Implement install-aws-cli as an interceptor chain

examples/install-aws-cli.scm

@@ -1,28 +1,66 @@
 (use-modules
  (ice-9 filesystem)
- (ordo))
+ (srfi srfi-71)
+ (ordo playbook)
+ (ordo play)
+ (ordo interceptor)
+ (ordo connection)
+ (ordo interceptor create-tmp-dir)
+ (ordo interceptor require-commands)
+ (ordo interceptor user-info)
+ (ordo util flatten))
+
+;; TODO: this should be in (ordo interceptor download) and it needs arg validation
+(define* (download name #:key url target-dir register)
+  (interceptor
+   name
+   #:enter (lambda (ctx)
+             (let* ((url target-dir (expand-vars ctx url target-dir))
+                    (file-name (file-name-join* target-dir (file-basename url))))
+               (run (context-connection ctx) "wget" "-O" file-name url #:check? #t)
+               (when register
+                 (var-set! ctx register file-name))))
+   #:leave (lambda (ctx) (when register (var-delete! ctx register)))
+   #:error (lambda (ctx) (when register (var-delete! ctx register)))))
+
+;; TODO: this should be in (ordo interceptor unzip) and it needs arg validation
+(define* (unzip name #:key file-name target-dir)
+  (interceptor
+   name
+   #:enter (lambda (ctx)
+             (let ((file-name target-dir (expand-vars ctx file-name target-dir)))
+               (run (context-connection ctx) "unzip" file-name "-d" target-dir #:check? #t)))))
+
+;; TODO: this should be in (ordo interceptor command)
+;; Maybe it could expose more of the run functionality?
+(define (command name prog . args)
+  (interceptor
+   name
+   #:enter (lambda (ctx)
+             (run (context-connection ctx)
+                  (expand-vars ctx prog)
+                  (map (lambda (a) (expand-vars ctx a)) (flatten args))
+                  #:check? #t))))
 
 (define* (install-aws-cli #:key (url "https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip") update? install-dir bin-dir)
-  (let* ((conn (current-connection))
+  (list (require-commands "wget" "unzip")
-         (tmp-dir (run conn "mktemp" "-d" #:return car #:check? #t)))
+        (create-tmp-dir #:register 'aws-cli-tmp)
-    (dynamic-wind
+        (download "download-aws-cli" #:url url #:target-dir (let-vars (aws-cli-tmp) aws-cli-tmp) #:register 'aws-cli-zipfile)
-      (const #t)
+        (unzip "extract-aws-cli" #:file-name (let-vars (aws-cli-zipfile) aws-cli-zipfile) #:target-dir (let-vars (aws-cli-tmp) aws-cli-tmp))
-      (lambda ()
+        (command "run-aws-cli-installer"
-        (let ((zipfile (file-name-join* tmp-dir (file-basename url))))
+                 (let-vars (aws-cli-tmp) (file-name-join* aws-cli-tmp "aws" "install"))
-          (run conn "wget" "-O" zipfile url #:check? #t)
+                 (when install-dir `("-i" ,install-dir))
-          (run conn "unzip" zipfile "-d" tmp-dir #:check? #t)
+                 (when bin-dir `("-b" ,bin-dir))
-          (run conn (file-name-join* tmp-dir "aws" "install")
+                 (when update? "-u"))))
-               (when install-dir `("-i" ,install-dir))
-               (when bin-dir `("-b" ,bin-dir))
-               (when update? "-u")
-               #:check? #t)))
-      (lambda ()
-        (run conn "rm" "-rf" tmp-dir)))))
 
-(playbook "Test Playbook"
+(playbook
-          (play "Test play"
+ #:name "Test Playbook"
-                #:host "localhost"
+ #:plays (list
-                (task
+          (play
-                 (install-aws-cli #:update? #t
+           #:name "Install AWS CLI"
-                                  #:install-dir (file-name-join* ($ #:fact.home-dir) ".local" "aws-cli")
+           #:host "localhost"
-                                  #:bin-dir (file-name-join* ($ #:fact.home-dir) ".local" "bin")))))
+           #:interceptors (list
+                           (user-info)
+                           (install-aws-cli #:update? #t
+                                            #:install-dir (let-vars (user-info) (file-name-join* (assoc-ref user-info #:home-dir) ".local" "aws-cli"))
+                                            #:bin-dir (let-vars (user-info) (file-name-join* (assoc-ref user-info  #:home-dir) ".local" "bin")))))))

modules/ordo/interceptor/require-commands.scm

@@ -0,0 +1,28 @@
+(define-module (ordo interceptor require-commands)
+  #:use-module (ice-9 exceptions)
+  #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-71)
+  #:use-module (srfi srfi-145)
+  #:use-module (ordo interceptor)
+  #:use-module (ordo connection)
+  #:export (require-commands))
+
+(define-exception-type &missing-command-error &external-error
+  make-missing-command-error
+  missing-command-error?
+  (command-name missing-command-error-command-name))
+
+(define (require-commands . commands)
+  (assume (every string? commands) "commands should be strings" commands)
+  (interceptor
+   (string-append "require-commands " (string-join commands ","))
+   #:enter (lambda (ctx)
+             (for-each (lambda (cmd)
+                         (let ((out rc (run (context-connection ctx) "which" cmd)))
+                           (unless (zero? rc)
+                             (if (string-contains (car out) (format #f "which: no ~a in" cmd))
+                                 (raise-exception (make-missing-command-error cmd))
+                                 (raise-exception (make-exception
+                                                   (make-external-error)
+                                                   (make-exception-with-message (string-append "error running which: " (car out)))))))))
+                       commands))))