I know there have been many similar questions, but none of them are what I want. I'm following this because I specifically need 5.5, at least for now. My java project (which accesses mysql) is in a container I built with
docker build -t projectname-testing .
The Dockerfile is pretty standard, it just copies over a built tarball and extracts it to a specific folder. The CMD is a shell script run_dev_server.sh that just launches the server with dev configurations rather than production ones.
I created a percona docker container with the command given in the link with
docker run --name projectname-mysql-server -e MYSQL_ROOT_PASSWORD="" -d percona:5.5
So now the way I see it, just need the link the two as mentioned in the link:
docker run -p 3306:3306 --name projectname-local --link projectname-mysql-server projectname-testing
Which gives me
docker: Error response from daemon: Cannot link to a non running container: /projectname-mysql-server AS /projectname-local/projectname-mysql-server.
ERRO[0000] error getting events from daemon: net/http: request canceled
Which isn't very helpful and doesn't tell me what happened. Am I understanding this process wrong? What should I be doing?
First of all, I would recommend using the official Percona docker image from Docker Hub, instead of building your own image. The official image has a 5.5 version; https://hub.docker.com/_/percona/
You can either extend this image if you need specific changes (such as a custom configuration), for example;
FROM percona:5.5
COPY my-config.cnf /etc/mysql/conf.d/
Important: I notice you are publishing port 3306 (-p 3306:3306). Publishing a port makes it publicly accessible on the host's network-interface. You should only do this if you have external software that needs to connect to the database. If only your application needs access to the database, publishing the port is not needed, because containers can connect with eachother through the docker container-container network, which is "private" and not reachable from outside the host.
The --link option on the default network is a legacy option that is still around for backward compatibility, but should not be used for most situations. The --link option has a number of limitations;
legacy links are not dynamic; it's not possible to replace a linked container without re-creating all containers linked to that container
restarting a linked container can break the link, with no option to re-establish a link
legacy links are uni-directional
environment variables are shared between containers, which can easily lead to leaking (e.g.) credentials to other containers.
Docker 1.9 introduced custom docker networks, which allows
A simple example;
create a network for your application;
docker network create mynet
create a database container, and attach it to the network; there is no need to publish its ports for other containers to connect to it. (I'm using an nginx image here, just to illustrate the concept);
docker run -d --name db --network mynet nginx:alpine
create an "application" container and attach it to the same network; doing so
allows it to communicate with the db container over that network;
docker run -dit --name app --network mynet alpine sh
The application container can now connect to the db container, using its name
as hostname (db); to illustrate this, open a shell in the app container, install curl and connect to http://db:80;
docker exec -it app sh
/ # apk add --no-cache curl
fetch http://dl-cdn.alpinelinux.org/alpine/v3.5/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.5/community/x86_64/APKINDEX.tar.gz
(1/4) Installing ca-certificates (20161130-r1)
(2/4) Installing libssh2 (1.7.0-r2)
(3/4) Installing libcurl (7.52.1-r3)
(4/4) Installing curl (7.52.1-r3)
Executing busybox-1.25.1-r0.trigger
Executing ca-certificates-20161130-r1.trigger
OK: 5 MiB in 15 packages
/ # curl http://db:80
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
You can read more about networks (also how to dynamically attach and detach a container from a network) in the []"docker container networking" section of the documentation](https://docs.docker.com/engine/userguide/networking/)
Related
This might sound repeated question but it is not and this is a crazy bug I feel, however, let me quickly explain my setup:
A simple Spring bootstrap application that runs pretty well on my local and JDBC connection string in application.properites file is as follows.
spring.datasource.url=jdbc:mysql://minesql:3306/datamachine?serverTimezone=UTC
spring.datasource.username=root
spring.datasource.password=****
The docker running instances are:
I copied (with the help of docker cp command) the war file to alpine (unix container) and running it in interactive mode to test and it is throwing exception as it is unable to ping the mysql server. I am certain that the database configurations are fine and clueless why the springboot app is failing to connect to mysql container instance. Note, the mysql container does have "datamachine" database created manually.
This is the error reported:
Please help me understand what I am missing here or what is going wrong.
