cluster-launch-installer-e2e: Wait on the create process ID

[wking]

Builds on #2030; review that first.

From the POSIX spec:

If the wait utility is invoked with no operands, it shall wait until all process IDs known to the invoking shell have terminated and exit with a zero exit status.

If one or more pid operands are specified that represent known process IDs, the wait utility shall wait until all of them have terminated. If one or more pid operands are specified that represent unknown process IDs, wait shall treat them as if they were known process IDs that exited with exit status 127. The exit status returned by the wait utility shall be the exit status of the process requested by the last pid operand.

Because the bare wait from d862f6f (#1957) contained no PID arguments, it was returning zero even when the install command failed. Here's a simple example demonstrating the effect:

$ false &
$ wait
$ echo $?
0

With this command, we use $! to get the installer's process PID, and pass that to wait. Now the wait call will exit with the installer exit status, and because it's the last command in the shell script, the script will also exit with the installer exit status. Here's a simple example demonstrating the new approach:

$ false &
$ wait "$!"
$ echo $?
1

/assign @abhinavdahiya

[abhinavdahiya]

/lgtm

[openshift-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: abhinavdahiya, wking

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• ci-operator/templates/openshift/installer/OWNERS [abhinavdahiya,wking]

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[openshift-ci-robot]

@wking: Updated the prow-job-cluster-launch-installer-e2e configmap using the following files:

• key cluster-launch-installer-e2e.yaml using file ci-operator/templates/openshift/installer/cluster-launch-installer-e2e.yaml

In response to this:

Builds on #2030; review that first.

From the POSIX spec:

If the wait utility is invoked with no operands, it shall wait until all process IDs known to the invoking shell have terminated and exit with a zero exit status.

If one or more pid operands are specified that represent known process IDs, the wait utility shall wait until all of them have terminated. If one or more pid operands are specified that represent unknown process IDs, wait shall treat them as if they were known process IDs that exited with exit status 127. The exit status returned by the wait utility shall be the exit status of the process requested by the last pid operand.

Because the bare wait from d862f6f (#1957) contained no PID arguments, it was returning zero even when the install command failed. Here's a simple example demonstrating the effect:

$ false &
$ wait
$ echo $?
0

With this command, we use $! to get the installer's process PID, and pass that to wait. Now the wait call will exit with the installer exit status, and because it's the last command in the shell script, the script will also exit with the installer exit status. Here's a simple example demonstrating the new approach:

$ false &
$ wait "$!"
$ echo $?
1

/assign @abhinavdahiya

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