Category Archives: cloud

Apache certificate chains

When I switched my main server to CentOS, described in an earlier post, one of the big pains was that I had to use CentOS 7, and there was a lot of software which had come a long way since CentOS 7, and I had to upgrade a log of things from upstream to get functionality that I had grown reliant upon.

I didn’t realize that Apache itself was one of those things that was sufficiently backwards in CentOS 7 that I would have trouble.

Ever since I move the server to CentOSdid that “upgrade”, I’ve been struggling with problems with the certificates not being honored. For the last few days I have been working pretty diligently to try to figure out this nagging problem, and today I finally figured it out. It is owing to an old Apache.

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Clamd signatures and Apache memory

After implementing the new tarragon the biggest problem I had involved the clamav package, and its loading of signatures. If clamd doesn’t come up and open its socket, then amavisd (the daemon who is consulted by postfix to handle all the checking of each piece of mail on input and output) will fail (assuming he is configured to do virus checking), This results in various problems. Amavis will mark the mail as “unchecked”, but worse, it will report failure back to postfix who gets confused and very often the message is delivered two or three times.

Clamd, the clamav daemon, now has over 6 million signatures. There are a lot of bad boys out there. The signatures are loaded by clamd from its database (in /var/lib/clamav) on startup, into memory. As a result, clamd has a large memory footprint, almost 800Mb on my system. The first issue, discovered before going live, was that systemd’s default parameters expect any daemon he starts to load within 90 seconds. If it fails to check in within that time, systemd considers it broken and terminates it. Clamd takes at least 3 minutes to load. I had to set a special TimeoutStartSec value in the systemd service script for clamd@.service.

Whew! I thought, boy I’m glad I figured that out. Hah!

Continue reading Clamd signatures and Apache memory

Tarragon Rebuild 2019

This server, on Amazon, hosts my website and a dozen others, provides mail service for several people’s email including my own with postfix, dovecot, opendkim, amavis, spamassassin and clamd, provides contacts and calendar service using radicale, provides vpn service with openvpn, provides a tor relay, provides nextcloud service, and hosts my svn repository.

The server was last rebuilt in 2017. Long, long ago when I built the first version of it, I was most familiar with Red Hat/Fedora, and since then it has been easiest just to upgrade it with Fedora, always grumbling to myself that someday I’m going to change it. The problem with being on Fedora, of course, is that Fedora changes every 6 months, so I’m constantly behind. And after a year I’m at end of life. This is dumb for a server that I don’t want to be messing with all the time.

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Setting Up Openvpn Server

The objective of this project was to install a vpn server on one of the boxes in the cloud (initially asafoetida, then moved to tarragon), in order to provide a VPN server service for a friend who was traveling. My friend uses the name Darrell for his client, so in what follows the vpn is called by this name.

Create a Certificate Authority

A lot of the instructions, even from openvpn site, say to use the “easyrsa” package to generate the certificates for openvpn. This package seems to be put out by the openvpn boys, or at least with their cooperation. But I didn’t do that. I created a ca with raw openssl.

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Certificates Redux

An earlier post talked about switching my server tarragon (where this blog sits) to a wildcard certificate from letsencrypt. There were two reasons why I was using a wildcard certificate. One had to do with test versions of websites that run on this server, and the need that some of those sites have for wildcards, of the form: bob.websitename.com, sally.websitename.com, etc. The other reason was that I have a lot of hosts (oregano, cinnamon, paprika, lemongrass) in addition to tarragon that “need” to have a certificate, for https, for imap, and for smtp, and when I was having to pay for them, it was cheaper to get one wildcard for wmbuck.net. Continue reading Certificates Redux

Dynamic DNS

I have used dynamic dns for around 20 years, I think. But I have always used dyndns.com which these days seems to want to call themselves dyn.com. And some years back they were bought by Oracle, the kiss of death, and now they are impossible to deal with, arrogant, unsupportive, insular – all the things I expect of Oracle.

And why have I kept using them? Because that is what the routers supported. Dyndns was  there first, and the ubiquitous linksys and netgear routers usually have a feature to do automatic updates for dynamic dns, but (often) the router will only update dyndns: nobody else. And I’ve got routers installed in various people houses that are doing this.

