From 73d6c9d469d1429999ea2e980b3ac4c63a3e0dd4 Mon Sep 17 00:00:00 2001 From: Darko Poljak Date: Sun, 27 Sep 2020 10:17:35 +0200 Subject: [PATCH] Add custom remote copy/exec examples --- docs/src/cdist-remote-exec-copy.rst | 389 +++++++++++++++++++++++++++- 1 file changed, 388 insertions(+), 1 deletion(-) diff --git a/docs/src/cdist-remote-exec-copy.rst b/docs/src/cdist-remote-exec-copy.rst index bb818310..e7b7b226 100644 --- a/docs/src/cdist-remote-exec-copy.rst +++ b/docs/src/cdist-remote-exec-copy.rst @@ -10,7 +10,7 @@ By default this is accomplished with ssh and scp respectively. The default implementations used by cdist are:: __remote_exec: ssh -o User=root - __remote_copy: scp -o User=root + __remote_copy: scp -o User=root -q The user can override these defaults by providing custom implementations and passing them to cdist with the --remote-exec and/or --remote-copy arguments. @@ -26,3 +26,390 @@ specified by enclosed in square brackets (see :strong:`ssh`\ (1) and With this simple interface the user can take total control of how cdist interacts with the target when required, while the default implementation remains as simple as possible. + + +Examples +-------- + +Here are examples of using alternative __remote_copy and __remote_exec scripts. + +All scripts from below are present in cdist sources in `other/examples/remote` +directory. + +ssh +~~~ + +Same as cdist default. + +**copy** + +Usage: cdist config --remote-copy "/path/to/this/script" target_host + +.. code-block:: sh + + #echo "$@" | logger -t "cdist-ssh-copy" + scp -o User=root -q $@ + +**exec** + +Usage: cdist config --remote-exec "/path/to/this/script" target_host + +.. code-block:: sh + + #echo "$@" | logger -t "cdist-ssh-exec" + ssh -o User=root $@ + +local +~~~~~ + +This effectively turns remote calling into local calling. Probably most useful +for the unit testing. + +**copy** + +.. code-block:: sh + + code="$(echo "$@" | sed "s|\([[:space:]]\)$__target_host:|\1|g")" + cp -L $code + +**exec** + +.. code-block:: sh + + target_host=$1; shift + echo "$@" | /bin/sh + +chroot +~~~~~~ + +**copy** + +Usage: cdist config --remote-copy "/path/to/this/script /path/to/your/chroot" target-id + +.. code-block:: sh + + log() { + #echo "$@" | logger -t "cdist-chroot-copy" + : + } + + chroot="$1"; shift + target_host="$__target_host" + + # replace target_host with chroot location + code="$(echo "$@" | sed "s|$target_host:|$chroot|g")" + + log "target_host: $target_host" + log "chroot: $chroot" + log "$@" + log "$code" + + # copy files into chroot + cp $code + + log "-----" + +**exec** + +Usage: cdist config --remote-exec "/path/to/this/script /path/to/your/chroot" target-id + +.. code-block:: sh + + log() { + #echo "$@" | logger -t "cdist-chroot-exec" + : + } + + chroot="$1"; shift + target_host="$1"; shift + + script=$(mktemp "${chroot}/tmp/chroot-${0##*/}.XXXXXXXXXX") + trap cleanup INT TERM EXIT + cleanup() { + [ $__cdist_debug ] || rm "$script" + } + + log "target_host: $target_host" + log "script: $script" + log "@: $@" + echo "#!/bin/sh -l" > "$script" + echo "$@" >> "$script" + chmod +x "$script" + + relative_script="${script#$chroot}" + log "relative_script: $relative_script" + + # run in chroot + chroot "$chroot" "$relative_script" + + log "-----" + +rsync +~~~~~ + +**copy** + +Usage: cdist config --remote-copy /path/to/this/script target_host + +.. code-block:: sh + + # For rsync to do the right thing, the source has to end with "/" if it is + # a directory. The below preprocessor loop takes care of that. + + # second last argument is the source + source_index=$(($#-1)) + index=0 + for arg in $@; do + if [ $index -eq 0 ]; then + # reset $@ + set -- + fi + index=$((index+=1)) + if [ $index -eq $source_index -a -d "$arg" ]; then + arg="${arg%/}/" + fi + set -- "$@" "$arg" + done + + rsync --backup --suffix=~cdist -e 'ssh -o User=root' $@ + +schroot +~~~~~~~ + +__remote_copy and __remote_exec scripts to run cdist against a chroot on the +target host over ssh. + +**copy** + +Usage: cdist config --remote-copy "/path/to/this/script schroot-chroot-name" target_host + + +.. code-block:: sh + + log() { + #echo "$@" | logger -t "cdist-schroot-copy" + : + } + + chroot_name="$1"; shift + target_host="$__target_host" + + # get directory for given chroot_name + chroot="$(ssh -o User=root -q $target_host schroot -c $chroot_name --config | awk -F = '/directory=/ {print $2}')" + + # prefix destination with chroot + code="$(echo "$@" | sed "s|$target_host:|$target_host:$chroot|g")" + + log "target_host: $target_host" + log "chroot_name: $chroot_name" + log "chroot: $chroot" + log "@: $@" + log "code: $code" + + # copy files into remote chroot + scp -o User=root -q $code + + log "-----" + +**exec** + +Usage: cdist config --remote-exec "/path/to/this/script schroot-chroot-name" target_host + +.. code-block:: sh + + log() { + #echo "$@" | logger -t "cdist-schroot-exec" + : + } + + chroot_name="$1"; shift + target_host="$1"; shift + + code="ssh -o User=root -q $target_host schroot -c $chroot_name -- $@" + + log "target_host: $target_host" + log "chroot_name: $chroot_name" + log "@: $@" + log "code: $code" + + # run in remote chroot + $code + + log "-----" + +schroot-uri +~~~~~~~~~~~ + +__remote_exec/__remote_copy script to run cdist against a schroot target URI. + +Usage:: + + cdist config \ + --remote-exec "/path/to/this/script exec" \ + --remote-copy "/path/to/this/script copy" \ + target_uri + + # target_uri examples: + schroot:///chroot-name + schroot://foo.ethz.ch/chroot-name + schroot://user-name@foo.ethz.ch/chroot-name + + # and how to match them in .../manifest/init + case "$target_host" in + schroot://*) + # any schroot + ;; + schroot://foo.ethz.ch/*) + # any schroot on specific host + ;; + schroot://foo.ethz.ch/chroot-name) + # specific schroot on specific host + ;; + schroot:///chroot-name) + # specific schroot on localhost + ;; + esac + +**copy/exec** + +.. code-block:: sh + + my_name="${0##*/}" + mode="$1"; shift + + log() { + # uncomment me for debugging + #echo "$@" | logger -t "cdist-$my_name-$mode" + : + } + + die() { + echo "$@" >&2 + exit 1 + } + + + uri="$__target_host" + + scheme="${uri%%:*}"; rest="${uri#$scheme:}"; rest="${rest#//}" + authority="${rest%%/*}"; rest="${rest#$authority}" + path="${rest%\?*}"; rest="${rest#$path}" + schroot_name="${path#/}" + + [ "$scheme" = "schroot" ] || die "Failed to parse scheme from __target_host ($__target_host). Expected 'schroot', got '$scheme'" + [ -n "$schroot_name" ] || die "Failed to parse schroot name from __target_host: $__target_host" + + case "$authority" in + '') + # authority is empty, neither user nor host given + user="" + host="" + ;; + *@*) + # authority contains @, take user from authority + user="${authority%@*}" + host="${authority#*@}" + ;; + *) + # no user in authority, default to root + user="root" + host="$authority" + ;; + esac + + log "mode: $mode" + log "@: $@" + log "uri: $uri" + log "scheme: $scheme" + log "authority: $authority" + log "user: $user" + log "host: $host" + log "path: $path" + log "schroot_name: $schroot_name" + + exec_prefix="" + copy_prefix="" + if [ -n "$host" ]; then + # we are working on a remote host + exec_prefix="ssh -o User=$user -q $host" + copy_prefix="scp -o User=$user -q" + copy_destination_prefix="$host:" + else + # working on local machine + copy_prefix="cp" + copy_destination_prefix="" + fi + log "exec_prefix: $exec_prefix" + log "copy_prefix: $copy_prefix" + log "copy_destination_prefix: $copy_destination_prefix" + + case "$mode" in + exec) + # In exec mode the first argument is the __target_host which we already got from env. Get rid of it. + shift + code="$exec_prefix schroot -c $schroot_name -- sh -c '$@'" + ;; + copy) + # get directory for given chroot_name + schroot_directory="$($exec_prefix schroot -c $schroot_name --config | awk -F = '/directory=/ {print $2}')" + [ -n "$schroot_directory" ] || die "Failed to retreive schroot directory for schroot: $schroot_name" + log "schroot_directory: $schroot_directory" + # prefix destination with chroot + code="$copy_prefix $(echo "$@" | sed "s|$uri:|${copy_destination_prefix}${schroot_directory}|g")" + ;; + *) die "Unknown mode: $mode";; + esac + + log "code: $code" + + # Run the code + $code + + log "-----" + +sudo +~~~~ + +**copy** + +Use rsync over ssh to copy files. Uses the "--rsync-path" option +to run the remote rsync instance with sudo. + +This command assumes your ssh configuration is already set up in ~/.ssh/config. + +Usage: cdist config --remote-copy /path/to/this/script target_host + +.. code-block:: sh + + # For rsync to do the right thing, the source has to end with "/" if it is + # a directory. The below preprocessor loop takes care of that. + + # second last argument is the source + source_index=$(($#-1)) + index=0 + for arg in $@; do + if [ $index -eq 0 ]; then + # reset $@ + set -- + fi + index=$((index+=1)) + if [ $index -eq $source_index -a -d "$arg" ]; then + arg="${arg%/}/" + fi + set -- "$@" "$arg" + done + + rsync --copy-links --rsync-path="sudo rsync" -e 'ssh' "$@" + +**exec** + +Prefixes all remote commands with sudo. + +This command assumes your ssh configuration is already set up in ~/.ssh/config. + +Usage: cdist config --remote-exec "/path/to/this/script" target_host + +.. code-block:: sh + + host="$1"; shift + ssh -q "$host" sudo sh -c \""$@"\"