Unterschiede

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--- admin_grundlagen:docker:build [2026/05/30 17:25] – [Docker Image aktualisieren] peter_rossbach2
+++ admin_grundlagen:docker:build [2026/10/09 20:58] (aktuell) – ingo_wichmann
@@ Zeile 1: / Zeile 1: @@
-====== erstes Docker Image selbst bauen ======
+====== Docker Image selbst bauen ======
 ===== Pakete =====
 === Rocky Linux (10): ===
@@ Zeile 8: / Zeile 8: @@
   apt install -y debootstrap
-===== Image bauen =====
+===== Image aus tar-Archiv bauen =====
 (( anders als das Image aus https://hub.docker.com/_/debian ist dieses Image nicht reproduzierbar ))
+  sudo debootstrap --variant=minbase trixie ./debian http://deb.debian.org/debian
+(( im Linuxhotel-Netzwerk lokalen Spiegelserver benutzen:
   sudo debootstrap --variant=minbase trixie ./debian http://debian/debian
+))
 (( unter RockyLinux ''--keyring'' ergänzen:
   sudo debootstrap --variant=minbase --keyring=/usr/share/keyrings/debian-archive-trixie-stable.gpg trixie ./debian http://debian.linuxhotel.de/debian
@@ Zeile 21: / Zeile 24: @@
 ==== testen ====
-  docker container run ingo/debian echo hello world
+  docker container run --rm ingo/debian apt update
--> ''hello world''
+-> Ausgabe von ''apt update'' ok?
-====== Dockerfile - Docker Images weiterbauen ======
-  mkdir nginx
-  cd nginx
-++++ podman |
-bei Podman darf die Datei auch ''Containerfile'' heißen
-++++
-<file txt Dockerfile>
-FROM ingo/debian:trixie
-ENV DEBIAN_FRONTEND=noninteractive
+(( Wenn nicht:
-RUN set -eux; \
+  docker container run --rm ingo/debian cat /etc/resolv.conf
-  apt-get -qq update; \
+-> Nameserver kommt von Docker, nicht aus dem Image
-  apt-get install -y --no-install-recommends nginx
-RUN echo 'A warm welcome from your Dockerfile' > /var/www/html/index.html
-EXPOSE 80
-ENTRYPOINT ["/usr/sbin/nginx", "-g", "daemon off;"]
-ARG REFRESHED_AT=2026-01-07
+Ändern mit:
-LABEL version="0.0.1"
+  docker container run --rm --dns 192.168.1.5 ingo/debian:local cat /etc/resolv.conf
-LABEL maintainer="me@example.com"
+  docker container run --rm --dns 192.168.1.5 ingo/debian:local apt update
-LABEL org.opencontainers.image.authors="me@example.com"
+))
-LABEL org.opencontainers.image.created=$REFRESHED_AT
-</file> (( https://docs.docker.com/reference/dockerfile/ ))
-++++ ENTRYPOINT / CMD / run-Command |
-^ ''ENTRYPOINT'' ^ ''CMD'' ^ run-Command ^ ausgeführt wird ^
-|<code>["script.sh"]</code>|                          |                        | <code>script.sh</code> |
-|<code>["script.sh"]</code>|                          | <code>/bin/dash</code> | <code>script.sh /bin/dash</code> |
-|<code>["script.sh"]</code>| <code>["httpd"]</code>   |                        | <code>script.sh httpd</code> |
-|<code>["script.sh"]</code>| <code>["httpd"]</code>   | <code>/bin/dash</code> | <code>script.sh /bin/dash</code> |
-|                          | <code>["/bin/sh"]</code> |                        | <code>/bin/sh</code>   |
-|                          | <code>["/bin/sh"]</code> | <code>/bin/dash</code> | <code>/bin/dash</code> |
-|                          |                          |                        | <code>/bin/bash</code> (( https://docs.docker.com/reference/dockerfile/#understand-how-cmd-and-entrypoint-interact sagt ''error, not allowed''. Docker Version 20.10.24+dfsg1 hat ''bash'' ausgeführt.)) |
-++++
-Image mit den Erweiterungen aus dem ''Dockerfile'' bauen:
-  docker build -t='ingo/nginx:0.0.1' .
-Image anzeigen:
-  docker image ls ingo/nginx:0.0.1
--> id rauskopieren (z.B. ''5879d7773761'')
-Image taggen:
-  docker image tag 5879d7773761 ingo/nginx:latest
-Container starten:
-  docker container run -d -p 80:80 --name my_nginx ingo/nginx
-Zugriff auf nginx testen:
-  curl -s http://localhost:80
--> im Browser http://localhost öffnen
-====== Docker Image aktualisieren ======
-<file txt Dockerfile>
-…
-RUN ln -sf /dev/stdout /var/log/nginx/access.log \
-    && ln -sf /dev/stderr /var/log/nginx/error.log
-…
-</file>
-  docker build --no-cache --pull -t='ingo/nginx:0.0.2' .
