Monno Knol, Deliverability Engineer for Tripolis Solutions presents at the 2018 Port25 Summit

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Zen & The Art of PowerMTA
Maintenance
Port25 Summit
Menno Knol
Deliverability engineer
Tripolis B.V.

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Managing multiple PowerMTA instances
• Web interface / GUI
• PowerMTA Management Console (PMC)
• Commandline / scripts
• Other methods

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Configuring PowerMTA using the command-line
Options available to us
• Monolithic configuration file (/etc/pmta/config)
• Split up the main configuration file and include
multiple files.
• Auto-generate using configuration folders (/etc/
pmta/conf.d)

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Disadvantages of auto-generation
• Initial setup is not entirely trivial
• Requires shell-scripting to work

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Advantages of auto-generation
• Simple, static main configuration file (/etc/pmta/config)
• Ability to easily add/remove/edit context-specific configuration
(customers, application-zones, etc.) simply by adding/removing files
• Ability to use placeholder-variables to abstract filesystem-paths,
interface-addresses, etc.
• Reasonably standard “[..] Generally when you see that *.d convention, it
means ‘this is a directory holding a bunch of configuration fragments
which will be merged together into configuration for some service.’”

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Simple main configuration file

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Advantages of auto-generation
• Simple, static main configuration file (/etc/pmta/config)
• Ability to easily add/remove/edit context-specific configuration
(customers, application-zones, etc.) simply by adding/removing files
• Ability to use placeholder-variables to abstract filesystem-paths,
interface-addresses, etc.
• Reasonably standard “[..] Generally when you see that *.d convention, it
means ‘this is a directory holding a bunch of configuration fragments
which will be merged together into configuration for some service.’”

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Splitting up our configuration
• Make sure we backup our original PowerMTA
configuration
• Create a ‘/etc/pmta/conf.d’ folder.
• Add additional ‘*.d’ sub-folders as required.
• Split up our PowerMTA configuration into
seperate small files and organise these into
the newly created directory-structure.

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Using ‘xargs’ to concatenate config files
find "${CONFDIR}" -maxdepth 1 -type f -print | sort -u |
xargs -I %% cat %% >> "${INCLUDEDIR}/config-settings.autogen"

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Advantages of auto-generation
• Simple, static main configuration file (/etc/pmta/config)
• Ability to easily add/remove/edit context-specific configuration
(customers, application-zones, etc.) simply by adding/removing files
• Ability to use placeholder-variables to abstract filesystem-paths,
interface-addresses, etc.
• Reasonably standard “[..] Generally when you see that *.d convention, it
means ‘this is a directory holding a bunch of configuration fragments
which will be merged together into configuration for some service.’”

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Using ‘sed’ to replace placeholder variables
DKIMPATH=”/etc/pmta/conf.d/dkim.d/keys.d"
find "${CONFDIR}/dkim.d/" -maxdepth 1 -type f -print | sort -u |
xargs -I %% cat %% | sed –e "s/[DKIM_PATH]/${DKIMPATH}/g” >> "$
{INCLUDEDIR}/config-dkims.autogen”
/etc/pmta/conf.d/dkim.d/100-example

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Advantages of auto-generation
• Simple, static main configuration file (/etc/pmta/config)
• Ability to easily add/remove/edit context-specific configuration
(customers, application-zones, etc.) simply by adding/removing files
• Ability to use placeholder-variables to abstract filesystem-paths,
interface-addresses, etc.
• Reasonably standard “[..] Generally when you see that *.d convention, it
means ‘this is a directory holding a bunch of configuration fragments
which will be merged together into configuration for some service.’”

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Tying it together

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Synchronizing our configuration across PowerMTA hosts

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Tying it together

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Tying it together

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Questions?
• Thank you!
• mknol@tripolis.com
§ www.tripolis.com