But I recently added a new house that I support, and that person has a proprietary and ponderous comcast router, which will barely do anything useful, and has no facility to update dynamic dns.

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LetsEncrypt Wildcard Certificates

Comodo is after me to renew, offering a free year. The last time I attempted to install a wildcard certificate from Lets Encrypt, shortly after they introduced the feature, I wasn’t able to figure it out. Now, 9 months later, there is a lot more information about how to do it. Before spending the money for a commercial cert, I thought I would give it a try.

I used the following on tarragon:


certbot certonly \
--server https://acme-v02.api.letsencrypt.org/directory \
--manual
-d wmbuck.net -d *.wmbuck.net \
--preferred-challenges dns

It is important that the server url by v02, because v01 servers can’t issue wildcard certs. I had to put TXT records in the DNS for them to verify, and they created the cert into the /etc/letsencrypt/live directory where all the others are.

This was trivially easy. Goodbye Comodo.

S3cmd on ubuntu 15.04

After installing ubuntu 15.04 my backups to S3 stopped working.

I tried running them manually to see what was happening and I got errors – some goofy stuff about the url I was using net.wmbuck.backups….s3.amazonaws.com not being part of *s3.amazonaws.com. When I searched the net I found that there was a change in python 2.7.9 having to do with evaluating certificates, and some conflict with the wildcard cert being used by Amazon S3, with the result that there is an error which occurs whenever an S3 bucket happens to contain the “.” character in its title.

My buckets are all named net.wmbuck.x so I am vulnerable to this error.

There is a fix for this in S3cmd version 1.6.0 but the latest ubuntu as of this writing has only S3cmd 1.5.x and attempting to upgrade using apt-get doesn’t get anything new.

I did an apt-get remove of s3cmd, and then downloaded a tarball, and installed it into /usr/local/bin.

Ubuntu 15.10 will be coming out next month, and when I get around to installing that perhaps the version of s3cmd will have the fix.

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Managing passwords on this server

This blog is running on my wmbuck.net server, tarragon, in the Amazon cloud. This server, in addition to hosting this blog, hosts about 20-25 websites (for friends, most of them very low traffic), including my own. It also operates mail for myself and a few others, and provides some other services.
One of the weaknesses has been that most of the people who use the server aren’t really very unix literate, and they don’t really WANT to be. Perhaps they want a website, or they want to have a good place to manage their mail. But in general, the last thing they want is to learn how to ssh into the server to change their password.
So, for most of them, they just use whatever password I set up for them.
One of my friends, who just began using mail on the server, was surprised that it was not convenient to change his password. That spurred me to address the long standing problem. How to let people manage their password for access to services.
The blog now has a new menu on the left, for access to the backend, and for linking to the reset-password screen. There is also a reset password link on the login page https://wmbuck.net/index/login.
The same password is used for all the wmbuck.net stuff: the password for access to mail, the password to get access to protected websites in apache, and the password for logging in to the wmbuck.net backend website.
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New Server

The server for wmbuck.net (tarragon is its name) has been moved to Amazon EC2.

In part this was an experiment, motivated by curiosity about the ease or difficulty of maintaining a server in the cloud. But also in part it was motivated by dissatisfaction with the previous hosting environment, superb hosting. I needed to upgrade the server capacity. It had not been improved for 7 years, and it was ancient hardware when I got it. But at superb I ran into a lot of trouble, because I wanted to use btrfs (see earlier post  about using btrfs on the home computer, oregano). Superb offers old stable kernels, but I really  needed a kernel new enough to have a stable btrfs in it. After I lost all my work owing to btrfs driver problems in an old CentOS kernel, I was highly motivated to try another hosting arrangement where I could have my kernel of choice.

In mid May I set about creating a new tarragon. It took less than a week to set up, including all my learning curve, and all the migration issues, data transfer, etc. It has been running as wmbuck.net for over a month. The few hiccups were mistakes of transition on my part. Up to this moment I have had no problem which has turned out to be of any but my own making.
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