Ignore Rust's target build directories in Deja-Dup
I use Deja-Dup, to backup my Ubuntu machines. And just like shimo describes in this blog post, I too want to avoid backing up gigabytes of node_module
directories1.
But I also want to avoid backup up gigabytes of target
directories from
building Rust projects with Cargo. I have accumulated some 50+ Rust codebases
scattered throughout my project directories. Their combined target
directories take up about 9GB at time of writing. And all of that is
reproducible, cache-like data. It doesn’t need to be backed up.
So, I adapted Shimo’s crontab to add .deja-dup-ignore
to all:
- All directories named target
- Where the parent directory has a
Cargo.toml
file
In a crontab:
05 10 * * * find ~/ -type d -name target -exec bash -c 'if [ -f "$(dirname {})/Cargo.toml" ]; then touch "{}/.deja-dup-ignore"; fi' \; 2>&1
The command runs find, which will execute a bash command on every directory
called target
. This bash command then gets for the parent dir - $(dirname
{})
- of this target
directory. It will then check if this parent dir has a
Cargo.toml file - if [ -f "$(dirname {})/Cargo.toml" ];
and if so, add a
.deja-dup-ignore ignore file in this target dir.
I don’t just want to ignore any target
directory. I have at
least one legit directory named target
(containing a business target). There
will be more, there probably are already. Hence the added check for the Cargo.toml file.
This speeds up my backup from over an hour a week, to under 20 minutes a week.
And it saves me some 20GB in backup space. Almost a quarter of the space of my
incremental backups were node_modules
and target
directories.
-
Unfortunately a feature request to add some pattern ignore system to Deja-Dup has been ignored for years. Personally, I’d love Deja-Dup to ignore any patterns found in any .gitignore file it encounters. Same as ripgrep and fd and some more modern CLI tools do. For me that’d be the opinionated simplicity that I seek in software. But alas. ↩
![Woodcut from Doré. Purely illustrative](/images//2024/08/10/ignore-rust-target-build-directories-in-deja-dup.png)