12

I am using the docker-compose.

Some commands like up -d service_name or start service_name are returning right away and this is pretty useful if you don't want the containers running to depend on the state of the shell, like they do with regular up service_name. The one use-case is running it from some kind of continious integration/delivery server.

But this way of running/starting services does not provide any feedback about the actual state of the service afterwards.

The Docker Compose CLI reference for up command does mention the relevant option, but, as for version 1.7.1, it is mutually exclusive with -d:

--abort-on-container-exit  Stops all containers if any container was stopped.
                           *Incompatible with -d.*

Can I somehow manually check that the container is indeed working and haven't stopped because of some error?

5
  • docker-compose ps -q <service_name> will display the container ID no matter it's running or not, as long as it was created.
  • docker ps shows only those that are actually running.

Let's combine these two commands:

if [ -z `docker ps -q --no-trunc | grep $(docker-compose ps -q <service_name>)` ]; then
  echo "No, it's not running."
else
  echo "Yes, it's running."
fi

docker ps shows short version of IDs by default, so we need to specify --no-trunc flag.

  • Nice one, and it also addresses problem with current answer that was stated in comments. Marking this as a new answer. – Ivan Kolmychek Oct 16 '18 at 6:01
  • If you are using a restart policy you also need to filter it to only include running containers (rather than ones in a restarting state): docker ps -q -f "status=running" --no-trunc | grep $(docker-compose ps -q <service_name>) – Max Oct 20 '18 at 21:58
10

As for version 1.7.1, there are no such commands built-in.

Instead, the exec can be used in similar way.

When you run it for the service which has some containers up it will run ok:

~/apperture-science $ docker-compose exec chell echo 'Still alive!'
Still alive!
~/apperture-science $ echo $?
0

But when you run it for the service which has no running service containers, it will show an error:

~/apperture-science $ docker-compose exec glados echo "Still alive!"
ERROR: No container found for apperture-science-glados_1
~/apperture-science $ echo $?
1

So, it can be used in order to check, is there any "alive" containers for given service.

5

You can run:

docker-compose ps -q service-name

And you will get the id of the container if service-name is running. Something like:

18a04e61240d8ffaf4dc3f021effe9e951572ef0cb31da7ce6118f681f585c7f

If the service is not running the output is empty, so if you want to use this in a script you can do something like:

IS_RUNNING=`docker-compose ps -q service-name`
if [[ "$IS_RUNNING" != "" ]]; then
    echo "The service is running!!!"
fi
  • Yes, that works too. Marked this as answer now. – Ivan Kolmychek Feb 5 '18 at 13:06
  • 9
    This doesn't tell you if the container is running or not, just if it exists or not. Try doing docker-compose up then Ctrl-C. docker-compose ps should then show that the container states are not "Up", but docker-compose ps -q service-name still gives you an id. – djanderson Feb 22 '18 at 22:13
2

I had a similar need. However, I have a restart: always in my environment. So it can be a bit tricky to detect if something is crashing and restarting in a loop.

I made an Icinga/Nagios check to also compare the created and start times. Maybe it's useful to someone else down the line:

#!/usr/bin/env python
from __future__ import print_function
import argparse
from datetime import timedelta
from datetime import datetime
import sys

from dateutil.parser import parse as parse_date
import docker
import pytz
parser = argparse.ArgumentParser()
parser.add_argument("compose_project",
                    help="The name of the docker-compose project")
parser.add_argument("compose_service",
                    help="The name of the docker-compose service")
args = vars(parser.parse_args())

client = docker.from_env()
service_containers = client.containers.list(filters={
    "label": [
        "com.docker.compose.oneoff=False",
        "com.docker.compose.project={}".format(args["compose_project"]),
        "com.docker.compose.service={}".format(args["compose_service"])
    ]})

if len(service_containers) == 0:
    print("CRITICAL: project({})/service({}) doesn't exist!".format(
        args["compose_project"], args["compose_service"]))
    sys.exit(2)
elif len(service_containers) > 1:
    print("CRITICAL: project({})/service({}) has more than 1 "
          "container!".format(
              args["compose_project"], args["compose_service"]))
    sys.exit(2)

service_container = service_containers[0]
created_at = parse_date(service_container.attrs['Created'])
status = service_container.attrs['State']['Status']
started_at = parse_date(service_container.attrs['State']['StartedAt'])
now = datetime.utcnow().replace(tzinfo=pytz.utc)
uptime = now - started_at

if status in ['stopped', 'exited', 'dead']:
    print("CRITICAL: project({})/service({}) is status={}".format(
        args["compose_project"], args["compose_service"], status))
    sys.exit(2)

if (started_at - created_at) > timedelta(minutes=5):
    if uptime < timedelta(seconds=5):
        print("CRITICAL: project({})/service({}) appears to be "
              "crash-looping".format(
                  args["compose_project"], args["compose_service"]))
        sys.exit(2)

if status == "restarting":
    print("WARNING: project({})/service({}) is restarting".format(
        args["compose_project"], args["compose_service"]))
    sys.exit(1)

print ("OK: project({})/service({}) is up for {}".format(
    args["compose_project"], args["compose_service"], uptime
))
sys.exit(0)
0

If you assume this scenario:

  • containers either start and run indefinitely or stop immediately with an error code (i.e. for missing configuration)
  • you do the check only once after docker-compose up -d returns

you can check if there is any stopped container due to an error with: docker ps -a | grep 'Exited (255)'.

This check works correctly even in case of containers which are expected to stop immediately with no error (i.e. data containers), as their status (from docker ps -a) is marked as Exited (0).

For example, in our docker-compose.yml, we start our containers with:

command: sh -c 'node dotenv_check.js && pm2 start --no-daemon src/worker.js --watch'

For php-fpm, we use a similar command:

command: >-
  sh -c '
  set -e;
  for PROJECT in frontend backend; do
    cd /var/www/$${PROJECT};
    php dotenv_check.php;
  done;
  php-fpm
  '

The dotenv_check.js and dotenv_check.php are scripts which exit with an error code in case a required env variable is missing.

The set -e command, tells the script to stop on error, which, in turns, will immediately stop the container. About set-e

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