Prevent conflicting mender services from running simultaneously.

[kacf]

Changelog: Fix: mender-client.service and the old mender.service
services can no longer run at the same time. If anyone has both, then
mender.service should be removed from the system.

Signed-off-by: Kristian Amlie kristian.amlie@northern.tech

[mender-test-bot]

@kacf, Let me know if you want to start the integration pipeline by mentioning me and the command "start pipeline".

[kacf]

@lluiscampos: This was inspired by this post. However, it may not be quite that simple, because older client releases are still using the old name, and may need to patch this out of the file. However, this caused quite severe breakage, so I reckon it's still worth it. What do you think?

Let's never rename the client again...

[kacf]

@mender-test-bot start pipeline

[mender-test-bot]

Hello 😸 I created a pipeline for you here: Pipeline-318210389

Build Configuration Matrix

Key	Value
AUDITLOGS_REV	origin/master
BUILD_BEAGLEBONEBLACK	true
BUILD_CLIENT	true
BUILD_QEMUX86_64_BIOS_GRUB	true
BUILD_QEMUX86_64_BIOS_GRUB_GPT	true
BUILD_QEMUX86_64_UEFI_GRUB	true
BUILD_VEXPRESS_QEMU	true
BUILD_VEXPRESS_QEMU_FLASH	true
BUILD_VEXPRESS_QEMU_UBOOT_UEFI_GRUB	true
CREATE_ARTIFACT_WORKER_REV	origin/master
DEPLOYMENTS_ENTERPRISE_REV	origin/master
DEPLOYMENTS_REV	origin/master
DEVICEAUTH_REV	origin/master
DEVICECONFIG_REV	origin/master
DEVICECONNECT_REV	origin/master
GUI_REV	origin/master
INTEGRATION_REV	master
INVENTORY_ENTERPRISE_REV	origin/master
INVENTORY_REV	origin/master
MENDER_ARTIFACT_REV	origin/master
MENDER_CLI_REV	origin/master
MENDER_CONNECT_REV	origin/master
MENDER_REV	pull/796/head
MTLS_AMBASSADOR_REV	origin/master
RUN_INTEGRATION_TESTS	true
TENANTADM_REV	origin/master
TEST_QEMUX86_64_BIOS_GRUB	true
TEST_QEMUX86_64_BIOS_GRUB_GPT	true
TEST_QEMUX86_64_UEFI_GRUB	true
TEST_VEXPRESS_QEMU	true
TEST_VEXPRESS_QEMU_FLASH	true
TEST_VEXPRESS_QEMU_UBOOT_UEFI_GRUB	true
USERADM_ENTERPRISE_REV	origin/master
USERADM_REV	origin/master
WORKFLOWS_ENTERPRISE_REV	origin/master
WORKFLOWS_REV	origin/master

[lluiscampos]

@lluiscampos: This was inspired by this post. However, it may not be quite that simple, because older client releases are still using the old name, and may need to patch this out of the file. However, this caused quite severe breakage, so I reckon it's still worth it. What do you think?

While the change you submit here is good, I don't really understand how this prevents another user to end up in the same situation. All that it will do is to block mender-client service, but the mender one will still be running right? So to my eyes "hides" the problem that the service file still will be wrong.

Let's never rename the client again...

Roger that!

[kacf]

While the change you submit here is good, I don't really understand how this prevents another user to end up in the same situation. All that it will do is to block mender-client service, but the mender one will still be running right? So to my eyes "hides" the problem that the service file still will be wrong.

What it does it prevent them from running at the same time. Either one can run in isolation. However, if both are enabled at boot, then both will fail to start, and it counts as an error from systemd's side. So this is the only thing that this patch changes, you cannot run them at the same time anymore. It does not fix the fact that there may be an old service file in the system, but that was the case before this patch as well.

I can see what you mean with "hiding" the issue, but the original issue was quite hidden as well, and the effect was much more severe than it will be after this patch. So we should still be on the lookout for the problem, but at least we have some protection from the worst effects.

[lluiscampos]

Okey, let's merge it then. Thanks for the discussion.

[kacf]

Thanks!

[mender-test-bot]

Hello 😸 This PR contains changelog entries. Please, verify the need of backporting it to the following release branches:
2.6.x (release 2.7.x)
2.5.x (release 2.6.x)
2.3.x (release 2.4.x)