Add Check Postgres Version Running In Docker Container as a Docker TIL

README.md

@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
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@@ -224,6 +224,7 @@ If you've learned something here, support my efforts writing daily TILs by
 
 ### Docker
 
+- [Check Postgres Version Running In Docker Container](docker/check-postgres-version-running-in-docker-container.md)
 - [Configure Different Host And Container Ports](docker/configure-different-host-and-container-ports.md)
 - [List Running Docker Containers](docker/list-running-docker-containers.md)
 - [Prevent Containers From Running On Startup](docker/prevent-containers-from-running-on-startup.md)

docker/check-postgres-version-running-in-docker-container.md

@@ -0,0 +1,28 @@
+# Check Postgres Version Running In Docker Container
+
+I have a docker container that I'm using to run a PostgreSQL development
+database on my local machine. It was a while ago when I set it up, so I can't
+remember specifically which major version of PostgreSQL I am using.
+
+I use `docker ps` to list the names of each container.
+
+```bash
+$ docker ps --format "{{.Names}}"
+still-postgres-1
+better_reads-postgres-1
+```
+
+I grab the one I am interested in. In this case, that is `still-postgres-1`.
+
+Then I can execute a `select version()` statement with `psql` against the
+container with that name like so:
+
+```bash
+$ docker exec still-postgres-1 psql -U postgres -c "select version()";
+                                                       version                                                 
+---------------------------------------------------------------------------------------------------------------------
+ PostgreSQL 16.2 (Debian 16.2-1.pgdg120+2) on x86_64-pc-linux-gnu, compiled by gcc (Debian 12.2.0-14) 12.2.0, 64-bit
+(1 row)
+```
+
+And there I have it. I'm running Postgres v16 in this container.