Update how-to-use-docker-volumes.md

docker/scenarios/how-to-use-docker-volumes.md

@@ -0,0 +1,28 @@
+# why we use volume in docker containers
+# In all containers has own logs if container crashed or exit from any reason the how we can troubleshoot bcz as we knows logs are in container to aviod these things
+# we user external volumes so containers log can persists.
+
+To check volumes:
+    docker volume ls
+# volumes are two types
+1. Managed by docker called volume
+# For Create volume
+   docker volume create volumename.
+# to check volume location or mountion point  
+   docker volume inspect volumename
+# We cant attache any volume in running container so we need to create new container with volume
+  docker run -d -P --mount type=volume,src=volumename,target=/opt/toomcat/logs image:v1
+  # now if we check mounting point all loged has captureed or stored
+  # targrt of logs can be different according to application or image build
+
+2. Managed by user called bind volume
+# why we need bind volume
+# because volume created by dokcer need sudo privladges to access this location to avoide such these conditons we use bind volume
+# we will create a dir. in any location wehere we didnt need sudo privladges
+
+  mkdir /home/ubuntu/Dlogos   
+# now only chanages in commad is 
+   type=bind, src=/home/ubuntu/Dlogs
+docker run -d -P --mount type=bind,src=/home/ubuntu/Dlogs,target=/opt/toomcat/logs image:v1
+
+