summaryrefslogtreecommitdiffstats
path: root/lib/prelude.sh
blob: e8c392bf3ccecc84fdfcc865f205d6ab12c3a8e2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
# clone_or_update : [user@]hostname x local_dir x git_url x git_rev -> ()
clone_or_update() {(
  target=$1
  nixpkgs_dir=$2
  git_url=$3
  git_rev=$4

  echo '
    set -euf

    if [ ! -d "$nixpkgs_dir" ]; then
      mkdir -p "$nixpkgs_dir"
    fi

    cd "$nixpkgs_dir"

    git init -q

    if ! current_url=$(git config remote.src.url); then
      git remote add src "$git_url"
    elif [ $current_url != $git_url ]; then
      git remote set-url src "$git_url"
    fi

    git fetch src

    git checkout "$git_rev"
  ' \
    | ssh "$target" env \
          nixpkgs_dir="$nixpkgs_dir" \
          git_rev="$git_rev" \
          git_url="$git_url" \
        /bin/sh
)}

# deploy : nixos-config x [user@]hostname -> ()
deploy() {(
  main=$1
  target=$2
  nixpkgs_dir='/var/tmp/nixpkgs'

  git_url=$(nixpkgs_url $main)
  git_rev=$(nixpkgs_rev $main)

  if [ "$git_url" = '' ] || [ "$git_rev" = '' ]; then
    echo "specify nixpkgs.url and nixpkgs.rev in $main !"
    exit 23
  fi

  filter=$(rsync_filter "$main")

  echo "$filter" \
    | rsync -f '. -' -zvrlptD --delete-excluded ./ "$target":/etc/nixos/

  clone_or_update "$target" "$nixpkgs_dir" "$git_url" "$git_rev"
  ssh "$target" nixos-rebuild switch -I nixos-config=/etc/nixos/"$main" -I nixpkgs="$nixpkgs_dir"

)}

# rsync_filter : nixos-config -> rsync-filter
rsync_filter() {(
  main=$1

  hosts=$(list_hosts)
  module_imports=$(set -euf; list_module_imports "$main")
  other_imports=$(
    echo "$module_imports" \
      | xargs grep -H . \
      | import_statements \
      | slash_path_relpath \
      | undot_paths \
      | sort \
      | uniq \
      | sed '/\.nix$/!s:$:/default.nix:' \
      )
  secrets=$(echo "$module_imports" | xargs cat | quoted_strings | filter_secrets)

  # TODO collect all other paths from *_imports

  abs_deps=$(
    echo "$hosts"
    echo "$module_imports"
    echo "$other_imports"
    echo "$secrets"
  )

  rel_deps=$(echo "$abs_deps" | make_relative_to "$PWD")
  filter=$(echo "$rel_deps" | make_rsync_whitelist)

  echo "$filter"
)}

# list_module_imports : nix-file -> lines nix-file
list_module_imports() {
  if echo "$1" | grep -q ^/; then
    :
  else
    set -- "./$1"
  fi
  imports=$(nix-instantiate \
      --strict \
      --json \
      --eval \
      -E \
      "with builtins; with import ./lib/modules.nix; map toString (list-imports $1)")
  echo "$imports" \
    | jq -r .[]
}

# list_hosts : lines tinc-host-file
# Precondition: $PWD/hosts is the correct repository :)
list_hosts() {
  git -C hosts ls-tree --name-only HEAD \
    | awk '{print ENVIRON["PWD"]"/hosts/"$$0}'
}

# filter_secrets : lines string |> lines secrets-file-candidate
# Notice how false positives are possible.
filter_secrets() {
  sed -n 's:^\(.*/\)\?\(secrets/.*\):'"${PWD//:/\\:}"'/\2:p'
}

# import_statements : lines (path ":" string) |> lines (path ":" relpath)
import_statements() {
  sed -n '
        s@^\([^:]\+:\)\('"$(bre_invert_word import)"'\)*\<import\s\+@\1@
        t1;d
    :1; s@^\([^:]\+:\)\(\.*/\S*\)@\1\2\n@
        t2;d
    :2; P;D
  '
}

# slash_path_relpath : lines (path ":" relpath) |> lines path
#
# Example: "/foo/bar: baz" => "/foo/baz"
#
slash_path_relpath() {
  sed -n 's@/[^/]\+:@/@p'
}

# undot_paths : lines path |> lines path
# Remove all dots (. and ..) from input paths.
undot_paths() {
  sed '
    :0
    s://\+:/:g
    s:/\.\(/\|$\):\1:g
    s:/[^/]\+/\.\.\(/\|$\):\1:g
    s:^/\(\.\./\)\+:/:
    t0
    s:^$:/:
  '
}

# quoted_strings : lines string |> lines string
# Extract all (double-) quoted strings from stdin.
#
# 0. find begin of string or skip line
# 1. find end of string or skip line
# 2. print string and continue after string
quoted_strings() {
  sed '
        s:[^"]*"::                  ;t1;d
    :1; s:\(\([^"]\|\\"\)*\)":\1\n: ;t2;d
    :2; P;D
  ' \
    | sed 's:\\":":g'
}

# bre_escape : lines string |> lines bre-escaped-string
bre_escape() {
  sed 's:[\.\[\\\*\^\$]:\\&:g'
}

# bre_invert_word : string -> BRE
# TODO escape chars in the resulting BRE.
bre_invert_word() {
  awk -v input="$1" '
    BEGIN {
      split(input,s,"")
      for (i in s) {
        c=s[i]
        printf "\\|%s[^%s]", y, c
        y = y c
      }
    }
  '
}

# ls_bre : directory -> BRE
# Create a BRE from the files in a directory.
ls_bre() {
  ls "$1" \
    | tr \\n / \
    | sed '
        s:[\.\[\\\*\^\$]:\\&:g
        s:/$::
        s:/:\\|:g
      '
}

# make_relative_to : lines path |> directory -> lines path
# Non-matching paths won't get altered.
make_relative_to() {
  sed "s:^$(echo "$1/" | bre_escape | sed 's/:/\\:/g')::"
}

# make_rsync_whitelist : lines relpath |> liens rsync-filter
make_rsync_whitelist() {
  set -- "$(cat)"

  # include all files in stdin and their directories
  {
    echo "$1"
    echo "$1" | make_parent_dirs | sort | uniq
  } \
    | sed 's|^|+ /|'

  # exclude everything else
  echo '- *'
}

# make_parent_dirs : lines path |> lines directory
# List all parent directories of a path.
make_parent_dirs() {
  set -- "$(sed -n 's|/[^/]*$||p' | grep . | sort | uniq)"
  if echo "$1" | grep -q .; then
    echo "$1"
    echo "$1" | make_parent_dirs
  fi
}

# nixpkgs_url : nixos-config -> git_url
nixpkgs_url() {
  nix-instantiate \
      -I nixos-config="$1" \
      --eval \
      --json \
      -E '(import <nixos-config> {config={}; pkgs={};}).nixpkgs.url' 2> /dev/null \
    | jq -r .
}

# nixpkgs_rev : nixos-config -> git_rev
nixpkgs_rev() {
  nix-instantiate \
      -I nixos-config="$1" \
      --eval \
      --json \
      -E '(import <nixos-config> {config={}; pkgs={};}).nixpkgs.rev' 2> /dev/null \
    | jq -r . 2> /dev/null
}

# verbose COMMAND [ARGS...]
verbose() {
  echo "$@" >&2
  "$@"
}