I need to emulate the Upstart "start on stopped" behavior, in which service B is started after service A runs to completion, but in systemd. How do I do that?

I've seen references to the "After=" and "Before=" clauses in the [Unit] section of the *.service file, but they appear to cause service B to start after service A has been started. Again, I need to wait until service A has run to completion before starting service B.

I put together a trivial example to play with the behavior. I put my *.service files in /etc/systemd/system, enabled the two services and then rebooted. I expected to see first.sh's "...and we're out" before second.sh's "sleep for 2 seconds," but I didn't get that result, as you'll see below.

I appreciate your guidance.

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Here are my service files, the scripts they invoke, and the journalctl output.

Here's "first.service":

[Unit]

Description=First of two services



[Service]

ExecStart=/home/steve/play/systemd/oneAfterTheOther/first.sh



[Install]

WantedBy=multi-user.target

Here's "first.sh":

#!/usr/bin/env bash

nsec=10

echo "sleep for ${nsec} seconds"

sleep ${nsec}

echo "...and we're out"

Here's "second.service":

[Unit]

Description=Second of two services

After=first.service



[Service]

ExecStart=/home/steve/play/systemd/oneAfterTheOther/second.sh



[Install]

WantedBy=multi-user.target

Here's "second.sh":

#!/usr/bin/env bash

nsec=2

echo "sleep for ${nsec} seconds"

sleep ${nsec}

echo "...and we're out"

And here, finally, is the journalctl output:

$ journalctl -u first -u second

-- Logs begin at Tue 2018-09-04 17:50:19 CDT, end at Tue 2018-09-04 17:56:37 CDT

Sep 04 17:50:38 sk-xenial-vm systemd[1]: Started First of two services.

Sep 04 17:50:38 sk-xenial-vm systemd[1]: Started Second of two services.

Sep 04 17:50:40 sk-xenial-vm first.sh[900]: sleep for 10 seconds

Sep 04 17:50:40 sk-xenial-vm second.sh[924]: sleep for 2 seconds

Sep 04 17:50:43 sk-xenial-vm second.sh[924]: ...and we're out

Sep 04 17:50:51 sk-xenial-vm first.sh[900]: ...and we're out