-++++ podman |
-  podman build --no-cache -t='ingo/nginx:0.0.2' .
--> allerdings werden dann alle 12 STEPs neu gebaut.
-TODO: liegt das an dem fehlenden --pull?
-AI Slop Vermutung:
-Docker built your image without errors because it keeps un-namespaced local images as-is. In contrast, Podman automatically prefixes locally built or untagged registry images with localhost/ to prevent collisions with official registries.
-When you use the --pull flag, Podman is forced to try downloading a fresh version of that base image from an external source. Because it sees localhost/ingo/debian:trixie, Podman literally looks for a web-facing registry running on your actual machine (https://localhost/v2/). Since you don't have a container registry service actively running on port 443 of your host machine, the network request fails with "connection refused"
-Unter Debian mit Docker version 26.1.5+dfsg1, build a72d7cd klappt ''--pull'' auch nicht.
-ERROR: failed to solve: ingo/debian:trixie: failed to resolve source metadata for docker.io/ingo/debian:trixie: pull access denied, repository does not exist or may require authorization: server message: insufficient_scope: authorization failed
-++++
-Jetzt noch mal Container starten und
-  docker logs
-ansehen.
-Bauen mit einem Release Zeitstempel:
-<code shell>
-REFRESHED_AT=$(date '+%Y-%m-%d')
-docker build --no-cache --pull \
-  --build-arg REFRESHED_AT=$REFRESHED_AT \
-  -t='ingo/nginx:0.0.2' \
-  -t=ingo/nginx:$REFRESHED_AT .
-</code>
-Nginx as Systemd:
-<code bash>
-mkdir ~/ubi9-nginx && cd ~/ubi9-nginx
-cat >Dockerfile <<EOF
-FROM registry.access.redhat.com/ubi9/ubi-init
-RUN dnf -y install nginx \
- && dnf clean all \
- && systemctl enable nginx
-STOPSIGNAL SIGRTMIN+3
-CMD ["/sbin/init"]
-EOF
-docker build -t ubi9-nginx-systemd:0.0.1 .
-docker run --name ubi9-nginx -d -p 8090:80 ubi9-nginx-systemd:0.0.1
-docker exec -it ubi9-nginx systemctl status
-docker exec -it ubi9-nginx journalctl -u nginx
-# ups..
-docker logs ubi9-nginx
-</code>
-<code bash>
-# build with compose
-cat >compose.yml <<EOF
-services:
-  nginx:
-    build: .
-    ports:
-      - "8090:80"
-    tmpfs:
-      - /run
-      - /run/lock
-      - /tmp
-    stop_signal: SIGRTMIN+3
-EOF
-docker compose build
-docker compose up -d
-docker compose exec nginx ps -ef
-docker compose down
-</code>
-++++ this doesn't solve the console logging problem |
-<code bash>
-cat >Dockerfile <<EOF
-FROM registry.access.redhat.com/ubi9/ubi-init
-RUN dnf -y install nginx \
- && dnf clean all
-# nginx logs to files (important for tail)
-RUN mkdir -p /var/log/nginx
-# systemd override for nginx
-RUN mkdir -p /etc/systemd/system/nginx.service.d && \
-    cat <<'EOF' >/etc/systemd/system/nginx.service.d/override.conf
-[Service]
-StandardOutput=journal
-StandardError=journal
-EOF
-# log forwarder service
-RUN cat <<'EOF' >/etc/systemd/system/nginx-log-forwarder.service
-[Unit]
-Description=Nginx log forwarder
-After=nginx.service
-Requires=nginx.service
-[Service]
-Type=simple
-ExecStart=/bin/sh -c '/usr/bin/tail -F /var/log/nginx/access.log /var/log/nginx/error.log'
-Restart=always
-[Install]
-WantedBy=multi-user.target
-EOF
-RUN systemctl enable nginx \
- && systemctl enable nginx-log-forwarder
-STOPSIGNAL SIGRTMIN+3
-CMD ["/sbin/init"]
-EOF
-podman compose build
-podman compose up -d
-curl 127.0.0.1:8090
-podman compose exec nginx systemctl status nginx-log-forwarder
-podman compose exec nginx journalctl -u nginx-log-forwarder
-# see access logs
-podman logs nginx_nginx_1
-# no logging output!
-</code>
-++++