108 lines
2.6 KiB
Markdown
108 lines
2.6 KiB
Markdown
# Create Images on The Fly
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## Requirements
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Have at least one image locally (run `podman image ls` to confirm).<br>
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If you don't have images locally, run simply `podman pull nginx:alpine`.
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## Objectives
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1. Run a container using a web server image (e.g. httpd, nginx, ...)
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- Bind container's port 80 to local port 80
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- Run it in detached mode
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- Name should nginx_container
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2. Verify the web server runs and accessible
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3. Create an HTML file with the following content and copy it to the container to the container to path where it will be accessed as an index file
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```
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<html>
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<head>
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<title>It's a me</title>
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</head>
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<body>
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<h1>Mario</h1>
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</body>
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```
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4. Create an image out of the running container and call it "nginx_mario"
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5. Tag the container with "mario" tag
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6. Remove the original container (container_nginx) and verify it was removed
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7. Create a new container out of the image you've created (the same way as the original container)
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8. Run `curl 127.0.0.1:80`. What do you see?
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9. Run `podman diff` on the new image. Explain the output
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## Solution
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```
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# Run the container
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podman run --name nginx_container -d -p 80:80 nginx:alpine
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# Verify web server is running
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curl 127.0.0.1:80
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# <!DOCTYPE html>
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# <html>
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# <head>
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# <title>Welcome to nginx!</title>
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# Create index.html file
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cat <<EOT >>index.html
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<html>
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<head>
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<title>It's a me</title>
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</head>
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<body>
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<h1>Mario</h1>
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</body>
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EOT
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# Copy index.html to the container
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podman cp index.html nginx_container:/usr/share/nginx/html/index.html
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# Create a new image out of the running container
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podman commit nginx_container nginx_mario
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# Tag the image
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podman image ls
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# localhost/nginx_mario latest dc7ed2343521 52 seconds ago 25 MB
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podman tag dc7ed2343521 mario
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# Remove the container
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podman stop nginx_container
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podman rm nginx_container
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podman ps -a # no container 'nginx_container'
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# Create a container out of the image
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podman run -d -p 80:80 nginx_mario
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# Check the container created from the new image
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curl 127.0.0.1:80
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#<html>
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#<head>
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#<title>It's a me</title>
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#</head>
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#<body>
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#<h1>Mario</h1>
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#</body>
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# Run diff
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podman diff nginx_mario
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C /etc
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C /etc/nginx/conf.d
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C /etc/nginx/conf.d/default.conf
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A /run/nginx.pid
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C /usr/share/nginx/html
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C /usr/share/nginx/html/index.html
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C /var/cache/nginx
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C /var
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C /var/cache
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A /var/cache/nginx/client_temp
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A /var/cache/nginx/fastcgi_temp
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A /var/cache/nginx/proxy_temp
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A /var/cache/nginx/scgi_temp
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A /var/cache/nginx/uwsgi_temp
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# We've set new index.html which explains why it's changed (C)
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# We also created the image while the web server is running, which explains all the files created under /var
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```
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