dental floss for your pc

February 2021

• OpenBSD backups...

  This is yet another one of the guides on how to do backups for a server, this time with restic and OpenBSD. This sets up a daily backup and mails the changes to root. Install restic This is the simplest part: $ pkg_add restic Setup a restic repository From the official instructions, the example here sets up an sftp repository over ssh. For this to work, root must have access to the backup server using its ssh key. $ cat /root/.ssh/config Host truenas HostName 192.168.4.2 User restic IdentityFile /root/.ssh/id_ed25519 $ restic --repo sftp:truenas:/mnt/Media/backups/fwall init Store the password that was used in plain text in /root/.ssh/restic: $ ls -lh /root/.ssh/restic -rw------- 1 root wheel 18B Dec 24 20:32 /root/.ssh/restic $ cat /root/.ssh/restic SomeReallyCoolResticPassword NOTE: Make sure that the ssh user, restic, has full access to the backup folder. Setup /etc/daily.local Create a new file /etc/daily.local.restic with the contents: # backup restic R_FILE="/root/.ssh/restic" R_REPO="sftp:truenas:/mnt/Media/backups/fwall" env RESTIC_PASSWORD_FILE="${R_FILE}" \ HOME="/root" \ /usr/local/bin/restic --repo ${R_REPO} \ --verbose backup \ --exclude-if-present=no_restic \ --exclude-file=/etc/restic.exclude \ --files-from=/etc/restic.include \ --tag="$(date +%c)" # list changes PREV=$(env RESTIC_PASSWORD_FILE="${R_FILE}" HOME="/root" \ /usr/local/bin/restic --repo ${R_REPO} \ snapshots --compact | tail -4 | head -1 | awk '{print $1}') LAST=$(env RESTIC_PASSWORD_FILE="${R_FILE}" HOME="/root" \ /usr/local/bin/restic --repo ${R_REPO} \ snapshots --compact | tail -3 | head -1 | awk '{print $1}') RDIFF_FILE="$(mktemp)" env RESTIC_PASSWORD_FILE="${R_FILE}" HOME="/root" \ /usr/local/bin/restic --repo ${R_REPO} \ diff ${PREV} ${LAST} > ${RDIFF_FILE} NLINES=$(wc -l "${RDIFF_FILE}" | awk '{print $1}') if [ ${NLINES} -gt 108 ] ; then head -n 100 "${RDIFF_FILE}" printf "======= SNIP ======\n" tail -n 8 "${RDIFF_FILE}" else cat "${RDIFF_FILE}" fi rm -f "${RDIFF_FILE}" unset R_REPO R_FILE RDIFF_FILE NLINES And in the /etc/daily.local, add a line which sources /etc/daily.local.restic: ... {other personal scripts} ... . /etc/daily.local.restic This sets up the daily script, which backs up the whole system. We still need to create the config files /etc/restic.include and /etc/restic.exclude. /etc/restic.include: /etc /root /home /usr /bin /sbin /var /etc/restic.exclude: /var/run /var/spool /var/tmp Any folder which contains a file named no_restic is also excluded. For example, if a user has multiple git repositories in /home/aisha/GIT/ and they wish to avoid backups of this folder, create a file /home/aisha/GIT/no_restic, an empty file is fine, it can also contain the reason for excluding this folder. $ locate no_restic /home/aisha/GIT/no_restic $ cat /home/aisha/GIT/no_restic no need to do backups of online version controlled folders Test backup To test it out, first do a full back of the system: $ env -i R_FILE="/root/.ssh/restic" \ R_REPO="sftp:truenas:/mnt/Media/backups/fwall" \ RESTIC_PASSWORD_FILE="${R_FILE}" \ HOME="/root" \ /usr/local/bin/restic --repo ${R_REPO} \ --verbose backup \ --exclude-if-present=no_restic \ --exclude-file=/etc/restic.exclude \ --files-from=/etc/restic.include \ --tag="$(date +%c)" Now do a test run of /etc/dailly.local.restic with: $ sh /etc/daily.local.restic open repository repository f719d564 opened successfully, password is correct lock repository load index files using parent snapshot 05b3f0dd start scan on [/etc /root /home /usr /bin /sbin /var] start backup on [/etc /root /home /usr /bin /sbin /var] scan finished in 2.230s: 35818 files, 2.111 GiB Files: 0 new, 10 changed, 35808 unmodified Dirs: 0 new, 12 changed, 1859 unmodified Data Blobs: 8 new Tree Blobs: 11 new Added to the repo: 817.516 KiB processed 35818 files, 2.111 GiB in 0:05 snapshot 11d4745c saved comparing snapshot 05b3f0dd to 11d4745c: M /root/.local/share/nvim/shada/main.shada M /var/cron/log M /var/cron/log.0.gz M /var/cron/log.1.gz M /var/cron/log.2.gz M /var/log/daemon M /var/log/dhcpd M /var/log/messages M /var/log/pflog M /var/log/rad Files: 0 new, 0 removed, 10 changed Dirs: 0 new, 0 removed Others: 0 new, 0 removed Data Blobs: 8 new, 8 removed Tree Blobs: 10 new, 10 removed Added: 815.139 KiB Removed: 821.155 KiB Congratulations This sets up proper daily backups for the server, with blazing speed.

