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| 1 | +# Copyright 2023 Simon Emms <simon@simonemms.com> |
| 2 | +# |
| 3 | +# Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | +# you may not use this file except in compliance with the License. |
| 5 | +# You may obtain a copy of the License at |
| 6 | +# |
| 7 | +# http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | +# |
| 9 | +# Unless required by applicable law or agreed to in writing, software |
| 10 | +# distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | +# See the License for the specific language governing permissions and |
| 13 | +# limitations under the License. |
| 14 | + |
| 15 | +clean_download() { |
| 16 | + # The purpose of this function is to download a file with minimal impact on container layer size |
| 17 | + # this means if no valid downloader is found (curl or wget) then we install a downloader (currently wget) in a |
| 18 | + # temporary manner, and making sure to |
| 19 | + # 1. uninstall the downloader at the return of the function |
| 20 | + # 2. revert back any changes to the package installer database/cache (for example apt-get lists) |
| 21 | + # The above steps will minimize the leftovers being created while installing the downloader |
| 22 | + # Supported distros: |
| 23 | + # debian/ubuntu/alpine |
| 24 | + |
| 25 | + url=$1 |
| 26 | + output_location=$2 |
| 27 | + tempdir=$(mktemp -d) |
| 28 | + downloader_installed="" |
| 29 | + |
| 30 | + _apt_get_install() { |
| 31 | + tempdir=$1 |
| 32 | + |
| 33 | + # copy current state of apt list - in order to revert back later (minimize contianer layer size) |
| 34 | + cp -p -R /var/lib/apt/lists $tempdir |
| 35 | + apt-get update -y |
| 36 | + apt-get -y install --no-install-recommends wget ca-certificates |
| 37 | + } |
| 38 | + |
| 39 | + _apt_get_cleanup() { |
| 40 | + tempdir=$1 |
| 41 | + |
| 42 | + echo "removing wget" |
| 43 | + apt-get -y purge wget --auto-remove |
| 44 | + |
| 45 | + echo "revert back apt lists" |
| 46 | + rm -rf /var/lib/apt/lists/* |
| 47 | + rm -r /var/lib/apt/lists && mv $tempdir/lists /var/lib/apt/lists |
| 48 | + } |
| 49 | + |
| 50 | + _apk_install() { |
| 51 | + tempdir=$1 |
| 52 | + # copy current state of apk cache - in order to revert back later (minimize contianer layer size) |
| 53 | + cp -p -R /var/cache/apk $tempdir |
| 54 | + |
| 55 | + apk add --no-cache wget |
| 56 | + } |
| 57 | + |
| 58 | + _apk_cleanup() { |
| 59 | + tempdir=$1 |
| 60 | + |
| 61 | + echo "removing wget" |
| 62 | + apk del wget |
| 63 | + } |
| 64 | + # try to use either wget or curl if one of them already installer |
| 65 | + if type curl >/dev/null 2>&1; then |
| 66 | + downloader=curl |
| 67 | + elif type wget >/dev/null 2>&1; then |
| 68 | + downloader=wget |
| 69 | + else |
| 70 | + downloader="" |
| 71 | + fi |
| 72 | + |
| 73 | + # in case none of them is installed, install wget temporarly |
| 74 | + if [ -z $downloader ] ; then |
| 75 | + if [ -x "/usr/bin/apt-get" ] ; then |
| 76 | + _apt_get_install $tempdir |
| 77 | + elif [ -x "/sbin/apk" ] ; then |
| 78 | + _apk_install $tempdir |
| 79 | + else |
| 80 | + echo "distro not supported" |
| 81 | + exit 1 |
| 82 | + fi |
| 83 | + downloader="wget" |
| 84 | + downloader_installed="true" |
| 85 | + fi |
| 86 | + |
| 87 | + if [ $downloader = "wget" ] ; then |
| 88 | + wget -q $url -O $output_location |
| 89 | + else |
| 90 | + curl -sfL $url -o $output_location |
| 91 | + fi |
| 92 | + |