Just in-case if you wish to know how I started these containers.
For mysql:
docker run -d --name minesql -e MYSQL_ROOT_PASSWORD=**** -p 3306:3306 mysql
Running Java app from the alpine container and this is how I am starting the alpine,
docker run -it --name unix alpine
The interactive mode present me the bash prompt to run the spring-boot war file. (..and running the war file after installing the java 8 in alpine)
You have two docker containers which are running and connected via default bridge network. From docker bridge documentation
Containers on the default bridge network can only access each other by
IP addresses, unless you use the --link option, which is considered
legacy. On a user-defined bridge network, containers can resolve each
other by name or alias.
If you need the second container to be able to resolve the name minesql from inside, you need to create a user-defined network bridge and connect the docker container containers to that.
Create a new network using
docker network create my-net
And add your containers as specified here
Other alternative is to use docker-compose and avoid manual creation of bridge networks for name resolution. For production environment, that would be ideal.
I have a war file that uses the MySQL database in the backend.
I have deployed my war file in a docker container and I am able to ping this from my browser.
I want to connect my app with the MySQL database. This database exists on my host machine's localhost:3306
As I am unable to connect this from inside container's localhost, what I tried is,
I run a command docker inspect --format '{{ .NetworkSettings.IPAddress }}' 213be777a837
This command gave me an IP address 172.17.0.2. I went to MySQL server options and put this IP address in the bind field and restarted the server. After that, I have updated my projects database connection string with 172.17.0.2:3306
But it is not working. Could anyone please tell what I am missing?
I have also tried adding a new DB user with root#% and then run command allow all permission to 'root#%' but nothing worked.
Follow the steps:-
docker network create -d bridge --subnet 192.168.0.0/24 --gateway 192.168.0.1 dockernet
docker run -p 8082:8080 --network dockernet -d 6ab907c973d2
in your project set connection string : jdbc:mysql://host.docker.internal:3306/....
And then deploy.
tl;dr: Use 172.17.0.1:3306 if you're on Linux.
Longer description:
As I understand what you need to do is to connect from your Docker container to a host port. But what you have done is to try to bind the host process (MySQL) to the container networking interface. Not sure what the implications of a host process trying to bind to another host process network namespace, but IIUC your MySQL process should not be able to bind to that address.
When you start MySQL with default settings that bind it to 0.0.0.0 it's available for Docker containers through the Docker virtual bridge. Therefore, what you should do is to route your requests from the WAR process to the host process through that virtual bridge (if this is the networking mode you're using. If you have not changed any Docker networking settings, it should be). This is done by specifying the bridge gateway address as the MySQL address and the port it's started with.
You can get the bridge IP address by checking your network interfaces. When Docker is installed, it configures the virtual bridge by default, and that should show up as docker0 if you're on Linux. The IP address for this will most probably be 172.17.0.1. So your MySQL address from the container's point of view is jdbc:mysql://172.17.0.1:3306/....
1 - https://docs.docker.com/network/
2 - https://docs.docker.com/network/bridge/
From your question, I am assuming you both your war file and MySQL is deployed locally, and you want to connect them. One way to allow both containers that are locally deployed to talk to each other is by:
Create your own network docker network create <network-name>
Then when you run your war file and MySQL, deploy both of them using the --network. E.g.
War File: docker run --name war-file --network <network-name> <war file image>
MySQL: docker run --name mysql --network <network-name> <MySQL image>
After that, if you should be able to connect to your MySQL using mysql:3306 from inside your war file docker container, since they are both on the same custom network.
If you want to read up more about this, can take a look at docker documentation on network. (https://docs.docker.com/network/bridge/).
Your setup is fine. You just need to do this one change.
While running the application container (the one in which you are deploying your war file), you need to add following argument in its docker run command.
--net=host
Example:
docker run -itd -p 8082:8080 --net=host --name myapp myimage
With this change, you need not to change connection string as well. localhost:3306 would work fine. And you will be able to set up a connection with MySQL.
