Rename exercises dir

Name it instead "topics" so it won't be strange if some topics included "exercises" directory.
2022-08-02 01:51:39 +03:00
parent ea1d94d67b
commit 99c4e02ecf
235 changed files with 283 additions and 74 deletions
--- a/topics/containers/solutions/commit_image.md
+++ b/topics/containers/solutions/commit_image.md
@@ -0,0 +1,107 @@
+# Create Images on The Fly
+
+## Requirements
+
+Have at least one image locally (run `podman image ls` to confirm).<br>
+If you don't have images locally, run simply `podman pull nginx:alpine`.
+
+## Objectives
+
+1. Run a container using a web server image (e.g. httpd, nginx, ...)
+  - Bind container's port 80 to local port 80
+  - Run it in detached mode
+  - Name should nginx_container
+2. Verify the web server runs and accessible
+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
+
+```
+<html>
+<head>
+<title>It's a me</title>
+</head>
+<body>
+<h1>Mario</h1>
+</body>
+```
+
+4. Create an image out of the running container and call it "nginx_mario"
+5. Tag the container with "mario" tag
+6. Remove the original container (container_nginx) and verify it was removed
+7. Create a new container out of the image you've created (the same way as the original container)
+8. Run `curl 127.0.0.1:80`. What do you see?
+9. Run `podman diff` on the new image. Explain the output
+
+## Solution
+
+```
+# Run the container
+podman run --name nginx_container -d -p 80:80 nginx:alpine
+
+# Verify web server is running
+curl 127.0.0.1:80
+    #  <!DOCTYPE html>
+    #  <html>
+    #  <head>
+    #  <title>Welcome to nginx!</title>
+
+# Create index.html file
+cat <<EOT >>index.html
+<html>
+<head>
+<title>It's a me</title>
+</head>
+<body>
+<h1>Mario</h1>
+</body>
+EOT
+
+# Copy index.html to the container
+podman cp index.html nginx_container:/usr/share/nginx/html/index.html
+
+# Create a new image out of the running container
+podman commit nginx_container nginx_mario
+
+# Tag the image
+podman image ls
+# localhost/nginx_mario     latest   dc7ed2343521   52 seconds ago   25 MB
+podman tag dc7ed2343521 mario
+
+# Remove the container
+podman stop nginx_container
+podman rm nginx_container
+podman ps -a # no container 'nginx_container'
+
+# Create a container out of the image 
+podman run -d -p 80:80 nginx_mario
+
+# Check the container created from the new image
+curl 127.0.0.1:80
+#<html>
+#<head>
+#<title>It's a me</title>
+#</head>
+#<body>
+#<h1>Mario</h1>
+#</body>
+
+# Run diff
+podman diff nginx_mario
+
+C /etc
+C /etc/nginx/conf.d
+C /etc/nginx/conf.d/default.conf
+A /run/nginx.pid
+C /usr/share/nginx/html
+C /usr/share/nginx/html/index.html
+C /var/cache/nginx
+C /var
+C /var/cache
+A /var/cache/nginx/client_temp
+A /var/cache/nginx/fastcgi_temp
+A /var/cache/nginx/proxy_temp
+A /var/cache/nginx/scgi_temp
+A /var/cache/nginx/uwsgi_temp
+
+# We've set new index.html which explains why it's changed (C)
+# We also created the image while the web server is running, which explains all the files created under /var
+```