Grafana on Docker - docker

I am using docker to run prometheus, grafana and node exporter. I am trying to use named volumes and I am having some issues with that. My docker-compose code is:
version: "3.7"
volumes:
grafana_ini:
prometheus_data:
grafana_data:
dashboards_data:
services:
grafana:
build: ./grafana
volumes:
- grafana_ini:/etc/grafana/grafana.ini
- grafana_data:/etc/grafana/provisioning/datasources/datasource.yml
- dashboards_data:/etc/grafana/provisioning/dashboards
- ./dashboards/linux_dashboard.json:/etc/grafana/provisioning/dashboards/linux_dashboard.json
ports:
- 3000:3000
links:
- prometheus
prometheus:
build: ./prometheus
volumes:
- prometheus_data:/etc/prometheus/prometheus.yml
ports:
- 9090:9090
node-exporter:
image: prom/node-exporter:latest
container_name: node_exporter
restart: unless-stopped
expose:
- 9100
and my dockerfile for grafana is:
FROM grafana/grafana:latest
COPY ./Ini/grafana.ini /etc/grafana/grafana.ini
COPY datasource.yml /etc/grafana/provisioning/datasources/datasource.yml
COPY ./dashboards/dashboard.yml /etc/grafana/provisioning/dashboards
COPY ./dashboards/server/linux_dashboard.json /etc/grafana/provisioning/dashboards
COPY ./dashboards/server/windows_dashboard.json /etc/grafana/provisioning/dashboards
EXPOSE 3000:3000
and I am getting this error while building it
ERROR: for 2022_grafana_1 Cannot create container for service grafana: source /var/lib/docker/overlay2/4ac5b487fd7fd52491b250c4afaa433801420cd907ac4a70ddb4589fdb99368b/merged/etc/grafana/grafana.ini is not directory
ERROR: for grafana Cannot create container for service grafana: source /var/lib/docker/overlay2/4ac5b487fd7fd52491b250c4afaa433801420cd907ac4a70ddb4589fdb99368b/merged/etc/grafana/grafana.ini is not directory
Can anybody please help me.

It looks like there are some problems with the volume configuration in your Grafana container:
First, I think this was simply a typo in your question:
- grafana_ini:/etc/grafana/grafana.inianticipated location in container
I suspect that you were actually intending this:
- grafana_ini:/etc/grafana/grafana.ini
Which doesn't make any sense: grafana.ini is a file, but a volume is
a directory. Docker won't allow you to mount a directory on top of a
file, hence the error:
ERROR: .../etc/grafana/grafana.ini is not directory
You have the same problem with the grafana_data volume, which you're
attempting to mount on top of datasource.yml:
- grafana_data:/etc/grafana/provisioning/datasources/datasource.yml
I think you may be approaching this configuration in the wrong way;
you may want to read through these documents:
https://grafana.com/docs/grafana/latest/installation/docker/
https://grafana.com/docs/grafana/latest/administration/configure-docker/
https://grafana.com/docs/grafana/latest/administration/provisioning/
It is possible to configure Grafana (and Prometheus!) using only bind
mounts and environment variables (this includes installing plugin,
data sources, and dashboards), so you don't need to build your own
custom images.
Unrelated to this particular problem, there are some other things in
your docker-compose.yml that are worth changing. You should no
longer be using the links directive...
links:
- prometheus
...because Docker maintains DNS for you automatically; your containers
can refer to each other by name with no additional configuration.

Related

How can I store data with Docker Compose containers?

