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Diffstat (limited to 'docs/sources/userguide/dockerlinks.md')
| -rw-r--r-- | docs/sources/userguide/dockerlinks.md | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/docs/sources/userguide/dockerlinks.md b/docs/sources/userguide/dockerlinks.md index 833f4aed98..20a5c1a179 100644 --- a/docs/sources/userguide/dockerlinks.md +++ b/docs/sources/userguide/dockerlinks.md @@ -94,7 +94,7 @@ yourself. This naming provides two useful functions: that makes it easier for you to remember them, for example naming a container with a web application in it `web`. -2. It provides Docker with reference point that allows it to refer to other +2. It provides Docker with a reference point that allows it to refer to other containers, for example link container `web` to container `db`. You can name your container by using the `--name` flag, for example: @@ -169,10 +169,12 @@ Docker exposes connectivity information for the parent container inside the child container in two ways: * Environment variables, -* Updating the `/etc/host` file. +* Updating the `/etc/hosts` file. Let's look first at the environment variables Docker sets. Let's run the `env` command to list the container's environment variables. + +``` $ sudo docker run --rm --name web2 --link db:db training/webapp env . . . DB_NAME=/web2/db @@ -182,6 +184,7 @@ command to list the container's environment variables. DB_PORT_5000_TCP_PORT=5432 DB_PORT_5000_TCP_ADDR=172.17.0.5 . . . +``` > **Note**: > These Environment variables are only set for the first process in the @@ -189,8 +192,8 @@ command to list the container's environment variables. > will scrub them when spawning shells for connection. We can see that Docker has created a series of environment variables with -useful information about our `db` container. Each variables is prefixed with -`DB` which is populated from the `alias` we specified above. If our `alias` +useful information about our `db` container. Each variable is prefixed with +`DB_` which is populated from the `alias` we specified above. If our `alias` were `db1` the variables would be prefixed with `DB1_`. You can use these environment variables to configure your applications to connect to the database on the `db` container. The connection will be secure, private and only the |