added download_github_jar.sh

install/download_github_jar.sh

@@ -0,0 +1,88 @@
+#!/usr/bin/env bash
+#  vim:ts=4:sts=4:sw=4:et
+#
+#  Author: Hari Sekhon
+#  Date: 2024-08-28 23:01:46 +0200 (Wed, 28 Aug 2024)
+#
+#  https://github.com/HariSekhon/DevOps-Bash-tools
+#
+#  License: see accompanying Hari Sekhon LICENSE file
+#
+#  If you're using my code you're welcome to connect with me on LinkedIn and optionally send me feedback to help steer this or other code I publish
+#
+#  https://www.linkedin.com/in/HariSekhon
+#
+
+set -euo pipefail
+[ -n "${DEBUG:-}" ] && set -x
+srcdir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+
+# shellcheck disable=SC1090,SC1091
+. "$srcdir/../lib/github.sh"
+
+# shellcheck disable=SC2034,SC2154
+usage_description="
+Quickly determines and downloads the given or latest version of a Java JAR from GitHub releases
+
+If the JAR url template contains {version} placeholders but no explicit version then the placeholds will be replaced with the latest version which will be automatically determined from GitHub releases
+
+If the JAR URL does not contain {version} placeholders then downloads the URL as given
+
+Version defaults to 'latest' in which case it determines the latest version from GitHub releases
+
+Designed to be called from adjacent download_*_jar.sh scripts to deduplicate code
+"
+
+# used by usage() in lib/utils.sh
+# shellcheck disable=SC2034
+usage_args="<jar_url> [<version>]"
+
+help_usage "$@"
+
+min_args 1 "$@"
+max_args 2 "$@"
+
+jar_url="$1"
+version="${2:-latest}"
+
+jar_url="${jar_url## }"
+jar_url="${jar_url%% }"
+
+shopt -s nocasematch
+# defined in lib/github.sh
+# shellcheck disable=SC2154
+if ! [[ "$jar_url" =~ ^$github_release_url_regex ]]; then
+    die "ERROR: Invalid URL given, not a GitHub release URL: $jar_url"
+fi
+shopt -u nocasematch
+
+download_url="$jar_url"
+
+if [[ "$jar_url" =~ {version} ]]; then
+    github_owner_repo="$(sed 's|^https://github.com/||i; s|/releases/.*$||i' <<< "$jar_url")"
+    if [ "$version" = latest ]; then
+        timestamp "Determining latest release of $github_owner_repo available"
+        version="$(github_repo_latest_release.sh "$github_owner_repo")"
+        # bash built-in variable substitution cannot replace all alpha prefix chars - tested this already
+        # shellcheck disable=SC2001
+        version="$(sed 's/^[[:alpha:]]*//' <<< "$version")"
+        timestamp "Determined latest version of $github_owner_repo to be version '$version'"
+    fi
+    download_url="${download_url//\{version\}/$version}"
+fi
+
+timestamp "Downloading: $download_url"
+echo >&2
+
+jar="${download_url##*/}"
+
+if type -P wget &>/dev/null; then
+    wget -cO "$jar" "$download_url"
+else
+    tmpfile="$(mktemp)"
+    curl --fail "$download_url" > "$tmpfile"
+    unalias mv &>/dev/null || :
+    mv -fv "$tmpfile" "$jar"
+fi
+
+timestamp "Download complete: $jar"