[TODO]: Check and replace existing sed substitute statements with sedfile wrapper

Subject

Something else that requires developers attention

Description

Description

This task is available for anyone that wants to tackle it.

sed substitution statements like sed -i 's/foo/bar/' somefile fail silently, when foo is not found.

This can lead to problems, when a file changed and the search pattern is not found anymore. If there is no explicit test for that, this bug will be unnoticed, until someone reports a problem, that is later tracked down to a sed statement, which no longer took place anymore.

Solution

The wrapper sedfile can replace sed -i [<other options>] <pattern> <file> statements. It checks the file before and after the substitution attempt. If no change is detected, it fails.

More information:

# Wrapper for 'sed -i': fail if file was not modified by sed and container was not restarted.
# Error output is suppressed, when container is restarted to avoid harmless error messages.
# Use "--strict" as first parameter, to fail regardless of the container state (fresh or restarted).

# When to use sedfile?
# Is a file change optional? --> use regular 'sed -i'
# Is a file change expected? --> use 'sedfile --strict -i'
# Is a file change only on the first container run expected? --> use 'sedfile -i'

Example

# Old
sed     -i 's/^discard-all-mails=true/discard-all-mails=false/' important.config

# New
sedfile -i 's/^discard-all-mails=true/discard-all-mails=false/' important.config

Todo

Evaluate all sed substitution statements and check, if an sedfile wrapper usage makes sense.