HI I have my web app running on my local machine and connected to Mysql workbench, I am now trying to dockerize the webapp. I can't seem to get it to connect to the DB on my local dev machine (I am running Docker Desktop for Windows), can anyone tell me how I would go about this? Here is what I have so far.
`docker run -it -e "CATALINA_OPTS=-Dspring.profiles.active=dev -DPARAM1=DEV" -p 8080:8080 -p 8005:8005 -p 8009:8009 -p 3306:3306 --add-host=docker:192.168.1.7 -v C:\myapp\trunk\target\myapp.war:/usr/local/tomcat/webapps/myapp.war --name waitapp tomcat:8.0.38-jre8`
after a few second, I run docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
2a1764dd9640 tomcat:8.0.38-jre8 "catalina.sh run" 2 minutes ago Up 2 minutes 0.0.0.0:3306->3306/tcp, 0.0.0.0:8005->8005/tcp, 0.0.0.0:8009->8009/tcp, 0.0.0.0:8080->8080/tcp waitapp
The container seems to be running, but I get a 404 Not found when I try the rest request, this is the same as I do when running from inside spring tool suite using built in tomcat server.
NOTE
I don't want to run a separate mysql container and link the two over a network, I just want to try get my newly created docker app to connect to my local DB MySQL.
As mentioned on this post, you can try 2 things:
Add gateway and use it from containers, like
docker network create -d bridge --subnet 192.168.0.0/24 --gateway 192.168.0.1 dockernet
In addition to your app container, run proxy (ngnix?) container, which will rout the calls to DB when required
This answer also show how can you obtain the host IP inside the docker container.
I am very newbie on all of this stuff of Docker. I've read on some sites that should exist one image per each application is running. This means that for run wordpress I would need at least 2 images: One for MySQL and another for Wordpress (and apache). In fact, the official Wordpress docker image does not include MySQL, requires an external connection.
But I've found some images in which MySQL is embedded on the image among wordpress and Apache. This gives you a more portable image because you only need that to deploy on any server. But if in the system is already running an image of docker you are wasting resources.
So, my question is if Wordpress should be runned on a same image with MySQL or not. And if not, how it should be done to move all data on MySQL to a different location.
The standart way is having a container per service, so you will have a container for MySQL and another one for Apache/PHP with the application.
If your are going to use the official MySQL container, and you want to persist the data, you just can to mount a volume from your host to the datadir in the mysql container:
$ docker run --name some-mysql -v /my/own/datadir:/var/lib/mysql -e MYSQL_ROOT_PASSWORD=my-secret-pw -d mysql:tag
This will create a folder in the /my/own/datadir path of your host with all the content of MySQL.
You can find more information about that in that link:
https://github.com/docker-library/docs/tree/master/mysql#where-to-store-data
I am trying to use my Scala-Akka application with my MySQL database on two separate Docker containers. I found out that Docker allows developers to link their application to their databases with the flag named --link. In my Dockerfiles in which I've used to create my images, I have add in EXPOSE 3306 8080 to it.
And this is how I run the containers:
docker run -d -p 3306:3306 --name mysql centos6mysql
docker run -d -p 8080:8080 --name scalaapp --link mysql:db centos6scala
After running the containers, I used docker ps and I am able to see the active containers. However, It seems like the application container is not using the database from the MySQL container. Anyone know what's wrong?
Linking in Docker allows network connections to be made between containers. Docker will define environmental variables to your linked containers for the URL, IP, port, and protocol. The names of these will be based on the name of your container. For instance:
DB_NAME=/web2/db
DB_PORT=tcp://172.17.0.5:5432
DB_PORT_5432_TCP=tcp://172.17.0.5:5432
DB_PORT_5432_TCP_PROTO=tcp
DB_PORT_5432_TCP_PORT=5432
DB_PORT_5432_TCP_ADDR=172.17.0.5
You can use these environmental variables to set up your Akka app container to connect to your DB container. However, you must manually configure the app container to do so. Docker will not make the connection for you automatically.
So, somewhere in your app, you will need to pass these values to your startup script, something that might look like:
./restcore --Ddb.default.db="jdbc:mysql//${DB_PORT_3306_TCP_ADDR}:${DB_PORT_3306_TCP_PORT"