp        0      0 0.0.0.0:5666                0.0.0.0:*                   LISTEN      -  

For my specific case, there is supposed to be an nrpe daemon (opsview install) listening on port 5666, but there is no nrpe daemon running. If I try to start it, it exits immediately.

lsof -i :5666 doesn't show any output either. There is no (x)inetd running on my system.

UPDATE

Yes, I was running those commands as root. Telnet would could, but there was never any response.

After further investigation, I found a kernel error in dmesg: this was an EC2 instance (actually several of them) running an older kernel (2.6.16 is apparently unstable). The fix to stop the crash was to upgrade kernels.

It looks like the way the kernel crashed caused the process to go away and leave the port open.