Dockerfile: use default apt mirrors

[crazy-max]

follow-up https://github.com/moby/moby/pull/44546#discussion_r1059776409

- What I did

Removes APT_MIRROR added in https://github.com/moby/moby/pull/39537 as I don't think we need an alternative mirror anymore. Also removes BUILD_APT_MIRROR added in https://github.com/moby/moby/pull/26375 that does not seem to be used.

- How I did it

- How to verify it

- Description for the changelog

- A picture of a cute animal (not mandatory but encouraged)

[thaJeztah]

I wonder if we should completely remove it from the Dockerfile;

• is this useful for people behind the GFW, or not needed there?
• does "apt" / "apt-get" have alternatives that allow passing (through env-vars?) would be nice, but don't think there is

That said; currently we unconditionally call sed to replace the config; perhaps we shouldn't and only do so if APT_MIRROR is non-empty.

[AkihiroSuda]

I agree with @thaJeztah , I'd prefer to retain APT_MIRROR in Dockerfile and Makefile. Can be removed from Jenkinsfile though.

[crazy-max]

Got many issue with the fastly CDN recently:

> [linux/amd64->arm64 containerd-build 2/3] RUN --mount=type=cache,sharing=locked,id=moby-containerd-aptlib,target=/var/lib/apt     --mount=type=cache,sharing=locked,id=moby-containerd-aptcache,target=/var/cache/apt         
apt-get update && xx-apt-get install -y --no-install-recommends             gcc libbtrfs-dev libsecret-1-dev:
100.8 E: Failed to fetch http://cdn-fastly.deb.debian.org/debian-security/pool/updates/main/u/util-linux/libmount-dev_2.36.1-8%2bdeb11u1_arm64.deb  Cannot initiate the connection to cdn-fastly.deb.debian.org:80 (2a04:4e42:6a::644). - connect (101: Network is unreachable) [IP: 199.232.170.132 80]
100.8 E: Failed to fetch http://cdn-fastly.deb.debian.org/debian/pool/main/p/pcre3/libpcre16-3_8.39-13_arm64.deb  Cannot initiate the connection to cdn-fastly.deb.debian.org:80 (2a04:4e42:6a::644). - connect (101: Network is unreachable) [IP: 199.232.170.132 80]
100.8 E: Failed to fetch http://cdn-fastly.deb.debian.org/debian/pool/main/p/pcre3/libpcre32-3_8.39-13_arm64.deb  Cannot initiate the connection to cdn-fastly.deb.debian.org:80 (2a04:4e42:6a::644). - connect (101: Network is unreachable) [IP: 199.232.170.132 80]
100.8 E: Failed to fetch http://cdn-fastly.deb.debian.org/debian/pool/main/g/gcc-10/libstdc%2b%2b6_10.2.1-6_arm64.deb  Cannot initiate the connection to cdn-fastly.deb.debian.org:80 (2a04:4e42:6a::644). - connect (101: Network is unreachable) [IP: 199.232.170.132 80]
100.8 E: Failed to fetch http://cdn-fastly.deb.debian.org/debian/pool/main/p/pcre3/libpcrecpp0v5_8.39-13_arm64.deb  Cannot initiate the connection to cdn-fastly.deb.debian.org:80 (2a04:4e42:6a::644). - connect (101: Network is unreachable) [IP: 199.232.170.132 80]
100.8 E: Failed to fetch http://cdn-fastly.deb.debian.org/debian/pool/main/p/pcre3/libpcre3-dev_8.39-13_arm64.deb  Cannot initiate the connection to cdn-fastly.deb.debian.org:80 (2a04:4e42:6a::644). - connect (101: Network is unreachable) [IP: 199.232.170.132 80]
100.8 E: Failed to fetch http://cdn-fastly.deb.debian.org/debian-security/pool/updates/main/z/zlib/zlib1g-dev_1.2.11.dfsg-2%2bdeb11u2_arm64.deb  Cannot initiate the connection to cdn-fastly.deb.debian.org:80 (2a04:4e42:6a::644). - connect (101: Network is unreachable) [IP: 199.232.170.132 80]
100.8 E: Failed to fetch http://cdn-fastly.deb.debian.org/debian/pool/main/g/glib2.0/libglib2.0-dev_2.66.8-1_arm64.deb  Cannot initiate the connection to cdn-fastly.deb.debian.org:80 (2a04:4e42:6a::644). - connect (101: Network is unreachable) [IP: 199.232.170.132 80]
100.8 E: Failed to fetch http://cdn-fastly.deb.debian.org/debian/pool/main/libs/libsecret/libsecret-1-dev_0.20.4-2_arm64.deb  Cannot initiate the connection to cdn-fastly.deb.debian.org:80 (2a04:4e42:6a::644). - connect (101: Network is unreachable) [IP: 199.232.170.132 80]
100.8 E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?
------
Dockerfile:208
--------------------
 207 |     ARG TARGETPLATFORM
 208 | >>> RUN --mount=type=cache,sharing=locked,id=moby-containerd-aptlib,target=/var/lib/apt \
 209 | >>>     --mount=type=cache,sharing=locked,id=moby-containerd-aptcache,target=/var/cache/apt \
 210 | >>>         apt-get update && xx-apt-get install -y --no-install-recommends \
 211 | >>>             gcc libbtrfs-dev libsecret-1-dev
 212 |     ARG DOCKER_STATIC
--------------------
ERROR: failed to solve: process "/bin/sh -c apt-get update && xx-apt-get install -y --no-install-recommends             gcc libbtrfs-dev libsecret-1-dev" did not complete successfully: exit code: 100

Would appreciate to have this one in :pray:

[cpuguy83]

The reason we added the knob was to work around mirrors having issues (and even deb.debian.org which was supposed to route to the best mirror for you).

[neersighted]

I think this is the best middle ground; unconditionally using Fastly isn't great. We should also consider not overriding security.debian.org since many mirrors do not carry the debian-security repo, but that can be a follow-up.