I have this docker-compose.yml, and I have a Postgres database and Grafana running over it to make queries on data.
version: "3"
services:
db:
image: postgres
container_name: db
ports:
- "5432:5432"
environment:
- POSTGRES_PASSWORD=my_secret_password
grafana:
image: grafana/grafana
container_name: grafana
depends_on:
- db
ports:
- "3000:3000"
I start this compose with the command docker-compose up, but then, if I want to not lose any data, I must run docker-compose stop instead of docker-compose down.
I also read about docker commit, but "the commit operation will not include any data contained in volumes mounted inside the container", so I guess it's no use for my needs.
What's the proper way to store the created volumes and reusing them with commands up/down, so even when recreating the containers? I must use some sort of backup methods provided by every image (so, for example, a DB export for Postgres, and some other type of export for Grafana), or there is a way to do this inside docker-compose.yml?
EDIT:
I also read about volumes, but is there a standard way to store everything?
In the link provided by #DannyB, setting volumes to ./postgres-data:/var/lib/postgresql instead of ./postgres-data:/var/lib/postgresql/data caused the container to not store the actual folder.
My question is: every image must follow a particular pattern like the one above? This path to data to store the volume underlying is present in every Docker image Readme? Or is there something like:
volumes:
- ./my_image_root:/
Docker provides for volumes as the way to persist volumes between container invocations and to share data between containers.
They are quite simple to declare and use in compose files:
volumes:
postgres:
grafana:
services:
db:
image: postgres
ports:
- "5432:5432"
environment:
- POSTGRES_PASSWORD=my_secret_password
volumes:
- postgres:/var/lib/postgresql/data
grafana:
image: grafana/grafana
depends_on:
- db
volumes:
- grafana:/var/lib/grafana
ports:
- "3000:3000"
Optionally, you can also set a local directory as your container volume
with the added convince of having the files easily accessible not only from inside the container. This is especially helpful for mounting specific config files to their location in the container, you can edit the file locally like any other file restart the container with the updated configuration (certificates and other similar files also make good use of this option). And you do that like so:
volumes:
- /home/myusername/postgres_data/:/var/lib/postgresql/data/
PS. I have omitted the container_name and version directives from this compose.yml because (as of docker 20.10), the docker compose spec determines version automatically, and docker compose exposes enough functionality that accessing the containers directly using short names isn't necessary usually.

Docker shared volume is not readable for a container after changing volume contents

I have got following compose file where i'm sharing some generated html data from Jenkins container to the host drive and reading this data by Nginx container from the host drive. I'm using Ubuntu Server 18.04 on AWS.
The problem is that I can read contents of the jenkins/workspace/allure-report only once. After updating of the html data it becomes inaccessible for Nginx and it throws 403 status code.
I tried all the possible solutions but nothing works. The only ugly solution is to restart Nginx container after every html data updating. I don't like this way and looking for some inbuilt docker features to resolve this.
What didn't help: sharing volume straight between containers without using docker host drive, using rslave option, using docker separate volume that can be used as buffer between the two containers... I believe it should be much more easier!
version: '2'
services:
jenkins:
container_name: jenkins
image: "jenkins/jenkins"
ports:
- "8088:8080"
- "50000:50000"
env_file:
- variables.env
volumes:
- ./jenkins:/var/jenkins_home
selenoid:
container_name: selenoid
network_mode: bridge
image: "aerokube/selenoid"
# default directory for browsers.json is /etc/selenoid/
command: -listen :4444 -conf /etc/selenoid/browsers.json -video-output-dir /opt/selenoid/video/ -timeout 3m
ports:
- "4444:4444"
env_file:
- variables.env
volumes:
- $PWD:/etc/selenoid/ # assumed current dir contains browsers.json
- /var/run/docker.sock:/var/run/docker.sock
selenoid-ui:
container_name: selenoid-ui
network_mode: bridge
image: "aerokube/selenoid-ui"
links:
- selenoid
ports:
- "8080:8080"
env_file:
- variables.env
command: ["--selenoid-uri", "http://selenoid:4444"]
nginx:
container_name: nginx
image: "nginx"
ports:
- "80:80"
volumes:
- ./jenkins/workspace/allure-report:/usr/share/nginx/html:ro,rslave
Found the solution: the easiest way to get access to the dynamic data is to use volumes_from in that container you want to look from.
When I configured my compose file like that I faced another issue - the 403 status has gone but the data was static. But that was my fault, I didn't use "cp -r " command correctly so my data has been copied only once.

