Why isn't this cron job restarting my docker containers? - docker

I currently have two docker containers running with the names fe and be, which I can see with docker container list, which gives the output:
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
2f342ab21447 dockerimage1/blahblah "docker-entrypoint.s…" 3 days ago Up About an hour 0.0.0.0:80->3000/tcp, :::80->3000/tcp fe
12ea03925500 dockerimage2/blahblah "docker-entrypoint.s…" 3 days ago Up About an hour 0.0.0.0:2053->3001/tcp, :::2053->3001/tcp be
When I do crontab -e I can see my cron file:
# Jobs
10 2 * * * docker container restart fe && docker container restart be && echo 'Restarting Docker Container" > /root/clogs.txt
But it doesn't ever run, I tried checking the logs in syslog with grep CRON /var/log/syslog but i only see this repeated a bunch of times:
Feb 3 04:15:01 ubuntu CRON[106860]: (CRON) info (No MTA installed, discarding output)
Feb 3 04:16:01 ubuntu CRON[106869]: (user) CMD (/var/tmp/.update-logs/./History >/dev/null 2>&1 & disown)
I can tell that the cron job didn't work, because running docker container list again I can see that the status is still about an hour ago even when it was supposed to run 3 minutes ago.

Related

Docker save: No such image

When i run docker save nifi > nifi_backup.tar i get
Error response from daemon: No such image: nifi
When i run docker ps -a i got
$docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
a8796cbf6cb1 apache/nifi:1.9.2 "../scripts/start.sh" 11 months ago Exited (0) 33 minutes ago nifi
f4ecf6ca0d16 apache/nifi "../scripts/start.sh" 12 months ago Exited (0) 12 months ago nervous_poincare
9a68c235bb3a apache/nifi "../scripts/start.sh" 12 months ago Exited (0) 12 months ago jolly_mendel
d608287fe560 superset_superset "/entrypoint.sh" 2 years ago Up 27 hours (healthy) 0.0.0.0:8088->8088/tcp, :::8088->8088/tcp superset_superset_1
fcea620b1983 postgres:10 "docker-entrypoint.s…" 2 years ago Up 27 hours 0.0.0.0:5433->5432/tcp, :::5433->5432/tcp superset_postgres_1
380782e0a024 redis:3.2 "docker-entrypoint.s…" 2 years ago Up 27 hours 0.0.0.0:6379->6379/tcp, :::6379->6379/tcp superset_redis_1
Also, i cant start nifi image
if i run docker start nifi
it try to start about a minute, but then stop silently.
And there is no logs in result.
docker events says exit code = 0:
Maybe it has some relation for unavailable saving, so i inform about it too.
How to fix No such image in such a case?
Use the command docker images to see if there is an image named nifi. If not first build that image and than execute the command:
docker save nifi > nifi_backup.tar
It should not show the error No such image: nifi if the command docker images has an image named nifi.
As per documentation here, docker save command expects an image name, not a container. You're probably looking for docker export (export docs) command to achieve what you want.
The error about starting your container could be container-specific. As it exited already a year ago, maybe data is lost and the container cannot be started again. Using command docker events&, you can start the docker event listener in the background. This way you can obtain the hex value of this very start attempt and use it to search specific logs: docker logs <startId hex>. Maybe it can tell you more details about why the container did not properly start.