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January 2021

• 5 minute podman...

  Machine - Gentoo amd64 + OpenRC. Installing podman We want to use app-emulation/crun instead of app-emulation/runc - Bug 723080. $ emerge -av1 app-emulation/crun $ emerge -av podman Setup podman The default configuration file provided (/etc/containers/registries.conf.example) does weird redirections, we don't want that. Create the config file (/etc/containers/registries.conf) from scratch: [registries.search] registries = ['docker.io', 'quay.io', 'registry.fedoraproject.org'] [registries.insecure] registries = [] #blocked (docker only) [registries.block] registries = [] Create the /etc/containers/policy.json file: $ cp /etc/containers/policy.json{example,} Optional: login to docker hub and quay.io: $ podman login docker.io Username: Password: $ podman login quay.io Username: Password: Extra - rootless mode To enable rootless mode, the tun kernel module must be loaded. If the tun module is built in to the kernel, then no further steps are necessary. Look at the Gentoo wiki article on kernel modules for an in-depth explanation. For loading the tun module, create the file /etc/modules-load.d/networking.conf, with the single line: tun Basic terminology Pods For practical purposes, pods are going to be a collection of containers. All containers inside a pod share a network namespace. If running a pod in macvlan mode, this means all containers in the pod get the same IP address. Containers containers are lightweight emulation environments, designed for running programs in isolation from each other. For our purposes, we will be running small services for our homeserver, with the specific example in this document for the jackett torrent tracker. Extra - creating a podman network - macvlan The default config provided only allows for publishing specific ports for containers/pods and provides the default network config podman. We will create a new network which will allow pods/containers to get real IPs on the LAN. Create the /etc/cni/net.d/88-macvlan.conflist config file: { "cniVersion": "0.4.0", "name": "macvlan", "plugins": [ { "type": "macvlan", "master": "br0", "isGateway": true, "ipam": { "type": "dhcp" } }, { "type": "portmap", "capabilities": { "portMappings": true } }, { "type": "firewall" }, { "type": "tuning" } ] } Note: br0 can be substituted for any preconfigured bridge on the host, or can even be an ethernet interface such as enp5s0f0, without losing connectivity for the host machine. Test the network config To check that the configuration is sane: $ podman network ls NAME VERSION PLUGINS podman 0.4.0 bridge,portmap,firewall,tuning macvlan 0.4.0 macvlan,portmap,firewall,tuning Virtual DHCP server for containers Most containers are not going to have a dhcp client present and thus will not get IP addresses from the dhcp server. Luckily, net-misc/cni-plugins provides a virtual dhcp server/client which assigns the IP addresses to them. It is pulled in automatically as a dependency. Start the dhcp server with: $ rc-update add cni-dhcp default $ rc-service cni-dhcp start Dangers of macvlan Exposing a pod can also expose unwanted and unsafe ports to the network, such as mistakenly exposing a redis port, if redis is employed in a container. Be careful in choosing the macvlan networking option for a pod/container. Running a container There are two ways of running a podman container free floating containers - not inside a pod containers inside a pod Here, we will only do containers inside a pod. Create a pod Create a very simple, empty pod, with the macvlan network. $ podman pod create --name homeserver --network macvlan Testing the pod Add an alpine container to the homeserver pod: $ podman run --detach --tty --pod homeserver --name homeserver_alpine docker.io/library/alpine:latest top man podman-run gives a more thorough review of all the command options: --detach: Detached mode: run the container in the background and print the new container ID. The default is false. --tty: Allocate a pseudo-TTY. The default is false. This creates an alpine linux container inside the homeserver pod and runs the command top in it. To view the IP address of this pod: $ podman exec homeserver_alpine ifconfig eth0 Link encap:Ethernet HWaddr 82:82:CF:4F:6F:DD inet addr:192.168.2.122 Bcast:192.168.2.255 Mask:255.255.255.0 inet6 addr: fe80::8082:cfff:fe4f:6fdd/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:14 errors:0 dropped:0 overruns:0 frame:0 TX packets:13 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:1976 (1.9 KiB) TX bytes:1552 (1.5 KiB) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:65536 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) Creating a container inside a pod We can now run the jackett container in this pod with: $ podman run --detach --tty --pod homeserver --name=homeserver_jackett ghcr.io/linuxserver/jackett Test the container From the above configuration, try to access the jackett webui - http://192.168.2.122:9117 Voila We are done! This setup gets rid of pesky port forwarding options and firewall configurations , though at the cost of a potential risk. Be wise before choosing this configuration. References Official documentation - https://docs.podman.io/en/latest/index.html

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