babashka migrate.clj that downloads postgres and mybatis jar and reads username and password from local .env compatible with https://caveman.mccue.dev/tutorial/clojure/15_read_environment_variables

migrate.clj

#!/usr/bin/env bb
; migrate command, invoker of org.apache.ibatis.migration.Migrator 
; Downloads maven artifact
; it adds --path=migrations if not specified as command-line-args
; this script is meant to be on root of the project, and when executed
; like ./migrate.clj it applies the migrations on the migrations subdirectory
; to initialize migrations path use:
; ./migrate.clj init
;
; After initializing the migrations subdirectory configure the credentials
; of the development database on migrations/enviroments/development.properties
; Example:
;## JDBC connection properties.
;driver=org.postgresql.Driver
;url=jdbc:postgresql://localhost:5432/mydatabasename
;username=${username}
;password=${password}
;
; To create new migration file use: './migrate.clj new migration_name'
; To see the status of applied ones use: './migrate.clj status'
; use './migrate.clj up' to advance pending migrations
; use './migrate.clj down' to retreat the migration one file
;
; Mybatis uses the same file for up and down
; Everything below -- //@UNDO line reverts the changes
; Everything above undo line is supposed be migrations commands
; Migration without undo line is considered just up
;
; Mybatis migration Documentation https://mybatis.org/migrations/index.html
; Github https://github.com/mybatis/migrations
(require
  '[babashka.classpath :as bc]
  '[babashka.fs :as fs]
  '[clojure.java.io :as io]
  '[clojure.java.shell :refer [sh]]
  '[clojure.string :as str]
  )

(def artifact 'org.mybatis/mybatis-migrations)
(def version "3.4.0")
(def deps-edn `{:deps {~artifact {:mvn/version ~version}
                       org.postgresql/postgresql {:mvn/version "42.7.4"}
                       }})
(def migrations-subdir "migrations")

(println (str artifact " " version))

(require '[babashka.deps :as deps])
(deps/add-deps deps-edn)

(def patched-args
  (if-not (some #(str/starts-with? % "--path=") *command-line-args*)
    (let [migrations-dir (-> (File. ".")
                             fs/canonicalize
                             fs/path
                             str ;; i'm transforming to str to get away of of no Coercion of sun.nio.fs.UnixPath
                             (io/file migrations-subdir))]
      (println (str "Defaulting to path " migrations-dir))
      (conj (into [] *command-line-args*)
            (str "--path=" migrations-dir )))
    *command-line-args*))

(def username "postgres")
(def env-file (fs/file ".env"))


(cond
  (not (.exists env-file))
  (str "env file " env-file " not found")

  :else
  ;; extracted from https://github.com/ivopt/dotenv.clj/blob/master/src/dotenv.clj#L21
  (let [env (->> (slurp env-file) 
                 (str/split-lines)                             ; split input by linebreak
                 (map str/trim)                                ; trim heading or tailing spaces
                 (remove #(-> % empty?                         ; discard empty lines
                              (str/starts-with? "#")))       ; discard commented lines
                 (map #(str/split % #"="))                     ; split by equal
                 (map #(let [[h & t] %]
                         [(str/replace h #"export *" "")    ; handle "exports declarations"
                          (str/join "=" t) ]))              ; join back values that got split
                 ; (map #(vec (->> % (map str/trim)              ; trim whitespaces on var and value
                 ;                 (map unquote-string))))     ; unquote values
                 (into {})
                 doall
                 )
              
              ]
    (println (:out (apply sh
                            "java"
                            "-Xms500m" "-Xmx500m" "-XX:-UseGCOverheadLimit"
                            "-classpath" (bc/get-classpath)
                            "-Dapp.name=migrate"
                            (str "-Dusername=" (get env "POSTGRES_USERNAME") )
                            (str "-Dpassword=" (get env "POSTGRES_PASSWORD"))
                            ; (str "-Ddatabase.schema=teste" )
                            "org.apache.ibatis.migration.Migrator"
                            patched-args)))))


; this was original migrate shell command that we are mimicking
; exec "$JAVACMD" $JAVA_OPTS -Xms500m -Xmx500m -XX:-UseGCOverheadLimit \
;   -classpath "$CLASSPATH" \
;   -Dapp.name="migrate" \
;   -Dapp.pid="$$" \
;   -Dapp.repo="$REPO" \
;   -Dapp.home="$BASEDIR" \
;   -Dbasedir="$BASEDIR" \
;   org.apache.ibatis.migration.Migrator \
;   "$@"