Docker fails to start container in detached mode

I have a Google VM that i am trying to start a container, that will start up a web server.
Since i want to be able to do other things with my terminal, i tried starting the container in detached mode.
This is what i typed:
sudo docker run -d -p 5001:5001 -v $(pwd):/mnt/translation -w="/mnt/translation" -e "TERM=xterm-color" f_translate
After this, i get back a string
9f8cc86f1e4a262bff8ff4f40f1a9036c686472b0ec3fded84980a60d26f6980
However, i couldn't connect to the server with docker exec.
I typed docker ps, to see all running containers, but there are none running.
EDIT:
This is the result of the docker ps -a:
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
9f8cc86f1e4a f_translate "/bin/bash" 28 minutes ago Exited (0) 28 minutes ago reverent_sinouss
i
faeec783edce f_translate "/bin/bash" 37 minutes ago Exited (0) 37 minutes ago adoring_chaum
1b96a5117aef f_translate "/bin/bash" 25 hours ago Exited (129) 24 hours ago xenodochial_noet
her
b364de5733b9 f_translate "/bin/bash" 41 hours ago Created nice_lumiere
5b042e459548 f_translate "/bin/bash" 41 hours ago Exited (0) 41 hours ago hardcore_elbakya
n
ea97b56d6822 f_translate "/bin/bash" 42 hours ago Created practical_lumier
e
2392c2b074a1 f_translate "/bin/bash" 42 hours ago Created hardcore_easley
e24c579f3094 f_translate "/bin/bash" 42 hours ago Created inspiring_merkle
3e4e412c551b f_translate "/bin/bash" 42 hours ago Created crazy_engelbart
8c198931c560 f_translate "/bin/bash" 42 hours ago Exited (0) 41 hours ago hardcore_cannon
67c5ad80b074 f_translate "/bin/bash" 42 hours ago Exited (0) 42 hours ago dreamy_margulis
b2b8773a9d77 a2f276018a81 "/bin/bash" 42 hours ago Exited (127) 42 hours ago jolly_greider
2c3c74ee073c a2f276018a81 "/bin/bash" 42 hours ago Exited (0) 42 hours ago pensive_chandras
ekhar
8563a35a96a7 cq_image "/bin/bash" 47 hours ago Exited (127) 46 hours ago gallant_rubin
44431d47308c cq_image "/bin/bash" 2 days ago Exited (129) 2 days ago peaceful_tesla
When i type docker logs 9f8cc86f1e4a262bff8ff4f40f1a9036c686472b0ec3fded84980a60d26f6980, i get nothing back.
You're run the container only with the bash command. This command returns exit code 0 immediately after the run. Then container finishing the work.
You have to run the container with some process that not returns the exit code right after a run.
This is a normal behavior that container finishing work when the job is finished with the success or with the error.
It seems as if there is a need to explain what containers do:
Containers have been designed to do one job. You tell them which command to execute and they will do that until it is done. Usually this is specified within a Dockerfile, in there you can define ENTRYPOINT and CMD to tell the container what to do when starting up. The container will then do that particular job until its done and then shut down.
And that's the case with your container. Your container executes the command /bin/bash as can be seen in the COMMAND column of the docker ps -a output.
So it actually is doing what it is supposed to do. It simply is executing the bash and since the command finished at that point it is shutting down, therefore you cannot connect to it anymore.
To be able to exec into a container it must be up and running, to do so you will have to change the entrypoint of your container. You can either do so by building a new image via a Dockerfile or you can overwrite it on the fly with the docker run command.
For debugging purposes, especially when wanting to exec into the container manually, you are most likely going to choose a command that does nothing but runs forever, perhaps something like sleep infinity.
TL;DR
With docker run after mentioning the image name you can define which command the container shall execute when starting up.
Execute the following command to ensure that your container does not exit immediately:
sudo docker run -d -p 5001:5001 -v $(pwd):/mnt/translation -w="/mnt/translation" -e "TERM=xterm-color" f_translate /bin/sh -c sleep infinity

What are the extra containers removed by "docker container prune" not listed by "docker ps -a"?

~/tmp/Counter1 ⌚ 10:18:24
$ docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
a46d397337e6 xx "echo ls" 20 hours ago Exited (0) 20 hours ago cranky_snyder
28d7339e57aa bf3a41a4ae8f "/bin/sh -c 'echo $e…" 21 hours ago Exited (0) 21 hours ago unruffled_archimedes
~/tmp/Counter1 ⌚ 10:18:27
$ docker container prune
WARNING! This will remove all stopped containers.
Are you sure you want to continue? [y/N] y
Deleted Containers:
a46d397337e68101fe983f354f87e8b4c0e086a4157dce7e7c4a2558105da525
28d7339e57aa222697851aaf4fdd36da2cbbc16f5fa9d4373ac499f8f8e15de5
a3cf99470e2f6e623c97db14249fa14e0afe9fd01eaac1ef6087ef98575f3690
5123adaa9fab02346c589aa23d3dd1eae1085138ec0e9cb23f388bbc5d668a92
45727d359ea4a036dd466f72fbaa750b135244d730b514c63a96518c71b4ad90
3260c4155074df32038ee31273e7059c1755fe6145b98d187ca006e1a39c3636
7d9c83d179932b1c97d43077cfe19fb6bcac123e295affcfa4cc791c43ddf513
3e32ee26e2e91ffc704cb27069cddf8f2f576ca407b4d8969e528c5a229cd855
46e8782774e2a6d5c8885fa5710134e1cc26e4abd75f29d883e4b32abec07d82
4728995a0162a033869e9fdd306435b1365309da643b2bcfa708c04839e7993c
Total reclaimed space: 0B
If I repeat the same thing, I see the right number of docker container removed. But after some time of playing with more containers, I again see a similar mismatch in the number of containers.
If I understand correctly, docker ps -a should show me all containers. Wonder what the other SHAs are from?

