Add support for accessing container logs. (#34)

* Add support for accessing container logs.

closes #27

-=david=-

* Don't add logs to configuration if not capturing the log

* Further refinements

project.clj

@@ -23,9 +23,9 @@
                                   [org.clojure/test.check "1.1.0"]
                                   [org.clojure/tools.namespace "1.0.0"]
                                   [org.testcontainers/postgresql "1.14.3"]]
-                   :githooks {:auto-install true
+;                   :githooks {:auto-install true
-                              :ci-env-variable "CI"
+;                              :ci-env-variable "CI"
-                              :pre-commit ["script/pre-commit"]}
+;                              :pre-commit ["script/pre-commit"]
                    :source-paths ["dev-src"]}}
 
   :target-path "target/%s")

src/clj_test_containers/core.clj

@@ -1,7 +1,8 @@
 (ns clj-test-containers.core
   (:require
    [clj-test-containers.spec.core :as cs]
-   [clojure.spec.alpha :as s])
+   [clojure.spec.alpha :as s]
+   [clojure.string])
   (:import
    (java.nio.file
     Paths)
@@ -9,6 +10,8 @@
     BindMode
     GenericContainer
     Network)
+   (org.testcontainers.containers.output
+    ToStringConsumer)
    (org.testcontainers.containers.wait.strategy
     Wait)
    (org.testcontainers.images.builder
@@ -24,17 +27,17 @@
 
 (defmulti wait
   "Sets a wait strategy to the container.
-   Supports :http, :health and :log as strategies. 
+   Supports :http, :health and :log as strategies.
-  
+
   ## HTTP Strategy
-  The :http strategy will only accept the container as initialized if it can be accessed 
+  The :http strategy will only accept the container as initialized if it can be accessed
-  via HTTP. It accepts a path, a port, a vector of status codes, a boolean that specifies 
+  via HTTP. It accepts a path, a port, a vector of status codes, a boolean that specifies
-  if TLS is enabled, a read timeout in seconds and a map with basic credentials, containing 
+  if TLS is enabled, a read timeout in seconds and a map with basic credentials, containing
-  username and password. Only the path is required, all others are optional. 
+  username and password. Only the path is required, all others are optional.
   Example:
-  
+
   ```clojure
-  (wait {:strategy :http
+  (wait {:wait-strategy :http
          :port 80
          :path \"/\"
          :status-codes [200 201]
@@ -42,14 +45,29 @@
          :read-timeout 5
          :basic-credentials {:username \"user\"
                              :password \"password\"}}
-        container))
+        container)
   ```
   ## Health Strategy
-  TBD
+  The :health strategy only accepts a true or false value. This enables support for Docker's
+  healthcheck feature, whereby you can directly leverage the healthy state of your container
+  as your wait condition.
+  Example:
+
+  ```clojure
+  (wait {:wait-strategy :health :true} container)
+  ```
 
   ## Log Strategy
-  TBD"
+  The :log strategy accepts a message which simply causes the output of your container's log
-  :strategy)
+  to be used in determining if the container is ready or not. The output is `grepped` against
+  the log message.
+  Example:
+
+  ```clojure
+  (wait {:wait-strategy :log
+         :message \"accept connections\"} container)
+  ```"
+  :wait-strategy)
 
 (defmethod wait :http
   [{:keys [path port status-codes tls read-timeout basic-credentials] :as options} container]
@@ -93,7 +111,7 @@
 
 (defn init
   "Sets the properties for a testcontainer instance"
-  [{:keys [container exposed-ports env-vars command network network-aliases wait-for]}]
+  [{:keys [container exposed-ports env-vars command network network-aliases wait-for] :as init-options}]
 
   (.setExposedPorts container (map int exposed-ports))
 
@@ -108,11 +126,11 @@
   (when network-aliases
     (.setNetworkAliases container (java.util.ArrayList. network-aliases)))
 
-  (merge {:container container
+  (merge init-options {:container container
-          :exposed-ports (vec (.getExposedPorts container))
+                       :exposed-ports (vec (.getExposedPorts container))
-          :env-vars (into {} (.getEnvMap container))
+                       :env-vars (into {} (.getEnvMap container))
-          :host (.getHost container)
+                       :host (.getHost container)
-          :network network} (wait wait-for container)))
+                       :network network} (wait wait-for container)))
 
 (s/fdef create
         :args (s/cat :create-options ::cs/create-options)
@@ -179,16 +197,58 @@
      :stdout (.getStdout result)
      :stderr (.getStderr result)}))
 