Share dir between host and multiple containers using docker-compose

I have 2 containers in a compose files,that i want to serve app static files through nginx.
I have read this: https://stackoverflow.com/a/43560093/7522096 and want to use host dir to share between app container and nginx container, for some reason I dont want to use named volume.
===
Using a host directory Alternately you can use a directory on the host
and mount that into the containers. This has the advantage of you
being able to work directly on the files using your tools outside of
Docker (such as your GUI text editor and other tools).
It's the same, except you don't define a volume in Docker, instead
mounting the external directory.
version: '3'
services:
nginx:
volumes:
- ./assets:/var/lib/assets
asset:
volumes:
- ./assets:/var/lib/assets
===
My docker-compose file:
version: "3.7"
services:
app:
container_name: app
restart: always
ports:
- 8888:8888
env_file:
- ./env/app.env
image: registry.gitlab.com/app/development
volumes:
- ./public/app/:/usr/app/static/
- app-log:/root/.pm2
nginx:
container_name: nginx
image: 'nginx:1.16-alpine'
restart: always
ports:
- 80:80
- 443:443
volumes:
- /home/devops/config/:/etc/nginx/conf.d/:ro
- /home/devops/ssl:/etc/nginx/ssl:ro
- ./public/app/:/etc/nginx/public/app/
depends_on:
- app
volumes:
# app-public:
app-log:
Yet when i do this in my compose, the dir always come up empty on nginx, and the static files in my app container got disappear too.
Please help, I tried a lot of ways but can not figure it out.
Thanks.
During the initialization of the container docker will bind the ./public/app directory on the host with the /usr/app/static/ directory in the container.
If the ./public/app does not exist it will be created. The bind is from the host to the container, meaning that the content of ./public/app folder is
reflected (copied) into the container and not viceversa. That's why after the initialization the static app directory is empty.
If my understanding is correct your goal is to share the application files between the app container and nginx.
Taken into consideration the above the only solution is to create the files in the volume after the volume is created. Here is an example for the relevant parts:
version: "3"
services:
app:
image: ubuntu
volumes:
- ./public/app/:/usr/app/static_copy/
entrypoint: /bin/bash
command: >
-c "mkdir /usr/app/static;
touch /usr/app/static/shared_file;
mv /usr/app/static/* /usr/app/static_copy;
rm -r /usr/app/static;
ln -sfT /usr/app/static_copy/ /usr/app/static;
exec sleep infinity"
nginx:
image: 'nginx:1.16-alpine'
volumes:
- ./public/app/:/etc/nginx/public/app/
depends_on:
- app
This will move the static files to the static_copy directory and link back those files to /usr/app/static. Those files will be shared with the host (public/app director)
and nginx container (/etc/nginx/public/app/). Adapt it to fit your needs.
In alternative you can of course use named volumes.
Hope it helps

docker-compose error: volume is needed not string

I'm starting to learn about docker and I want to run a nextcloud using the docker-compose file.
The docker-compose file I am using. I only specified the volumes which are folders I have created.
version: ‘2’
volumes:
nextcloud:/home/ahmed/Desktop/docker-storage/nextcloud
db:/home/ahmed/Desktop/docker-storage/db
services:
db:
image: mariadb
restart: always
volumes:
- db:/var/lib/mysql
environment:
- MYSQL_ROOT_PASSWORD= anha1985
- MYSQL_PASSWORD= anha1985
- MYSQL_DATABASE=nextcloud
- MYSQL_USER=nextcloud
app:
image: nextcloud
ports:
- 8080:80
links:
- db
volumes:
- nextcloud:/var/www/html
restart: always
The error message that I have is.
ERROR: In file ‘./docker-compose.yml’, volume must be a mapping, not a string.
Please advice me.
The volume section at the top of the compose file is for defining named volumes. If you only have host volumes with an absolute or relative path, then you would only define the volume within each service. For a named volume, you would define it both at the top level and within each service that needs access to the named volume. These two sections, while named similarly, have a different syntax.
See this documentation for the volume section at the top level of the yml file: https://docs.docker.com/compose/compose-file/#volume-configuration-reference
And this documentation applies to the volume section within each service: https://docs.docker.com/compose/compose-file/#volumes

Docker: Write to disk of linked container

I have a Docker container that runs a simple web application. That container is linked to two other containers by Docker Compose with the following docker-compose.yml file:
version: '2'
services:
mongo_service:
image: mongo
command: mongod
ports:
- '27017:27017'
tomcat_service:
image: 'bitnami/tomcat:latest'
ports:
- '8080:8080'
web:
# gain access to linked containers
links:
- mongo_service
- tomcat_service
# explicitly declare service dependencies
depends_on:
- mongo_service
- tomcat_service
# set environment variables
environment:
PYTHONUNBUFFERED: 'true'
# use the image from the Dockerfile in the cwd
build: .
ports:
- '8000:8000'
Once the web container starts, I want to write some content to /bitnami/tomcat/data/ on the tomcat_service container. I tried just writing to that disk location from within the web container but am getting an exception:
No such file or directory: '/bitnami/tomcat/data/'
Does anyone know what I can do to be able to write to the tomcat_service container from the web container? I'd be very grateful for any advice others can offer on this question!
you have to use docker volumes if you want one service to write to other service. If web writes to someFolderName the same file will exist in the tomcat_service.
version: '2'
services:
tomcat_service:
image: 'bitnami/tomcat:latest'
volumes:
- my_shared_data:/bitnami/tomcat/data/
web:
volumes:
- my_shared_data:/someFolderName
volumes:
my_shared_data:
Data in volumes persist and they will be available even next time you re-create docker containers. You should always use docker volumes when writing some data in docker containers.

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