| 93 | + # NOTE: the cleanup procedure was not implemented using `trap X RETURN` only because |
| 94 | + # alpine lack bash, and RETURN is not a valid signal under sh shell |
| 95 | + if ! [ -z $downloader_installed ] ; then |
| 96 | + if [ -x "/usr/bin/apt-get" ] ; then |
| 97 | + _apt_get_cleanup $tempdir |
| 98 | + elif [ -x "/sbin/apk" ] ; then |
| 99 | + _apk_cleanup $tempdir |
| 100 | + else |
| 101 | + echo "distro not supported" |
| 102 | + exit 1 |
| 103 | + fi |
| 104 | + fi |
| 105 | + |
| 106 | +} |
| 107 | + |
| 108 | + |
| 109 | +ensure_nanolayer() { |
| 110 | + # Ensure existance of the nanolayer cli program |
| 111 | + local variable_name=$1 |
| 112 | + |
| 113 | + local required_version=$2 |
| 114 | + |
| 115 | + local __nanolayer_location="" |
| 116 | + |
| 117 | + # If possible - try to use an already installed nanolayer |
| 118 | + if [ -z "${NANOLAYER_FORCE_CLI_INSTALLATION}" ]; then |
| 119 | + if [ -z "${NANOLAYER_CLI_LOCATION}" ]; then |
| 120 | + if type nanolayer >/dev/null 2>&1; then |
| 121 | + echo "Found a pre-existing nanolayer in PATH" |
| 122 | + __nanolayer_location=nanolayer |
| 123 | + fi |
| 124 | + elif [ -f "${NANOLAYER_CLI_LOCATION}" ] && [ -x "${NANOLAYER_CLI_LOCATION}" ] ; then |
| 125 | + __nanolayer_location=${NANOLAYER_CLI_LOCATION} |
| 126 | + echo "Found a pre-existing nanolayer which were given in env variable: $__nanolayer_location" |
| 127 | + fi |
| 128 | + |
| 129 | + # make sure its of the required version |
| 130 | + if ! [ -z "${__nanolayer_location}" ]; then |
| 131 | + local current_version |
| 132 | + current_version=$($__nanolayer_location --version) |
| 133 | + |
| 134 | + |
| 135 | + if ! [ $current_version == $required_version ]; then |
| 136 | + echo "skipping usage of pre-existing nanolayer. (required version $required_version does not match existing version $current_version)" |
| 137 | + __nanolayer_location="" |
| 138 | + fi |
| 139 | + fi |
| 140 | + |
| 141 | + fi |
| 142 | + |
| 143 | + # If not previuse installation found, download it temporarly and delete at the end of the script |
| 144 | + if [ -z "${__nanolayer_location}" ]; then |
| 145 | + |
| 146 | + if [ "$(uname -sm)" = 'Linux x86_64' ] || [ "$(uname -sm)" = "Linux aarch64" ]; then |
| 147 | + tmp_dir=$(mktemp -d -t nanolayer-XXXXXXXXXX) |
| 148 | + |
| 149 | + clean_up () { |
| 150 | + ARG=$? |
| 151 | + rm -rf $tmp_dir |
| 152 | + exit $ARG |
| 153 | + } |
| 154 | + trap clean_up EXIT |
| 155 | + |
| 156 | + |
| 157 | + if [ -x "/sbin/apk" ] ; then |
| 158 | + clib_type=musl |
| 159 | + else |
| 160 | + clib_type=gnu |
| 161 | + fi |
| 162 | + |
| 163 | + tar_filename=nanolayer-"$(uname -m)"-unknown-linux-$clib_type.tgz |
| 164 | + |
| 165 | + # clean download will minimize leftover in case a downloaderlike wget or curl need to be installed |
| 166 | + clean_download https://github.com/devcontainers-extra/nanolayer/releases/download/$required_version/$tar_filename $tmp_dir/$tar_filename |
| 167 | + |
| 168 | + tar xfzv $tmp_dir/$tar_filename -C "$tmp_dir" |
| 169 | + chmod a+x $tmp_dir/nanolayer |
| 170 | + __nanolayer_location=$tmp_dir/nanolayer |
| 171 | + |
| 172 | + |
| 173 | + else |
| 174 | + echo "No binaries compiled for non-x86-linux architectures yet: $(uname -m)" |
| 175 | + exit 1 |
| 176 | + fi |
| 177 | + fi |
| 178 | + |
| 179 | + # Expose outside the resolved location |
| 180 | + export ${variable_name}=$__nanolayer_location |
| 181 | + |
| 182 | +} |
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