Monthly Archives: April 2010

Setup a lightweight IMAP server on MacOS X Leopard with Dovecot

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Last week I needed a local IMAP server on MacOS X Leopard (10.5) for temporary testing. After struggling with courier-imap for hours, I’ve finally settled on Dovecot. You’ll see below how easy it is to install and configure it.

We’re lucky, Dovecot is available in Mac Ports, so we can install it easily:

port install dovecot

It’s time to configure it. We start with the default configuration template:

cp /opt/local/etc/dovecot/dovecot-example.conf /opt/local/etc/dovecot/dovecot.conf

Then we can edit the dovecot.conf configuration file as we wish. FYI, here are my modifications:

--- /opt/local/etc/dovecot/dovecot-example.conf	2010-04-23 14:29:52.000000000 +0200
+++ /opt/local/etc/dovecot/dovecot.conf	2010-04-23 14:51:06.000000000 +0200
@@ -21,7 +21,7 @@

 # Protocols we want to be serving: imap imaps pop3 pop3s
 # If you only want to use dovecot-auth, you can set this to "none".
-#protocols = imap imaps
+protocols = imap

 # A space separated list of IP or host addresses where to listen in for
 # connections. "*" listens in all IPv4 interfaces. "[::]" listens in all IPv6
@@ -45,7 +45,7 @@
 # SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
 # matches the local IP (ie. you're connecting from the same computer), the
 # connection is considered secure and plaintext authentication is allowed.
-#disable_plaintext_auth = yes
+disable_plaintext_auth = no

 # Should all IMAP and POP3 processes be killed when Dovecot master process
 # shuts down. Setting this to "no" means that Dovecot can be upgraded without
@@ -221,7 +221,7 @@
 #
 # <doc/wiki/MailLocation.txt>
 #
-#mail_location =
+mail_location = maildir:~/Maildir

 # If you need to set multiple mailbox locations or want to change default
 # namespace settings, you can do it by defining namespace sections.

Before starting Dovecot, we have to create a dummy SSL certificate:

mkdir -p /opt/local/etc/ssl/{certs,private}
openssl req -new -x509 -days 3650 -nodes -out /opt/local/etc/ssl/certs/dovecot.pem -keyout /opt/local/etc/ssl/private/dovecot.pem

And finally, we can launch the Dovecot server itself as root:

dovecot

That’s all !

You can now access your local IMAP server with any client. Here is an example with Thunderbird:

And if you have problems, the first reflex is to read dovecot’s logs:

tail -F /var/log/mail.log

Subversion commands

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Native commands

  • Revert current local folder to revision 666:
    svn merge -rHEAD:666 ./
  • Create an empty repository:
    svnadmin create ./my-repo
  • Dump a repository (a sure way to migrate a subversion repository from one version to another):
    svnadmin dump ./my-repo > ./my-repo.dmp
  • Migrate a remote Subversion repository without creating an intermediate dump file:
    ssh -C user@myserver.com "svnadmin dump /home/user/my-repo" | svnadmin load /home/user2/my-new-repo
  • Launch a standalone Subversion server listening on port 3690 and serving all repositories located in ./repos/:
    svnserve --daemon --listen-port 3690 --root ./repos/

Local working copy hacking

  • Recursive and case insensitive content search on non-binary files from the current folder, while ignoring .svn folders and their content:
    find ./ -type f -not -regex ".*\/.svn\/.*" -exec grep -Iil "string to search" {} \;
  • Same thing as above but with an alternative approach (that don’t work with large folder content):
    grep -Ii "string to search" $(find . | grep -v .svn)

    Other alternative: use ack.

  • Use sed to replace text in all files except in subversion metadatas:
    find ./ -type f -not -regex ".*\/.svn\/.*" -print -exec sed -i 's/str1/str2/g' "{}" \;
  • Use svn delete to remove all files containing a tilde in their name without touching local subversion metadatas:
    find -type f -not -regex ".*\/.svn\/.*" -name "*˜*" -print -exec svn delete "{}" \;
  • In a repository structure containing sub-projects (thinks of Plone’s collective repository as an example), get the list of all folders in all trunks, while ignoring subversion metadata folders:
    find ./ -type d -regex ".*\/trunk\/?.*" -not -regex ".*\/.svn\/?.*" -print
  • Similarly to the command above, replace all occurrences of the string @coolcavemen.fr by @coolcavemen.com in all trunk subfolders while ignoring .svn content:
    find ./ -type f -regex ".*\/trunk\/.*" -not -regex ".*\/.svn\/.*" -print -exec sed -i 's/@coolcavemen\.fr/@coolcavemen\.com/g' "{}" \;
  • Set a svn property to ignore all .mo files during commit in every folder of our local working copy containing .po files:
    find ./ -type f -name "*.po" -regex ".*\/trunk\/.*" -not -regex ".*\/.svn\/.*" -printf "%h\n" | uniq | xargs svn propset "svn:ignore" "*.mo"

Optical illusion: circles in motion (SVG source included)

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Here is an optical illusion I generated with Inkscape. I created this file some years ago and found it recently while cleaning my archives.

Using a contrast trick it appears that circles are in motions. Click on the image below to get a full-size preview:

And as the title say, you can download my original SVG source file (released under a Creative Commons BY-SA license).