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HW3 – Node.js server in Docker

In this task, my objective was to create a configuration of Node.js server, that could run in a Docker container.

Server

The server is a simple Node.js server, which just responds "Hello, {name}" to any request in format /[a-zA-Z0-9_], otherwise, it answers 404 NOT FOUND.

Dockerfile

The Dockerfile defines how the server will be created. I’m using base image node:19-alpine3.16, which already has Node.js installed, so the server can be run just with node server.js.

To be able to run the server, I created a new work directory /server, in which I copy the server.js file which can be run.

As the server will be running on port 8888, I have to expose this port.

Running

Firstly, I have to build an image from my Dockerfile.

kvetinac97@e-79-148 src % docker build -t hw03 .
[+] Building 1.3s (8/8) FINISHED
 => [internal] load build definition from Dockerfile                                                                                                                   0.0s
 => => transferring dockerfile: 36B                                                                                                                                    0.0s
 => [internal] load .dockerignore                                                                                                                                      0.0s
 => => transferring context: 2B                                                                                                                                        0.0s
 => [internal] load metadata for docker.io/library/node:19-alpine3.16                                                                                                  1.2s
 => [internal] load build context                                                                                                                                      0.0s
 => => transferring context: 31B                                                                                                                                       0.0s
 => [1/3] FROM docker.io/library/node:19-alpine3.16@sha256:f5b2f5862dec95bd1d83991efe71470b31607e915b7d3495f73e078726a0ab04                                            0.0s
 => CACHED [2/3] WORKDIR /server                                                                                                                                       0.0s
 => CACHED [3/3] COPY server.js .                                                                                                                                      0.0s
 => exporting to image                                                                                                                                                 0.0s
 => => exporting layers                                                                                                                                                0.0s
 => => writing image sha256:e63e8d6b1acabf492d00e77ce0db94140861d88e2058ce44e7611ec6b94f8a94                                                                           0.0s
 => => naming to docker.io/library/hw03

Then, I create and start a new container from that image:

kvetinac97@e-79-148 src % docker run -p 8080:8888 --name hw03_container hw03
Server running at http://0.0.0.0:8888/

Now, let’s check the container in container list:

kvetinac97@e-79-148 src % docker container ls
CONTAINER ID   IMAGE     COMMAND                  CREATED              STATUS              PORTS                    NAMES
75c22343b765   hw03      "docker-entrypoint.s…"   About a minute ago   Up About a minute   0.0.0.0:8080->8888/tcp   hw03_container

And let’s send some requests to the server:

kvetinac97@e-79-148 src % curl 127.0.0.1:8080/John
Hello John
kvetinac97@e-79-148 src % curl 127.0.0.1:8080/Alice
Hello Alice
kvetinac97@e-79-148 src % curl 127.0.0.1:8080/Bob
Hello Bob

kvetinac97@e-79-148 src % curl -v 127.0.0.1:8080/another/site
*   Trying 127.0.0.1:8080...
* Connected to 127.0.0.1 (127.0.0.1) port 8080 (#0)
> GET /another/site HTTP/1.1
> Host: 127.0.0.1:8080
> User-Agent: curl/7.86.0
> Accept: */*
>
* Mark bundle as not supporting multiuse
< HTTP/1.1 404 Not Found
< Date: Mon, 06 Mar 2023 12:49:45 GMT
< Connection: keep-alive
< Keep-Alive: timeout=5
< Content-Length: 0
<
* Connection #0 to host 127.0.0.1 left intact

And check that the commands have been run successfully in the server log:

Response to: John
Response to: Alice
Response to: Bob

Finally, let’s stop the Docker container.

kvetinac97@e-79-148 src % docker stop hw03_container
hw03_container