til, docker output format

Author: zuzhi

content/md/pages/til.md

@@ -1,6 +1,73 @@
 {:title "Today I Learned"
  :page-index 0}
 
+## 2024-07-25
+
+`docker ps` 和 `docker compose ps` 命令，有一个可以指定输出格式的参数 `--format`[^1]，默认是 table。
+
+可以指定按 json 格式输出，再结合 jq 进行格式化，比如：
+
+```bash
+docker compose ps --format json | \
+jq '{Service: .Service, State: .State, Status: .Status}'
+```
+
+```json
+{
+  "Service": "hive-metastore",
+  "State": "running",
+  "Status": "Up 55 minutes (healthy)"
+}
+{
+  "Service": "mc",
+  "State": "running",
+  "Status": "Up 55 minutes"
+}
+{
+  "Service": "metastore_db",
+  "State": "running",
+  "Status": "Up 55 minutes"
+}
+{
+  "Service": "minio",
+  "State": "running",
+  "Status": "Up 55 minutes"
+}
+{
+  "Service": "spark-hudi",
+  "State": "running",
+  "Status": "Up 54 minutes (healthy)"
+}
+{
+  "Service": "starrocks-fe",
+  "State": "running",
+  "Status": "Up 55 minutes (unhealthy)"
+}
+{
+  "Service": "starrocks-toolkit",
+  "State": "running",
+  "Status": "Up 53 minutes"
+}
+```
+
+`--format` 参数默认的是 table，而 table 可以指定 TEMPLATE[^2]，比如：
+
+```bash
+docker compose ps --format "table {{.Service}}\t{{.State}}\t{{.Status}}"  
+```
+
+```
+SERVICE             STATE     STATUS
+hive-metastore      running   Up 42 minutes (healthy)
+mc                  running   Up 42 minutes
+metastore_db        running   Up 42 minutes
+minio               running   Up 42 minutes
+spark-hudi          running   Up 42 minutes (healthy)
+starrocks-fe        running   Up 42 minutes (unhealthy)
+starrocks-toolkit   running   Up 41 minutes
+```
+
+
 ## 2023-08-10
 
 可选链运算符 (?.) (Optional chaining) 允许读取位于连接对象链深处的属性的值，而不必明确验证链中的每个引用是否有效。在引用为空 (nullish) (null 或者 undefined) 的情况下不会引起错误，该表达式短路返回值是 undefined。
@@ -63,3 +130,7 @@ In Git, when you run a `git pull` command, it combines two actions: `git fetch`
 ## 2023-07-19
 
 JSONPath is a query language for JSON, similar to XPath for XML.
+
+
+[^1]: [docker ps | Docker Docs](https://docs.docker.com/reference/cli/docker/container/ls/)
+[^2]: [Format command and log output | Docker Docs](https://docs.docker.com/config/formatting/)