+(defmulti log
+  "Sets a log strategy on the container as a means of accessing the container logs.
+   It currently only supports a :string as the strategy to use.
+
+   ## String Strategy
+   The :string strategy sets up a function in the returned map, under the `string-log`
+   key. This function enables the dumping of the logs when passed to the `dump-logs`
+   function.
+   Example:
+
+   ```clojure
+   {:log-strategy :string}
+   ```
+
+   Then, later in your program, you can access the logs thus:
+
+   ```clojure
+   (def container-config (tc/start! container))
+   (tc/dump-logs container-config)
+   ```
+   "
+  :log-strategy)
+
+(defmethod log :string
+  [_ container]
+  (let [to-string-consumer (ToStringConsumer.)]
+    (.followOutput container to-string-consumer)
+    {:string-log (fn []
+                   (-> (.toUtf8String to-string-consumer)
+                       (clojure.string/replace #"\n+" "\n")))}))
+
+(defmethod log :slf4j [_ _] nil)
+
+(defmethod log :default [_ _] nil)
+
+(defn dump-logs
+  "Dumps the logs found by invoking the function on the :string-log key"
+  [container-config]
+  ((:string-log container-config)))
+
 (defn start!
   "Starts the underlying testcontainer instance and adds new values to the response map, e.g. :id and :first-mapped-port"
   [container-config]
-  (let [container (:container container-config)]
+  (let [{:keys [container log-to]} container-config]
     (.start container)
-    (-> container-config
+    (-> (merge container-config
-        (assoc :id (.getContainerId container))
+               {:id (.getContainerId container)
-        (assoc :mapped-ports (into {}
+                :mapped-ports (into {}
-                                   (map (fn [port] [port (.getMappedPort container port)])
+                                    (map (fn [port] [port (.getMappedPort container port)])
-                                        (:exposed-ports container-config)))))))
+                                         (:exposed-ports container-config)))}
+               (log log-to container))
+        (dissoc :log-to))))
 
 (defn stop!
   "Stops the underlying container"
@@ -196,6 +256,7 @@
   (.stop (:container container-config))
   (-> container-config
       (dissoc :id)
+      (dissoc :string-log)
       (dissoc :mapped-ports)))
 
 (s/fdef create-network

src/clj_test_containers/spec/container.clj

@@ -35,7 +35,9 @@
 (s/def ::log
   keyword?)
 
-(s/def ::strategy #{:http :health :log})
+(s/def ::wait-strategy #{:http :health :log})
+
+(s/def ::log-strategy #{:string})
 
 (s/def ::path
   string?)
@@ -45,3 +47,6 @@
 
 (s/def ::check
   boolean?)
+
+(s/def ::string
+  string?)

src/clj_test_containers/spec/core.clj

@@ -5,11 +5,15 @@
    [clojure.spec.alpha :as s]))
 
 (s/def ::wait-for
-  (s/keys :req-un [::csc/strategy]
+  (s/keys :req-un [::csc/wait-strategy]
           :opt-un [::csc/path
                    ::csc/message
                    ::csc/check]))
 
+(s/def ::log-to
+  (s/keys :req-un [::csc/log-strategy]
+          :opt-un [::csc/string]))
+
 (s/def ::network
   (s/nilable (s/keys :req-un [::csn/network
                               ::csn/name
@@ -22,7 +26,9 @@
                    ::csc/env-vars
                    ::csc/host]
           :opt-un [::network
-                   ::wait-for]))
+                   ::wait-for
+                   ::log-to]))
+
 
 (s/def ::init-options
   (s/keys :req-un [::csc/container]
@@ -31,6 +37,7 @@
                    ::csc/command
                    ::network
                    ::wait-for
+                   ::log-to
                    ::csc/network-aliases]))
 
 (s/def ::create-options
@@ -40,6 +47,7 @@
                    ::csc/command
                    ::network
                    ::wait-for
+                   ::log-to
                    ::csc/network-aliases]))
 
 (s/def ::create-network-options

test/clj_test_containers/core_test.clj

@@ -23,7 +23,7 @@
     (let [container (sut/create {:image-name "postgres:12.2"
                                  :exposed-ports [5432]
                                  :env-vars {"POSTGRES_PASSWORD" "pw"}
-                                 :wait-for {:strategy :log :message "accept connections"}})
+                                 :wait-for {:wait-strategy :log :message "accept connections"}})
           initialized-container (sut/start! container)
           stopped-container (sut/stop! container)]
       (is (some? (:id initialized-container)))