feat: add ability to deploy images generated via docker save with git:load-image

Closes #4559

plugins/git/help-functions

@@ -31,6 +31,7 @@ fn-help-content() {
     git:auth <host> [<username> <password>], Configures netrc authentication for a given git server
     git:from-archive <app> <archive-url> [<git-username> <git-email>], Updates an app's git repository with a given archive file
     git:from-image <app> <docker-image> [<git-username> <git-email>], Updates an app's git repository with a given docker image
+    git:load-image <app> <docker-image> [<git-username> <git-email>], Updates an app's git repository with a docker image loaded from stdin
     git:sync [--build] <app> <repository> [<git-ref>], Clone or fetch an app from remote git repo
     git:initialize <app>, Initialize a git repository for an app
     git:public-key, Outputs the dokku public deploy key

plugins/git/internal-functions

@@ -78,6 +78,51 @@ cmd-git-auth() {
   netrc set "$HOST" "$USERNAME" "$PASSWORD"
 }
 
+cmd-git-load-image() {
+  declare desc="updates an app's git repository with a docker image loaded from stdin"
+  local cmd="git:load-image"
+  [[ "$1" == "$cmd" ]] && shift 1
+  declare APP DOCKER_IMAGE USER_NAME USER_EMAIL
+  local BUILD_DIR
+
+  ARGS=()
+  skip=false
+  for arg in "$@"; do
+    if [[ "$arg" == "--build-dir" ]]; then
+      skip=true
+      continue
+    fi
+
+    if [[ "$skip" == "true" ]]; then
+      BUILD_DIR="$arg"
+      skip=false
+      continue
+    fi
+
+    ARGS+=("$arg")
+  done
+
+  APP="${ARGS[0]}"
+  DOCKER_IMAGE="${ARGS[1]}"
+  USER_NAME="${ARGS[2]}"
+  USER_EMAIL="${ARGS[3]}"
+
+  verify_app_name "$APP"
+  [[ -z "$DOCKER_IMAGE" ]] && dokku_log_fail "Please specify a docker image"
+  [[ ! -t 0 ]] || dokku_log_fail "Expecting tar archive containing docker image on STDIN"
+
+  cat | docker load
+
+  if ! verify_image "$DOCKER_IMAGE"; then
+    dokku_log_fail "Loaded image tarball but the specified docker image was not found: $DOCKER_IMAGE"
+  fi
+
+  if ! plugn trigger git-from-image "$APP" "$DOCKER_IMAGE" "$BUILD_DIR" "$USER_NAME" "$USER_EMAIL"; then
+    return 1
+  fi
+  plugn trigger deploy-source-set "$APP" "docker-image" "$DOCKER_IMAGE"
+}
+
 cmd-git-from-image() {
   declare desc="updates an app's git repository with a given docker image"
   local cmd="git:from-image"

plugins/git/subcommands/load-image

@@ -0,0 +1,6 @@
+#!/usr/bin/env bash
+source "$PLUGIN_AVAILABLE_PATH/git/internal-functions"
+set -eo pipefail
+[[ $DOKKU_TRACE ]] && set -x
+
+cmd-git-load-image "$@"