Home » How to set environment variable in systemd service?

How to set environment variable in systemd service?

Solutons:


Times change and so do best practices.

The current best way to do this is to run systemctl edit myservice, which will create an override file for you or let you edit an existing one.

In normal installations this will create a directory /etc/systemd/system/myservice.service.d, and inside that directory create a file whose name ends in .conf (typically, override.conf), and in this file you can add to or override any part of the unit shipped by the distribution.

For instance, in a file /etc/systemd/system/myservice.service.d/myenv.conf:

[Service]
Environment="SECRET=pGNqduRFkB4K9C2vijOmUDa2kPtUhArN"
Environment="ANOTHER_SECRET=JP8YLOc2bsNlrGuD6LVTq7L36obpjzxd"

Also note that if the directory exists and is empty, your service will be disabled! If you don’t intend to put something in the directory, ensure that it does not exist.


For reference, the old way was:

The recommended way to do this is to create a file /etc/sysconfig/myservice which contains your variables, and then load them with EnvironmentFile.

For complete details, see Fedora’s documentation on how to write a systemd script.

The answer depends on whether the variable is supposed to be constant (that is, not supposed to be modified by user getting the unit) or variable (supposed to be set by the user).

Since it’s your local unit, the boundary is quite blurry and either way would work. However, if you started to distribute it and it would end up in /usr/lib/systemd/system, this would become important.

Constant value

If the value doesn’t need to change per instance, the preferred way would be to place it as Environment=, directly in the unit file:

[Unit]
Description=My Daemon

[Service]
Environment="FOO=bar baz"
ExecStart=/bin/myforegroundcmd

[Install]
WantedBy=multi-user.target

The advantage of that is that the variable is kept in a single file with the unit. Therefore, the unit file is easier to move between systems.

Variable value

However, the above solution doesn’t work well when sysadmin is supposed to change the value of the environment variable locally. More specifically, the new value would need to be set every time the unit file is updated.

For this case, an extra file is to be used. How — usually depends on the distribution policy.

One particularly interesting solution is to use /etc/systemd/system/myservice.service.d directory. Unlike other solutions, this directory is supported by systemd itself and therefore comes with no distribution-specific paths.

In this case, you place a file like /etc/systemd/system/myservice.service.d/local.conf that adds the missing parts of unit file:

[Service]
Environment="FOO=bar baz"

Afterwards, systemd merges the two files when starting the service (remember to systemctl daemon-reload after changing either of them). And since this path is used directly by systemd, you don’t use EnvironmentFile= for this.

If the value is supposed to be changed only on some of the affected systems, you may combine both solutions, providing a default directly in the unit and a local override in the other file.

http://0pointer.de/public/systemd-man/systemd.exec.html#Environment= – you have two options (one already pointed by Michael):

Environment=

and

EnvironmentFile=

Related Solutions

Extract file from docker image?

You can extract files from an image with the following commands: docker create $image # returns container ID docker cp $container_id:$source_path $destination_path docker rm $container_id According to the docker create documentation, this doesn't run the...

Transfer files using scp: permission denied

Your commands are trying to put the new Document to the root (/) of your machine. What you want to do is to transfer them to your home directory (since you have no permissions to write to /). If path to your home is something like /home/erez try the following:...

What’s the purpose of DH Parameters?

What exactly is the purpose of these DH Parameters? These parameters define how OpenSSL performs the Diffie-Hellman (DH) key-exchange. As you stated correctly they include a field prime p and a generator g. The purpose of the availability to customize these...

How to rsync multiple source folders

You can pass multiple source arguments. rsync -a /etc/fstab /home/user/download bkp This creates bkp/fstab and bkp/download, like the separate commands you gave. It may be desirable to preserve the source structure instead. To do this, use / as the source and...

Benefits of Structured Logging vs basic logging

There are two fundamental advances with the structured approach that can't be emulated using text logs without (sometimes extreme levels of) additional effort. Event Types When you write two events with log4net like: log.Debug("Disk quota {0} exceeded by user...

Interfaces vs Types in TypeScript

2019 Update The current answers and the official documentation are outdated. And for those new to TypeScript, the terminology used isn't clear without examples. Below is a list of up-to-date differences. 1. Objects / Functions Both can be used to describe the...

Get total as you type with added column (append) using jQuery

One issue if that the newly-added column id's are missing the id number. If you look at the id, it only shows "price-", when it should probably be "price-2-1", since the original ones are "price-1", and the original ones should probably be something like...

Determining if a file is a hard link or symbolic link?

Jim's answer explains how to test for a symlink: by using test's -L test. But testing for a "hard link" is, well, strictly speaking not what you want. Hard links work because of how Unix handles files: each file is represented by a single inode. Then a single...

How to restrict a Google search to results of a specific language?

You can do that using the advanced search options: http://www.googleguide.com/sharpening_queries.html I also found this, which might work for you: http://www.searchenginejournal.com/how-to-see-google-search-results-for-other-locations/25203/ Just wanted to add...

Random map generation

Among the many other related questions on the site, there's an often linked article for map generation: Polygonal Map Generation for Games you can glean some good strategies from that article, but it can't really be used as is. While not a tutorial, there's an...

How to prettyprint a JSON file?

The json module already implements some basic pretty printing in the dump and dumps functions, with the indent parameter that specifies how many spaces to indent by: >>> import json >>> >>> your_json = '["foo", {"bar":["baz", null,...

How can I avoid the battery charging when connected via USB?

I have an Android 4.0.3 phone without root access so can't test any of this but let me point you to /sys/class/power_supply/battery/ which gives some info/control over charging issues. In particular there is charging_enabled which gives the current state (0 not...

How to transform given dataset in python? [closed]

From your expected result, it appears that each "group" is based on contiguous id values. For this, you can use the compare-cumsum-groupby pattern, and then use agg to get the min and max values. # Sample data. df = pd.DataFrame( {'id': [1, 2, 2, 2, 2, 2, 1, 1,...

Output of the following C++ Program [closed]

It works exactly like this non-recursive translation: int func_0() { return 2; } int func_1() { return 3; } int func_2() { return func_1() + func_0(); } // Returns 3 + 2 = 5 int func_3() { return func_2() + func_1(); } // Returns 5 + 3 = 8 int func_4() { return...

Making a circle out of . (periods) [closed]

Here's the maths and even an example program in C: http://pixwiki.bafsoft.com/mags/5/articles/circle/sincos.htm (link no longer exists). And position: absolute, left and top will let you draw: http://www.w3.org/TR/CSS2/visuren.html#choose-position Any further...

Should I use a code converter (Python to C++)?

Generally it's an awful way to write code, and does not guarantee that it will be any faster. Things which are simple and fast in one language can be complex and slow in another. You're better off either learning how to write fast Python code or learning C++...

tkinter: cannot concatenate ‘str’ and ‘float’ objects

This one line is more than enough to cause the problem: text="რეგულარი >> "+2.23+ 'GEL' 2.23 is a floating-point value; 'GEL' is a string. What does it mean to add an arithmetic value and a string of letters? If you want the string label 'რეგულარი...