Comment 7 for bug 1926463

It's starting to look like a CI-only issue - deployed C8 Stream on same Ubuntu host, works:

++ cat /run_command
+ CMD='/opt/prometheus_alertmanager/alertmanager --config.file=/etc/prometheus/alertmanager.yml --web.listen-address=10.0.3.78:9093 --web.external-url=http://10.14.10.254:9093 --storage.path /var/lib/prometheus'
+ ARGS=
+ sudo kolla_copy_cacerts
+ [[ ! -n '' ]]
+ . kolla_extend_start
++ [[ ! -d /var/log/kolla/prometheus ]]
+++ stat -c %a /var/log/kolla/prometheus
++ [[ 2755 != \7\5\5 ]]
++ chmod 755 /var/log/kolla/prometheus
+ echo 'Running command: '\''/opt/prometheus_alertmanager/alertmanager --config.file=/etc/prometheus/alertmanager.yml --web.listen-address=10.0.3.78:9093 --web.external-url=http://10.14.10.254:9093 --storage.path /var/lib/prometheus'\'''
+ exec /opt/prometheus_alertmanager/alertmanager --config.file=/etc/prometheus/alertmanager.yml --web.listen-address=10.0.3.78:9093 --web.external-url=http://10.14.10.254:9093 --storage.path /var/lib/prometheus
Running command: '/opt/prometheus_alertmanager/alertmanager --config.file=/etc/prometheus/alertmanager.yml --web.listen-address=10.0.3.78:9093 --web.external-url=http://10.14.10.254:9093 --storage.path /var/lib/prometheus'
level=info ts=2021-05-06T09:54:17.604Z caller=main.go:231 msg="Starting Alertmanager" version="(version=0.20.0, branch=HEAD, revision=f74be0400a6243d10bb53812d6fa408ad71ff32d)"
level=info ts=2021-05-06T09:54:17.605Z caller=main.go:232 build_context="(go=go1.13.5, user=root@00c3106655f8, date=20191211-14:13:14)"
level=info ts=2021-05-06T09:54:17.623Z caller=cluster.go:161 component=cluster msg="setting advertise address explicitly" addr=10.0.3.78 port=9094
level=info ts=2021-05-06T09:54:17.628Z caller=cluster.go:623 component=cluster msg="Waiting for gossip to settle..." interval=2s
level=info ts=2021-05-06T09:54:17.706Z caller=coordinator.go:119 component=configuration msg="Loading configuration file" file=/etc/prometheus/alertmanager.yml
level=info ts=2021-05-06T09:54:17.707Z caller=coordinator.go:131 component=configuration msg="Completed loading of configuration file" file=/etc/prometheus/alertmanager.yml
level=info ts=2021-05-06T09:54:17.716Z caller=main.go:497 msg=Listening address=10.0.3.78:9093
level=info ts=2021-05-06T09:54:19.629Z caller=cluster.go:648 component=cluster msg="gossip not settled" polls=0 before=0 now=1 elapsed=2.000228154s
level=info ts=2021-05-06T09:54:27.630Z caller=cluster.go:640 component=cluster msg="gossip settled; proceeding" elapsed=10.001328241s
root@piotr-kayobe:~# docker exec -ti prometheus_alertmanager bash
(prometheus-alertmanager)[prometheus@piotr-kayobe /]$ cat /etc/redhat-release
CentOS Stream release 8