Why does the name column of the docker ps -a always different

I was just playing around with docker!!
Ran ps command -a option
docker run -a
C:\Users\sarkan1>docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
3d6db385321c busybox:1.24 "sleep 1000" 26 seconds ago Up 24 seconds lucid_ramanujan
e6acd65398b2 hello-world "/hello" 43 minutes ago Exited (0) 43 minutes ago nifty_brattain
c5576137580d hello-world "/hello" 4 days ago Exited (0) 4 days ago dreamy_aryabhata
2594fbf1fa82 hello-world "/hello" 4 days ago Exited (0) 4 days ago nostalgic_hopper
c0102bc64c45 hello-world "/hello" 4 days ago Exited (0) 4 days ago vibrant_khorana
c4af79ea96e9 hello-world "/hello" 4 days ago Exited (0) 4 days ago cranky_heyrovsky
Questions :
Why did I get the values in the names column always different? I ran the same container I guess!!
What is command column? Does the slash before the hello (/hello) have any significance?
Unless you launch a container specifying its name (docker run --name), docker will generate one for you.
That is easier than referencing said container with its ID.
You can then make docker commands with its (generated) name instead.
See more at "How does Docker generate default container names?".
(and the source code: moby/moby pkg/namesgenerator/names-generator.go)
The command column is the full command executed by the container: once this command stops, the container stops.
That command is specified in the docker image, and is a combination of:
Dockerfile ENTRYPOINT
Dockerfile CMD
(See "difference between cmd and entrypoint in dockefile")
Basically they are random container names generated!! The left and right parts of the names are hardcoded and can be found in
https://github.com/moby/moby/blob/master/pkg/namesgenerator/names-generator.go
Docker engine generates it if default name is not provided when you create a new docker container.

dokku error: cannot find entity for app

trying to restart dokku after a server reboot. Everything I do (redis:link, dokku deploy, pushing a new version of the app from my computer..) fails with a could not find entity error message.
2014/07/16 09:02:45 Error: Could not find entity for domain_freek
I feel like it might have something to do with the docker containers or images, so I tried restarting the latest docker container for the app, but no dice. Dokku still gives me a could not find entity error.
root#domainfreek3:/home/dokku/domain_freek# docker restart `cat /home/dokku/domain_freek/CONTAINER`
b5823fa2703f
root#domainfreek3:/home/dokku/domain_freek# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
b5823fa2703f dokku/domain_freek:latest /bin/bash -c '/start 6 minutes ago Up 10 seconds 5000/tcp compassionate_tesla
f6d165a32e92 2c035b41f308 /bin/bash -c '/start 27 minutes ago Up 25 minutes 5000/tcp boring_heisenberg
96c33f5458de jezdez/redis:latest /usr/bin/redis-serve 27 minutes ago Up 27 minutes 6379/tcp redis_domain_freek
f76d9f0d944b postgresql/domain_freek:latest /usr/bin/start_pgsql 24 hours ago Up 18 hours 0.0.0.0:49153->5432/tcp sick_einstein
root#domainfreek3:/home/dokku/domain_freek# dokku deploy domain_freek
-----> Checking status of PostgreSQL
Found image postgresql/domain_freek database
Checking status... ok.
2014/07/16 09:04:47 Error: Could not find entity for domain_freek
root#domainfreek3:/home/dokku/domain_freek# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
f6d165a32e92 2c035b41f308 /bin/bash -c '/start 27 minutes ago Up 25 minutes 5000/tcp boring_heisenberg
96c33f5458de jezdez/redis:latest /usr/bin/redis-serve 27 minutes ago Up 27 minutes 6379/tcp redis_domain_freek
f76d9f0d944b postgresql/domain_freek:latest /usr/bin/start_pgsql 24 hours ago Up 18 hours 0.0.0.0:49153->5432/tcp sick_einstein
Any advice would be appreciated!

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